Category: Invasive Species

Introduction

In this paper the discussion presented will briefly discuss the role of feral swine in relation to livestock within the United States. This issue is considered important given the fact that these animals have considered a potential threat to livestock within the country based on research findings.

According to Witmer, Sanders and Taft, the swine were introduced into the United States during the period around the 1400’s as a source of meat (2). Following this initial introduction there have been numerous subsequent introductions.

The introduction of the animals has been found to be possible through a number of ways including translocation, a number that escape from shooting preserves, dispersal of already established populations, avoiding capture or in some cases abandonment (316).

The management of these animals is a very controversial issue due to the diverse views held by government and private individuals and groups. However, despite this position it would appear that there is a need to readdress the issue given that these animals have the potential of harboring disease causing organisms that may threaten livestock in these regions.

Main Assertion

The main assertion that makes the basis of this report is in the fact that feral swine populations are reported as having many negative impacts. Due to this there has arisen some considerable interest in the swine which are considered as an invasive species in a variety of settings (Witmer, Sanders and Taft 317).

Reports indicate that the swine are responsible for considerable losses in native flora and fauna. In addition to this the swine are able to cause soil erosion, declines in water quality, reduced bio diversity, crop and reforestation damage.

In addition to environmental degradation it is reported that the swine can harbor a number of diseases and parasites that can infect humans and livestock.

This position has been discussed in several national symposia in recent years with documentation produced on possible problems and solutions. Estimates from these reports indicate that feral swine may be responsible for an estimated $800 million to agriculture and the environment (Witmer, Sanders and Taft 317).

Because of their ability to harbor a number of parasites it is suspected these diseases are transmissible to humans, livestock and wildlife. Due to this there has been concern over the role that feral swine may play in the outbreak of a foreign animal disease such as hog cholera or foot and mouth disease (Witmer, Sanders and Taft 320).

Because of the disease threat posed by the swine there has been disease surveillance conducted in a number of states. Following this surveillance some measures have been undertaken to control the spread of specific livestock disease. One major setback to these efforts is the prevalence of the swine in populations across the country.

At the same time the pork industry within the US is major consumer of produce that comes from swine across America. It is reported that annual farm sales are in the range of $34 billion (Witmer, Sanders and Taft 320).

This produce is mainly sourced from swine kept in free ranges or in fenced populations. Due to this major business it is difficult to reduce the production from free ranges (Witmer, Sanders and Taft 320).

According to Witmer and Lewis, each species of wildlife occurs as a part of an ecosystem, interacting in many ways with other parts of the eco system. This interaction may include abiotic components such as soil, air and water as well as other substrates (Witmer and Lewis 423).

Species that are normally referred to as native or indigenous naturally occur in a particular area and have been there for a very long time. However due to a variety of events there are occasions when outside species may be introduced to an eco system.

These species in some cases are very successful and are then referred to as invasive species (Witmer and Lewis 423). Such species bear the ability to spread unchecked and increasing to high population levels. Due to this rapid spread such a species may become capable of compromising large portions of the biota

The process of introduction of a species can occur through a variety of mechanisms, both purposeful or by accident.

Accidental introductions include those in which animals escape from captivity, as stowaways on ships, trains or other vehicles. On the contrary purposeful introductions include those where the species are introduced to serve a specific purpose such as to provide substitute source of food (Witmer and Lewis 424).

It has been observed that it is very important to understand the potential ecological consequences of wildlife introductions. For this reason it is deemed better to prevent introduction of an unwanted species rather than deal with the management or attempts to eradicate it later (Witmer and Lewis 424).

Based on this therefore it is possible to conclude that to assist in managing the feral swine areas where the animals have minimal populations may consider complete eradication of the species.

Based on this report it emerges that estimates indicate almost 42 species have been introduced in Oregon and Washington (Witmer and Lewis 440). Though these introductions have taken place for a wide variety of reasons, some have made major contributions to outdoor recreation, state wildlife agency revenues, other have led to adverse effects on the environment in various locations.

This adverse effect arises mainly due to direct or indirect mechanisms such as resource competition, predation, and displacement. This suggests a need for improved measures to the management of introduced species across the nation.

In another report on the issue of feral swine and their impact on the environment it has been reported that these animals are known to have serious adverse effects on the environment (Campbell and Tyler 2319). The geographic distribution and abundance of feral swine is increasing throughout the United States, where estimates reports losses to the tune of $ 800 million annually.

Due to this significant threat they cause to the environment natural resource managers are beginning to give recognition to these exotic animals. As a result feral swine management programs are being implemented throughout their range.

It is unfortunate that these feral swine damage management programs are conducted in a piecemeal fashion and are poorly funded (Campbell and Long 2319). Due to this situation it has been suggested that additional guidance is required for feral swine damage identification and management.

In this report several types of environmental damage are mentioned in relation to the feral swine. It is reported that in areas where these swine prevail rooting is very common due to the swine burrowing nature (Campbell and Long 2319).

The practice is the major source of conflict with agricultural producers due to the damage to farming equipment it causes. In addition to this it is reported that the swine can cause extensive crop damage to both row crops and forested areas. This particularly common during the seedling stage of development where the swine root up seedlings to consume the roots.

The feral swine are also responsible for forested eco system damage due to their practice of reducing the recruitment and growth of saplings. The swine can also cause significant damage in deciduous forests. The report also highlights several management approaches to handling the feral swine such as fencing, trapping, shooting and toxicants (Campbell and Long 2323).

In another report on the potential importance of swine and influenza it has been observed that the swine share common receptors with birds and humans (Hall 362). Due to this nature swine have the potential to be affected by both avian and mammalian strains of influenza. This position has seen some experts consider swine as a form of mixing vessel and new strains of influenza may arise due to genetic re assortment.

In this report it is also indicated that feral swine pose a serious threat to natural ecosystems and agriculture where they become established. This is because of their feeding and rooting habits can destroy native plant communities, damage irrigation sheds and displace native species (Hall 363).

The main reservoir of avian influenza is waterfowl and both swine and fowl reside in the same habitat. This factor makes the swine play a considerable role in influenza transmission cycles given that there is significant possibility of shared pathogens.

Strengths and Weaknesses

In the United States populations of wild boars have escaped and lived in the wild for many years. Owing to this the population of these wild swine has risen and in some areas led to a need to consider appropriate management (Nugent 19). The swine are very adaptive and are capable of rapid reproduction.

In response to the dilemma the State of Oregon has led to a need for serious management consideration. The action plan currently in place has both strengths and weaknesses as will be explained further below. The main strength of the plan lies in the fact that areas for eradication have been identified though compliance is not 100% (Nugent 20).

However, the weakness of the plan lies in the fact that pig hunting is a popular activity in the region and as such the role of hunting revenues has limited what can be done in relation to the swine. Whereas hunters harvest 40% annually, it remains difficult to contain the population unless 70% is removed from each generation (Nugent 20).

Usefulness of presentation

This report is considered important due to the fact that it provides information on the current situation in relation to feral swine. The report provides some statistics and general information on the potential effects that feral swine can have on the environment. In addition to that it provides information on the current solutions in place that deal with this specific problem.

Works Cited

Campbell, Tyler A., and David B. Long. “Feral Swine Damage and Damage Management in Forested Ecosystems.” Forest Ecology and Management. 257 (2009). Web.

Hall, Jeffrey S. et al. “Influenza Exposure in United States Feral Swine Populations.” Journal of Wildlife Diseases. 44 (2008). Web.

Nugent, Martin. “Oregon Invasive Species Action Plan.” Oregon Department of Fish and Wildlife (2005). Web.

Witmer, Gary W., and Jeffrey C. Lewis. “Introduced Wildlife of Oregon and Washington.” USDA National Wildlife Research Center-Staff Publications. Paper 656 (2001).Web.

Witmer, Gary W., Robert B. Sanders, and Arnold C. Taft. “Feral Swine: Are They A Disease Threat To Livestock in the United States?” USDA National Wildlife Research Center – Staff Publications. Paper 292 (2003). Web.

Abstract

Some pests and weeds are considered by the Australian government to be of national significance. Most of these species were introduced from other countries and continents. Red fox (Vulpes vulpes) and the Alligator Weed (Alternanthera Philoxeroides) are some of the invasive species which threaten the ecology and several sectors of the Australian economy.

This document discusses why and how these species were introduced in Australia, factors which ensured their successful establishment in the country, as well as, their ecological and economic impacts. Finally, it examines the advantages and disadvantages of the control methods used to manage them.

Introduction

Numerous invasive species have been introduced in Australia over the years. These species are considered pests and have become a serious threat to biodiversity as well as agriculture in the country. Generally, pests have a direct effect on the environment/ecosystem as well as on human life wherever they exist.

Their rate of reproduction is high making it difficult to control them. Most of them were introduced either deliberately or by accident, including some brought in to assist with the control of other nuisance species.

Among the animal pests in Australia is red fox (Vulpes vulpes) also known as the European red fox was introduced in Australia in 1855 from Europe (Department of Sustainability, Environment, Water and Communities 2010).

Since its introduction in Australia, it has spread across most parts of the country, although it is no longer found in the tropical north as well as some off-shore islands (Tasmanian Department of Primary industries, Parks, Water and Environment, 2010). Vulpes vulpes is classified as a serious invader to native animals as it kills them.

On the other hand, one of the weed species which has invaded the ecological system of Australia is the Alligator Weed (Alternanthera Philoxeroides). It was also introduced from Parana River region, South America (Everitt, Little & Lonard, 2007, 55).

They have spread in Queensland, Victoria, Western Australia, New South Wales, Northern Territory, Tasmania and South Australia. According to Bonila and Gunasekera (2001, 17) Alternanthera Philoxeroides is among the top 20 weeds posing serious threats and therefore causes significant concern in Australia.

How and why the species were introduced in Australia

According to Cuthbertson and Parsons (1992, 155) Alternanthera Philoxeroides was first introduced in Newcastle, New South Wales from South America and has since spread to all states in Australia. It has viable seed which aids its dispersal. As a result it spread from South America through pieces of mud which it used to attach itself to ships which sailed from South America.

It was first introduced in this region during in 1946 when ship ballast was abandoned near New Castle (Cuthbertson and Parsons 1992, 155). According to the Rural Industries Research and Development Corporation (2011) Alternanthera Philoxeroides was introduced to Newcastle, New South Wales as a culinary herb.

Red fox which has also greatly contributed to serious breakdown of Australian ecology was first introduced in the country from 1855 (Cowan & Tyndale-Biscoe 1997, 31).

They were first released in Melbourne, Victoria. They were deliberately introduced to the country for recreational hunting. European red fox was hunted by humans beginning 1865. Hunting had started back in 1839 in Australia as people sought after kangaroos, rabbits and dingoes.

Factors which contributed to their successful establishment

The weed has the ability to survive in terrestrial, Aquatic as well as semi-aquatic habitats in temperate, tropical plus in sub-tropical regions. All the regions in Australia where the weed has spread all have the characteristics of these climatic regions. The existence of rivers, wetlands and river tributaries provided the optimum condition for their survival.

Red fox can survive in various habitats which include alpine, urban, as well as, arid areas (Pearson & Pyres 1998, 87). It can also live in lightly wooded regions, and grasslands. Australia has wooded areas which are found in the country’s agricultural landscapes. This offers a wide range of food and shelter for the fox. The fox can also survive in a cleared farming land which has some livestock such as lambs which it can prey on.

Besides, the fox can eat almost anything including small animals, insects and fruit (Larivière & Pasitschniak-Arts 1996, 6). In each environment, red fox is at the apex of the food chain. This enables it to survive even when its preferred prey, small animals, is less available during the summer seasons.

Australia has all types climates which the fox can survive in, and due to this, red fox has established itself firmly across the country. On the contrary, native animals of Australia have not yet evolved to protect themselves against the fox because of the circumstances in which red fox was introduced.

