Category: Invasive Species

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 Cods 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 OConnor 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 OConnor 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 worlds coasts. Cape Cod is one of the worlds 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 OConnor 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 OConnor 69).

The species dominates almost all the habitats occupied by the other organisms. For example the mud crabs 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): 703710. Print.

Bourdeau, Paul and OConnor, 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): 225237. 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): 5966. 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): 4754. Print.

Ledesma, Ellison and OConnor, 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): 203217. 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): 905909. Print.

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.

Modern man has built an empire. As a species, humans have made it to every continent, every ocean, and even space. The species did not begin this way; in fact, all modern humans can be traced to Homo erectus, a species that originated in Africa roughly 1.7 million years ago (Ayala 1995). Slowly making their way out of Africa, H. erectus introduced themselves to new environments, where they dominated the native species. 1.3 million years after migrating out of the African continent, the H. erectus slowly gave way to H. sapiens, more commonly known as humans (Ayala 1995).

Charles S. Elton, hailed as the father of invasive ecology, first used the term ‘invasive species’ in 1958. His book, titled The Ecology of Invasions by Animals and Plants, foreshadowed the invasion of nonnative species that plagues the modern world. Since then, many different definitions have gained popularity. For the sake of simplicity, it is common to use the definition found in the United States Executive Order 13112. The document establishes that an invasive species is one “whose introduction does or is likely to cause economic or environmental harm or harm to human health” (Exec. Order 13112, 1999). Many animals fit this description; common examples are the mosquitofish, the common goldfish, and the Sambar deer (Colautti & MacIsaac, 2004). The list, however, seems to be forgetting the animal with the greatest threat to the economy, the environment, and human health: Homo sapiens.

An economy can best be defined as, “the ?system of ?trade and ?industry by which the ?wealth of a ?country or ?region is made and used” (Cambridge University Press, 2008). According to the American government, invasive species must be inherently damaging to the economy. Humans damage the economy periodically, due to the nature of the business cycle. The Great Depression and its causes exemplify humans damaging the economy. Before the crash of the stock market, investors began getting involved in what is known as speculation. This caused a market bubble, which led to the crash in 1929, preceding the worst economic situation the country has ever seen. It is evident then, that human activity (in this case, the investors’ speculative tendencies) is damaging to the economy.

An invasive species must also have adverse effects on the environment. Humans fit this description far too easily. The greatest impact humans have made is on the land. Transformations of the terrain (executed by humans to better suit their purposes) began at least 10,000 years ago, with the beginning of agriculture (“Our Imprint Deepens” 1996). However, the composition of the terrain is not the only component of the Earth to suffer from human activity. The atmosphere, composed of nitrogen, oxygen, and minute traces of other gases, has also been negatively affected by humans. The United States alone produces two billion tons of carbon dioxide every year via coal-burning power plants and transportation. These emissions lead to global warming, a phenomenon that–despite clear evidence–many people have yet to believe. According to the Natural Resources Defense Council, “over the past 50 years, the average global temperature has increased at the fastest rate in recorded history” (MacMillan 2016). This trend is accelerating, not coincidentally, with the increased rate of carbon dioxide emissions. A 134-year record of average annual temperatures has seen all but one of the 16 hottest years to have been recorded since 2000 (NOAA 2016). Humans have evidently changed the Earth, and not for the better.

Lastly, invasive species must pose a threat to human health. Every negative effect imposed on human health can be traced to human activity. The most obvious examples include lung cancer developed from smoking (cigarettes were not only invented by man, but so was the machine that makes them today), and alcoholic liver disease due to overconsumption of alcohol (“Cigarettes and Cancer” 1953; “How Does Alcohol Damage the Liver?” 1978).

As an invasive species, humans have caused more damage to the economy, environment, and human health than any other similarly classified species. Acknowledging humans’ status as an invasive species is only the first step. It is of utmost importance to lessen the impact on the three components that make humans an invasive species.

There are many things that impact the environment and the ecosystems within them. Some of the impacts are beneficial, while others tear the ecosystem apart such as climate change, overpopulation and invasive species. While some of these events are natural many of these events are caused by the human population. In chapter five of Environmental Geology: Science, Land and Earth Systems by William A. Marsh and John Garcia Jr. there is a section that talks about ecosystem patterns and disturbances. One of these disturbances are invasive species. According the Encyclopedia of Life and invasive species is defined as “an alien whose introduction does or is likely to cause economic or environmental harm to human health…. ‘Alien species’ means, with respect to a particular ecosystem, any species… that is not native to that ecosystem.”

