Planet Earth and its environment are affected and destroyed by the people living in it. One of the most important concepts that are raising concerns is ecological footprint. Ecological footprint gauges the resources that are extracted from the earth and from waste that is produced by the same resources. Ecological footprint identifies the quantity of land and utilities that are required to support our life (Schaller, 2001). UAE is one of the most consuming countries in the world alongside US which has also been ranked among the most consuming countries.
This is obviously not a good thing for people and the animals and plants. This excess consumption of natural resources is due to increase in human population which forces manufacturers to increase their products. In addition to that, industrialization and urbanization has led to global warming, which depletes the environment. As more manufacturers come on board the resources are overused unlike when there were only a few companies.
To begin with, global warming is the abnormal rise of average temperature on the surface of the earth. This has been caused by human advancement towards industrialization and modernization. The outcome of global warming has been exhibited by the melting of ice and snows in areas such as the Antarctic which has changed the average sea level of the whole world because the ice and snow has been converted into water. If this situation persists the animals that live in those areas will be eliminated because their dwelling place will be destroyed.
Green house gases have contributed to the process of global warming. Green house gases are gaseous compounds that occupy the atmosphere and when their concentration is not stable they cause temperatures on the lower level of the atmosphere to hike. The components of these gases include carbon dioxide and methane (Peel Data Centre, 2004). Global warming can be avoided by reducing emissions from cars or other electronics; governments should encourage people to share vehicles and use hybrid vehicles, hence reducing the effects of global warming as a factor in ecological footprint.
When humans exploit the earths resources they release the waste of the same resources into the environment which in return affects their lives and those of other living creatures. Most organizations and private entities are not concerned about the harm they cause to the environment. The wastes from factories pollute air and water, thus endangering living things. We can say that their ignorance is due to lack of knowledge because they think the natural resources will continue to exist as they are today.
This is one of the reasons why ecological footprint will continue to swell in some countries where the people are not aware of these latest findings (Global Footprint Network, 2010). In addition, the increase in automobile production enables people to extend their operations to rural areas. Most people are now using their personal cars to travel to work, and this in return speeds urban sprawl. As more people use cars, there is rise of congestion in urban places since going to work is more difficult when using bicycle or walking. This is considered to be motorized urban sprawl which is one of the causes of environmental problems.
Environmental problems caused by this aspect include global warming and change in climate. This is because of the use of cars that emit dangerous gases to the environment. In addition, ecological issues raised by emission of dangerous gases such as carbon dioxide include loss of cultivation land and forest, loss of recreational space, and increase in public noise. Lack of land for cultivation may lead to reduced food supply thus resulting to increased food prices and social imbalance due to the fact that many people would consider migrating to urban areas (Gonzalez, 2005).
Today the development in technology has replaced human labor with machine labor. Again the machines such as those that are used in picking tea use fossil fuel which obviously emits green house gases. Its not only the equipments that contribute to ecological footprint but also the chemicals that are sprayed on crops to control diseases and pests. According to Huber (2001), safeguarding these resources might sound expensive and is actually expensive but it helps to reserve the current resources for future use. Ecological footprint is directly related to sustainable development because both are in support of conservation of resources. Humans should use alternative resources that do not pollute the environment such as bio fuels which are eco-friendly.
In conclusion, every one can make positive contribution towards the conservation of our natural resources. We can use other sources of energy to power our electrical appliances such as bio-gas and solar power which can be tapped directly from the sun. Alternatively, people who dont live far from their work places can walk instead of driving. Organizations are also being encouraged to recycle their products to ensure that the waste is not released into the environment.
All of these measures are important because the human population is increasing and will continue to swell hence these conservative measures will assist in preserving the natural resources. The internet and computers are playing a major role towards the conservation of natural resources. They are doing this by offering a platform where businesses can operate. In fact most transactions are paperless because of electronic transactions. If these measures are not implemented, manufacturers will continue to exploit the natural resources to meet the increased demand for goods and services.
References
Global Footprint Network. (2010). Footprint Basics. Web.
Gonzalez, G. A. (2005). Urban Sprawl, Global Warming and the Limits of Ecological Modernization. Environmental Politics. 14:3: 34-362.
Huber, P. (2001). American Wealth and Consumption Patterns Enhance the Environment. In W. Dudley, The Environment Opposing Viewpoints (pp.122-125). San Diego: Greenhaven.
Schaller, D. (2001). American Wealth and Consumption Patterns Degrade the Environment. In W. Dudley, The environment opposing view points.(pp.118-121). San Diego: Greenhaven.
Healthcare facilities will always generate hazardous waste because of the materials used. Hazardous waste that is not well managed and disposed of can have adverse effects on the health of human beings and the immediate environment around the hospital (Blackman, 2001). Those responsible for healthcare facility planning should always consider putting in place the necessary measures and strategies to effectively manage hazardous waste in healthcare facilities in line with legal and regulatory requirements. An effective waste management outline will ensure the waste generated in the healthcare facility does not impact negatively the environment and human health.
Chemical products, radioactive waste, and chemotherapy agents are examples of hazardous wastes generated in healthcare facilities (Blackman, 2001). Some of the dangerous characteristics of hazardous wastes include toxicity, corrosivity, reactivity, and ignitability. Most of the hazardous waste in health facilities is generated in X-rays units, operating rooms, laboratories, pharmacies, and laundry areas. There are quite a several strategies that can be used to effectively manage hazardous waste in healthcare facilities. To begin with, hazardous waste must be sorted and stored in well-labeled containers that should always remain closed (Reinhardt, 1991). According to the state of Utah regulation on hazardous waste management, the waste should not be accumulated for more than 180 days and 600kg should be the maximum quantity. Secondly, there should be weekly inspections to check for any leaks or any kind of deterioration and the inspection report documented. All hazardous waste management facilities must be regularly maintained to minimize any risks of explosions, fires, and accidental release of the waste (Reinhardt, 1991).
For proactive measures, several plans need to be put in place to cater to emergencies (Blackman, 2001). The alarm systems and other communication channels should be accessible for fast communication and response in case of an emergency as a result of hazardous waste. The healthcare facility management should make emergency arrangements with the state emergency authorities for help in case of any emergencies (Blackman, 2001). Satellite accumulation areas that have less than 55 containers should be located near the generation point with all the containers marked and closed. The satellite areas should be always under the watch of an operator who should ensure that the standard procedure of hazardous waste disposal is followed. There are various bodies within the United States and specifically the state of Utah that are responsible for regulating hazardous wealth management and disposal (Reinhardt, 1991). These bodies operate at the federal or state level and have turf penalties for hazardous waste generators that do not comply with the laid down requirements. Some of the common regulatory bodies include OSHA, JCAHO, DHHS, and CLIA.
Each type of waste has specific regulations governing its disposal and management and therefore the healthcare facility should always be in touch with waste management experts for advice to ensure that no rule is violated. The local sewer authority should approve which type of hazardous waste should be discharged in the local sanitary sewer. The healthcare facility should furnish the local sewer treatment authority with all discharge reports with a certificate of waste minimization program.
References
Blackman, W. C. (2001). Basic hazardous waste management. New York, NY: Lewis Publishers.
Reinhardt, P. A. (1991). Infectious and medical waste management. New York, NY: Lewis Publishers.
Decision Support System tools are critical for making robust and reliable decisions. Predictive models could enhance decisions and improve future outcomes. Therefore, this proposal presents a predictive time-series model as a Decision Support System for cyclone forecasting in Northern Queensland and other areas in Australia, which are prone to cyclones. The model would rely on readily available historical cyclone records and current data to forecast future outcomes on a long-term basis. It would also account for future weather patterns. Insights derived from the data would help farmers to make informed decisions regarding their farm operations. In the past, farmers have incurred massive losses because they relied on traditional, historical patterns, and normal methods of cyclone and weather forecasts. However, these patterns would not be necessarily similar in the future. Therefore, a predictive model can provide insights that farmers require for better decision-making. Adoption of such a model would enhance efficiency, help farmers to avoid expensive investments that cyclones would damage, save costs, and improve the public good.
Introduction
A Decision Support System (DSS) is an application platform for decision-making (Decision Support System, 2009). It relies on data modelling, communication technologies, knowledge, and documents to recognise and solve issues, run decision processes, and make decisions (Power, 2014). DSS computer applications enhance decision-making capabilities of an individual or a group. DSSs may also reflect academic areas of research for designing and studying analytical information processes.
Therefore, the proposal focuses on how such a system can enhance decision-making capabilities for farmers if the Bureau of Meteorology, Australia adopts it. The DSS shall be a data-driven system for analytical and data modelling purposes.
In the past, Cyclone Larry had hit hard Northern Queensland with devastating results to farmers and residents. Northern Queensland has a wide sugar belt and other tropical horticultural crops like bananas (United States Department of Agriculture, 2006). The region has over 8,500 farmers. Cyclones result into massive damages, including destruction of crops and farm equipment (United States Department of Agriculture, 2006). Northern Queensland accounts for Australias banana industry and over 25% of the countrys sugar cane. Some reports indicated that Cyclone Larry had destroyed over 200,000 tonnes of bananas, worth $ASD 300 million or $USD 215 million (United States Department of Agriculture, 2006).
Consequently, farmers live in constant fears of cyclones. Although cyclone is a complex natural process with forces that exceed human control, science and technologies can help in predicting its patterns and allow farmers to make informed decision about planting and investing in farm machinery.
Current Practices
The Bureau of Meteorology provides current patterns of cyclones in Australia. However, the organisation does not provide long-term forecasts for cyclone and weather patterns. The Bureau can only predict cyclones at 12, 24, and 48 hour time-steps (Bureau of Meteorology, 2014). Although short-term weather forecasts are suitable for farmers on their day-to-day farming activities (IBM Research, n.d), there is a need to address several issues regarding changes in weather patterns due to global warming. For instance, a study by Haig, Nott, and Reichart (2014) noted that the number of tropical cyclones hitting Queensland and Western Australia has fallen to low-levels not seen for more than 500 years (p. 667).
However, the current statistical methods of weather prediction have drawbacks. These methods involve collection of statistical data about different weather patterns at a given period of the season. Afterwards, analysts show results on charts. The charts indicate averages of highest and lowest possible weather patterns based on prevailing circumstances of the day. Once analysts depict information on charts, they presume that weather patterns will follow previous sequences in the future. Such simple assumptions can no longer work with the dynamic and unpredictable weather patterns. Moreover, they cannot account for a large number of variables based on big historical data on cyclone patterns. Past and future weather patterns are no longer identical, as traditional forecasting methods had depicted.
Analysis and Design
The proposed approach shall rely on predictive big data-driven algorithms to provide cyclone forecasts, including other weather patterns for farmers. The proposed analytic approach will use data from tropical cyclone records, which are less than 50 years based on the available records. The analysis shall review past records and current patterns to derive long-term insights for future cyclone patterns with lead times of several years.
This is big data. It would involve several calculations that entail hundreds of cyclone patterns collected over the last 50 years. The model will provide quantitative probabilistic forecasts that would be able to depict correlation between past cyclone patterns, present observational patterns, and long-term forecasts.
The specific predictive model would be time-series forecasting. This would involve specific variables, which have depicted past changes. Forecasts from data-driven approaches are credible because the core data have distinct historical trends based seasonality (Bala, 2012).
Cyclone variables would include changes in intensity or course, speed, and specific environmental patterns, such as temperature, cloudiness, wind rate, direction, season, and humidity at the time of occurrence. The predictive approach would account for temperatures and other weather variables.