The fox was introduced so suddenly that the native animals were killed to feed the young foxes. This helped sustain the population of the red fox, which has since become the head of the food chain.

Ecological effects

Red foxes have had several long-term effects on the Australian environment. One major effect is the decline of biodiversity. Predation by red fox has contributed significantly to the decline of native species in the country and still continues to undermine the efforts of the Australian community to conserve the threatened species which includes the night parrot, malleefowl, as well as, the bridled nail-tail wallaby.

The fox has greatly contributed to the reduction in populations of ground-nesting birds, reptiles like the green turtle, as well as, small-to-medium sized mammals like the greater bilby. The fox often loots loggerhead turtle nets. Furthermore, it eats eggs in nests found on the beach. Loggerhead turtles are protected at Mon Repos Conservation Park in Queensland since they are endangered.

If these foxes are allowed to continue to breeding, as well as remain among the wild animals for much longer period, the fragile ecology of Australia will be destroyed. This means that it will be difficult to recover this unique environment. In addition, they are carriers of rabies.

The spread of rabies could destroy the fragile Australian ecosystem. The disease affects both human beings and animals. Thus eradicating it would be very difficult.

Red foxes normally eat berries in summer seasons when their favourable food resources are not available. In addition, the fox competes alongside native predators which include eagles. In the past, the fox has competed against Tasmania Devils which were once abundant across the mainland; however, it is now found in Tasmania only. Others included Tasmania Tiger, Thylacine, and Tasmania Wolf which are now extinct in the country.

Even though the red fox endangers the existence of many native animals, it is itself endangered by some animals. These animals include the Western Quoll, Red-Tailed Phascogale, Numbat, as well as, Brush-Tailed Bettong which are majorly found in South-Western Australia.

These animals are poisonous to the red fox since they eat Gastrolobium, as well as, Oxylobium plants, which are poisonous to animals especially the red fox (Cowan & Tyndale-Biscoe 1997, 31).

These plant species have flouroacetate which is the chemical used to make the poison baits used in 1080 (Cowan & Tyndale-Biscoe 1997, 31). On the contrary, these animals considered to be dangerous to the fox have developed immunity to the chemical, and therefore they store the poison in their flesh. When the red fox eats the animal, it dies.

Alligator weed disrupts the aquatic environment by covering the surface and therefore hindering penetration of light into the water or soil (Groves, Richardson & Shepard 1995, 07). This adversely distresses aquatic fauna as well as flora. Economic impacts

Economic Impacts

Alligator weed has impacts on several sectors of the economy. The plant has increased the would-be costs to irrigation farming (Groves, Richardson & Shepard 1995, 10). It is expected that should the alligator weed not be controlled, then, the Barren Box Swamp infestation will cost about $250 million annually (Department of Sustainability, Environment, Water and Communities 2010).

It is also threatening the sustainability of the turf industry in the Sydney Basin. The vegetable industry in the Hawkesbury-Nepan region is also threatened; the industry is estimated to be worth $150 million a year (Department of Sustainability, Environment, Water and Communities 2010).

Other than the vegetable industry, there is the extraction industry in the same region, which also under threat. Should these resources be contaminated with the alligator weed, then the resources will have to be restricted. Moreover, it also threatens soy bean as well as sugar cane industries in the Richmond region (Groves, Richardson & Shepard 1995, 11).

Alligator weed also interferes with livestock farming. The plant contaminates grazing pastures and causes cancerous lesions in cattle. At some point, they become so dense that they deny livestock access to drinking water. This also implies that it limits access to, as well as, use of water. It can also block and damage pumps.

In Warragamba Dam in Sydney, the weed causes sedimentation and therefore its major water supply, as well as, storage system (Department of Sustainability, Environment, Water and Communities 2010). It obstructs stream flow of water and as a result leads to sedimentation. This contributes to flooding of the region, and structural damage to infrastructure.

Red foxes have significant impacts on the Australian economy. It threatens the existence of native species as well as ecological communities. This impacts on the national heritage as it reduces species population (wildlife resources) in the country.

The night parrot, malleefowl, as well as, the bridled nail-tail wallaby are some of the species which have been identified as threatened by red fox (Department of Sustainability, Environment, Water and Communities 2010).

Red fox also causes losses to farmers especially those who keep livestock. The fox preys on the kid goats, poultry, as well as, newborn lambs. Moreover, they can also pass rabies on to livestock as well as native mammals. This costs the Australia economy millions of dollars per year since they kill livestock as well as by being a pest to farmers.

Advantages of the methods used to control red fox

Among the methods the government and the Australian community has employed is the prevention of the spread of red foxes to new regions which includes islands.

Protection of the islands has been major priority in controlling red fox population. Islands have often been used as refugee habitats for species which are not available on the mainland any more. This has been effective in eradicating red fox from high-conservation-value islands.

Adoption of poison baits on fences has also been successful in reducing the population of red foxes. This has been applied in south-west Western Australia and Eastern Australia. It has enabled native mammals to start to recover, and as a result, return to their former habitats.

This method has also reduced the pressure on native species threatened by the red fox. It helps promote the maintenance, as well as, recovery of native animals together with the ecological communities which have been affected by red fox predation.

Demerits of the methods used to control red fox

Although the Australian community has adopted payment of bounties to encourage people to remove red foxes from among the wild animals, reduction of damages from the fox has not been effective (Tasmanian Department of Primary industries, Parks, Water and Environment, 2010). Again, hunting has not been able to achieve significant or long-term impact red fox population as well as the damage they cause.

The application of poison baits in controlling red fox could have effects on other animals which are the target for elimination. Poison baits may also have similar effects on other animals, and therefore lead to their decline in areas where they are used. Besides, poison baits are very expensive and requires much resources to maintain them indefinitely. In south-west Western Australia, a large scale 1080-poison baits is used to control red fox.

Advantages of the methods used to control alligator weed

There are several methods which have been applied in Australia to control alligator weed. These control methods include physical, chemical and biological controls, and through legislation.

Physical control method which involves the manual digging and burying of the alligator weed after having applied herbicides which kills any above-underground plant growth. This ensures immediate eradication of the alligator plant (NSW Department of Primary Industries 2008). It has successfully reduced floating mats which grow in Georges River as well as parts of Hawkesbury-Nepean region.

Disadvantages of the methods used to control alligator weed

One of the methods which have been applied in managing alligator weed is the adoption of alternative vegetable as part of the eradication program.

The most notable alternative vegetable that has been adopted is the lesser joy weed which is scientifically known as Alternanthera denticulata (Bonila and Gunasekera 2001, 19). However, this does not help eliminate alligator weed as most of it grows wildly. Wetlands and river habitat where the weed grows is not affected by this program.

Chemical control method applied in Australia is not effective as it takes long to eradicate the weed. Alligator weed can tolerate most herbicides. This means that application of these herbicides may only suppress the weed. Consequently, this method may take as a long as 6 years to completely eradicate the weed since in some cases, the herbicides are applied annually.

Again, since the alligator weed is tolerant to most of these herbicides (NSW Department of Primary Industries 2008), it implies that large quantities are used in process.

This can be dangerous to other plant species and could lead to their death. This means that chemical control method may lead to further loss of biodiversity. Application of chemicals could also lead to the death of soil micro-organisms which play key role in breaking and enriching the soil.

Physical control on the other hand, cannot be adopted in large and extensive alligator coverage areas. It is difficult to carry out deep manual digging for burying the weed that covers a wide area. Besides, applying herbicides to prevent above-underground plant growth could affect many plant and animal species which were not intended.

Conclusion

Red fox and alligator weed are among the invasive species which are of great significance to Australia. Both of them cause great damage to the environment, which in turn affects the country’s economy. If they are not carefully controlled, then they may cause reduction of population of various species and even lead to their extinction.

Thus, it is important to devise better and more environmentally friendly ways of managing them and their impacts. This means that more research has to be done to enable the Australian community understand their impacts and develop more advanced ways of controlling their population and impacts on the ecology, other species and human life.

It is also important to understand that these species also play vital roles in the ecosystem, and therefore the control measures adopted should not aim at eliminating them, but also protecting them. Finally, the local community should be involved in controlling these pests and weeds in order to achieve sustainable environmental management.

Reference List

Bonila, J., & Gunasekera, L., 2001, Alligator weed: Tasty vegetable in Australian backyard. Journal of Aquatic Plant Management, 39: 17-20.

Burgman, M., & Lindenmayer, D., 1998, Conservation biology for the Australian Environment. Sydney: Surrey Beatty & Sons. p. 83.

Cowan, P. E., & Tyndale-Biscoe, C. H., 1997, Reproduction, fertility & development: Australia and New Zealand mammal species considered to be pests or problems. CSIRO, 9: 27-35.

Cuthbertson, E., & Parsons W., 1992, Noxious weeds of Australia. Plant Protection Quartely, 3: 154–157.

Department of Sustainability, Environment, Water and Communities, 2010, European red fox (vulpes vulpes). Canberra ACT: Commonwealth of Australia.

Everitt, J. H., Little, C. R., & Lonard, R. L., 2007, Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press. pp. 55.

Groves, R., Richardson, R., & Shepard, R. 1995, Biology of Australian weeds, Vol. 1. Taipei City: Kluwer Academic Publishers. pp. 1–12.

Larivière, S., & Pasitschniak-Arts, M., 1996, Vulpes vulpes. Mamallian Species, 537: pp. 1-11.

National Land & Water Resources Audit, 2008, Assessing invasive animals in Australia 2008,NLWRA, Canberra./SEWPaC (2010). Web.

NSW Department of Primary Industries, 2008, Alligator weed control manual: Eradication and suppression of alligator weed in Australia. Orange: NSW Department of Primary Industries.

Pearson, J., & Pyres, G., 1998, Ecosystem of Australia: Deserts. Port Melbourne: Heinemann Library. p. 87.

Tasmanian Department of Primary industries, Parks, Water and Environment, 2010, Locations of fox activity inTasmania. Web.

Introduction

The natural living environment is characterized by high biological diversity, which predetermines the relationship between populations and species. It is wrong to believe that the natural evolutionary mechanisms, which led to the formation of a new species, were aimed at creating absolutely friendly conditions in which different taxons could coexist freely. On the contrary, among a large number of representatives of flora and fauna, it is possible to find organisms that purposefully cause damage to other animals or plants: both for food and to meet the ethological needs. Thus, the most dangerous species are invasive species, which is defined as artificially introduced species into an isolated area, embedded in trophic chains and threatening the local biological diversity. The Asian giant hornet, Vespa mandarinia, which is the subject of this study, is described as one of the most prominent examples of invasive animals destroying populations of honeybees in East Asia and recently discovered for the first time on the North American continent. The purpose of this term paper is to discuss the current state of knowledge about the invasiveness of V. mandarinia and the consequences it may have.

Brief Systematic Information

• The common name for the species: Asian giant hornet, or murder hornet, or Japanese giant hornet.
• Scientific name:Vespa mandarinia or V. mandarinia.

Biological Description of the Species

External Anatomy

It is known that Vespa mandarinia is a member of the hornet species belonging to the wasp group: thus, all the features traditionally prescribed for wasps are characteristic of the species under study. In particular, V. mandarinia has a narrow waist, a rigid pair of oppositely spaced side wings, the yellow and black color of the segmented torso, and straight antennae, as shown in Figure 1 (“Asian giant hornet,” n.d.). Moreover, as any wasp, V. mandarinia is characterized by a thin and sharp sting that penetrates the surface layers of the victim and kills the animal. Although the Asian hornet is very similar to an average wasp, it would be wrong to assume that this animal has no distinctive qualities. On the contrary, it is the unique features that form the body of V. mandarinia that determine the increased research interest and justify the environmental position of the hornet as a killer.