One problematic example of invasive species harming ecosystems in Florida is the introduction of pythons and boa constrictors. People buy these snakes as exotic pets but often they don’t realize that they can reach lengths between 10 and 20 feet. When these reptiles become larger than the owners had expected they release them into the wild and let them roam freely. Florida’s climate is similar to their native environment in Asia, because of this they thrive in their new environment and become an invasive species to the local habitat. This is a problem that has been going on for about 11 years in the Florida Everglades. Researchers at Davidson College, Virginia Tech University and the U.S. Geological Survey found that “Burmese pythons have eaten so many small mammals in Everglades National Park that populations of rabbits and foxes have disappeared and numbers of raccoons, opossums and bobcats have dropped as much as 99%”. These snakes are getting brave enough to attack deer and alligators as well.

Sometimes humans accidentally introduce new critters to environments that they don’t belong in. An example of this occurred in the southern states of America. Asian carp were brought to the southernstates to control water quality and vegetation in controlled farms. These fish were doing exactly what they were designed to do and weren’t creating a problem in America until a flood happened in the area. The farm had not planned for a flood and this accident led to the Asian carp making their way into local watersheds. When the carp got into the local water ways they began to head north towards the Great Lakes. PBS claims that if the fish make it to the Great Lakes they would become the secondary consumers and consume most of the native fish in the lakes. This could endanger the native fish and leave fishermen without any of their usual fish to catch which would could destroy the fishing industry and hurt the economy.

Invasive species are a problem all over the world. The northern grey squirrel has made its’ way to Italy and Great Britain where it has caused a decline in the population of the native red squirrels. The northern grey squirrel is consuming anything that it can find to eat, leaving nothing for the red squirrel population. Over time this will lead the red squirrel population to starvation and then extinction. Similarly in the United States, the Asian shore crab is more dexterous and faster than the native crabs. This means that they are naturally better at hunting for and gathering food than the native species of crabs.Similar to the red squirrels, the native crabs will end up starving and slowly become endangered because they are pushed out of their ecosystem by the invasive species.

If invasive creatures continue to kill species in other ecosystems than we will lose biodiversity around the word. If one animal in an ecosystem dies, it can lead to the decline of other species in the ecosystem as well. This is a problem for humans as well as the environment because scientists rely on the biodiversity of plants for medical uses. For example, Aloe is a plant used to relieve burns, milk weed is used to treat warts and penicillin was created from a type of mold. Native species also indicate when there is a problem in the environment. In Florida the largemouth bass population indicates when there is a mercury contamination in freshwater ecosystems and miners use canary’s to indicate trouble in mines. The decline of the bald eagle population told people that there was a problem with air quality due to DDT pollution. These native species have saved people in many cases by revealing environmental problems through their behavior and populations. The University of Florida revealed that the environment provides us many free services such as “energy fixation, chemical cycling (oxygen production through rain forests), soil generation and maintenance, ground water recharge, water purification and flood protection.”

If we continue to let invasive species into new environments than we risk harming the native animals, plants, ourselves and the goods that nature freely provides us with. Invasive species also cause economic trouble by eliminating the resources that we use for profit (fish, plants, etc.). If people would be more aware of their local ecosystems and understand what species are native or invasive than they could be proactive or even reactive to reverse the damage that has been done.

From Giant Hogweed to feral cats Invasive species need to be stopped. Defining the Impact/Activity: Invasive species are species that have been introduced to an ecosystem that affect the habitats and bioregions they invade economically, ecologically, socially, and culturally in a negative manner. This paper will describe the intentional and non-intentional causes, ecological, social, cultural, and economic impacts, the solutions, and the ways to prevent invasive species. Causes- Unintentional:

Many invasive species were introduced into other ecosystems when the industrial and human transportation industries took off. Many invasive species were introduced through trading, travel and tourism, transport, release of ballast waters from ships, escape from fish farms, openings of canals and waterways, use of live bait, escape from aquariums or water gardens, escape from live food fish trade, recreational boating and movement of equipment and gear, gardening, seed mixtures, escaped pets, and fire wood.

Many present day invasive species were introduced through human imprudence and negligence, like the spiny water flea, big head, silver, and black carp, sea lamprey, round goby, fanwort, bass, pike, and zebra mussels. However, many introductions of invasive species were intentional. Causes- Intentional: Although most invasive species were unintentionally brought into an ecosystem, many were 100% intentional, granting the consequences were unknown. For example, the Giant Hogweed was introduced into Canada from Asia because it was considered decorative.