Tools for the project would include robust analytic software, such as R, SPSS, and SAS (Stanton and De Graaf, 2013). However, the choice of specific software shall depend on its availability.
Farmers would adopt insights from data analysed to minimise losses incurred because of cyclones and other extreme weather patterns, such as drought and flood.
Feasibility
The project is highly feasible, and other sectors have already adopted big data predictive modelling to guide their future operations.
SWOT
Strength
The predictive model would offer great values on long-term cyclone and weather forecasts
The techniques are highly robust with deep analytical skills
Some analytical tools are open source
Farmers will have comprehensive understanding of cyclones and weather impacts on their farm operations
Weaknesses
Some analytic tools are extremely expensive
Failure to account for critical variables may lead to poor outcomes
Predictive model may not always be accurate (there is a confidence level)
Opportunities
Predictive models are applicable in other fields
It is a growing area with a promising future
Abundant data from past records
Threats
There are no adequate data scientists for the job
Expensive software renders the model impractical for many potential users
Data may be inconsistent
Conclusion
The ability to forecast cyclones, weather patterns, and associated risks on a long-term basis is an idea that farmers have long sought. The project outcomes would protect farmers from risks, enhance profitability, and public good. By relying on robust, new predictive analytic models to forecast cyclones and weather risks, farmers will gain significant edge in their operations and markets. Moreover, the model would enhance efficiency and help farmers to avoid planting and investing in farm inputs during downtime caused by unpredictable adverse cyclone and weather patterns. This would reduce costs and save resources.
Reference List
Bala, D 2012, Time Series Forecasting: choosing from data driven vs. model based methods, Web.
Haig, J, Nott, J, and Reichart, G-J 2014, Australian tropical cyclone activity lower than at any time over the past 5501,500 years, Nature, vol. 505, pp. 667671. Web.
IBM Research n.d., Weather modeling and data analytics empower an island nation to save its natural resources, Web.
Power, D J 2014, DSS Basics, Web.
Stanton, J and De Graaf, R 2013, An Introduction to Data Science, Syracuse University, Syracuse, NY.
United States Department of Agriculture 2006, Cyclone Larry Lashes Northeastern Queensland, Web.
Price and financial side of a power station appear to be essential aspects while bearing in mind new constructs. Grants have a significant role in the energy segment; moreover, both coal and nuclear power receive considerable communal grants. Coal and nuclear are equally at the lowest in standings of manufacture prices related to other manufacturing. In recent times, nonetheless, electricity manufacture by nuclear power stations prices remained less per kWh in comparison to coal, and this phenomenon could be explained by an inferior price of fuel for nuclear-powered stations and growing prices for coal (Kharecha & Hansen 2013).
Fuel for nuclear-powered stations is comparatively reasonably priced. Due to the fact that nuclear fuel requires to be administered from natural uranium mineral, the price for it demands to take under attention the dispensation prices along with the raw matter prices. Coal, on the contrary, has higher prices for fuel. A benefit for nuclear-powered stations is that they produce no carbon releases for the period of action of the station. This is significant while examining the influence of a carbon tariff in the forthcoming.
Power stations have need of an ingesting of energy for producing energy. In this perspective, coal-fired power stations demand considerably more matter in order to function than nuclear-powered stations. A significant aspect to think through for energy production, particularly while meaning the anticipated duration of both energy equipment, is an examination of residual fuel. Coal and uranium are limited assets, contrasting from renewable matters. So, although both resources are restricted, nuclear fuel possesses a superior impending for permanency.
Ecological impacts from the power stations are a vital aspect. Power stations could be a cause for pollution and are able to upsurge the progression of global warming with CO2 releases. During the past 20 years, half of all increases in energy-related carbon dioxide emissions were from electricity generation. The operation of coal-fired power stations releases between 700 and 950 g CO2/kWh. The operation of nuclear stations releases no carbon emissions (Odell 2011, p. 5). Coal ash contains oxides of silicon, aluminium, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small quantities of uranium and thorium (Lamb & Brain 2014, para. 3).
Moreover, coal ash comprises commonly glass that is derivative from the inflammable silicon in the coal. In order to decrease the number of contaminants in the atmosphere, coal-fired stations apply particulate precipitators that are able to detect up almost all of the fly ash beforehand. Nonetheless, eighty per cent of the coal capacity is abridged by means of incineration that increases the absorption of the contaminations in the leftover (Kutscher & Mazria 2010).
In nearly every single characteristic, nuclear power stations are more appropriate machinery for the upcoming while being related to coal-fired power stations: the price of producing energy from nuclear-powered stations is lesser than the price of producing energy from coal-fired stations; in case when imminent administration principles are interminably endorsed to regulate radiation pollution for coal-fired power stations, energy production from nuclear stations would develop into a more efficient choice; nuclear fuel possesses the probability of being accessible for longer than coal; coal-fired stations contaminate the atmosphere and emerge radioactivity at amounts, which turn the emanations of nuclear stations into insignificant; coal-fired stations materially create a bigger amount of leftover per element of energy manufactured than nuclear-powered stations; nuclear-powered stations are believed to be almost harmless for the surroundings, for the employees, and to the adjoining inhabitants than coal-fired stations (Markandya & Wilkinson 2007).
In conclusion, while energy manufacture through coal-fired stations could be essential regarding the absolute enormousness of worldwide energy necessities, it is unblemished that nuclear power ought to have a much greater part in the upcoming energy scenery.
Reference List
Kharecha, P & Hansen, J 2013, Prevented mortality and greenhouse gas emissions from historical and projected nuclear power, Environmental Science & Technology, vol. 47, no. 1, pp. 4889-4895.
Kutscher, C & Mazria, E 2010, Options for near-term phaseout of CO2 emissions from coal use in the United States, Environmental Science & Technology, vol. 44, no. 1, pp. 4050-4062.
The issue of sustainability has been receiving a lot of attention lately; people in many sectors are recognizing that the utilization of the resources of the earth cannot be without consequence. The depletion of the resources is driven both by the growth in the population and the quest for greater economic growth.
Despite the large volumes of information that is generated everyday regarding the utilization of resources on the planet, the trend of unsustainable activities still continues unabated (Adams & Jeanrenaud, 2008); the big question today therefore is what the fate of the planet is.
The Story of Easter Island: Rapa Nui
Located in the southeastern Pacific Ocean, Easter Island or Rapa Nui offers a chilling example of the consequences of unabated exploitation of natural resources. This island, located 3,510 km west off the coast of Chile, is among the most isolated islands on the planet; basically, it was a closed ecological system.
Paleobotanical studies (of fossil pollen and tree moulds left by lava flows) show that the original vegetation of the island was a subtropical moist broadleaf forest. This ecosystem was quickly depleted by the growing population on the island. A lot of the resources were spent on waging war and building giant stone gods known as moai; for example, large trees were felled to make rollers to transport the statues from the quarry to the sacred site. The drive to create these gods was so great that at some point, there was one moai for every ten inhabitants of the island (Wright, 2004).
Eventually, so much of the forest was cut down that their large trees used to make large canoes able to venture into deep waters became extinct effectively denying the islanders of their major source of food, deep sea fish. The inhabitants turned to the islands fauna and ate all the mammals and birds making them extinct. Additionally, deforestation resulted in soils erosion making cultivation unproductive. There have been speculations that the severe lack of food on the island forced people to cannibalism (Diamond, 2005). By this point, the Easter Island civilization was gone and the population severely reduced.
Earth Island
The earth is also an island; it is a closed system without resource input from any other source; at least for now. As such if we deplete all the resources from this planet, we might suffer the same fate as that of the Easter Islanders; while the end result may not be necessarily cannibalism, it might be worse; wars, famine and collapse of society are all possible.
The big question is whether, unlike the islanders we might see the folly in our ways and put in place measures to reduce and/or reverse the negative effects of unsustainable utilization of the earths resources. There are several issues that are of major concern.
A growing population
An unsustainable growth in population is not defined by absolute numbers or density only; rather by also the availability of the resources needed to support such a growth. The human population has been able to overcome some of the factors that limit the population growth of other species; technology and agriculture have enabled the exploitation of the environment to produce more food, water and energy (Hopfenberg, 2003). However, as mentioned before, earth is a closed system; and at some point even with technology, it may be impossible to produce any more life-sustaining resources.
Fossil fuels
The growing human population has increased the demand for energy; this is required to fuel various domestic and commercial activities; and has been compounded by rising of the standard of living of large parts of the population (and the utilization of energy for non-essential activities). Additionally, the energy required to exploit other resources has increased due to the depletion of these; for example, a lot more energy is needed to raise water from water table whose levels have dropped significantly in some areas due to overexploitation such as Arizona, United States.
Fossil fuels have emerged as an easy and cheap way of producing this energy. This is achieved through combustion either to generate electricity or to power internal combustion engines for kinetic energy. This source of energy, however result in the production of carbon dioxide most of which is released into the atmosphere. This gas, together with others such as methane and ozone are known as greenhouse gasses due to their ability to trap the solar radiation into the planet resulting in the increasing global temperatures. Global warming has been blamed for the increasingly extreme weather with increased incidence of occurrence such as hurricanes, floods and droughts (Houghton, 2009).
Food availability
The ability of agriculture to supply the world population with sufficient food has been put into question. This has been attributed in part by the global climate change and extreme weather which rendered parts of the world incapable of producing food either due to excess or reduced precipitation (Hopfenberg, 2003).
Advances in technology will enable man to produce more food in the future if need arises. Indeed, some experts are of the view that there are enough resources to satisfy the food needs of a growing population if only proper methods of farming were used. However, the agricultural sector may grow at the expense of the world forest cover. Widespread deforestation will lead to loss of plant and animal species; soil erosion and pollution. Additionally, agriculture comes with a raft of other problems such as contamination of the environment with pesticides and fertilizers.
Water is Life
No single species can exist in the absence of water. Fresh water is one of the commodities that are among the most exploited in the planet. On the other hand, the traditional sources of fresh water are being destroyed by other factors outside direct utilization (Shiklomanov, 2000). For example, deforestation results in a reduction of surface water flow due to the loss of catchments areas. Additionally, human activities have resulted in contamination of surface water both as point-source (industrial and sewer contamination); and non-point source pollution (wash-off from farms and city storm-drainage); making it unsuitable for human consumption.
The reduction in surface water flow had turned people to ground water most of which is essentially non-renewable. When this is depleted, no doubt the prevailing fresh water shortage will be exacerbated (Shiklomanov, 2000).
Will the 21st century earth population learn from the mistakes of the Easter Islanders before them? Some may urge that the humans today know more about their environment than the people of Rapa Nui in the 18th century. However, the trends seen then are being seen now; the exploitation of scarce resources for non-essential uses is as alive as the building of hundreds of giant stone gods.
With the current trend, we will be trapped in a barren piece of rock called Earth-Island with no boats to escape, no food and surrounded by the useless monoliths we are building today.
Works cited
Adams, W. M. and Jeanrenaud, S. J. Transition to Sustainability: Towards a Humane and Diverse World. Gland, Switzerland: IUCN. 108 pp 2008.
Diamond, Jared. Collapse. How Societies Choose to Fail or Succeed. New York: Viking 2005.
Hopfenberg, Russell. Human Carrying Capacity Is Determined by Food Availability, Population & Environment, vol. 25, no. 2, (2003), pp. 109-117.
Houghton J. Global Warming: The Complete Briefing, Cambridge University Press, 2009.
Shiklomanov A. I. Appraisal and Assessment of World Water Resources . Water International 25(1): 11-32 (2000).
Wright, Ronald. A Short History of Progress. Indiana University, Indiana 2004.