It would be fair to note that V. mandarinia is justifiably considered the largest hornet of all currently described ones. The external anatomy of the insect attracts attention in several aspects at once. First of all, the hornet’s head is comparatively more extensive than the heads of other wasps. This increase is due to two reasons: the broader distance between the two complex eyes and the development of the masticatory muscles that form the structure of the cheek — this is how the insect copes with the enemy (“Common name: Asian giant,” n.d.). Another characteristic feature of the animal is a combination of complex facet eyes and three photosensitive ocelli, located in the interocular region of the face, as illustrated in Figure 2. Due to the unique peculiarities of the structure of simple eyes — broken focus location and geometric configuration — they do not allow the owner to distinguish between individual objects (Warrant, 2019). In other words, it means that the simple hornet’s eyes have a low visual perception, and with their help, a bee can only distinguish the degree of change in light intensity. Thus, simple eyes increase the overall light sensitivity of complex eyes.

The presence of an elongated sting, usually numerically larger than 0.3 inches, is the prerogative of wasp females. Without detailing the environmental aspects of V. mandarinia‘s social life here, it is only necessary to note that the use of the sting as a murder weapon is justified by evolutionary mechanisms (“Common name: Asian giant,” n.d.). In crisis situations, a female hunter must be able to withstand the threat, and consequently, she uses the sting to inject a nerve toxin into the victim (Gill et al., 2020). Undoubtedly, males also protect their nest and queen, but they cannot have a sting due to reproductive features of this organ formation.

Reproductive and Life Cycles

The life cycle of V. mandarinia is a closed ring process with a tendency of annual recurrence. More specifically, Asian hornet females who survive the winter anabiosis, stimulated by the rising temperatures of spring days, tend to create a social nest where wasps will live for the next year (“Asian hornet,” n.d.). The nest usually consists of a bark of branches, which the royal female crushes with its powerful jaws. Then, wood particles are wetted with the secret of salivary glands, resulting in the composition taking roughly ground paper, forming a nest of the necessary shape. Having found shelter, the female postpones the first batch of larvae. Although initially, the role of the hunter lies only on the queen, it is worthwhile for the cubs to grow up a little, and all the care for the management of the birth nest goes to them. This means that the only mission of the main female hornet will be to continue the birth while other females and males are doing the rest functions. Mating with males occurs in early autumn: as soon as the Asian hornet gives its seed to the main female, it dies. Soon, the fertilized female gives off offspring that will have to wait for winter to wake up and build a new nest.

Ecological Characteristics

Habitat and Prevalence

The traditional habitat of the Asian hornet is the subtropical climate zones, rich in woody vegetation. In combination with groves, forests, and parks isolated from urban settlements, V. mandarinia‘s nests can be located in wooden houses, apiaries, or in urban natural spaces (Gill et al., 2020). The common name of this species justifies its history of origin: the hornet grew from Asia and migrated to the nearby states of India, Afghanistan, eastern China, and the Indonesian archipelago. Meanwhile, more relevant data allow establishing that the habitat of V. mandarinia were also European settlements, namely France, Spain, and Belgium (“Asian hornet,” n.d.). Soon, the Asian hornet also reached the North American continent, laying the foundation for a change in the ecological levels of these natural communities (Wilson et al., 2020). The nature of the insect’s settlement underscores the urgent need to carefully study the ecological, genetic, and geographical features of the hornet in order to eliminate the undesirable effects of the invasion.

Feeding

The food ration of insects is quite diverse and directly depends on the age of the wasp. In the initial personality stages, V. mandarinia is prone to predation through the consumption of killed flies, butterflies, locusts, and, most importantly, honeybees. Closer to adulthood, individuals become more restrained in its diet and mainly use fruits and sugar-containing vegetables. However, this does not mean that the adult wasp will not attack the bees if it meets the hive. If it happens, a hornet marks the bee’s nest with a smelling pheromonic fluid, which allows it to return to the find together with other hornets (McClenaghan et al., 2019). During an attack, giant insects dismember the bodies of its victims, ripping heads from the trunk with powerful jaws (Ugajin et al., 2012). Once the adults have been slaughtered, the hornets take away the larvae and honey that will serve as food for them.

Explanation of Evolutionary Patterns

The first point to discuss when describing Asian giant hornets is its dimensional characteristics. It seems strange that hornets born in Asia have such a severe superiority over its competitors. In fact, there are at least two biologically evidenced factors that have contributed to this growth. First, the explanation can be based on Allen’s environmental model, which affirms the relationship between the size of protruding body elements and ambient temperature (Fan et al., 2019). According to this rule, the larger the individual sizes of the body (wings, head, tail, limbs), the higher the ambient temperature: this approach can improve thermal regulation through increased evaporation area. Given that the homeland of the Asian hornet is a subtropical zone, this factor has good reasons for trust (“Asian hornet,” n.d.). At the same time, large body sizes can only be caused by evolutionary mechanisms. In particular, such sizes are a vivid example of evolutionary struggle and the ability of species to adapt to adverse environmental conditions. In the rich diversity of the animal world, which is typical for subtropical countries, large and poisonous insects are much more likely to find its food and not fall prey to natural enemies itself than its smaller and harmless related species. Thus, the apparent advantage of the Asian giant hornet, its size, can be due to either one of two factors or a combination of both.

Threats

For Honeybees

Insect mining is an integral part of the Asian hornet’s existence. The most significant damage that the hornet does to the natural community is expressed in the attack on honeybees. Thus, if a hive is found, a wasp marks the nest walls with pheromone, showing the other hornets the discovery. A group of several insects attacks a flock of bees, beheading them and eating its insides (Ugajin et al., 2012). However, some species of bees were able to develop protective mechanisms. Over thousands of years, Japanese bees, Apis cerana japonica, have learned to resist Asian giant hornets. Having smelled its pheromones, they immediately begin to reshape: about a thousand bees gather in a hive near the entrance, and a hundred more fly outside and look for approaching scouts. When they find the enemy, they lure it in and pounce on all sides. The hornet is surrounded by several bees, each of which begins to vibrate. It is known that such actions lead to a local temperature increase: McClenaghan et al. (2019) reported that when bees vibrate, the temperature reaches 46 degrees Celsius, which is a sufficient minimum for the hornet to die due to overheating. It is interesting to note the fact that the approach to protection strategies is differentiated: there is a correlation with the age of the population. The interaction of Asian hornets and honeybees is, apparently, a relatively new phenomenon that has not yet had time to form resistance genes in the gene pool of bees. This means that while Japanese honeybees may cause overheating through vibrations, European populations are not familiar with such strategies (McClenaghan et al., 2019). That is why they cannot destroy predators one by one and, therefore, become easy prey. In fact, this creates a problem of invasiveness: endemic species are not stable in the migrant’s influence, and the ecosystem is damaged. Thus, a colony of Asian hornets settled near the apiary, where there are several thousand individuals, which can cause very significant damage to the beekeeping industry.

For Human

It would be erroneous to assume that V. mandarinia poses a danger only to its immediate neighbors in trophic chains. In fact, there are two reasons why the Asian hornet can be dangerous to humans. First of all, insect damage concerns the economic damage that the human community will suffer from hornet invasion. According to Holland (2013), the loss of bees involved in the production of honey, wax, and other by-products will take the U.S. budget $15.0 billion. Coupled with a potential financial crisis, this means that the workers involved in this sector of agricultural production will remain unemployed, and the existing apiaries will be closed. At the same time, the toxin emitted by the hornet glands is extremely toxic and, at certain doses, poses a severe danger to humans. Although adult wasps use sting only in rare cases when the threat is very significant, improper human behavior near the nest can cause death (Main, 2020). The poison is known to contain several toxins, the most dangerous of which is mandaratoxin, the substance with a pronounced nerve action (Hirano & Tanikawa, 2020; Liu et al., 2016). Toxic components have a destructive effect on internal organs tissues, which is accompanied by severe pain and degradation of mucous membranes.

For Other Species

However, honey bees and humans do not limit the range of Asian hornet victims. It is about countless fruits, flowers, and other insects such as flies, caterpillars, spiders, and bumblebees, which become food resources for omnivorous V. mandarinia. Thus, hornet infestation becomes a threat to the existence of the entire equilibrium ecosystem because (i) the insect directly affects any of the sacrificial species, and (ii) it changes the natural food and energy chains.

Asian Giant Hornet Invasion

As long as the existence of Asian giant hornets in East Asia was not surprising, their expansion into areas of other states was a matter of concern. In light of the threats described above to local flora, fauna, and human communities, zoologists around the world are seeking to track hornet’s migratory flows and prevent it from settling in time. However, it is worth mentioning that the preventive guides developed today became possible only due to negative experiences in South Korea, France, Spain, and other European cities. Before discussing possible ways of invasion, it is necessary to discuss in detail two traces of insects of this species outside Asia.

The first victim of this expansion was South Korea, where the Asian hornet arrived in 2003. Studies conducted by specialists from Korea National University and other universities have shown that the hornet is now present throughout the country, causing significant damage to beekeeping and the environment (Choi et al., 2012). For instance, in the 15 years since the arrival of the Asian hornet, the populations of two of Korea’s most abundant native bumblebees have declined by 20% and 10%. Moreover, according to the authors, Asian hornet populations continue to move at a speed of up to 20 km a year northwards.

The first mention of Asian hornets in France dates back to 2004, when, according to some specialists, a female in a natural biological pause, was delivered to a European country from the Chinese province of Jiangsu along with commercial assets for sale (“Asian hornets claim another victim in France,” 2018). The wasp was able not only to settle in France but also to become one of the main threats to agricultural and economic development. It can be assumed that the spread of Asian hornets has contributed to deepening the systemic crisis experienced by beekeeping in France in recent years. Subsequently, bees settled in Spain, Portugal, Belgium, Italy, and the UK.

It is fair to note that the cases described above, although officially documented in European countries, actually refer to a slightly different biological species. Reports received from different labs of the world until 2019 were an erroneous identification of wasps as V. mandarinia, while they were related species: V. orientalis and V. velutina (Osterloff, 2020). Nevertheless, the first official fact of finding V. mandarinia outside Asia was described in August 2019, when the dead bodies of three Asian hornets were found in Canada (Wilson et al., 2020). A month later, their nest was found and destroyed, but probably there were others. In November 2019, another giant hornet was seen on the other side of the strait, and in early December, they were seen in the American state of Washington, which borders Canada. Thus, the Asian hornet snuck into the United States.

Hypotheses of Invasion

The Asian hornet infestation into new countries and the inclusion of the insect in sustainable ecological chains are unlikely to stop in the near future, and therefore, the study of migrations routes is key to the development of preventive measures. There are at least three different versions of how V. mandarinia could spread to new lands. First of all, one should take into account the migratory characteristics of the insect: it is rather fast-flying (“Asian hornet,” n.d.). Thus, it is assumed that the insects may have intended to end up on the North American continent. However, in this case, the migratory population would have to cross the Pacific Ocean, which is hardly possible for a swarm of wasps. Then, the truest hypothesis, the second one, refers to the trade routes linking the export-import relations of Asian countries and Canada (Kaufman, 2020). It is assumed that the royal female may have crossed the ocean on a ship with containers, and this seems to have happened in the fall when the female mates and enters the phase of anabiosis.

It is logical to assume that the Asian hornet female entered the territory of North America, began to develop local lands, and soon gave birth to offspring. In such a case, if to follow the chain of cause-and-effect relations, the subsequent generations of V. mandarinia should be phylogenetically connected with those who remained on the territory of Canada. Nevertheless, the genome analysis of microflora, by 16sRNA, for two species from different American locations, carried out in 2019, showed that they are not near related, and have parallel maternal lines (Suenami et al., 2019; Chen et al., 2016). Simply put, it results that Asian hornets from different populations could have been transported to the continent independently several times.