However, Giant Hogweed has a watery sap that is like acid to human skin and if it gets into the eyes can cause permanent or temporary blindness. Other invasive species are the dandelion, purple loosestrife, and English ivy. Some species are introduced for ornamental properties, economic gain, cultural beliefs, improving environmental problems, making an area feel more like another, habitat restoration activities, authorized fish stocking, biological control of pests, and releasing pets that someone can’t or won’t look after. (Boa constrictors, feral cats, feral dogs) Impacts- Ecological:

Invasive species have caused the extinction and endangerment of hundreds of native species; they cause irreversible changes to habitats, kill and crowd out other species through predation, parasitism, disease, and competition. They also alter ecological processes such as water, nutrient, and energy cycles. They can also breed with native species to cause hybrid species. They can bring new diseases that native species can’t fight. The effects are “immense, insidious, and usually irreversible. ” (https://wwf. panda. org/about_our_earth/species/problems/invasive_species/) Impacts- Social:

Along with dangers to the environment invasive species can be very disruptive of our social and recreational areas. Invasive species like the snakehead fish, boa constrictor, red fire ants, and the African Rock Python (a new snake found in the Florida everglades and expected to become invasive) all are potentially dangerous to humans. Aquatic invaders can make recreation like swimming and boating difficult, and sometimes camping, hiking, and biking can be made impossible by alien species. They can also invade in parks and public places and decrease public appeal.

Impacts- Economical: Along with the social and Ecological impacts, it costs a lot of money in damages, preventions, and solutions relating to invasive species. The damages due to invasive species costs the world $1. 7 trillion every year, in the Great Lakes Zebra mussels cost $3-$7. 5 billion in damages every year, and cost forest and agriculture industries in Canada $7. 3 million, they also decrease property value and reduce the value of commercial and recreational fishing. Impacts- Cultural: An affect that is not widely recognized is cultural impacts.

Many aboriginal tribes lose the medicinal plants and cultural materials needed in cultural practices. Many invasive species alter culturally significant sites and take away food sources, some native species vital to cultural practices are killed with non-target pesticide contamination. Solutions- Prevention: There is no simple solution to invasive species; one of the most common characteristics of invasive species is their fast growth, rapid reproduction, high dispersal ability, and high adaptability, this makes many invasive species very hard to eradicate.

Because of this the main solution for invasive species is preventing their spread. One of the best ways to prevent the introduction of indigenous species is to be cautious of the pathways. For example, people should clean their boats thoroughly before moving it to different bodies of water. Dredging, dams, traps, electrical fields, mechanical barriers, trenching, and sticky bands are some other good ways to prevent there spread. Solutions: Because of many invasive species growth, reproduction, dispersal, and adaptability rates getting rid of them can be very difficult.

Some methods people have used are; mechanical harvesting, hand-pulling plants, cutting and destroying infested material, poison, use of a living organisms, and pesticides. However, with many of these species leaving one pregnant female of one solitary plant can lead to a re-infestation. Removing invasive species is easier said then done.

In America, we have a growing issue of feral hogs, and they are becoming very destructive. Hogs are not native to America and are considered an invasive species also known as an alien species. Invasive species are a major problem that must be understood and controlled. Invasive species, as defined by the NOAA (National Oceanic and Atmospheric Administration), are organisms that cause ecological or economic harm in a new environment where it is not native. Alien species affect native species by taking over their habitats, overpopulating, reducing all the natural food resources, then eventually pushing out the native species. Most of these organisms are unintentionally introduced into new areas. These species can be introduced by the simplest mode of transportation such as the propeller on boats or even by the bottom of someone’s shoe. Barnacles, clams, or muscles can attach themselves to the bottom of boats and can travel hundreds of miles before detaching themselves and inhabiting new areas. When tourist explores caves such as the mammoth cave in Kentucky, they can walk through spores, funguses, mosses, and molds. They then can spread to multiple areas before eventually removing their shoes. Invasive species are responsible for approximately forty-two percent of endangered or threatened species. Most of these invasive species are harmful but in rare cases they can benefit the new environment. One of those rare cases is when Canada introduced wolves into the Northern United States to control the population of elk.