GCC is a sub-region of the ESCWA economic realm that is located in the Middle-East, and consisting of six members that include Qatar, The Kingdom of Saudi Arabia, Bahrain, Oman, Kuwait and the United Arabs Emirates (UAE). This region is located in the arid ecosystem and one plight that is common to the entire members is the scarcity of renewable water resources. As a result, they have resorted to investing in desalination technologies (MED, RO, MSF) to suffice the demand of the ever increasing population. Nonetheless, this journey has never been that rosy since there are a number of challenges that have come their way. Among the challenges include the unit cost (OPEX and CAPEX), environmental pollution, and also the number of contracted capacity.
However, it is upon the management to frame reliable policies so as to overcome these challenges lest the problems persist. For instance, in Abu Dhabi, in order to realize Vision 2030, then there is need to recycle wastewater for use in agricultural production instead of using desalinated water that comes directly from the plants.
Introduction
GCC (Gulf Cooperation Council) is an economic region consisting of six Middle-East economies including Qatar, The Kingdom of Saudi Arabia, Bahrain, Oman, Kuwait and the United Arabs Emirates (UAE). These countries are grouped together since they have a lot in common. Ideally, these nations have comparable socio-economic situation and oil exploration forms the backbone of their economies, spanning four decades back. Importantly, merchandise in oil-related products dominates their export markets, accounting for more than 90% of their total exports. One major resource that has been impeding the faster development of this region has been the scarcity in natural water resources at the backdrop of increasing demand (Al-Rashidi, 2008). The increasing demand is a consequence of population growth, and as such, the surface water resources are now exhausted. In some countries, the aquifers are already drained. To this end, to supplement the declining fresh water resources, the GCC countries have resorted to investing, massively, in desalination plants much to their success. The desalination plants invested in GCC countries typify a successful project that has lived up to its expectation of serving its population with continuous supply akin to economies that are sufficiently endowed with natural and renewable water resources (Hanbury, 2010).
According to a research conducted by the World Health Organization (WHO), this region, located within an arid ecosystem, has already hit the water scarcity line of less than 1000 m3 per year per capita. In area, this region covers a space of approximately 2.55 million Km2 and it has a common climate with a few surface water resources. The available surface water resources are localized along the coasts of both Saudi Arabia and Oman but to the south. In a synopsis, this realm represents the harshest of the entire realms making up the world. This region is endowed with the least fresh water resources around the world, accounting for less than 370 cubic metres. With a growing population, it is projected that these resources will decrease to less than half the current capacity by the year 2030 when the population will be standing at 56 million people. With these facts, it goes without saying that the GCC countries have an uphill task of efficiently managing the limited water resources. This is why they have taken to desalination plants to meet the demand (Mezher & Fath, 2011).
Desalination plants have been part and parcel of the economies forming up the GCC, supplying both municipalities and industries for the past two to three decades. Overreliance to the same is projected to increase as the population swells. Among the common desalination processes employed include Multi-Stage-Flash (MSF), Multiple-effect Desalination (MED) and Reverse Osmosis (RO). Of the three, the later technology is becoming common to the region owing to the fact that it is cost-efficient and more reliable. While the amount of desalinated water consumed the world over is immaterial, this region accounts for almost 100% of their total needs. According to Global Water Intelligence (GWI) report, the cumulative capacity of the entire desalination plants contracted in the GCC countries since the year 1994 was 24 million cubic metres per day by 2010 (Al Zawad, 2008).
The energy requirement of any given technology is vital in determining the process economies since any slight variation in the oil prices has a greater effect on the production cost. Moreover, the more intensive a process is in terms of energy requirements the more are the emissions (CO2 gas) released to the environment. Importantly, the cost of desalinated water is dependent on a myriad of factors that can be grouped as either capital related (CAPEX) or operation related (OPEX).
In the face of all these challenges comes another factor that is the competing demand from various sectors of the economy. For ages, GCC countries have successfully managed to balance their limited water resources among domestic, animal and agricultural sectors. Nonetheless, in the past 50 years, urbanization, industrialization and population growth have entered the fray. Today, these economies grapple with the rising competing demands, for instance, urban versus rural and human versus industrial among others (Hoepner & Lattemann, 2002).
With the background information on the water resource situation of this region, we can objectively analyze the desalination plants in the GCC countries. As such, the rest of the literature in this paper will focus on; the cumulative contracted capacity, number of contracted plants, proportions of different technologies, daily water production volumes, the cost per unit and the future projections in terms of demand/supply. Moreover, this paper will suggest policy initiatives for Abu Dhabi Vision 2030.
The cumulative contracted capacity and the number of contracted plants
The history of desalination technology stretches way back in history. However, in the modern history, Bahrain and Kuwait represent the first members of the GCC countries to have enjoyed desalination technology in the name of multi-effect distiller (MED). Kuwait is, too, the first member of the GCC countries to launch the MSF in the mid twentieth century. Currently, the number of plants installed in the MENA (Middle East and North Africa) region is a manifestation of the increasing demand of freshwater in this water-scarcity region. The most striking feature, however, is the increasing number of the contracted firms in this region. When you look at the numbers of the contracted firms in the MENA region in the figure 1 below, it goes without saying that this number is relatively high in the GCC countries. Among the first six nations of the MENA region with high numbers of contracted capacity, four hail from the GCC sub-region with the Kingdom of Saudi Arabia leading the pack.
As manifested in the figure 2 below, the number of contracted firms in this region is projected to increase in the subsequent decade. This large expansion requires a review of the present policies and practices including how to increase local capacity, knowledge, and added value to the local economies (AL-Rashed, 2000).
The local capacity in this realm is biased on only operations and maintenance, assuming manufacturing and design yet this is a region that is highly dependent on the desalination technology to provide freshwater for both domestic and industrial use. Even though there are exceptional local-based engineers in this region, they are not adequate to meet the ever soaring needs of the region. Not unless the governments forming up the GCC region do something to support the local talent, the situation is likely to remain delicate like in other technology-based industries which are dependent on imported talent.
Among the policies proposed by IWRM (Integrated Water Resource Management) to curb this trend is to seal all the water leakages present in the current facilities before engaging in a white elephant project of contracting more capacity. To this end, IWRM explains that sealing the leakages is relatively cheaper, and it will give a true picture of the actual capacity that is required for addition.
Proportions of different technologies
Reverse Osmosis, a membrane technology, has dominated the world desalination industry over the past three decades as manifested in the figure 4 below. Nonetheless, in the ESCWA (Economic and Social Commission for Western Asia) region, and more so in the GCC economies, thermal technologies are dominant. This is exhibited in the figure 5 below (Sommariva, 2010).
Figure 3: Global desalination Capacity.
Thermal technologies are a common place in the GCC region owing to the fact that many of the firms in this region optimize on the fuel to co-generate both water and electricity. However, in the regions where electricity is available and the feed water is brackish, membrane technology comes in handy. Ideally, contemporary commercial technologies in place today can be classed as either thermal or membrane technologies. The thermal technologies include MSF, MED and VC (Vapor Compression). On the other hand, the membrane technologies include SWRO (Seawater Reverse Osmosis), BRO (Brackish Water Reverse Osmosis), ED (Electro-dialysis) and NF (Nano-Filtration).
The membrane technology to be adopted is dependent on the degree of salinity in the brackish water. While ED is more efficient for low salinity brackish water, RO is more efficient for higher salt concentration feed-water. In the MENA region, the MSF technology is the dominant technology. The figure 6 below shows proportions of a diversity of technologies applied in this region but cumulatively since the year 1944. However, over the years, RO has been slowly gaining dominance.
RO is slowly gaining dominance owing to the fact that it is cost-efficient, and of late, there has been an improvement in the membrane technology to enhance its efficiency. Contemporary applications adopt hybrid technologies which combine both thermal and membrane technologies to achieve efficiency, low-cost operations and to co-generate electricity. Some of the hybrid combinations include MED/RO and MSF/RO. In the meantime, there is a pilot project to determine the competitiveness of NF/MSF/MED/RO combination which is set to revolutionize the desalination technology. The world over, there are a number of novel desalination technologies that are slowly being developed. These technologies include membrane distillation, carbon nanotube membranes, aquaporin (biomimetics) membrane, forward osmosis, and electro-dialysis/deionization (Dawoud & Al-Hussayen, 2012). Nonetheless, skeptics doubt whether these technologies would have a significant effect in the desalination industry.
The GCC sub-region has the highest concentration of desalination plants worldwide. The Arabian Gulf Coast is shared among seven ECSWA economies. Of these members, it is only one member who does not belong to the GCC sub-region. As a matter of fact, for most of the GCC members, the Arabian Gulf is the only source of their feed-water. To these nations, most of the plants are stationed near the major cities which are always located at the coastal line (figure 6). For instance, in Saudi Arabia, they are located in Al-Jubail and Al-Taweelah among other coastal cities. Figure 6 shows the locations of different plants by technologies located along the coastal strip of the Arabian Gulf.
Figure 6.
Daily water production volumes
The daily water production in the GCC countries is dependent on the demand, a function of population growth. Water demand in this region is can be grouped into three sectors including domestic, agricultural and industrial sectors. Figure 7 below is a depiction of the requirements per sector in the ESCWA region. Individually, most countries align their specific requirements with the regional demand. An economy in the GCC region that doesnt fit well in the regional sector includes Bahrain which uses only 50% of its requirements to agriculture.
Figure 7.
In the GCC region, the average consumption rate takes approximately 80% of the total requirements. This figure is forecasted to increase by at least 40% come 2020. However, the agricultural sector accounts for a paltry 10% of the GDP in the entire region. The investors in the agricultural sector have continued to be skeptical about this industry because the ratio of the agricultural GDP to agricultural the labor force has always been below 1.0 in some GCC countries (Abdulrazzak, 1995). As such, investors in the sector are seeing an investment in the industry as beneficial to labor industry. As for the domestic demand, the consumption rate is dependent on the standard of living (figure 8). From the figure (8) below, it is evident that the most of the GCC nations which have higher standards of living consume a lot of water per day.
Figure 8. By comparison, the industrial demand in the ESCWA region vis-a-vis other regions continues to hit a low (United Nations, 2009). Nonetheless, it has continued to grow gradually. The industrial demand is specifically meant for cooling purposes.
Population is one factor that has led to increased water demand. As typified in the figure 10 below, the population in the GCC sub-region continues to soar. As such, the water demand is projected to increase as the population swells to the 56 million mark by 2030. With these projections, the pressure is directed to the governments making up this region to ensure a regular and constant supply of water to its citizens. As shown in figures 1 and 2 above, the numbers of the contracted plants continue to increase to meet the rising demand.
The cost per unit
Desalination industry is a capital intensive project that requires optimization of factors to limit on the cost of the product. Those technologies with lower operation cost (OPEX) options always tend to be responsive to both the operating skills and the quality of the raw material (feed water). The CAPEX is a function of the quality of the raw material, production capacity, required infrastructure, plant efficiency, material selection and other location factors (Dawoud, 2006). For majority plants, the CAPEX always ranges between $1000 and $2000 per cubic metres. Both the CAPEX and OPEX are vital in determining the final cost of water. Also, as typified in the figure 9 below, the unit cost is dependent on the technology which is proportional to the cost of oil.
Figure 9.
Also, as typified in the figure 10 below, OPEX is a function of the technology. To this end, the RO technology attracts the least operation cost.
Figure 10.