Fascinating in origin is the third version of the Asian hornet invasion due to culinary techniques based on the juice of these insects. In the Japanese bar Suzumebachi, which literally translates as the Asian giant hornet, the practice of drinking alcoholic beverages infusion on dead wasps is common (Kotzer, 2017). This liqueur is very popular in an Asian country and has apparently been exported to American lands. It may be assumed that, together with the “poisonous” liqueur, the sleeping hornet larvae were brought to the United States and Canada, which became active later.

Conclusion and Forecast

The Asian giant hornet represents a group of wasps with incredible size, strong jaws, and high speed of flight. Initially appeared in Asian countries, this species began to migrate to other lands, penetrating local ecosystems. Such an invasion could hardly bring positive results, and in the decades since the first media publications about single cases of individuals in unusual ranges, hornet populations have become a serious threat to countries. Hornet populations have the potential to cause a severe economic crisis, as they tend to destroy entire apiaries. In addition, the very existence of Asian hornets in unconventional habitats poses a threat to the survival of other species.

It is difficult to say in which country new hornet infestation cases will be detected, but the study by displacement allows predicting scenarios. About a year has passed since V. mandarinia was found in the U.S., and during this time, the hornets may have taken a stable position in the ecosystems. Alaniz et al. (2020) reported that the development of hornet populations would cause severe financial losses for America. For this reason, the country’s authorities seek to take preventive measures, including by informing the population. For instance, the state of Washington has already released an online form asking citizens to report cases of such hornets being discovered (“Hornet watch report form,” 2020). Therefore, it is difficult to underestimate the scale of the problem, and in the future, it is likely that humanity will observe ecosystem structural changes caused by V. mandarinia invasion.

References

Alaniz, A. J., Carvajal, M. A., & Vergara, P. M. (2020). Giants are coming? Predicting the potential

spread and impacts of the giant Asian hornet (Vespa mandarinia, Hymenoptera: Vespidae) in the USA. Pest Management Science, 4-14.

Asian hornet. (n.d.). BeeAware. 2020, Web.

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Asian giant hornet. (n.d.). National Invasive Species Information Center. 2020. Web.

Chen, P. Y., Wei, S. J., & Liu, J. X. (2016). The mitochondrial genome of the Vespa mandarinia Smith (Hymenoptera: Vespidae: Vespinae) and a phylogenetic analysis of the Vespoidea. Mitochondrial DNA Part A, 27(6), 4414-4415.

Choi, M. B., Martin, S. J., & Lee, J. W. (2012). Distribution, spread, and impact of the invasive hornet Vespa velutina in South Korea. Journal of Asia-Pacific Entomology, 15(3), 473-477.

Common name: Asian giant. (n.d.). Featured Creatures. 2020. Web.

del Pico, C. (2012). Giant Japanese hornet kill´s honey bee. Flickr.

Fan, L., Cai, T., Xiong, Y., Song, G., & Lei, F. (2019). Bergmann’s rule and Allen’s rule in two passerine birds in China. Avian Research, 10(1), 34-42.

Gill, C., Jack, C., & Lucky, A. (2020). Vespa mandarinia Smith (1852) (Insecta: Hymenoptera: Vespidae). EDIS, 2020(3), 5-5.

Hirano, K., & Tanikawa, A. (2020). Ocular injury caused by the sprayed venom of the Asian giant hornet (Vespa mandarinia). Case Reports in Ophthalmology, 11(2), 430-435.

Holland, J. S. (2013). The plight of the honeybee. National Geographic. Web.

Hornet watch report form. (2020). Washington State Department of Agriculture. Web.

Kaufman, M. (2020). How ‘murder hornets’ came to the U.S. Mashable. Web.

Kotzer, Z. (2017). I got buzzed on killer Japanese hornet cocktails. Vice. Web.

Liu, Z., Li, X. D., Guo, B. H., Li, Y., Zhao, M., Shen, H. Y.,… & Liu, T. (2016). Acute interstitial nephritis, toxic hepatitis and toxic myocarditis following multiple Asian giant hornet stings in Shaanxi Province, China. Environmental Health and Preventive Medicine, 21(4), 231-236.

Main, D. (2020). Why are ‘murder hornet’ stings so intense? National Geographic. Web.

McClenaghan, B., Schlaf, M., Geddes, M., Mazza, J., Pitman, G., McCallum, K.,… & Otis, G. W. (2019). Behavioral responses of honey bees, Apis cerana and Apis mellifera, to Vespa mandarinia marking and alarm pheromones. Journal of Apicultural Research, 58(1), 141-148. Web.

Osterloff, E. (2020). Why Asian hornets are bad news for British bees. Natural History Museum. Web.

Suenami, S., Nobu, M. K., & Miyazaki, R. (2019). Community analysis of gut microbiota in hornets, the largest eusocial wasps, Vespa mandarinia and V. simillima. Scientific Reports, 9(1), 1-13.

Ugajin, A., Kiya, T., Kunieda, T., Ono, M., Yoshida, T., & Kubo, T. (2012). Detection of neural activity in the brains of Japanese honeybee workers during the formation of a “hot defensive bee ball”. PLoS One, 7(3), 3-9.

Warrant, E. (2019). Invertebrate vision. Lund University Publications, 2, pp.64-79.

Wilson, T. M., Takahashi, J., Spichiger, S. E., Kim, I., & van Westendorp, P. (2020). First reports of Vespa mandarinia (Hymenoptera: Vespidae) in North America represent two separate maternal lineages in Washington State, United States, and British Columbia, Canada. Annals of the Entomological Society of America, XX(X), 1-5.

Introduction to Cape Cod

Nature and science have provided us with some of the best and most beautiful sceneries on the face of the earth. People are always fascinated by the complex features that are to be found on the surface of the earth since ancient times. Cape Cod is one such feature that nature has given mankind. The feature is to be found on the shores of the Atlantic Ocean.

The cape stretches for approximately 60 miles into the Atlantic Ocean. The feature takes up an area of about 44, 600 acres of land made up of different ecosystems which are home to different species of organisms. The ecosystem around Cape Cod is characterized by among others robust marine life, an estuarine, inlets where freshwater from the hinterland comes into contact with saltwater from the ocean and terrestrial land among other features.

The ecosystem is unique in the world as it forms the habitat for different organisms that attract tourists from all over the world as well as scientific studies. Cape Cod is characterized by ever-changing geomorphic actions giving it distinct scenery which is unique and which favors the life of different aquatic and non-aquatic organisms.

The change can be attributed to various phenomena such as the rise and fall of tidal waves which shape the surrounding environment forming a very distinct ecosystem. Cape Cod’s freshwater ecosystem consists of kettle ponds, swamps and such other features. The terrestrial ecosystem is unique and plays host to different species that draw attention from different parts of the world.

Invasive Species in Cape Cod

As already indicated earlier in this paper, Cape Cod is inhabited by different organisms representing different species. Some of these species are invasive while others are not. In this section, the author will dwell on the invasive species of Cape Cod.

Asian Shore Crab and European Green Crab

Overview

There are several invasive species that are to be found in the Cape Cod ecosystem. Some of them have caused a lot of havoc in the area. The species include the Asian Shore Crab and the European Green Crab. They are scientifically referred to as Hemigraspus sanguineus and Carcinus maenas respectively. They are considered to be among the 100 most invasive species in the world (Cohen and Carlton 230).

The Asian Shore Crab (Hemigraspus sanguineus)

Characteristics

The species has three teeth or spines that are triangular in shape and which are located on either side of the body. These organs are used for feeding. The species has a carapace that gives the body a rigid structure which is strong and massive. It is on this rigid structure where all parts of the body are attached.

The carapace is hard with different colors ranging from green, red, and purple and in some cases brown. Scientists have examined the variations in color and they have concluded that the differences are genetic. They are also brought about by different environments within which the species thrives (Yamada and Hauck 907).

The males can be differentiated from the females given that they have pincers with fleshy, bulb-like features. They are less active as compared to the female crabs. Their sizes are smaller ranging between 35 and 42 millimeters of carapace width. They are smaller than their European Green crab counterparts (Bourdeau and O’Connor 320).

Hemigraspus Sanguineus: Habitat

The species dominates the shallow waters with hard bottoms. It thrives well in intertidal as well as the sub tidal areas. It thrives in rock crevices and it usually populates areas where certain organisms cannot survive. Artificial substrates can also serve as a good environment for this species. Saline environment is not a threat to these organisms as they can venture into moderate and high salinity waters. The crabs are adapted to different range of temperature and that is why they have successfully invaded different coasts in the world. This trait enables them to travel long distances without being affected negatively by the change in environment (Bourdeau and O’Connor 324).

Having discussed the characteristics as well as the features of this species, the author will now focus on its invasion history. Here the author will discuss how the species spread from its native location to Cape Cod which is the reference location for this paper. Its consequences in the area will also be put into perspective.

Invasion History

The species was discovered in the western part of the Pacific Ocean in 1817. The native location for the species is thought to be Russian, Japanese, Korean and Chinese coasts. In 1988, the species was sighted in New Jersey in the United States of America through ballast water that was ejected from the ships being cleaned. A few decades later, the species was found in abundance on the coast of the Atlantic Ocean where Cape Code is located (Lohrer and Whitlatch 209)

The species was estimated to move at an average speed of 750 kilometers in ten years. As a result of its invasive nature, it is a threat to the ecosystem. Efforts have been made to stop or minimize its distribution in the world’s coasts. Cape Cod is one of the world’s coasts with a unique ecosystem hosting different and equally unique organisms. But with the invasion of the species, the organisms are moving away (Lohrer and Whitlatch 212). At this juncture, it is important to discuss the impacts of the species in the Cape Cod ecosystem.

Impacts of the Invasion

The species has a great impact on the ecosystem. It is noted that Hemigraspus Sanguineus is omnivorous as it feeds on quite a number of organisms and plants creating competition and stress in the available food web. Due to the wide range of foods forming part of its diet, the food web is altered and the environment niche changes significantly posing a danger to the other organisms. The Asian Crab feeds on other crabs such as the Rock Crab scientifically known as the Cancer irroratus.

The Asian species has also been identified as the most dangerous species as compared to the European crab since in spite of its relatively small size, it can feed on the European Green crab (Ledesma and O’Connor 66).

Other organisms found in the ecosystem (such as oysters and lobsters) are being affected since the Asian crabs feed on them. When food is scarce, the invasive species preys on the few remaining organisms creating an imbalance in the ecosystem (Ledesma and O’Connor 69).

The species dominates almost all the habitats occupied by the other organisms. For example the mud crab’s habitat is invaded by this species which preys on these organisms. The great impact is as a result of direct predation that gives the species an advantage over the others. This is seen when the species effectively competes with other large organisms in the ecosystem (organisms such as the blue and rock crabs) without exhausting its food. This is given that almost the entire ecosystem provides a preying ground for the species (McDermott 325).

Statistics show that native organisms especially the shore crabs are decreasing in number while the population of the invasive species is rising. This is a threat to the Cape Cod ecosystem as the environment is prone to changes from the current state to one that may not support the organisms that completes it (McDermott 327).

For the past few years, the marsh grassland has decreased as large swathes of marshland are mysteriously disappearing leaving behind a muddy bare land. It has been noted that the Asian crabs are the cause of this menace. Many aquatic animals breed in the marshland and this supports future generations. However the invasive species are feeding on the young organisms which make reproduction among aquatic animals difficult. Such impacts have raised concerns in some governmental departments such as the Fish and Wildlife Departments. The authorities in Cape Cod have made efforts to control the situation (McDermott 233).

Control of the Asian Crab

Some short term measures were taken to control the situation. Some of the measures are analyzed in subsequent sections of the paper.