The southern part of the United States is unfortunately being affected by feral pigs. Pigs are not native to America and were first introduced around 1539. These pigs were brought to America as domesticated animals for a food source. Over time these pigs have escaped, and by natural selection they have become larger and more dangerous creating the feral pigs. These pigs are causing a great deal of damage to farmers’ incomes and their farms. They are causing a staggering two and half billion dollars’ worth of damage a year (CNBC). These hogs ravage farmers’ fields during the night, they uproot and tear the ground up. Depending on the size of the group of hogs, they can destroy several acres of crops in one night. To a small-town farmer these few acres could be very devastating to their income. For just of the few reasons mentioned these feral pigs, people need to understand the issues they are causing to America’s agriculture economy, and they must be controlled.

Farmer, Richard Beyer, speaking to CNBC stated, “Feral swine have been around as long as he can remember but it used to be one or two caught occasionally in fields and they were manageable. They’ve gotten a lot worse, so bad that you can’t hardly trap them anymore because the numbers are so big.” An effective method to control these animals before they become too overpopulated is trapping, but as Beyer said once they have overrun your area trapping is nearly ineffective. Another method of removal is night hunting. This method is simply the process of staking out a bait stash or a field where pigs are known to be and using night vision optics to shoot and kill these pigs. Although this method will not eliminate the total population of pigs in your area it is an easy and cheap way to reduce them. A higher tech approach is by hunting or trapping them from above in a helicopter. One company named, HeliBacon, has taken Advantage of this opportunity. They take rather wealthy hunters on a hunt of a life time. HeliBacon takes these hunters up in the air putting the odds in the hunters favor to decimate the wild hogs’ population. These trips can cost upwards to thirty-five thousand dollars, in return of HeliBacon taking care of the farmers hog issues the farmer often gives them permission to hunt their property for free. Invasive species are a major problem and should be taken more seriously. Feral pigs are destroying many southern U.S. farmers and we must act to eliminate this issue. We must do more research to understand these animals and start to better control them.

A biome selected to describe is a tropical rainforest biome and an ecosystem chosen is the Amazon rainforest. This rainforest is among the largest in the world, having a wide variety of species. In this essay, the example of a keystone species, the Brazil nut tree, found in the biome and ecosystem will be provided. The author will also describe an invasive species, the golden mussel, in the ecosystem and its negative impacts. Finally, jaguar as an endangered species in the Amazon rainforest will be studied.

Keystone Species

A typical keystone species found in the Amazon rainforest is the Brazil nut tree. It can be considered a keystone species because it grows widely in the Amazon rainforest (Duarte & Paull, 2015). In addition, the Brazil nut trees are relatively large and are habitats for different animals, such as monkeys and other species living on trees. These plants provide nectar and different substances to insects and birds.

Invasive Species

An example of an invasive species found in the Amazon rainforest is Limnoperna fortunei, or the golden mussel, which is native to China. It is a freshwater mollusk that was accidentally introduced in South America in the beginning of 1990s. This species is tolerant of different negative factors and can spread quickly in fresh water, causing harm to different activities of people related to using water. In rivers, golden mussels grow quickly and can form large aggregates that create obstacles for other organisms to spread and move (Barroso, Muñoz, & Cai, 2019). Thus, this organism can provide a significant impact on the existing habitats of Amazon organisms, such as preventing them from finding food in the areas where the number of mussels is huge. In order to mitigate a negative influence of the golden mussel on the ecosystem of the Amazon rainforest, various measures are taken. Disinfection is used for boats and other human-made objects to prevent golden mussels from detaching to them and breeding there.

Endangered Species

One of the most endangered species found in the Amazon rainforest is jaguar. It is a large wild cat and one of the biggest predators in the Amazon rainforest. The causes of decline of jaguars include mostly deforestation and destruction of the natural habitats of these animals by economic activities of people. Jaguars require large areas of tropical forests to hunt and survive, but these areas are declining gradually. In addition, jaguars are often hunted for their skin. In order to prevent the further decrease in the number of jaguars, different actions are taken by various non-governmental organizations, including prevention of deforestation (Eisenberg, 2014). For instance, World Wildlife Fund cooperates with the government of Brazil to protect large areas of Rainforest and to enable more jaguars to live in them (WWF, 2019). In addition, this organization tracks jaguars to know more about their life and how to help them.

Conclusion

In conclusion, the Amazon rainforest is one of the biggest rainforests in the world with a wide variety of species. The Brazil nut tree is a common example of a keystone species in this ecosystem. The golden mussel brought from China is an example of an invasive species that can do harm to the native species, and therefore, people intervene to mitigate its negative influence. Finally, jaguar is Amazonian endangered species because of habitat ruining and hunting. To preserve jaguars, it is necessary to reduce deforestation and control hunting.