As outlined above, cost management is very sensitive in determining the final cost of the product. A different policy discourse can have a massive effect on the unit cost (GWI, 2010). For instance, government agencies need to shift focus to being purchasers of the product (water) rather than procurers of plants. This will enhance the establishment of most efficient technologies. Furthermore, this would shift the government roles from being an operator to a regulator.
The future projections in terms of demand and supply
The desalination plants in the GCC region are meant to meet the current and the future water demand due to increasing population. Of the GCC countries, Kuwait and Saudi Arabia are first nations to launch the modern desalination plants back in the 1950s. Among the desalination plants gracing the world today, 50% hail from this region. The desalination plants with their unique technologies are expected to increase in this realm in the future owing to increasing demand. The ever increasing population (Figure 11) coupled with the scarcity of non-renewable water resources are the reasons that is an increase in desalination plants.
Figure 11.Figure 13: Trend capacity between 1950 and 2000 he figure (12) below depicts the trend of the total capacities per day of desalination plants since 1950 until the year 2000 in the region.Figure 14: of the projected capacity deally, from the year 2000, when the total capacity was 3000 million cubic metres per year, to the year 2012, when the total capacity stood at 5000 million cubic metres per year, researchers are predicting an increase in the total capacity to approximately 9000 million cubic metres per year by the year 2030. This pattern is projected to follow the trend depicted in the figure 14 below.
Even as investors struggle to meet the ever increasing water demand, with the above projections there seem to be a looming battle between stakeholders- investors versus environmentalists (Dawoud & Al-Mulla, 2012). While desalination plants offer socio-economic benefits by providing potable water devoid of affecting the freshwater ecosystem, the niche that faces potential destruction is the marine ecosystem.
Policy initiatives for Abu Dhabi Vision 2030
In order for Abu Dhabi to realize Vision 2030 of establishing a sustainable economy, then availability of water, a sector vital to its economy need to be effectively managed (World Bank, 2007). Since the dominant technology in this region is thermal-related, there is need to limit on the over-reliance on fossil fuel (a non-renewable energy). This can be minimized through recycling of wastewater. The product (water) can be useful for both agriculture and landscaping. Also, this vision can be realized when initiatives are in place to minimize losses emanating from leakages and wasteful usage. Control of wasteful usage of water can be realized through public awareness. Finally, the government ought to encourage potential investors to employ renewable energy-based technologies in desalination plants, an environmentally sound technology (Dawoud & Allam, 2006).
References
Abdulrazzak, J. (1995). Water supplies versus demand in countries of Arabian Peninsula. Journal of Water Resources Planning Management ASCE, 121(3) 227234.
Al Zawad, M. (2008). Impacts of Climate Change on Water Resources in Saudi Arabia. New York: New York University.
AL-Rashed, H. (2000). Water Resources in the GCC Countries: An Overview. Chicago, IL: University of Chicago Press.
Al-Rashidi, M. (2008). Sea surface temperature trends in Kuwait Bay, Arabian Gulf Background Report to Seminar on Water and Energy Linkages in the Middle East. Stockholm: Stockholm International Water Institute.
Dawoud M., & Allam, A. (2006). Using renewable energy sources for water production in arid regions: GCC countries case study , Arid Land Hydrogeology, 2(9), 56-90.
Dawoud, M. (2006). The Role of desalination in the augmentation of water supply in GCC countries , Desalination, 186 (34), 187-198.
Dawoud, M., & Al-Hussayen, A. (2012). Strategic Water Reserve: New Approach for Old Concept in GCC Countries. New York, NY: Russell Sage Foundation.
Dawoud, M., & Al-Mulla, M. (2012). Environmental impact of seawater desalination: Arabian Gulf Case study. International journal of environment and sustainability, 1 (3), 22-27.
GWI. (2010). Water Market Middle East 2010. Geneva: Global Water Intelligence.
Hanbury, W. (2010). Personal communication with William Hanbury. New York, NY: Russell Sage Foundation.
Hoepner, T., & Lattemann, S. (2002). Chemical impacts from seawater desalination plants a case study of the northern Red Sea, Desalination, 152(56), 133140.
Mezher, T., & Fath, H. (2011). Techno-economic assessment and environmental impacts of desalination technologies. Journal of Desalination, 266 (97), 263-273.
Sommariva, C. (2010). Efficiency improvements in power desalination for better environmental impact. Desalination, 102 (35), 1340.
United Nations. (2009). ESCWA water development report 3: Role of desalination in addressing water scarcity. New York: Dover.
World Bank (2007). Making the most of Scarcity: Accountability for Better Water Management in the Middle East and North Africa. Washington, D.C: World Bank.
Mangroves are woody plants that thrive in shallow seawater in coastlines and estuaries. The plants are salt tolerant and only within the last decade did scientists acknowledge their significance towards the marine environment. For instance, a Florida survey in the 1970s referred to the mangroves as &freaks of nature& and a form of wasteland& (Anon 2011 p. 1).
The mangroves have been in danger from human destruction and their global distributions have been on the decline. During the past fifty years, mangrove distributions have been on the decline across the globe (Valiela, Bowen and York 2001). Experts predict that by 2025 mangrove distributions will be lost by twenty-five percent in the developing countries.
The paradox of mangrove loss is that the mangrove ecosystems provide human beings and other species with many benefits yet the ecosystems continue to experience destruction year in year out. Human activities account and will continue to account for the largest reasons for mangrove loss in the world. In addition, climate change will also contribute to the loss of mangrove distribution.
The essay paper is organized into four sections. The first section is the introduction and the causes of mangrove ecosystems loss in the world. The second section looks at the mangrove ecosystem benefits, the third section looks at the consequences of mangrove ecosystem losses, and the final part looks at the reaction to mangrove ecosystem conversion. The implications of the loss of the mangrove ecosystem such as food insecurity, loss of human life are discussed. The loss of mangroves has dire global implications.
Disappearance of Mangrove ecosystems in the world
The Mangrove ecosystems in the world are declining even though the rate has been on the decline lately. The coastal wetlands are disappearing due to anthropogenic reasons and the climate change and natural disasters. The statistics on mangrove losses are not conclusive but the available data shows that close to thirty-five percent of the mangrove forests have disappeared.
The annual lose of the mangrove forests is estimated at 2.1 per cent annually and the highest lose is reported in the Americas at 3.6 per cent annually as shown in Table 1. The mangrove forests are the most threatened habitats in the world (Valiela et al. 2001).
Table 1: Current mangrove swamp areas, per cent loss, annual loss rate, and percent of original area lost per year, for the mangroves of the continents and the world.
Current mangrove area (Km2)
% loss of mangrove forest area
Annual rate of loss (Km2y-1)
% of original area lost per year
Asia
77, 169
36
628
1.52
Africa
36, 529
32
274
1.25
Australasia
10, 287
14
231
1.99
Americas
43, 161
38
2,251
3.62
World
166,876
35
2, 834
2.07
Source: Valiela et al. 2001.
Causes of mangrove distributions decline
Communities from all over the world have had a negative perception towards the mangroves. They have undervalued the mangroves and seen them as useless plants that take up land that they would otherwise use for agricultural activities. The perception of the people towards the mangroves is caused by lack of knowledge about the usefulness of the plants (Upadhyay, Mishra and Sahu, 2008 ).
The only communities that knew about the significance of the mangroves were the scientific communities that had not shared the knowledge with the wider society hence the negative attitude towards the mangroves. Moreover, many governments had also been ignorant as the rest of the communities and thus did not protect the mangroves from destruction earlier on, as they should have done.
Mangrove ecosystems are not easy to protect because they are a shared resource. However, recently there has been a change of the negative perception of the mangroves by the people and governments as they have learnt about the usefulness of the mangroves. The change in the perception has led to a decline in the loss rate of the mangroves since 2000.
The proof of the change in the perception is the mangrove conservation projects that have come up across the globe. Furthermore, legislation regarding the protection of the mangroves has also been enacted in many areas. However, in spite of the change in perception mangrove ecosystems are still at risk of extinction (Valiela et al 2009).
Population increase
Population increase is the other cause of the declining mangrove distributions. It is estimated that about thirty-five percent of the mangrove forests are lost through deforestation by humans since 1980. The loss of the mangrove forests has been due to the increase of people living at the coastal areas. The pressure of high population density causes destruction of mangroves for human settlement.
Moreover, due the increase in human population more mangroves are lost as large portions of mangrove forests are cleared to create agricultural land so that people can grow food for consumption. Tracts of land are cleared to grow crops such as rice or for other economic activities such as salt production (FAO 2007). Once land is reclaimed for agricultural use, rainwater is used to reduce the salt content and embankments created to prevent seawater from accessing the reclaimed land.
Due to population increment, more land is required for urbanization as well as industrialization hence tracts of mangroves are destroyed. Urbanization has also contributed to the loss of mangrove forests in place of urban areas. Mumbai is an urban area that shows how destructive urbanization can be to the mangroves as all its islands were once mangrove ecosystems. Other urban areas created from the destruction of mangroves include, Jakarta, Lagos, Bangkok, Doula and Singapore among others (kathiresan n.d.).
Human beings also destroy the mangroves for firewood and charcoal and timber. Large tracts of mangroves are cleared to provide fuel for the people living around the coastlines and as the wood is very rich in calorific vales hence forms very good source of firewood.
Paper millers and chipboard makers prefer to use mangrove trees in manufacturing their products as the tree gives out quality products. Thus, many paper-milling factories have been opened around the mangrove ecosystems. For example in Indonesia, many such paper companies have contributed to destruction of about 1, 37, 000 ha of mangrove area in a period of two years (kathiresan n.d.).
Oil spillage
Oil pollution is another human factor that contributes to the loss of mangroves in the world. Through gas and oil explorations, mangroves are cleared to create space for the production such in Nigeria where many oil wells are located in areas that were once mangrove forests. Oil spillage in the sea through accidents also devastates mangrove forests.
The oil covers the mangroves trees and causes them to die, as they cannot carry out photosynthesis. Furthermore, the other species living in the ecosystems also die. It is difficult to recover from the destruction caused from oil spillage as it takes a minimum of ten years to grow back the mangroves although full recovery cannot be attained.
Mangroves also destroyed through pollution. The industrial companies near the coastline dump their wastes into the mangrove ecosystems. For instance, mangroves in Panama have been affected negatively by pollution (Duke, Pinzon and Prada 1997).
Wars
Other human activities such as wars lead to destruction of mangroves significantly. The Vietnam War between 1962 and 1971 is a good example of how wars lead to mangrove destruction. Many litres of chemicals destroyed large tracts of the mangrove ecosystem during the Vietnam War (Ross 1974).
Tourism
Tourism activities also lead to the loss of mangrove distributions across the world. Tourism is a great earner of foreign exchange for many countries and thus tourism development is vital in order to attract more visitors.
Tourism development especially in Africa leads to the loss of the mangroves as land is cleared to build infrastructure such as beach resorts, hotels. Mangroves also cleared to create boat ways for the tourists. Tourism is a major economic activity but it also contributes greatly to the loss of mangroves (Valiela et al. 2009).
Aquaculture
Aquaculture contributes greatly towards the loss of mangroves worldwide. Shrimp aquaculture since the 1980s rose and hence more land was required to build ponds to grow the shrimps. The ponds created for shrimp rearing also leads to pollution of the surrounding areas.
The aquaculture has led to dramatic loss of mangroves for instance in Asia about fifty to eighty percent of the mangroves have been lost to aquaculture. Other regions greatly affected by aquaculture are Latin America and the Caribbean (Upadhyay, Mishra and Sahu, 2008).