Departments were formed to monitor the presence of the Asian crab along the entire coast. Guidelines have been put in place such that if anyone spots the Asian crab (including tourists) they are advised to report to the authorities who will take action and get rid of the organism. In addition to this, the species has been declared harmful to the ecosystem and a law has been enacted to proscribe the possession of an Asian crab. Local tourists are being educated on the danger of the species and how to curb the menace (Lohrer and Whitlatch 215).

Laws have also been enacted to check the spread of the species by prohibiting people from carrying shells around and any such things that may transport the species from one place to the other. These were thought to be some of the practices encouraging the spread of the species.

The Green Crab (Carcinus Maenas)

Overview

Another invasive crab species in the region is the European Green Crab. It is believed to have originated from Europe in the Atlantic coasts and also from the Northern parts of Africa. It is known under different names around the world and it is recognized as one of the most dangerous and invasive species. It is scientifically known as the Carcinus maenas (Jare and Rock 49).

Characteristics

The organism acquires different colors as it undergoes molting. The color is not necessarily green but it ranges from red to orange depending on the stage of molting. Unlike the Asian Crab, the European Green Crab has five spines on every side of the body which makes it larger than the Asian species. Its size ranges from 65mm to 80mm with extremely flat legs (Greccon 259)

The crab has been noted to be a great forager as it has the capability of adopting different styles to capture food. Its diet is made up of a wide range of foods that gives it an advantage over other organisms in the ecosystem. It has a bivalve shell that can take different shapes which enables it to capture different types of foods in different ways (Greccon 261).

The species is an omnivorous feeding on different types of food that include many aquatic organisms such as oysters, mussels and even juvenile crabs making reproduction among other aquatic life difficult (Jare and Rock 48).

Habitat

The species dominates different kinds of environments ranging from rocky and flat shores. The European Green crab also thrives in the tidal marshes and the changing environment conditions is not a threat to it. The organisms can tolerate different levels of salinity ranging from low to high (4 to 52 range of salinity). A wide range of temperature (including temperatures below the freezing point) favors the organism (Grosholz and Ruiz 49).

Invasion History

The species originated from Europe and has invaded many coasts around the world. In 1817, the species found its way into the United States (in New Jersey and New York) and it has expanded to other coasts in the world. Like the Asian crab, the species is also estimated to travel at a speed of 750 kilometers in ten years. It has also reached the South African (Cohen and Carlton 235).

Impact of the European Green Crab

This organism is a voracious predator since it can feed on a wide range of organisms in the ecosystem. Various species living in the ecosystem risk being wiped out by this organism. Since its arrival in Cape Cod, it has been noted that native organisms have decreased at a very high rate. For example the shore crab has reduced in number after the European green crab showed up in the ecosystem (Jare and Rock 49).

Different feeding habits as well as the ability to tolerate different environments has given the species an upper hand. It preys on almost all species in the ecosystem. This inhibits the growth of other organisms suppressing their distribution in the ecosystem (Grosholz and Ruiz 63)

Management and Control

Different strategies have been adopted in attempts to control and manage this invasive species. Like in the case of the Asian crab, there is regular monitoring to manage the spread of this organism.

Rules have been put in place to regulate individuals carrying equipments around the shoreline since this can transport the species from one place to the other. This is for example moving shells along the shoreline. Ships which are believed to be the major transporters of crabs along the coast are inspected thoroughly to make sure that they do not introduce ballast carrying crabs into the Cape Cod coast (Bedini 710).

Another effective method to manage and control the menace is through the introduction of another parasite feeding on this invasive crab. The Sacculina carcini has been tested and found to suppress this organism at different stages. This is for example by feeding on the molting crab and even altering the development of the males. This method is effective but scientists are still assessing its impact on the ecosystem before introducing the parasites (Bedini 709).

Conclusion

Different species are important in any given ecosystem. They create a natural balance that is needed to sustain the ecosystem. Using emerging scientific knowledge, invasive species can be controlled effectively without affecting the others in the ecosystem. This is for example through the introduction of parasites. It is important to monitor the invasion rate and respond appropriately to protect native species.

Works Cited

Bedini, Brian. “Color Change and Mimicry from Juvenile to Adult: Carcinus Maenas.”Crustaceana 75.5 (2008): 703–710. Print.

Bourdeau, Paul and O’Connor, John. “Predation by the Nonindigenous Asian Shore Crab Hemigrapsus sanguineus on Macroalgae and Molluscs.” Northeastern Naturalist 10.2 (2010): 319-334. Print.

Cohen, Andrew and Carlton, Jerald. “Introduction, Dispersal and Potential Impacts of the Green Crabs in San Francisco Bay, California.” Marine Biology 122.2 (2011): 225–237. Print.

Greccon, Jensen. “East Meets West: Competitive Interactions between Green Crab Carcinus Maenas and Native and Introduced Shore Crab Hemigrapsus spp.” Marine Ecology Progress Series 225.6 (2008): 251-262. Print.

Grosholz, Edwin and Ruiz, Michael. “Predicting the Impact of Introduced Marine Species: Lessons from the Multiple Invasions of the European Green Crab Carcinus Maenas.” Biological Conservation 78.12 (2009): 59–66. Print.

Jare, Brian and Rock, Fernandes. “Patterns of Morphological and Genetic Variability and Populations of the Shore Crab: Carcinus Maenas.” Journal of the Experimental Marine Biology 329.1 (2005): 47–54. Print.

Ledesma, Ellison and O’Connor, John. “Habitat and diet of the Non-native Crab Hemigrapsus sanguineus in Southeastern New England.” Northeastern Naturalist 8.3 (2009): 63-78. Print.

Lohrer, Allan and Whitlatch, James. “Structural Complexity and Verticalzonation of Intertidal Crabs with Focus on Habitat Requirements of the Invasive Asian Shore Crab Hemigrapsus Sanguineus.” Journal of Experimental Marine Biology and Ecology 244.17 (2011): 203–217. Print.

McDermott, Jackson. “A Breeding Population of the Western Pacific Crab Hemigrapsus.” Journal of Experimental Marine Biology and Ecology 12.2 (2003): 23-24.

Yamada, Susan and Hauck, Luke. “Field Identification of the European Green Crab Species Carcinus Maenas.” Journal of Selfish Research 20.3 (2010): 905–909. Print.

Introduction

Invasive species can degrade an ecosystem’s natural environment and jeopardize human usage of these resources. Invasive species can wipe out native wildlife and ecosystems, diminishing biodiversity and competing for finite resources with native creatures (Kuşku 12). This research paper explores Zebra mussels as the most common invasive species in Missouri, investigating the damage created to the ecosystem and the future damage. This research also highlights how Zebra mussels were introduced in Missouri and some of the measures initiated to stop the invasion. The ecological disruption necessitates intervention to manage the invasive species.

Invasive Species in Missouri

Zebra mussels wreak havoc on indigenous species in Missouri, directly affecting the quality of the natural environment of aquatic animals. The most significant challenge associated with zebra mussels is the need to cling to a hard item for survival (Dölle and Kurzmann 13). Studies on the aquatic ecosystem in Missouri have shown that numerous indigenous mollusk species are threatened with extinction or are already endangered due to zebra mussels (Bouska et al., 347). Zebra mussels’ natural behavior interferes with the aquatic ecosystem, threatening other indigenous species’ survival (Bouska et al., 347). The species spread quickly with water flow and relocation of infested native species in water bodies.

The Introduction of Zebra Mussels in Missouri

In Missouri, the zebra mussel dominates their concurred environment as invaders that interfere with the natural setting of the aquatic life. A study on the origin of Zebra mussels in Missouri reveals that species were first detected in the late 1980s on the shores of lake Detroit (Kuşku 16). The invasive species have now migrated throughout the Mississippi and Missouri rivers (Bouska et al., 351). Originally endemic to the lakes of southern Russia and Ukraine, the species was mistakenly transferred to various other locations. The invading species have become a primary ecological concern in several nations globally.

Today, Zebra mussels are still a primary ecological concern in most of Europe and America. Zebra mussels have established a foothold in North America, the United Kingdom, Ireland, France, Spain, and Sweden (Dölle and Kurzmann 13). The tiny larvae may thrive in lake water with access to hard surfaces supporting reproduction (Bouska et al., 353). Zebra mussels often invade new lakes or rivers when a boat or piping system is transferred to other aquatic environments. The spread of the Zebra mussels can cause several ecological disruptions.

The Damage Created to the Ecosystem

For instance, invasive species cause ecological disruption by monotypic proliferation and cause damage to marine life as well as water treatment and the dynamic aquatic environment. Zebra mussels have also adversely affected water treatment plants in Missouri (Kuşku 17). Research into the behavior of the invasive species revealed that the tiny larvae often enter the piping systems. Zebra mussels attach to and block pipes submerged in water (Bouska et al., 351). Zebra mussels reproduce quickly and may establish dense colonies on the body of native species, pipelines, and other submerged structures.

Future Damages

Such damages can wipe out native plants and animals, diminish biodiversity, compete for scarce resources with native creatures, and change environments. The disruption of the natural ecosystem can have a significant economic effect and fundamentally damage the quality of water and the life of the native aquatic species. Invasive species’ economic and social costs directly affect property values, farming practices, public service operations, tourism, and recreational opportunities (Dölle and Kurzmann 7). The invasive species are also associated with indirect expenses connected with management efforts (Kuşku 18). Zebra mussels can push native species to extinction and increase equipment maintenance costs in the water.

Measures Initiated to Stop Zebra Mussels Invasion

The potential adverse effects in Missouri have necessitated strategic interventions to control the spread of Zebra mussels. Two of the most common interventions for preventing invasive species include pesticides and sensitization on preventive procedures among fishers and plumbers. In Missouri, chlorine and metal-based solutions have been extensively employed to control the spread of Zebra mussels (Dölle and Kurzmann 17). The Molluscicide Zequanox is a naturally occurring aquatic pesticide demonstrated to be effective against invasive Zebra and Quagga mussels (Luoma et al., 425). The use of pesticides is complemented with proper sensitization on the need for populations interacting with infested waters to take appropriate precautions when shifting between water bodies.

Conclusion

Zebra mussels are an invasive species in Missouri that can harm the natural ecology of an ecosystem and risk human use of its resources. Zebra mussels can annihilate indigenous fauna and ecosystems, reduce biodiversity, fight for scarce resources with indigenous critters, and negatively alter the local natural environment. First detected in the late 1980s on the shores of Lake Detroit, Zebra mussel has spread to Europe and America, increasing the risk of biodiversity of the aquatic life. Some of the control measures adopted in Missouri include pesticides such as Molluscicide Zequanox and proper sensitization among fishers. The intervention efforts are necessary to avoid the chances of native species becoming extinct due to the disruption of their natural aquatic environment.

Works Cited

Bouska, Kristen, et al. “State‐Level Freshwater Mussel Programs: Current Status and a Research Framework to Aid in Mussel Management and Conservation.” Fisheries, 1, 2018, pp345-360. Web.

Dölle, Klaus, and David E. Kurzmann. “The freshwater mollusk Dreissena polymorpha (zebra mussel)-a review: living, prospects, and jeopardies.” Asian Journal of Environment & Ecology, 13, 2020, pp1-17.

Kuşku, Halit. “Biological Control of Invasive Zebra Mussel (Dreissena polymorpha) in a Freshwater Ecosystem through Potamon Ibericum.” Aquatic Research, 5.1, 2022, pp11-19. Web.

Luoma, James A., et al. “Effects of Temperature and Exposure Duration on Four Potential Rapid-Response Tools for Zebra Mussel (Dreissena polymorpha) Eradication.” Management of Biological Invasions 9.4, 2018, pp425. Web.

Environmental issues have a rather unpleasant property of recurring after they have been considered partially solved. When it seemed that the environmental awareness craze had become less topical compared with other issues on the world’s agenda, the extinction of species and the subsequent alteration of the environment were discovered.