Originally belonging to African territories, the Gambian rat quickly became an invasive species to Florida. In general, the natural habitat of this mammal is not densely populated residential areas, but for several decades the Gambian rat has been causing damage to Florida’s urban ecosystem, namely Grassy Key. Specifically, eight rodents were accidentally released by a local breeder (Perry et al., 2006). Over time, with an abundance of basement living space and garbage for subsistence, the rats quickly multiplied, and their population increased in numbers.

This rat species is justifiably considered invasive because its introduction has shown to be detrimental to both the agricultural industry and wildlife in general. Gambian rats create burrows in arable land, causing them to dry out and kill crops. In addition, the relatively large size of the rodent should be taken into account, which is a critical advantage in the struggle for survival: the Gambian rat is able to compete effectively for resources. In addition, this species has been shown to be a vector of some serious animal diseases.

The local Wildlife Service initiated several programs to capture and eradicate the rodents. These have included the use of video cameras with tracking sensors, the use of peanut butter baits. However, these are not the most effective strategies: alternatives include the use of rodenticides: Ramik minibars, 2% zinc phosphide bait (“Cricetomys gambianus,” 2020). Still, chemical baiting also requires an attractive trap and selectivity so as not to harm native species. Finally, one recent development is using a mixture of urine and feces from congeners that is most attractive to invasive rodents.

At the core of the ethical debate in invasive species extermination programs is the dilemma between destroying animals and trying to preserve the local ecosystem. However, it should be understood that invasive plants are not endowed with intelligence like animals, and therefore exterminating them does not seem unethical. Thus, destroying invasive plants is much less of an ethical concern due to their irrationality as compared to animals.

Regardless of the animal species, the most ethical control method is collection and deportation to the natural environment. For rodents, this could mean initial trapping and subsequent transport to Africa. It should be recognized, nevertheless, that for different animal species, collection and deportation methods can be complicated both technically and economically while maintaining ethical well-being.

The basic definition of an invasive breed is when one species native to a different habitat is transported into a foreign ecosystem. Without any natural predators, it completely messes up the food chain for the native genus. Some of the ways an invasive species takes over its host habitat is that it has no natural predator, reproduces quickly, and outcompetes the native species in getting food. In other word, foreign inhabitants can potentially harm an already stable ecological unit. It is important that this needs to stop because some animals can become extinct because they are hunted by the unknown predator or starves by the lack of food.

An example of this is the Crown-of-Thorns starfish, the true origin of this species are found in Indian and Pacific waters. The invasion started in the 1960s when the larval stage of the Crown-of- Thorn starfish migrated into another area that was not their native habitat; a reason why they were placed in a location because of their natural predators like the Triton Shell. These species of starfish are known for their voracious appetites of consuming coral. If there is no natural predator that handles its poisonous spines than it will wreck havoc on the coral community, and indefinitely bleach the coral. Because that coral was destroyed many fish had lost their food source and home to the crown-of-thorns starfish. Not to mention it is quick to reproduce, and the larva can also find new coral to satisfy their hunger.

Crown-of -Thorns starfish are actually good for a coral, however if there is a mass number of them than their bigger competition for food. Thus, this leads more consumption and more likely hood of coral bleaching. This also decreases diversity on reefs, since fish flee the reef because they are no longer protected. The dramatic change in the coral reef reduces it into an algae-dominated system and becomes barren. If this continues only a few coral reef communities will have a diversity of marine life. Not only that, but also the decrease in colorful coral will also affect the economy of exotic places that depend on those places for money, in which tourists flock from all over the world to see.

To control the dense population of starfish and keep away from intact coral reefs is for divers to inject the deadly starfish with sodium bisulfate, which kills them within a few days. However, this substance is non-toxic to other marine organisms so it does not travel up the food chain is the poisoned starfish is eaten. Secondly, to make sure that the numbers of the crown-of-thorns stays manageable by monitoring their populations. But also find alternatives to not only remove the invasive species, and have a cost-effective way of doing so. However, it important for marine biologists to know the difference between nutrient run-off and larval outbreaks of the crown-ofthorns starfish.

Firstly to prevent the decay of ecosystem from foreign invaders, the people in charge of importing exotic creature who think the creature will benefit the native environment, should do extensive research. More specifically how often it reproduces, its natural predators, and finally the appetites of these exotic specimens. The person should also predict how the potential new animal would influence their new environment and if they can potentially rob the habitat from its native occupants. In order for this incident not to occur, cargo should be checked for any exotic animals. If so there at least should be a limited number in which you could bring, and have animals that will not disrupt an already stable ecosystem.

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.