Climate change
Climate change in addition to human activities is a major future long-term threat of the mangroves. The change in the climate poses various threats to the mangrove distributions. The change in climate leads to sea level rise, which is the major change that poses a major threat to the mangroves. The rising sea level leads to increased water levels that decreases the land available for human beings hence they clear mangrove forests in such of land.
The success of mangroves depends on adequate sediment accretion that can counter the rising water hence the rise in sea levels is the greatest threat to the survival of mangroves as at one point they may not cope with the rising water levels hence they may die back. The other threat of climate change is atmospheric and ocean warming. The rise of temperatures leads to the expansion of mangroves in the poles.
Precipitation is a form of climate change because when it reduces the mangroves do not grow properly and their overall survival is threatened. The precipitation changes also leads to a change in the composition of the mangroves. Extreme reduction in precipitation can also lead to extermination of the mangroves (Valiela and York, 2001).
Diseases
Diseases cause devastating loss of mangroves. One of the diseases has led to the damage of about 45 million Huritiers fomes species of the mangrove trees. The disease destroyed about twenty percent of mangrove forests in Bangladesh (Hussain and Acharya 1994). Mangrove diseases are caused by salinity, which occurs when the flow of water to the mangroves is reduced.
Sedimentation also causes diseases to the mangroves. Parasites and pests affect mangrove ecosystems. For example, certain caterpillars may eat the mangrove fruits. The caterpillars hinder the mangrove seeds from germinating. The mangrove species affected by the caterpillars is the Rhizophora.
Animals such as sheep, camels, and buffaloes affect the mangroves when they graze in the mangrove ecosystems. Other organisms such as the crabs feed on the leaves of the young mangrove plants hence destroy the mangrove ecosystems.
Benefits of mangroves
Mangroves are very important to the community because they help in biodiversity, economic activities because they are productive ecosystems and coastal protection. The mangroves act as coastline protection. The mangrove trees protect the coastlines against hurricane and storms hence save lives.
Mangroves have other benefits such as soil formation, habitat for marine life and filters of upland runoff. The mangrove trees stores up the sun energy and nutrients carried by silt in their leaves. The mangroves shed their leaves and grow new ones continually throughout the year. The falling leaves forms a foundation for food chain for the surrounding terrestrial and marine life.
Due to the huge constant foods, supply by the mangroves, many commercial and fishes thrive very well in the mangroves ecosystems. In addition, about $ 1.6 billion is generated from the mangrove ecosystems globally (Upadhyay, Mishra and Sahu, 2008).
Implications of global loss of mangrove ecosystems
The loss of mangrove ecosystems has negative effects and communities yet the communities continue engaging in activities that threaten the mangroves. The continued destruction of mangroves occurs because the communities are more concerned about their current economical survival and even though they may know about the future dangers of their activities in the mangrove ecosystems they have no choice but to think of today. The mangrove ecosystems have an estimated economic value of $ 1.6 billion per year worldwide (Upadhyay, Mishra and Sahu, 2008).
Loss of fisheries
One of the implications of mangrove ecosystems loss is the loss of fisheries. Mangroves ecosystems provide nurseries and breeding habitats for fish and other species. The community depends on the marine life such as fish, which they sell and make a living. Thus, the destruction of the mangroves affects lives of the people who depend on the economic activities that are related to the mangroves such as loss of fish.
The decline in the numbers of fish and prawns has had a negative impact in El Salvador (Daugherty 1975). Other fisheries in Venezuela also reported a decline in fisheries related to the mangroves in spite of the efforts put in increasing the fishing sector since the 1980s. Thus, loss of mangrove ecosystems leads to a decline in the fishing sector and loss of income.
Climate change
The loss of mangrove ecosystems leads to changes in the climate. The change in the climate is severe and affects even the shrimp aquaculture that is responsible for the destruction of large tracts of mangrove forests for conversion to shrimp ponds such as in Bangladesh where the total mangrove forest today is less than half of its original size about two decades ago.
Shrimp growing is very uneconomical because it requires farmers to utilize extensive operations that hurt the mangrove ecosystems further. The farmers result to methods that are unethical as they aim to make a profit at the expense of climate. The shrimp ponds put environmental pressures on the land beyond the farms.
According to studies, one hectare of shrimp pond which produces an estimate of four thousand kilos of shrimp annually requires the productive and assimilative capacity of between 38 and 289 hectares of natural ecosystem per year (Islam and Wahab 2005 p. 175). The fore mentioned shrimp farming is semi-intensive that means intensive shrimp farming requires even greater land.
Furthermore, shrimp farming relies on shrimp fry. The shrimp fry is fed to the shrimps. The impact of the shrimp fry is felt because many people along the coastline who do not have another source of income engage in shrimp fry catching and during the process, they catch fish and shrimps, which are destroyed in the process before catching the required shrimp fry.
The exploitation of the marine ecosystem for the shrimp fry leads to a decline in the number of shrimps harvested every year. The decline in shrimp has to be recovered hence more dangerous methods are employed that pose a threat to commercial fishers and artisanal. Moreover, the shrimps grown in semi-intensive methods require to be fed on fishmeal-based pelleted feeds.
The feeds puts more pressure on fishing as people look for the fishmeal feeds all over the world as more fishing and shrimp growing area becomes necessary putting more mangroves at risk of destruction. The pressure further leads to a decline in the coastlines. The pressure in the fishing areas occurs because only a small portion of the total catch constitutes the required tiger shrimp.
Hence, other species die in the process of catching the tiger shrimps. A report shows that about 12 to 551 post larvae of other shrimp species and 5 to 152 macrozooplankton finfish larvae are lost during the catching of one tiger shrimp (Hoq et al. 2001). In other words, the people involved in catching the tiger shrimp only have a success rate of one percent and a failure rate of ninety nine percent.
The report urges that a hundred thousand tiger shrimp collectors contributed to a loss of an estimate of one hundred and eighty thousand other aquatic species (Kamal 2000). Thus, the shrimp fry fishing posed a threat not only to the other fish species, but also to the other aquatic organisms through reduction of their food for instance, the reptiles and birds.
Destruction of marine species
Harvesting of shrimps leads to destruction of marine species. Reports say that the shrimp trawlers represent wastefulness in fishing. The shrimps caught by the trawlers represent less than two percent of the global seafood yet during their catch about a third of fish are wasted as by catch. The shrimp anglers have to destroy fourteen pounds of fish plus other organisms to get a pound of the prized shrimp.
Turtles are the biggest casualties of the shrimp trawlers that kill them more than any other human activity (Rodriguez 2001). The shrimps need to be fed continually to grow and their food is thrown into the ponds. They also require to be sprayed with antibiotics, chemicals to prevent diseases. The ponds are washed using detergents and all the things added to the ponds contaminate them and must be removed.
However, it is difficult to remove all the accumulated wastes from the ponds and the wastes spread to the adjacent marine ecosystem and leads to their degradation. The adjacent ecosystems are degraded and the species that inhabit them put at risk as the degradation is irreversible (Anon 2001). Thus, the destruction of the mangrove ecosystems have short term benefits to the commercial companies that grow shrimps but long term disadvantages to the communities and the entire countries economies.
Destruction of biodiversity
Besides, shrimp farming leads to a negative effect on the biodiversity. Mangrove ecosystems create unique biodiversity that are very productive. The biodiversity acts as a habitat for various species such as birds, marine creatures and flora. The mangroves aerial roots harbour a host of creatures and acts as breeding and refuge for many species such as crustaceans and fish.
Some of the species that breed and thrive in the mangrove ecosystems are a source of food for the communities living around the coastlines as well for economic activities. Birds such as the kingfishers, herons and eagles find their food in the mangroves. The mangroves hence benefit both animals and human beings who live in their surroundings.
Once the biodiversity are destroyed, they cannot be reclaimed and the community that depends on them suffers in the process. The communities living near the mangrove ecosystems feel the implications of destruction of mangrove ecosystems firsthand, as they no longer have a source of livelihood once the mangroves disappear under the hands of commercial growers of shrimps.
The communities come together and try to stop the invasion of the mangroves as their lives are affected greatly by the destruction as the artisan fisheries loss their way of life. In the fight for the mangroves, some members of the community have lost their precious lives in regions such as Mexico, and Honduras (Rodriguez 2001). The communities also lose their source of firewood and building materials (Anon 2001).
In addition, countries also lose because the benefit from the mangrove ecosystems (Rodriguez 2001). The shrimp ponds that lead to destruction of thousands of mangrove hectares are consequently abandoned once their usefulness has been exploited.
The people leave behind an impoverished mangrove ecosystem and communities (Anon 2001). The loss of mangrove ecosystems affects the whole society as all economic activities supported by the mangroves are lost by the destruction of the mangrove forests for other activities.
Change in coastline
Destroying the mangroves contributes to changes in the coastlines such as coastal erosion. The rapid destruction of the mangrove forests for economic activities leads to the increase in the sediment load in the water that leads to the increase in siltation. The surrounding land becomes useless for any other useful activities leaving the locals in problems.
The locals may be forced to migrate and look for other places to settle because they need to live in a place that is economically viable for their basic survival. Another reason that may force the locals to migrate is the danger posed by storms and they have to move to safer grounds. Thus, the lives of the people are disrupted as they start life all over again in the new places.
Loss of mangrove ecosystems exposes the coastline to storms and hurricanes, which causes loss of life and property. The roots of the mangrove trees are massive as seen in Figure 1 and very effective in dispersing wave energy away from the shorelines (Massel, Furukawa and Brinkman 1999).
Fig. 1. Photograph Theo Allofs/Corbis.
The mangroves roots silt the sediments hence create a fertile environment suitable for the aquatic marine. They also reduce the accumulation of sediments in the surrounding marine environments in addition to the protection of the coastal shoreline. Thus, the destruction of the mangroves ecosystem puts human beings at the risk of death from tsunamis, hurricanes and storms due to lack of a barrier.
Several storms have led to loss of lives in many parts of the world such as in Australia where mangroves have been cleared due to urbanization. Furthermore, destroying the mangroves also means a threat to the aquatic life that depend on the ecosystem such as fish, some reptiles, birds, insects and amphibians among others.
The people who depend on fishing suffer as the fish declines hence they lose their source of livelihood. For instance, communities in West Africa depend on the mangrove ecosystem to earn their livelihoods. They fish and sell the fish found in the mangrove and sell the salt they collect in the mangroves. To extract the salt they use mangrove woods to heat it and in the process contribute to the destruction of the mangroves.
If the destruction trend continues, it means they will destroy their source of livelihood and find themselves in deep poverty. Fortunately, conservation projects are underway and the community is being taught the importance of the mangroves and ways of protecting the valuable resource (Mintzer 2010).
Destroying mangrove ecosystems indiscriminately affects the environment negatively because the mangroves act as the balancing tool. They balance the environment by absorbing the excess nutrients together with pollutants and prevent them from entering into the seawater. Moreover, the mangroves help to transport organic matter through the tidal current to the adjacent marine environment in the form of detritus and increase the productivity of the areas.
The mangroves serve as a sewerage plant that treats the water and improves its quality. However, when the mangroves are destroyed their natural processes of silting the sediments and only realising important nutrients into the water is compromised. In addition, the mangroves also help in oxygen and carbon release and fixation and if cut down the process is interfered with and carbon dioxide is not fixated through the photosynthesis process, yet it is not necessary for the marine life and human beings.
The mangrove forests are very efficient in sequestering carbon more than tropical forests hence cutting down the mangrove forests increases the level of greenhouse gases in the atmosphere that leads to global warming. Therefore, cutting down mangrove ecosystems leads to loss of an opportunity to address the issue of greenhouse gases (Mintzer 2010).