As the pace of habitat change increases, species migrate in order to find more favorable environment. As a result, these migrating species conflict with the ones that emerged in the chosen habitat naturally. After the conflict between the alien species and the local one erupts, the change in the ecosystems ensues.

The situation that can be witnessed in Spain is a graphic example of the phenomenon in question. Because of the introduction of such alien species as Agave Americana, Carpobrotus spp., Eriocheir sinesis, etc. into the local habitat as a result of economic and particularly trading relationships, the existence of Junipenis phoenicea, Corema album, Limonium emarginatum, etc. has been jeopardized (Garrido 50).

According to the traditional definition of the term, alien species are the “plants and animals that have been intentionally or unintentionally introduced, have established populations and have spread into the wild in the new host region” (Otero, Cebrian, Francour,. Galil and Savini 8).

The implications of having alien, or, as they are also termed quite often, exotic, introduced or non-native species, are quite negative. These species disrupt the habitat of the area, creating imbalance and, thus, leading to the extinction of the local species, deterioration of the land, and the following economic issues caused by the lack of the specified natural resources.

A closer analysis of the issue will show that the change in the climate of a range of regions is not the only factor that has caused the invasion of alien species into the Spanish natural habitats. Apart from the obvious need for species to relocate in order to find the environment with a proper climate, hunting, trade and other human induced factors must be mentioned (European Commission 12).

Overall, the human factor has played a major role in the spreading of alien species in Spain. Although, technically, climate change can be viewed as a human-induced catastrophe, there are more obvious and direct effects that people have had on the Spanish environment and the increase of the alien species population within the area mentioned above.

To be more specific, such phenomenon as hunting deserves to be listed among the key causes for the current prevalence of the alien species within certain Spanish habitats. In addition, a range of species, particularly, fish and amphibians, have been carried to Spain with the ocean currents.

The origins of these alien species, therefore, are rather diverse. 28% of them come from Central and South America; 21% floats to Spain from North America; 31% of alien species invade Spain from Asia; 12% come from Africa, and the remaining 8% originate from Australia (Andreu and Vila 130). As the above-mentioned data shows, the contact established with Asia clearly is the greatest threat to the biodiversity of Spain at present.

As far as the habitat of the species in question is concerned, the environments that are viewed as favorable also differ greatly; what may be suitable for one of the species will not be acceptable for another one. However, for the most part, the species in question enjoy the coastal areas with their Mediterranean climate, which Spain is famous for (Godoy, Castro-Dı´ez, Valladares and Costa-Tenorio 7).

When it comes to suggesting the solutions for the current environmental issue that Spain is facing at present, one must bear in mind that the economic links between Spain and the rest of the states are crucial to the former’s growth and financial sustainability. Hence, it will be unreasonable and even highly dangerous to terminate the trade with the states that contribute to the problem. Therefore, a more rigid approach towards the trading process must be established.

The same can be said about the geological processes that make species relocate in search for a more appropriate environment. Blocking the way for the specified plants and animals to intervene the Spanish ecosystems is barely possible; however, fostering the growth and evolution of the endangered species clearly is a viable opportunity for restoring the balance. It should be kept in mind, though, that the creation of the environment required for the local species to prosper will demand that impressive financial resources should be located (Integrated Analysis of Factors Influencing Plants Spatial Distribution 1).

Another approach that will possibly help address the situation and resolve the problem concerning the invasion of the alien species in Spain, the actions aimed at protecting the areas in danger from the “invaders.” There is one problem, though, and a crucial one at that.

By modifying the environment so that it could become unsuitable for the alien species to dwell and repopulate in, one may put the local species under a giant threat as well. Utilizing a chemical compound, which the alien species in question react negatively with, will most likely be incompatible with the Spanish local plants as well and, therefore, trigger a drop in the amount of the local flora.

The same can be said about allowing hunting for alien species on the grounds that their elimination will lead to the following restoration of the state’s natural flora and fauna. While the reduction in the number of alien species will be evident, the remaining ones will still have their toll on the evolution of the local animals and plants, as well as shape the local habitat consistently.

Therefore, inspections and fees for transporting the species that are classified as alien to the Spanish environment will have to be imposed on the international trading companies. From an economic perspective, though, the revenues received from trade are most likely to exceed the costs for fee payment, which is why the given step can be considered only a temporary measure and the first step towards ridding Spain of alien flora and fauna.

Introducing a set of very specific rules on the treatment of the commodities that are imported into Spain, especially the ones that can be viewed as the environment for the growth of microorganisms, can be viewed a reasonable step to take. These instructions have to include fumigation, immersion, spraying, heat and cold treatment, and pressure (Global Strategy on Invasive Alien Species 2).

Finally, the audits aimed at checking the compliance with the WTO trading Agreement must be conducted. While the measures listed above will not release Spain from the alien species that inhabit it at present and alter its environment, they will set the course for developing other advances for addressing the problem.

Works Cited

Andreu, Jara and Montserrat Vila. ”Risk Analysis of Potential Invasive Plants in Spain.” Journal for Nature Conservation 17 (2009), 129–141. Print.

European Commission 2013, Invasive Alien Species. Web.

Garrido, Jose Raphael. “Management of Invasive Alien Species in Andalusia (Southern Spain): Some Successful Experiences.” Academia.edu. 2009.

Global Strategy on Invasive Alien Species 2000. Web.

Godoy, Oscar, Pablo Castro-Dı´ez, Frederick Valladares and Maria Costa-Tenorio. “Different Flowering Phenology of Alien Invasive Species in Spain: Evidence for the Use of an Empty Temporal Niche?” Plant Biology 11.8 (2011), 803–811. Print.

Integrated Analysis of Factors Influencing Plants Spatial Distribution2010. Web.

Introduction

Exotic organisms cause a great harm to the existing a balanced ecosystem in forests and grasslands. Their devastating effects on ecology have led to long periods of research. However, there has been insufficient research on the impact of invasive plants on ecological associations in native communities (Klopfer, 2009). Their effects on a new environment is that they may perform better in the new conditions and may interfere chemically with the performance of existing native plants (Stinson et al, 2006). When exotic and native species invade an area, their existence will be determined by the mutual associations of native birds, insects with soil microbes by symbiosis.

Biological invasions are commonly caused by global changes in the environment that are the result of human pollution activities (Vitousek et al, 1997). Such invasive species can have detrimental effects on the health of humans, alter stabilized ecosystems, and threaten the biological diversity of native lands. Therefore researchers are working towards changing the approach of humans towards the global environment (Tye, 2009).

The following are talks by scientists and researchers on invasive species and exotic organisms, and their detrimental effects on the environment.

First talk titled “Ecology of the Asian longhorned beetle and tools for eradicating it in urban environments” by Melody Keena

The Longhorned beetle first originated in China with other appearances in Korea, New York and Chicago. Their origin in China dates back to 50 years ago whereby, deforestation was done in many areas around the country in order to introduce trees that were first growing. The new species of trees would be used for various purposes; however, they were planted in the wrong places. The regions that they were planted in had beetles which made a huge amount of destruction and thus destroyed the trees’ original purpose. Hence, the Chinese decided to come up with the next purpose which was to make packing material from the trees which would then move around the world thus spreading the invasive species to areas that did not previously have them.

The Longhorn beetles spread through mating. The female lays eggs at the back of trees in specific spots. Some of the risks that have been posed by these insects are waste, destruction of wood and their numbers in landfills is an increased risk.

There are specific types of tree species that these beetles attack like the Maples, especially the sugar Maple. Such species are the primary susceptible hosts of the insects. Therefore, the trees that are susceptible need to be replaced by other trees like the sycamore, fig tree. This is carried out during refurbishing in urban environments and the tourism industry.

Eradication of these beetles is done by keeping more infestations out by having the soluble material coming into the United States treated using heat treatment or metal Bromide to kill the insects in the wood. This should be done by the country of origin. If it is in the United States, a systemic insecticide will be used which slows the spread by preventing insects from establishing themselves in the trees. This method is referred to as tree destructing mechanism for eradication. Any trees found infected are cut and checked.

Finding the infested trees involves carrying out a ground survey. This is done by looking around the trees (probably by climbing it) with a pair of binoculars, and searching for signs of infection. However, this method seems to be expensive, time consuming and it is not possible to do it every where that the insect can be. Another way they spread is by flying where, males have been found to fly more than females. If the wind is too high, few of the insects would fly, while if it is low, more would fly. The females lay their eggs above 15°Celcius but at high temperatures, as high as 35°Celcius, no eggs are laid since it is too hot for the hatching to take place. It has also been established that at very low temperatures the beetles live longer while in warmer temperatures the opposite happens. Thus their population reduces during summer. It is only the small larvae that are sensitive to temperature. For instance, the low temperatures in Vermont and Florida are sufficient for their development.

In order to find them, testing traps have been used in China, and the male pheromones tested. Later on traps will be placed in New York using beetle killing fungus. In order to prevent beetles form attacking other trees, they should be treated for three years in a row. The treatment moves up the tree to the leaves to areas where the beetles can be. In areas that have a lot of water the chemical is not effective therefore trap congestion method will be used.

Challenges that have been faced in eradicating this insect is that since it is not native in the US it does not come with its natural controls therefore difficult to trap. Moreover, it prefers to host Maples trees which are plenty in the United States, this makes it difficult to detect.

Second talk titled “Faunal invasives in New York City waterways and the exotics we can fuhgedd about” by Chris Anderson

Exotics are alien species that have been transported out of their natural environment into another by humans. Invasives are the same thing but have a detrimental effect on the species around their new environment. Plant organisms can be invasive in that they cause detrimental effects by making other plants unable to photosynthesize.

Organisms get in the waterways mostly accidentally by ship holes moving from one country to another resulting in an exchange of microorganisms. They become difficult to detect especially when they get to the new area. In fact, they may die due to lack of food, different salinity, temperature, different environment with more pollution than in areas they came from. If they live their population expands and affect the stability of the ecosystem. Sometimes plants are brought into New York because they are beautiful, but in the long run disrupt ecosystem. For instance, Water Chestnut creates huge masses of plant blankets, in beaches and become dangerous to humans. They are brought here because of their beauty and in the long run it grows quickly and takes oxygen from the water thereby posing as a danger to other organisms that require oxygen for survival. Some invasive species were also introduced through the oyster restoration projects.

The Hudson river contains many species such as the zebra mussel species. This species consumes lots of food, thus reducing oxygen drastically posing as a danger to other organisms that need oxygen. They also consume vital planktons which leads to the increase of planktonic bacteria while native planktons decrease. Organisms that feed on planktons become affected. These species also decrease turbidity of water. They do this by taking out large bacteria and plankton, making plants to photosynthesize more because they provide more light to the bottom as they consume more.

Species of crabs such as green crabs compete with the native crabs, in that they breed a lot, are aggressive, they compete for food and habitats, are versatile, and under any rock. Actually, they disrupt the biodiversity that was previously balanced. Invasive crabs compete with native crabs, by eating anything bad for the ecosystem, they even consume oyster. Butterfly fish, blue angel fish among others carry organisms living in warmer climates to colder climates thus acting as agents of invasive species. Other fauna that result from shipping are planktons, algae, snails that are exotic but present in water.

The damage caused by these invasive species is that they follow turbines, under water equipment, and water pipes in industrial companies that is used to cool down capacitors. These organisms follow the water and the only way to remove them is pull them out which is a big daunting task. Not much can be done to remove the invasive species though more has been done to monitor them. It is a tough process that needs millions of dollars to effect.

Benefits of such species is that some fish species bring money to the economy by increasing their population, provide a source of food, result in fish farming, maintains a flowing food chain, keep plankton levels at bay, are a food source for top predators, reduce unintentionally introduced species. There needs to be a call for monitoring of ships and the introduction of restrictor laws against the introduction of natives in waterways.