Destroying the mangroves interferes with the process of soil formation because as the mangroves decompose its biomass improves the soil matter and helps in improving aeration (Hazarika 2000).
Decline in tourism
The tourism sector is also affected by the global loss of mangroves ecosystems. The ecosystem acts as habitats for some unique species that can only survive in the mangroves. The species attract tourists who come to view the fauna and the birds that live in the mangroves and once the ecosystems are destroyed, the species perish.
Besides, the mangrove ecosystems form beautiful sceneries that tourists enjoying watching and riding boats along the waterways but once the mangroves are destroyed, the tourists have nothing more to watch as the sceneries are taken over by shrimp ponds or urban areas and an area loses its ecotourism potential (Valiela et al. 2009).
The people who had been employed by the tourism sector in such areas risk losing their jobs as visitor turnover declines. The lost job opportunities lead to problems to the dependants of the workers and the people are left unable to meet their basic needs. The loss of employments leads to many other related problems hence the whole community suffers.
Food insecurity
Destruction of mangrove ecosystems leads to the problem of food insecurity. The locals living along the mangrove ecosystems depend on the food they get acquire from the ecosystem in terms of fish. Others buy their food from engaging in economic activities related to the ecosystem. Hence, a whole community has a source of food.
Conversely, the food security of the community is threatened when mangrove ecosystems are destroyed to pave way for shrimp ponds. The owners sell the shrimps harvested, the locals are left without food, and even if they could afford to buy the shrimp, it could not sustain them as the shrimp makes up a small percentage of the total seafoods.
The money made from the sell of the shrimp may not go back to the community. On the other hand, animals that depend on the mangrove ecosystems also face food insecurity because their source of foliage is destroyed (Valiela et al. 2009). The animals die due to lack of food and those that can are forced to go and look for food elsewhere but those that only survive in wetlands perish together with their habitats.
The animals that inhabit the mangrove ecosystems acts as a source of food for the locals and once they lack food they cannot continue being a source of food for the people and the threat of food insecurity heightens. Thus, the global loss of mangrove ecosystems has far-reaching implication such as food insecurity.
Social effects
The other implication of the global loss of mangroves ecosystem is social effects. Mangrove destruction leads to lack of employment. Unemployed people may result to criminal activities because they do not have food. The rise of crimes in an area lead to many other negative effects such as use of violence by the gangs and people are injured.
The injured people require medical attention and the cost maybe unaffordable because of lack of finances. It is also important to note that the local people derive medicines from some of the plants that grow in the mangrove ecosystem. For example, the mangrove species called Bruguiera gymnorrhiza is used to treat blood pressure and diarrhoea, the Acantanthus ilicifolius treats rheumatism and asthma, Excoecaria agallocha treats leprosy, Lumnitzera racemosa treats itches and herpes (Upadhyay, Mishra and Sahu, 2008).
The mangrove species also treat other ailments such as skin, headaches and abdominal pains. The plants disappear as the ecosystems are cleared for other uses. Businesses in such areas are affected because investors lack faith in such environments and pullout their investments. Investors who may want to come to such places fear because of the bad reputation associated with the area due to crime.
When businesses close down people who had found employment in the closed firms, lose their jobs. Such an area suffers from lack of development because people are not able to send their kids to school hence they never learn any skills that can make them employable in the future. The future of a whole generation can be affected by the loss of mangrove ecosystems.
Mangrove conservation
The effects of the loss of mangrove ecosystems around the world have been negative and thus action has been taken to try to reserve the loss trend by mangrove expansion and protection. Awareness about the significance of the mangrove ecosystems has increased and people realise the economic and social value of the mangrove ecosystems.
Moreover, they are now aware of the ecological values of the mangroves and are willing to protect them. However, it is important to note that recourse action to protect the mangroves is still outweighed by the rate of mangrove loss due to various human activities, the cost of mangrove reforestation is high, and some rare species cannot be replaced.
Various governments have started reforestation programs for the mangroves. For example, in Bangladesh extensive reforestation of the mangroves along the coastal area began from 1966, many mangrove plants have been planted, and the area under mangroves has increased significantly (Alongi 2002). In other countries such as Senegal in West Africa, conservation groups have been established to educate the locals about the importance of the mangroves and the ways of conserving them so that they can continue reaping the benefits of the mangrove for a long time.
The group provides the locals with stoves that do not require the use of firewood in their salt extraction activities to save the mangroves that are used as firewood. In Australia, the people have learnt about the value of the mangroves and reforestation has been done increasing the area under the mangroves as shown in table 2 below.
Table 2: Area of mangrove forest, 2003 and 2008 (000 hectares).
2003
2008
Difference
Difference, %
Mangrove forest
749
980
+231
+31
Source: NFI (2003).
Most countries active legislation regarding the protection of the mangrove ecosystems such as in Asia and Australia but in Africa there is little legislation. Thus, there is a big challenge regarding the conservation and protection of the mangroves in various parts of the world as the mangroves continue to decline in spite of the knowledge about their values.
Conclusion
Mangrove ecosystems are under threat of disappearing if the human anthropogenic activities continue to destroy them at the rate the destruction is occurring. The importance of the mangroves ecosystems cannot be over emphasised because they are vital for the biodiversity they create and benefits to adjacent environments. The loss of the mangroves have been massive the world over in the last fifty years and more than half of the total mangrove area has already been destroyed.
The implications for the global loss of mangrove ecosystems are huge as they affect the communities and animals living along the coastlines greatly by disrupting their normal lives. All the stakeholders need to be involved in the mangrove conservation and protection efforts so that the level of awareness about the value of mangrove ecosystem can translate into equal level of conservation and protection of the invaluable trees.
In addition, there is the need of getting accurate statistics on the global distributions of mangroves so that people can get a clear and real picture of the extent of mangrove destruction. Hence, the urgency of their conservation and protection to try to curb the already negative implications that communities are experiencing because of clearing mangrove ecosystems for other activities.
People need to learn how their activities affects the mangroves now and in the future so that they can know the possible behaviour of the mangroves in the future and take corrective measures now before it is too late. The current expansion of the mangroves is a step in the right direction that may allow even the tomorrows generations to enjoy and reap the vast benefits of the mangrove ecosystems.
Therefore, all must join hands in protecting and conserving the mangrove ecosystems because failure to do so is declaring a blink future for the current and future generations. Mangrove ecosystems are very important and as Rodriguez puts it Mangroves are life, long live mangroves (2001p. 1).
References
Alongi, D. M. 2002. Present state and future of the worlds mangrove forests. Environmental Conservation, 29, pp. 331-349.
Anon. 2011. Mangrove Conservation through Education. Web.
Anon, 2001. Mangroves and their uncertain future. Web.
Daugherty, H. E., 1975. Human impact on the mangrove forests of El Salvador. In G. E. Walsh, S. C. Snedaker and H. J. Teas (Eds.). Proceedings of the International symposium on biology and management of mangroves pp. 816-824. Institute of Food and Agricultural Sciences, University of Florida, Gainesville.
Duke, NC Pinzon, ZS and Prada, MCT., 1997. Large scale damage to mangrove forest following two large oil spills in Panama. Biotropica, 29, pp. 2-14.
FAO 2007. The Worlds Mangroves 1980-2005. FAO Forestry Paper. Rome: Food and Agriculture Organization of the United Nations (FAO) no.153.
Hazarika, M. K., 2000. Monitoring and impact assessment of shrimp farming in the East Coast of Thailand using remote sensing and gigs. International Archives of Photogrammetry and remote sensing, 33 pp. 504-510.
Hoq, M. E., Islam, M. N., Kamal, M. and Wahab, M. A., 2001. Abundance and seasonal distribution of penaeus monodon post larvae in the Sundarbans mangrove, Bangladesh, Hydrobiologia, 457pp. 97-104.
Hussain, Z., and Acharya, G. (Eds.)., 1994. Mangroves of the Sundarbans, Volume 2: Bangladesh . IUCN, Gland, Switzerland, 257 pp.
Islam, S. and Wahab, A., 2005. A review on the present status and management of mangrove wetland habitat in Bangladesh with emphasis on mangrove fisheries and aquaculture. Hydrobiologia, 542 pp.165-190.
Kamal, M., 2000. Assistance to fisheries research Institute- A report prepared for the Assistance to Fisheries research Institute. Consultancy report on Marine Fisheries resource Management. BGD/89/012. FRIGOB/UNDP/FAO.
Kathiresan, K. Threats to mangroves. Web.
Massel, S. R.; Furukawa, K., and Brinkman R. M., 1999. Surface wave propagation in mangrove forests. Fluid Dynamics Research 24(4), pp. 219249.
Mintzer, R., 2010. Destroying mangroves in West Africa detrimental to people, climate, and wildlife. Web.
NFI (National Forest Inventory). 2003. Australias State of the Forests Report 2003, Bureau of Rural Sciences, Canberra.
Rodriguez, E. L., 2001. Mangroves are life, long live mangroves. Web.
Ross, P., (1974). The mangrove of South Vietnam; the impact of military use of herbicides. In: Walsh, G.E., Snedaker, S.C. and Teas, H.J. (Eds.), Proceeding of International Symposium on Biology and Management of Mangroves, 811 Oct. 1974, Hawaii, Gainsville, Unit. of Florida, pp. 126136.
Valiela, I., Bowen, J. L. & York, J. K., 2001. Mangrove forests: one of the worlds threatened major tropical environments. Bioscience, 51, pp. 807-815.
Valiela, I., Bowen, J. L., Cole, M. L., Kroeger, K. D., Lawrence, D., Pacich, W. J. and Tomasky, G., 2001. Following up on a Margalevian concept: Interactions and exchanges among adjacent parcels of coastal landscapes. Scientia Marina, 65, pp.215-229.
Upadhyay, V. P., Mishra, P. K. and Sahu, J. R., 2008. Distribution of Mangrove Species within Bhitarkanika National Park in Orissa, India. Trees for Life Journal, 3 (4).
Estuaries are transition zones between land and sea and are important to aquatic organisms. (Levin et al. 2001). They are increasingly under threat from anthropogenic influence the world over. The size, shape and volume of water distinguish one estuary from another and these features are greatly influenced by the geofraphical landscape of the region. However estuaries have certain common features, such as gradients in their salinity and sediments which are known to influence the biological communities found within the systems.
Estuaries are among the most productive natural habitats on earth due to sea and fresh water inflow that adds nutrients to the water column and sediment. This makes them highly productive and enables them to support large diversity of aquatic organisms. Intertidal,macrobenthos are found between high and low tide marks, either permanently living on or within soft sediments. These organisms are of ecological importance and are mainly used as indicator species within these habitats. Faunal distribution within the estuary is determined greatly by salinity, temperature, organic matter, concentration of oxygen and composition of sediments.
Primary productivity, competition and adaptation to the estuarine climate also influence the temporal and spatial and temporal differences in benthic species composition. However, the composition of the fuana present at a given estuary are a clear indicator of the state of the aquatic environment (Warwick & Ruswahyuni, 1987). Salinity and sedimentation are however the two major challenges faced by organisms living within the estuaries. Bacteria; most of which have high oxygen demand are found in abundance within the sediment hence reduce the amount of oxygen in these zones (Elliott, 2004).
Aim of the study
The major aim of the study was to examine the influence of the major gradients in physical factors (salinity and sediments) on the distribution of benthic organisms within the Waiwera Estuary.
Literature review
Macrobenthic invertebrates are important components of estuarine ecosystems, in terms of productivity. They provide an important food source for other organisms which depend on these eshtuaries for survival. (Herman et al., 1999). Estuarine organisms can be described as bioindicators in three ways, as: 1) indicators of a defined set of environmental conditions; 2) indicators of contaminant loads on the system; and 3) indicators of the overall health of the system (Wilson, 1994).
The assemblage of macrobenthos along estuarine salinity gradient are classified into polyhaline, mesohaline and oligohaline zones corresponding to marine , brakish water and fresh water respectively. (Giberto et al., 2007). However the species within these zones are not permanent due to spatial and temporal fluctuations in environmental conditions along these areas. (Ysebaert et al., 1998). Studies by Sanders et al., 1965 found that salinities in the interstices are more stable and different from those of the water column and hence organisms living in these interstices are not always directly affected by salinity changes (Sanders et al. 1965).
The variation in salinity both vertically and horizontally are the determinants of salinity structure within the estuaries. Its distribution within an estuary is a reflection of the relative influx of fresh water andn marine water. The ocean currents and wind aid in mixing of marine and fresh water. Most aquatic macrobenthos function properly at optimum salinity levels below or above which they may lose their ability for osmoregulation. Consequently, the distribution of macrobenthos can be affected by shifting salinity distributions. Few species are usually characteristic of estuaries with wide ranging morphological and physico-chemical parameters (Kanandjembo et al., 2001). For instance, while bivalves and gastropods are affected by sediment characteristics, polychaetes and amphipods do not (Wu and Shin, 1997).
Dissolved oxygen (DO) is the amount of oxygen dissolved in water and it is meassured in mg/l O2 . It is slightly soluble in water ranging between 6 to 14 mg/l. However, its solubility varies inversely with salinity, temperature and pressure. D.O defines the type of organisms that are most likely to be found in a given water body and its concentration varies diurnally due to tidal exchange (Connel and Miller, 1984; Best et al., 2007). Estuarine health and balance can be assessed by its biodiversity levels.
The densities of some organisms may be high in some parts of an estuary, however this should not be taken as an indicator of a productive habibtat since it may just be a reflection of the adaptability of that particular organism to that specific habitat. Sedimentation refer to the amount of organic and mineral material deposited on the bottom of a water body over a given period of time. It is measured in terms of sediment density per unit area over a given time period or as vertical accumulation over time. Macrobenthos are mostly controlled by the nature of sediment present on the sea floor and the dissolved oxygen status at the bottom of the water bottom of the water body.
Study site description
The study was carried out along Waiwera estuary situated about 35 km North of Auckland on the Eastern coast (Fig. 1). Two major streams, the Waiwera and the Wainui form the Waiwera Estuary. The drainage area is a steep slope covering an area of approximately 500-600 ha of pastoral agricultural land and bush. The Waiwera estuary is a relatively small tideway, which extends only 3.5 km inland. It is well flushed with tidal velocities of up to 0.50 m s-l.
At mean high tide there is about 1.5-2 m of water covering the shore while at low tide the water flow is restricted to a single 20 m wide by 1-1.5 m deep river channel, leaving extensive tidal flats throughout large parts of the estuary. The drainage basin receives an annual rainfall of between 1250-1400 mm with the lowest monthly precipitation occurring during the month of February and the highest in August and September. The sediment consists of a mixture of dead shells, sand and silt.
Fig. 1 Map of Waiwera estuary showing the sampling areas along the length of the estuary. The stations are shown as numbers 1-14.
Materials and Methods
Benthic organisms inhabiting the sediment habitat were selected for this study as most of them are bottom dwellers and are known to occupy specific niches on the floor of the sea therefore serving as a reflection of the state of the estuary. A total of eight stations along the estuary spreading from the mouth of the estuary up to nearly the extent of tidal influence- a distance of approximately five kilometers were sampled. Students were divided into equal teams of 4-6 individuals and each team sampled one to three stations along the estuary.
Samples were collected at three tidal levels (lower, middle and upper shores) at each station. In areas that had mangroves, the upper level was taken as the inner part of the mangrove forest, the middle level as the seaward edge of the mangrove forest and the lower level as the edge of the tidal channel. Sampling was only done in areas that had thick layers of sediment while areas with emergent rocks and compacted mud (plastic or clay-like) were avoided. During sampling, great care was taken to avoid trampling the emergent pneumatophores and seedlings of mangrove plants.
Using a 0.1m2 quadrant, a total of five 0.1 m2 samples were collected using a trowel to depths of 15cm at each station and sieved using a 3 mm mesh size sieve. One sediment sample scooped by half a trowel full down to 5cm depth was collected also collected and placed in a plastic bag labeled using a marker pen. The sediment sample was later dried and sieved into major fractions to determine the particulate composition.
For each replicate sample, organisms were removed from the mesh, identified, counted and recorded on the datasheet. Seaweeds, mangrove pneumatophores, seedlings and seeds were also included. Unidentified specimens were placed in separate; carefully labeled jars for later matching and identification of species. The unidentified species were recorded appropriately in a data sheet for later identification. A representative range of specimen from each site were then put into a plastic bag so that at the end of the day, all the other groups could see what organisms were at the stations they didnt sample.
At each level the presence of burrow openings, casts, trails of organisms on the surface and profile (from the intact side of the hole where sampling was done) were recorded. The colour of sediments on the surface and down the subsurface profile were also recorded (since the depth of the anoxic layer was of great interest in the study). Identification of organisms was done using an illustrated guide to common macroinvertebrates species. Data on the water column depth measured using Hummingbird handheld depth sounder, and salinity and temperature, measured using a YSI probe at each site from a small boat in 2002 was provided. The present station numbers were matched with the ones sampled initially in 2002. However, some new stations were sampled in this study while others were ignored or extrapolated as appropriate from those sampled in 2002.
Study Findings: Environmental Parameters
Salinity in the Waiwera estuary remained considerably high throughout five stations while station the sixth (station 13) had relatively low salinity (below 5ppt) for high and mid tide while the low tide was slightly higher. Station 8 displayed a strong variation between the low, mid and high tides at 31, 24 and 21 ppt respectively whereas there was no significant variations in salinity between the three different regions for station 1, 2 and 4. However, there were slight variations in salinities between the stations. Salinity values were almost similar for low and mid tide for station 9 but showed a higher value for the high tide.( Fig 2A)
Temperatures were mostly constatnt (btw 15-160C) in three stations (1, 2 & 4) and among the different tide levels whereas it showed a slight variation in temperature with high and mid tide recording 140C each while high tide recorded 16.50C. (Fig 2B).
The six stations varied greatly in terms of depth with station 9 being the deepest at 1.7m and station 2 the shallowest at 0.4m. Stations 1, 4, 8 & 13 were 0.9m, 0.5m, 1.3m and 1.2m respectively.The approximate depth of annoxic layer (mm) was extremely low in stations 8 and 13 but high in station 1. Stations 2 and 4 showed a significant variation especialyy in the low, mid and high tides.(Fig 2C) The wide variation between high and low tide was clear in station 4 (at about 5mm annoxic depth for lowtide and 140mm for high tide).The depth of the anoxic layer was highest in the three tide levels of station one. This station showed significantly higher depths of anoxic layer and interesting the trend was the same for all the tide levels (low, mid and high tides). Station two and four had significant variations between low, mid and high tide levels. Station 8 and 13 however had extremely low depths of anoxic layer in the three tide levels (Fig 2D).
Figure 2. Graphs of environmental parameters collected from Waiwera Estuary showing 2A. Salinity (ppt), Fig 2B. Temp 0C, Fig 2C Depth (m) and Fig 2D the approximate depth of anoxic layer (mm).
Sediment composition
All the six stations sampled had just a small percentage (less than 1%) of gravel above 2mm in size in the low and mid and some high tide. The high tide of station 8 and 9 however had 4.5% and 3% gravel of <2mm respectively (Fig. 3A). Silt and clay on the other hand varied significantly between the six stations. Whereas stations 1 and 2 had silt and clay percentages of less than 10, stations 4, 8 & 9 were relatively high ranging between (20-40%).
Percentage silt in station 13 for low, mid and high tide were slightly higher. (Fig 3B). this was a clear indication of the variability of sediment composition between the six stations sampled along Wawira estuary. Generally, all stations had high percentages of silt as compared to other sediment types. Station 1 and 2 comprised of about 100% sand in all the three tide levels while station 4 had asignificant variation between the high, mid & low tide in terms of percentage composition of sand, whereby high, tide had 60%, mid tide 70% and low tide 90%.(Fig. 3C).
Figure 3: Graphs of sedimant samples collected from Waiwera Estuary showing: Fig 3A Percentage of gravel (< 2mm); Fig. 3B Percentage of silt and Sand and Fig. 3C Percentage of Sand
Diversity, abundance and distribution
A maximum of 26 species were recorded across the six stations that were sampled.(Fig. 4). The most abundant specie was Austrovenus stutchbury (Cockle) which had the largest number of individuals in low and mid tide. However, this specie was completely absent in the high tide probably because of the harsh conditions at this site which inhibited their survival. Paphies australis (pipi) and Helice crassa and F. nereididae (tunneling and mud crab) also occured in significant quantities within the estuary. Only two species F nereididae and Helice crassa (tunnelling mud crab) occured across all the tide levels though in relatively smalller numbers.
Other species which occured within the estuary albeit in smaller numbers in the low, mid and high tide included, zeacumantus lutucentus (mud flat hornshell) which was present in low and high tide and absent in mid tide., Cominella glandiformis (whelk), Macomona liliana (wedge shell), Diloma subrostrata (mud flat topshell) and Nucula hartvigiana (nut shell). F corophiidae and potamopyrgus estuarinus (snail) only occured in the high tide though in small numbers. Talorchestia quoyana (sand hoppers), F paguridae (hermit crab), Pyromaia tuberculata (crab) occured in very low numbers and were completely absent in the three different habitats. Chiton glaucus (green chiton) was only found in the low tide but in very low numbers. In general, a relatively large number of species inhabited the low tide region (14 spp) as compared to mid tide (12 spp) and high tide (6 spp).
Figure 4. A graph of the Species abundance collected from the five stations in the Waiwera Estuary.
Discussion
The change in faunal abundance was roughly linked to changes in sediment characteristics within the Waiwera Estuary. On the low tide, the influence of wave action is considered to be the major factor affecting the fauna as it results in a decrease in evenness and species richness; on the other hand, muddy substratum were found to decrease the density of fauna. The highest species diversity was found on the silty and sand substratum. There is therefore a close correlation between the sediment size and the abundance of fauna.In an estuary there is a clear gradient of water salinity from the seaward to the upstream area due to river water inflow.
However, the salinity profile of the water changes over time as the result of tidal action, meteorological influences and wind. Estuarine organisms must tolerate such strong and variable environmental stresses. In general, the diversity of aquatic organisms tends to be limited in estuaries due to the relatively severe environmental conditions. Benthic species also have a response to changes in fresh water inflow. Under high inflow, macrobenthic organisms adapted to low salinities flourish until higher salinity conditions return. The more marine species reappear and rebuild to higher levels that existed before the high inflow conditions commenced In conclusion, the high density of macrobenthos are considered to be related to relatively stable conditions.
References
Best, A. A., Wither, A. W. and Coates, S. (2007). Dissolved oxygen as a physico-chemical supporting element in the water framework directive. Marine Pollution Bulletin 55, 53-64.
Connell, D. W. and Miller, G. J. (1984). Chemistry and Ecotoxicology of Pollution. John Wiley & Sons, N.Y.