Third talk titled “Report from the battlefield: WildMetro Earth Tenders versus invaders in the New York Metro region” by David Burg

WildMetro, an independent metro project is in the process of working with New York City agencies to control the spread of invasive species. It is an organization that is interested in nature and people and has the aim of protecting the planet. As the human culture changes, technology and the values of people also change. The result of this is that there will be unintended changes in the environment. It becomes people versus nature even if the goal of humans was not to save nature.

Invasives are other species that invades a habitat that was kept in check by other species thereby introducing destabilization. The firsts step to discover the beauty of nature that has been invaded is by liking it and then having the need to protect it. Species that existed thousands of years ago, like the ones under glaciers no longer exist because nature was not protected. Many people have questioned the basis of protecting nature on the grounds of species that existed in the Jurassic park will not re-evolve therefore there is no basis of the struggle. Grazing animals are an example of species that have a huge impact on vegetation through grazing. People can destroy the environment by burning grasslands or trees for making charcoal, therefore damaging species

Invasive species have a competitive behavior in that they increase in population once they inhabit a new area. They also have a relationship with human development. When talking about stopping invasive species, one should think about persistent biological systems. The problem of invasive species is that they result in new species that might have died off. The examples of invasives were brought in the New York City are chestnut trees. Invasives are a threat to diversity in that they will result in extinction of other species. Therefore, natural areas should be protected, avoiding any kind of disturbance.

Fourth talk titled “Invasive plants of New York City forests” by Timothy Wenskus

Invasive plants problems are bigger than imagined.

There are about 50 invasive plants in the New York City such as vines, trees and shrubs. Invasive vines have berries that germinate when they hit the ground, strangle the tree next to it, by twining it since it does not have strong enough width to support itself; and then chokes off the flow of water from the roots and nutrients from the leaves necessary for the growth of the tree; and later the tree dies. The vines can be cut off at the base by killing the roots to save the tree. Maples, being the number one selling tree in America, are examples of invasive trees that form canopies such that plants growing underneath are deprived of light. It is known to be a very competitive type of invasive plant. Invasive herbaceous plants disrupt the balance of plants while invasive shrubs produce berries that have carbohydrates or sugar in them but provide lesser quality of food. Their shoot elongation offers them a competitive advantage over other plants. The locally invasive plants grow on certain properties and spread.

Prevention of invasive plants can be done by using biological control methods, and cutting trees, which is a reliable way of stopping its spread. Satellite populations should also be captured since they can reinfest an area that has been cleared. Mechanical removal can be used whereby only native plants are left. However, there are invasive plants that have been treated but they do not go away, due to the satellite populations that have not been captured. To control the spread of invasive species there have been restrictions of selling maples in the United States.

Fifth talk titled ” Opportunities and constraints of large-scale ecological restoration in Phragmites-dominated sites” by Mike Feller

Phragmites are tall grasses that are bushy and cover hundreds of acres. They can appear even in shorelines and are hypercompetitive. A monoculture is referred to as a community of phragmites and are familiar with fresh water islands. Due to its height and competitive nature, nothing grows underneath phragmites. Ecosystems have certain self-organizing abilities and species exist in dynamic equilibrium, coevolving with one another, each having its niche. What invasive species do to these ecosystems is that they destabilize the ecosystem, by giving negative feedback mechanisms.

Specific restoration projects have been used to get rid of these invasive species. Landscapes and parks dominated by phragmites have been filled with garbage and sand to control their spread. Herbicides have also been sprayed on phragmites, by running through the phragmites, and behind them, using direct application right on to the phragmites and not other plants. Some plants which may not be invasives such as other types of berries are nitrogen fixers and support the growth of invasive species.

Sand resists invasion by nonnative plants and phragmites do not grow well, it is nutrient limited and moisture limited. Fire is not a good way to manage phragmites dominated communities but they can be mowed if they occupy a small area.

Conclusion

Therefore, the overall theme of these talks being the detrimental effects of invasive species and exotic organisms on the native species, there seems to be a need to eliminate these species from the environment by all means. They destroy the existing equilibrium of the native species by depriving them of the essential requirements of plants to grow such as sunlight, water and nutrients. Thus, more research needs to be done on how to control their spread or eliminate them from the environment in order to maintain a balanced ecosystem.

Reference List

Jager, H., Kowarik, I., Tye, A. (2009). Destruction Without Extinction: Long Term Effects of an Invasive Tree Species on Galapagos Highland Vegetation. The Journal of Ecology, 97 (6), 12-52. Web.

Klopfer, E., Scheintaub, H., Huang, W., & Wendel, D. (2009). Constructing Learning: How will the Ecology of Silver Lake Change If An Invasive Species is Introduced? Learning and Leading With Technology, 37 (5), 26. Web.

Stinson, K.A., Stuart, A.C., Powell, J.R., Wolfe, B.E., Callaway, R.M., Thelen, G.C., et al. ( 2006). Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms. PloS Biology 4, 1-3.

Vitousek, P.M., D’Antonio, C.M., Loope, L.L., Rejmanek, M., & Wetbrooks, R. (1997). Introduced Species: A Significant Component Of Human-Caused Global Change. New Zealand Journal of Ecology, 21(1), 1-16. Web.

Abstract

The aim of this study was to explore the effect of invasive plant species on birds in Wattle Park in Melbourne, Australia. The study would help in understanding the complex interplay between invasive plant species and bird types. Four sites measuring 100 ft x 100 ft were surveyed in Wattle Park for two days to gather data on bird types in the invasive plant species. Data were collected within 15 minutes in every site by observing and identifying bird species on the marked tree and shrub species within the study sites. Data on bird type distribution in the study sites were analyzed using Excel. The results indicated that certain bird types were common in some sites than in other sites. It was concluded that invasive plant species influenced bird species distribution and community composition in the Park.

Introduction

Invasive plants have greater potential to influence the number, population composition, and stability of bird populations by changing resources availability, altering habitat compositions, and transforming food quality or interfering with the entire food chain. As a result, Grice (2006) claims that plant invasions present a serious threat to biodiversity. Plant invasion has affected the conservation and management of species globally. This is clearly the case in Australia in which plant invasion is linked to “habitat clearance, livestock grazing, forestry and soil degradation due to pressure on native species and communities” (Grice 2006, p. 27). On the contrary, Gan, Li, Chen, and Ma (2007) noted that invasive fruiting plants were sometimes beneficial to an ecological setup. Various exotic taxa such as plants, mammals, and birds, among others, had significant effects on ecology. For instance, any exotic species have abilities to influence native bird species in various ways. There are predatory mammals that come with invasive plants. Other bird species and mammals may compete for habitats and foods. Hybridization may occur and lead to a loss of the genetic composition of the native species. Invasive plant species may also cause direct or indirect changes in native habitats and food resources of birds. In addition, there could be loss and fragmentation of native birds’ habitats due to changes in the composition of the species and structures of native plant composition (Gan et al. 2007). Holland-Clift, O’dowd, and Nally (2011) found that willow invasion affected food resource and changed habitat, which in turn reduced native bird biodiversity and disrupted interrelations in the affected riparian zone.

A study by Scheiman, Bollinger, and Johnson (2003) explored whether exotic grass had any effects on the abundance of birds, plants, and arthropods. The researchers established that the number of birds was significantly lower in exotic-grass-dominated areas of the study (Scheiman et al. 2003). In addition, the “density of the ground-foraging bird guild was lower on exotic sites because the seeds and insect resources located on the ground were less abundant on exotic sites” (Scheiman et al. 2003, p. 648). In this particular study, invasive grass species had negative influences on the functional relationship between birds and their habitats, foods, and prey. Invasive grass offered few foods for breeding bird populations. In addition, invasive grass also suppressed native plant species and reduced niches for arthropods (Scheiman et al. 2003). Milton et al. (2007) observed that some invading species of plants had abilities to change the savanna by suppressing native trees. This transformation led to an ecosystem-level effect (Milton et al. 2007). Exotic host trees also had similar effects on the open savanna. There were changes in the diversity, presence, and composition of tree species. Overall, invasive plant species bring about complex interplay in an ecological setup by affecting food distribution and habitats of birds (Milton et al. 2007; Ortega, McKelvey & Six 2006).

Aim of the Study

The aim of this study was to explore the effect of invasive plant species on birds in Wattle Park. In this regard, the study addressed the following issues:

1. Whether invasive plant species attracted specific bird species than others
2. Whether invasive plant species affected the presence of birds in various study sites in Wattle Park

Study Area

The study was conducted at the Wattle Park in Melbourne, Australia, which is a large area with various indigenous and invasive plant species. The Park is a significant place because of its high diversity of common native and exotic fauna and flora. Plant species range from ground covers and shrubs to big trees that provide habitats and food for various bird species and other mammals. Thus, it is imperative to understand the effect of invasive plant species on the birds in the Park.

Study Methodology

Sites with invasive trees and shrubs in the Park were chosen for the study. These study sites were chosen because they had various plant and bird species. The major birds found in the study sites included magpie, crow, rainbow parrot, and noisy miner among others.

Stratification of study sites

Data were collected on two field trips. Invasive trees and shrub species were sampled to identify various birds they attracted. The investigators collected data from the identified invasive tree and shrub species with the aim of sampling several species.

Invasive vegetation species were classified into tree and shrub species with further classification as trees 1, 2, and 3 and shrub 1, 2, and 3. Study sites were classified as sites 1 and 2 for both shrubs and trees. For every vegetation type, there were two sites. This represented four sites for the study. Samples from these sites were used for data analysis and reporting.

Care was taken not to damage the vegetation species or cause harm to birds.

Data Collection

The investigators used a tape measure to measure 100 ft x 100 ft for every study site. They then used a marker to transect each study site. All four sites were studied within two days. Each site was studied within 15 minutes by counting bird species on various invasive trees and shrubs. Binoculars were used to look at distant birds while a bird’s book was used to identify various birds.

Data recorded included the following:

1. Location sites with regard to tree and shrub species
2. Bird species
3. The number of experiment in each study site

The investigators identified various bird species and named them. However, they failed to identify only a single bird type, which was noted as Species number 1.

Care was taken to ensure that the correct birds were identified in each site and on specific vegetation.

Data Analysis

Data were analyzed using Excel to determine frequencies and percentages.

Study Results and Discussion

All birds observed in all the four study sites were 374. They included magpies, crows, rainbow parrots, Rosella parrots, noisy miners, green parrots, ravens, and unidentified bird types (Species number 1). The most common bird type was the noisy miner, while the least common was the raven (Table 1).

Table 1: All bird types observed across all the study sites

Tree Sites

Site 1 had 113 bird species, while site 2 had 110 bird species.

Shrub Sites

Site 1 had 55 bird types, while Site 2 had 96 birds.

There were 223 bird types observed in the Tree Sites, while Shrub Sites had 151 bird types.

Whether invasive plant species affected the distribution of birds in various study sites in Wattle Park

The invasive plant species affected the distribution of bird communities across various study sites. For instance, the Tree sites had more birds than the Shrub sites (figure 2). In addition, the distribution of bird types also differed significantly within the Tree and Shrub sites (figure 3-5).

Bird communities were highly distributed in some trees than in others.

Whether invasive plant species attracted specific bird species than others

The most common bird type observed in the study sites was the noisy miner, while the least observed bird type was the raven (table 1 and figure 1). The noisy miner was common in Site 2 Tree 1 than in other locations. The raven was not observed in the study Tree Site 2.

On the other hand, there were more ravens in Shrub sites than other bird species, while Species number 1 was not present in Shrub Site 2.

These results indicated that specific invasive plant species attracted specific bird species than others. In addition, not all bird species were distributed in all the study sites. The bird type distribution varied from site to site in both Tree and Shrub sites.