Elliott, M. (2004) The Estuarine Ecosystem: ecology, threats and management. New York: Oxford University Press Inc. Web.
Giberto, D. A., Bremec, C. S., Cortelezzi, A., Rodrigues Capitulo, A. and Brazeiro, A. (2007). Ecological boundaries in estuaries: macrobenthic beta-diversity in the Rio de la Plata system (34-36oS). Journal of the Marine Biological Association U.K. 87: 377-381.
Herman, P. M. J., Middleberg, J. J., Van De Koppel, J. and Heip, C. H. R. (1999). Ecology of marine macrobenthos. Advances in Ecological Research. 29: 195-240.
Kanandjembo, A. N., Platell, M. E. and Potter, I. C. (2001). The benthic macroinvertebrate community of the upper reaches of an Australian estuary that undergoes marked seasonal changes in hydrology. Hydrological Processes 15: 2481-2501.
Levin, L. A., Boesch, D. F., Covich, A., et al. (2001). The function of marine critical transition zones and the importance of sediment biodiversity. Ecosystems 4: 430-451.
Sanders, H. L., Mangelsdorf, P. C. and Hampson, G. R. (1965). Salinity and faunal distribution in the Pocasset River, Massachusets. Limnology and Oceanography 10: R216-R229.
Warwick, R. M. and Ruswahyuni, K. (1987). Comparative study of the structure of some tropical and temperate marine soft-bottom macrobenthic communities. Marine Biology. 95: 641-649.
Wilson, J. G. (1994). The role of bioindicators in estuarine management. Estuaries 17: 94-101.
Wu, R. S. S. and Shin, P. K. S. (1997). Sediment characteristics and colonization of soft-bottom benthos: a field manipulation experiment. Marine Biology 128: 475-487.
Ysebaert, T., Meire, P., Coosen, J. and Essink, K. (1998). Zonation of intertidal macrobenthos in the estuaries of Schelde and Ems. Aquatic Ecology 32: 53-71.
Ozone is mainly found in the stratosphere, and a small volume of O3 is also found in the troposphere. One of the major roles of the Ozone Layer is to absorb ultraviolet rays from the sun. UV-B rays are quite harmful to living organisms on the Earth, but three oxygen molecules in ozone absorb the energy in the UV light. Ozone is also instrumental in regulating the temperature of the Earth. As UV light energy is absorbed by ozone, the stratosphere heats up; thus, absorbing the heat energy that would otherwise hit the Earths surface. Increased volumes of CFCs in the atmosphere develop more free radicals that break down the ozone molecules; thus, depleting the amount of ozone in the stratosphere. This allows more UV-B rays to reach the earth, and this subsequently leads to more harm to the biosphere ( Science: Ozone Basics par. 1). As more heat energy reaches the earth and more greenhouse gases are released into the atmosphere, a greenhouse effect occurs, resulting in global warming. Global warming, on the other hand, has led to various adverse geological changes on the earth, including the rise in sea levels, melting glaciers in different parts of the world, and a disruption in the hydrosphere system of the earth. The depletion of ozone in different parts of the world will increase the current issues in the biosphere, geosphere, atmosphere, and hydrosphere.
The future should be characterized by a society that is cautious about the number of greenhouse gases released into the atmosphere. Some parts of the ozone layer have experienced up to 60% depletion, and this has translated into an increase in the number of cases of cancer and other harmful effects on living organisms. Ozone molecules are always being produced; hence, the reduction of CFCs in the atmosphere will ultimately help in the repairing process of the ozone layer ( Ozone Layer Protection Science par. 2). Global associations should continue applying restrictions on greenhouse gas emission rates in different nations.
The rank of accuracy among the four students is D, B, A, C. In essence, CFCs are stable molecules, and they are broken down by UV radiations to release chlorine and bromine atoms, which destroy the ozone layer ( The process of ozone depletion par. 1). CFCs contain hydrogen, chlorine, carbon, and fluorine. Chlorine is particularly dangerous in the stratosphere because it acts as a catalyst in the decomposition of Ozone into oxygen molecules. A single molecule of chlorine in the stratosphere can deplete a very large amount of ozone before it decomposes. This implies that a unit emission of CFC in the atmosphere depletes a very large portion of the ozone layer if it dissociates into free radicals.
Global warming is the steady rise in the temperature of the Earth, which occurs in cycles over time. As far as the history of the earth is concerned, global warming and cooling are natural phenomena, which have occurred over time (Peters par. 2). However, the greenhouse effect has increased the rate of global warming over the past several decades (Lallanila par. 2). The greenhouse effect is a phenomenon that entails an increased CFCs concentration in the atmosphere, which prevents heat from the earth to radiate back to space ( The greenhouse effect par. 3). The greenhouse gases trap more heat in the earths atmosphere, resulting in an increased rate of global warming.
The Washington Times reported on Thursday, April 28, 1988, that employees of EPA had complained to the management about the agencys lack of progress in fixing ventilation problems that caused headaches and dizziness. The article was written by Dan Vuleichs. The employees claimed that the re-carpeting program was the source of their health problems. Indeed, EPAs Occupational Health and Safety staff confirmed they had received complaints of headaches, nausea, fatigue, sinus congestion and psychological signs of confusion and disorientation from the employees. According to the Federal Report, the major culprit was Shaw Industries that manufactured the carpets. The Times, further, reported that the EPAs Environmental Response Team discovered significant amounts of benzene, toluene, formaldehyde and styrene in the workplace where observations were made. This prompted the employees to storm out of the meeting. Possibly this could be the chemicals responsible for the health complications of the EPA employees. The chemical most likely responsible for the adverse effects could be one of those chemicals that were discovered at the workplace.
The fumes and glue that were used in the installation and the chemicals used in the manufacturing of the carpets were blamed on the symptoms exhibited by the employees. The chances of the chemicals aforementioned above being used in the manufacture of the carpets cannot be ruled out as the major health contaminants. However, the main source of the chemicals remains the industry (Shaw Industry) involved in carpet manufacturing. The numerous complaints launched by the 64 employees of EPA got the attention of many players including the representatives of the House of Congress. The member of Congress ordered laboratory investigations to be conducted by the EPA and independent scientists to get to the bottom of the matter.
The House of Representatives demanded that the EPA scientists and Dr. Anderson perform parallel experiments to ascertain whether the re-carpeting program was the single source of the health problems at EPA premises of work. The research methodology used was that which had been used by Dr. Anderson over one year to perform toxicological tests on mice. According to Mr. Bernard Sanders (a member of the congress), in his letter to Mr. Kimm (an Assistant Administrator-EPA team), he indicated that the tests performed on mice proved the carpets were the source of the adverse effects. Evidently, the Laboratory tests that were conducted by the two groups showed that, in each, of the two parallel teams, the results showed that one of the four mice died (25 percent). Bernard further said that mice exposed to carpet off-gassing exhibit many, similar and abnormal health effects in both the experiments conducted by the two EPA scientists and Dr. Anderson. These results were coherent with those that had been performed a year earlier by Dr. Anderson and replicated by Dr. Alarie of the University of Pittsburgth. This toxicological test ascertained that the carpeting program was the source of the health problems of the employees at EPAs work place-excellent move.
The responsibility of the Arizona State University professor, Dr. Anderson cannot be overstated. She played a significant role in unearthing the truth as far as the carpet emissions were concerned. Her results a year ago before the two parallel experiments by the EPA team were consistent. The professor provided independent results that were similar to those that were done by the EPA scientists in the parallel experiments performed. This dismisses any possible allegations that the results had a bias if only the EPA scientists had performed the tests singly. Therefore, the investigation by an Arizona State University professor played a critical role in the carpet store. It is fabulous.
The Carpet Manufacturer (Shaw Industry) had reported that it had received numerous complaints apart from the case of EPA employees. Shaw industries had previously been involved in a lawsuit filed by, Concannon, a lawyer representing a family in a case against Shaw industries, the biggest carpet manufacturer. The family sought compensation from the company because of the respiratory problems prompting the family to sell the house at a loss. However, the family lost the case as the judge ruled in favor of the industry, citing a lack of good science and lack of solid evidence from experts. The trade association that represented Shaw Industries in the Carpet emissions saga was IEQS. The association tried to protect the carpet manufacturer by withholding crucial information that would have, otherwise made it possible for EPA scientists, members of the public and even the Federal Government to discover the company was manufacturing carpets that are health hazardous.
The Carpet Policy Dialogue revolved around increased complaints of the members of the public and the media interests in the issue. In spite of this, it also attracted others; the members of the congress coming in to scrutinize the companies environmental and health effects of its products. There were allegations that the lead carpet Manufacturer was colluding with CRI and University researchers to delay and even hide some critical research evidence that would bring to book the culprit in the numerous claims by members of the public about the health problems of the carpets from the companies. According to Concannon, the carpet policy dialogue took a political dimension as opposed to a scientific approach. The debate still was seen as a battle to be won-by the manufacturer of carpets. The manner in which communication was being done as far as research is concerned was not genuine. The purpose of research was to validate the complaints. Also what raised eyebrows with respect to previous cases was the way in which Consumer Safety Product Commission conducted itself with respect to accessing of what is so called confidential documents by interested parties. The refusal by CSPC to allow concerned parties to access its confidential information further complicated the carpet issue. The officials also refused to elaborate why it rejected to make public research findings regarding the complaints funded by AEQS, CRI and IAG.
As we are all aware, the media played a great role in making the members of the public to become aware about the carpet issue. We can say the media might have contributed to making known the developments on the carpet story. This is demonstrated by the continued coverage of the story by The Washington Times. The article by Dan Vuleich, that appeared in The Washington Times on Thursday, April 28, 1988, is a clear testimony of the role of the media in information dissemination in the entire story-toxic carpet emissions by Shaw Industries. Furthermore, the reports by the mass media on cases of employees complaining of nausea, headaches, dizziness, and psychological complications were documented. This showed the strengths of the story.
The Congress too played a pivotal role in resolving the problem. This is demonstrated by the action taken by Mr. Bernard Sanders (a member of the Congress) writing to Victor Kimm (Assistant Deputy Administrator EPA) demanding him to immediately perform toxicological experiments parallel to those done by Dr. Anderson, to get to the bottom of the matter regarding the carpet emissions. The letter send to the agency is a clear indication of the roles pursued by the Congress aimed at investigating the source of the emissions. Bernard Sanders was instrumental in pursuing the issue.
Despite the previous denials by Shaw Industries, the eventual outcome of the Carpet Policy Dialogue revealed that the health problems were as a result of chemicals used by the company in the manufacturing of the carpets. The delay in releasing of research reports by CRI and University contract deals in maneuvering the research results sums it up or in itself is clear evidence. The media was also to be manipulated.
The results of the test experiments performed by the two teams confirmed multiple health effects/multiple sensitivity occurred on the mice. This refers to a situation where a test subject exhibits several or many reactions/effects to particular toxicological experiments. For instance, in the case of the experiments by Dr. Anderson and the EPA scientist, the mice exhibited multiple health effects when they were exposed to carpet off-gassing. The results were also meant to investigate whether the industry had met the required standards for Green tag labeling Program. The result was the last proof.
The Green Tag labeling Program is a certification label or mark that shows that a company has met certain relevant health and safety standards. It builds confidence of the consumers in the products they purchase. This can be equated to ISO certification. The green labeling Tag Program had to be revised for Shaw industries because of the health complications of the products it was making. The Congress member suggested withdrawing the company from green tag program. A part from this, the company had to be banned from publishing in the bronchure and it had to revise the standards of labeling program. Lastly, stronger warnings had to be issued from the Attorney General.