Certainly, invasive plant species affected the presence of birds in various study sites in Wattle Park. Invasive plant species affected bird species distribution in different ways. For instance, there were many specific bird species in other parts of the sites than in others. That is, invasive tree sites had many bird species than invasive shrub sites. Past studies have established that invasive plant species affected bird species distribution and population by altering food resources and habitats (Ortega et al. 2006; Holland-Clift et al. 2011). Consequently, there were more bird species in certain sites than other sites. Food resource availability is an imperative factor for any bird species and influences their choices of habitat. Hence, the invasive plant species provided supportive ecosystem for the noisy miner than other bird species.

This study supported previous findings by other researchers that invasive plant species altered the biodiversity, distribution, and species composition of birds in a given area (Lau 2013; Gan et al. 2007; Ortega et al. 2006). In addition, invasive plant species affected many species throughout the entire Park, particularly those species whose survival was highly connected to other affected species. The study results showed the complex interplay between invasive plant species and bird types in Wattle Park.

Reference List

Gan, X, Li, B, Chen, J, & Ma, Z 2007, ‘The ecological effects of biological invasions on birds’, Biodiversity Science, vol. 15, no. 5, pp. 548-557. Web.

Grice, A C 2006, ‘The impacts of invasive plant species on the biodiversity of Australian rangelands’, The Rangeland Journal, vol. 28, pp. 27–35. Web.

Holland-Clift, S, O’dowd, D & Nally, R M 2011, ‘Impacts of an invasive willow (Salix × rubens) on riparian bird assemblages in south-eastern Australia’, Austral Ecology, vol. 36, no. 5, pp. 511–520. Web.

Lau, J A 2013, ‘Trophic consequences of a biological invasion: do plant invasions increase predator abundance?’, Oikos, vol. 122, no. 3, pp. 474–480. Web.

Milton, S, Wilson, J, Richardson, D, Seymour, C, Dean, W & Ipongaş, Ş 2007, ‘Invasive alien plants infiltrate bird-mediated shrub nucleation processes in arid savanna’, Journal of Ecology, vol. 95, no. 4, pp. 648–661. Web.

Ortega, Y, McKelvey, K & Six, D 2006, ‘Invasion of an exotic forb impacts reproductive success and site fidelity of a migratory songbird’, Oecologia, vol. 149, no.2, pp. 340-351.

Scheiman, D, Bollinger, E and Johnson, D 2003, ‘Effects of Leafy Spurge Infestation on Grassland Birds’, The Journal of Wildlife Management, vol. 67, no. 1, pp. 115-121.

Introduction

It should be noted that almost any living organism that has been alien in a particular environment can be considered an invasive species. They move to a new habitat from different parts of the planet where they used to live, and new conditions allow them to adapt to the setting successfully. After invasive species adapt to new conditions, they begin to conquer the territory and actively multiply displacing native populations (Enger & Smith, 2016). Many researchers emphasize that invasive species can adversely affect local flora and fauna, for this reason, they are often considered predators. Nonetheless, this effect does not appear immediately but in the course of several years with the increase in the population of the invasive species. The purpose of this paper is to review cane toad as an invasive species and to analyze its peculiarities.

Characteristics

The basic characteristics of invasive species type are that they are non-native and they do not have the threats to their further dissemination. As a rule, such dangers are the vultures or disease-causing living organisms that can serve as natural checks to the increase in the populace (Enger & Smith, 2016). Importantly, invasive species do not face any strong predators or organisms in the new habitat that might threaten their breeding. Another characteristic of this type of species is that the majority of them are generalists. It implies that they can adapt and live in various habitats and settings. Moreover, such as animals, plants, or organisms mature quickly, breed intensely, and their young have a high survival rate (Enger & Smith, 2016). In terms of other particular characteristics, invasive species have strong and efficient dispersal systems, and they can easily win in the competition with native organisms.

Summary, Origin, and Relocation

The cane toad is one of the representatives of invasive species that threaten the life of flora and fauna. Cane toad (or Rhinella marina) was introduced in Australian Queensland in 1935 in order to fight with insect pests of sugar cane. The number of toads released on the territory was close to 60000; however, sugarcane plantations did not become suitable conditions for this species, and they spread throughout the territory while ignoring insect pests (Cogger, 2014). Thus, the introduction of an invasive species to control the size of another invader was not only ineffective but also led to uncontrolled consequences.

This type of toad has warty, keratinized skin. Individuals of this species have dark brown skin with spots. The belly of the amphibian usually has a yellowish tinge. The cane toad has characteristic round glands and supraorbital ridges. On the hind legs, the individuals have leathery membranes. Due to the fact that this is a nocturnal amphibian, the toad has horizontal pupils. It should be stressed that this amphibian type is toxic. An individual of this species can weigh up to two kilograms and reach 23 centimeters in length (Cogger, 2014). Initially, the cane toad is from Central and South America; however, as noted above, it was brought to the islands to reduce the number of beetles that devoured sugar cane plantations. In no way influencing the number of beetles, the toad bred in a vast territory and led the local fauna into decline (Simberloff, 2013). This amphibian has a good appetite and can hunt lizards, marsupial mammals, songbirds, and the eggs laid by saltwater crocodiles.

The peculiarity of this kind of toad is that its skin has toxic secretions; for that reason, Australian predators could not eat it. Consequently, as in the case of other invasive species, the number of this amphibian remains artificially high in the new environment due to the absence of predators capable of feeding on them or predators that are resistant to toxins (Cogger, 2014). Despite the attempts made by Australians to fight the toad, at present, no measure has brought significant success. For instance, to combat these amphibians, the local population tried using dry cat food. Residents poured food near the location of the toads, while scientists attracted to this place the ant species that could attack the amphibians and their offspring. As a result of the attacks, about 80% of all the progeny of the cane toad died; nonetheless, the surviving individuals bred very quickly (Cogger, 2014). In addition, the native population considered fighting them with the help of viruses. However, in the long term, such a measure could cause a chain reaction and result in irreparable damage to the local fauna. Therefore, this method has not been applied yet.

Limiting Factor

It should be emphasized that invasive species could be considered a limiting factor especially in the case of the cane toad. A limiting factor is an aspect that prevents the species from uninterrupted growth in the number of the populace. As stated by Enger and Smith (2016), certain aspects that prevent the population from growing can come from outside the species itself. Such an agent should be considered an extrinsic limiting factor. In particular, predators should be referred to as this type of limiting factor (Simberloff, 2013). Therefore, due to the fact that cone toads affect the populations of certain species types directly, they should be considered an extrinsic limiting factor for the native organisms.

Further on, invasive species are a density-dependent limiting factor. Despite the fact that cone toads can breed rapidly, which means that predators have higher chances of catching them, this type of toad is toxic. It implies that no predator apart from humans can influence the density of cane toad. On the other hand, as the population growth of this species is uncontrolled, it means that the greater their population is, the more they can eat themselves threatening the population of other species such as lizards, birds, and so on (Simberloff, 2013). Thus, the size of the predator population remains the same or decreases while the size of invasive species continues to grow. Nevertheless, a density-dependent limiting factor also implies the growth in disease epidemics (Enger & Smith, 2016). As illnesses are more likely to spread faster in larger populations, it means that toads are more likely to transmit parasites among their kind.

Conclusion

Therefore, it can be concluded that new ways of invasions of potentially dangerous alien organisms continue to emerge. At present, scientists cannot offer effective or universal control measures to cease the spreading of invasive species. The criticality of the situation lies in the fact that they are a serious enemy of local populations since invaders are highly competitive. As in the example of cane toads, the invasive species thrive in new territories monopolizing food sources. Their consolidation in new territories and further distribution entails undesirable environmental, economic, and social consequences. Therefore, the scientific world, governments, and people, in general, are highly concerned about finding ways to combat the critical occurrence.

References

Cogger, H. (2014). Reptiles and amphibians of Australia. Melbourne, Australia: Csiro Publishing.

Enger, E., & Smith, B. (2016). Environmental science (14th ed.). New York, NY: McGraw-Hill.

Simberloff, D. (2013). Invasive species. New York, NY: OUP USA.

Introduction

Over the last three centuries, Globalization has brought a worldwide dispersal of human communities. The process has benefitted human communities throughout the world because it has allowed an easy way of moving people, goods and services. However, it has brought adverse biological impacts. For instance, there has been both intentional and unintentional transfer of organisms and genes among the ecosystems that were previously separated from each other. Europe is one of the areas that have faced ecological problems due to invasion by foreign plants introduced during the European invasion and colonialism of foreign lands. The purpose of this paper is to provide an in-depth but brief report on invasive species in Europe, with a special reference to the problems brought by the invasion and possible solutions.

Ecological nature of the problem

According to Pyšek, Lambdon, Arianoutsou, Kühn and Pino, (2009), almost 67% of the established plants in continental Europe were brought from foreign ecosystems with an aim of boosting horticultural, ornamental or agricultural products. Over 30% of the established plants were introduced unintentionally by through movement of people, vectors or contaminants. Fungi and lower plants are some of the most important invasive plants in Europe (Keller, zu-Ermgassen & Aldridge, 2009). The also have the most adverse effect on the ecosystem, including crop and livestock diseases. For instance, Phytophthora Infestans is an invasive fungus that has been causing potato blight in Europe after it was first introduced from North American colonies in the 19^th century (Bourke, 2010).

Most of the plants introduced from foreign continents have become invasive weeds with the capacity to affect agricultural and horticultural production. Others normally hybridize with closely related species, which leads to the loss of distinctive genotypes. Moreover, invasive species such as Himalayan balsam (Impatiens glandulifera) and Japanese knotweed (Fallopia japonica) are highly invasive. In Europe, they have become a nuisance because they always occupy large tracts of land, including invasion on roads and along rail lines. Others are more dangerous because they cause health problems to both humans and animals. For example, Herracleum mantegazzianum (giant hogweed) has been found to have an adverse effect on human skin due to its high content of allergic compounds. In fact, studies have shown that this plant causes massive skin lesions, which cost countries like Germany more than 30 million Euros every year. In addition, Carpobrotus species of terrestrial plants are highly invasive plants that cause economic loses to countries like Spain because they are difficult to eradicate and control.

Possible solutions

Establishment of ecological management Policies is one of the major initiatives that are effective in controlling the spread of invasive species. For instance, it is necessary to ensure that rapid eradication of new populations is applied in cases where a new species have been identified. Secondly, coordinated jurisdictions and policy development is necessary as it allows countries to adopt similar efforts to eradicate and management invasive plant species (Perrings, Burgiel, Lonsdale & Mooney, 2010). Thirdly, control of trade and movement of goods and people should be enacted in order to minimize invasion. For instance, large marine vessels are loaded with sand or water to increase their weighs. Such materials are collected from any port in the world, may come with new species. To control this behaviour, policies should be enacted to ensure that ship owners and operators use standard methods of operation that will not introduce new species. Finally, control of immigration in and out of Europe is necessary. There must be coordinated policies to ensure that foreigners who come to Europe or Europeans who return from international trips are subjected to vigorous checks to reduce the rate of invasion of new species.

References

Bourke, P. (2010). Emergence of potato blight, 1843-46. London, UK: Springer

Keller, R. P., zu-Ermgassen, P. E., & Aldridge, D. (2009). Vectors and timing of nonindignenous freshwater species establishment in Great Britain. Conserv Biol, 23, 1526-1534

Perrings, C., Burgiel, S., Lonsdale, W. M, & Mooney, H. (2010). International cooperation in the solution to trade-related invasive species risks. Ann NY Acad Sci, 1195, 198-212

Pyšek, P., Lambdon, P. W., Arianoutsou, M., Kühn, I., & Pino, J. (2009). Alien vascular plants of Europe. In Handbook of Alien Species in Europe. Dordrecht: Springer.