Global trades of fish have evolved to meet the restraints and limitations on fishing loads and major liners which has affected both the pace of fishing legally and the strenuous pull on the food chain that overfishing has caused.
Global trades of fish have evolved to meet the restraints and limitations on fishing loads and major liners which has affected both the pace of fishing legally and the strenuous pull on the food chain that overfishing has caused. Shrimp production has been one of the sources of increased attention as shrimp production increased nine fold between 1982 and 1992. As numbers trend towards ever increasing fishing and advancement of aquaculture, global tried becomes more reliant on ocean fishing and shrimping in particular.
The expansive scale of shrimp fishing is evident in the form of food production shifting to aquaculture. Among all of aquaculture shrimp is the most common form and fastest growing. According to Clay and Boyd, “Approximately 1.1 Million Metric Tons (MT) is produced globally of which 91% is produced for export. Prices remain high, an average of $6,334 per MT, and profits in the industry are also high.” (Clay & Boyd) Such a lucrative market does not go unnoticed in the global community. The rise in numbers and trading of shrimp production also has environmental impacts that affect the food chain throughout the world.
Environmental Impacts of Shrimp Production
Globally, a great number of environmental impacts can be attributed to shrimp aquaculture. The extent of the impacts depends upon the intensity of the production in the region in question. The four most significant environmental impacts are: i) its effect on the ecology of fragile coastal environments; ii) water quality issues; iii) the introduction of non-native shrimp species and iv) the destruction of mangrove forests. The latter will be discussed in greater detail in Part II.
The shrimp aquaculture industry damages important coastal wetlands by altering the natural interactions between fauna, land and water. Correlations have been appearing to suggest that as much as 90% of the environmental disturbances caused by shrimp aquaculture can be attributed to facilities processing the production of shrimp. (Clay & Boyd) When construction of ponds and other shrimp processing infrastructure alters shorelines and wetlands, they cease to be a natural buffer to the affects of storms and high tides. When the hydrology of estuaries and tidal basins are damaged, they no longer protect coral reefs and sea grass beds from siltation. (Hellier) The destruction of coastal wetlands is a loss of habitats, (i.e. hunting, breeding and nesting grounds) for migratory animal species.
Concerns about water quality in shrimp aquaculture are also presented. Much like when large cow farms are given acres of land in California, environmental damage to grass, earth, and air are undeniable. Large quantities of life in relatively small spaces will no doubt influence the environment around them in unequal proportion. A single group of shrimp may produce acceptable levels of evacuation, but too many ponds could exceed local carrying capacity. Much of the waste in the effluent in shrimp ponds is leftover food and has high concentrations of fish meal and fish oils. (Boyd & Tucker) Any one of these bioindicators will bring new amounts of content into the immediate habitats around the shrimp which will stimulate responses from neighboring communities of life.
Finally, for some time, Asian shrimp species have been brought to Latin America and Latin American species have been transported from Pacific fisheries and introduced into the Caribbean and as far north on the Atlantic coastline as North Carolina. The impact of the introduction of foreign shrimp species is unknown and probably of insignificant in small quantities. However, with the massive quantities of shrimp coming into ponds it is possible to understand how the escape and possible inbred genetic pollution might disturb the wild populations’ genetic variety. (Boyd & Clay)
The introduction of disease pathogens from non-native species is equally a concern. This is evident in cases where pathogens and disease once found only in one area become spread to other continents through travel and import of foreign species. One example is found in Taiwan and China where pathogens once unique to these two regions transferred to Latin America, U.S. Gulfs, and beyond. Both genetic pollution and disease could drastically reduce population, as with North Carolina shrimp farms. A 1996 outbreak of Taurus Syndrome Virus (TSV) caused an estimated ~30-50% loss on affected farms. (Farley) Such impact needs to be further evaluated in order to protect the genetic variation and disease resistance of shrimp and all aquaculture.
Global Trends in Shrimp Production and Trade
Shrimp aquaculture is a booming business worldwide. Thailand, China, Indonesia, Vietnam, Bangladesh, India and Ecuador have emerged as the principle (by weight) world export leaders with the United States, European Union and Japan as the primary importers. (Clay & Boyd, 1998) Poorer regions have caught on to aquaculture much like during the initial boom of high yielding varieties (HYV) of seeds and crops. Dictating concerns of environmental impact from global leaders in politics becomes difficult when these regions struggle to feed their general populations and have limited exports to the global economy.
The United States, European Union and Japan are the largest importers, with the U.S. currently importing around 80% of the shrimp it consumes. (Farley) Despite a nine fold increase in the production of shrimp, supply has kept pace with demand. Profits in the industry have been so high, that there are no economic pressures to change inefficient production methods even though a number of sustainable methodologies and technologies have been identified.
Social and Economic Impacts of Shrimp Production
Globally shrimp aquaculture has reached equilibrium. Profits are high in the industry, so there is no incentive for inefficient producers to change their practices because they have been rewarded for so long for doing things so “wrong”. Global standards are deemed secondary at times to food and economic needs of the countries involved. Consequently, no incremental social or economic impacts should be expected until environmentally sustainable shrimp fisheries, government regulation or new business practices and/or technologies are implemented.
Currently there are two competing scenarios for the sustainable development in shrimp aquaculture which represent the two extremes. First, a landscape approach, where farming techniques for small-scale producers are integrated into intertidal areas in a way that ecosystems are maintained and shrimp farming diseases are controlled. This would allow more control on the local populations and reduce the risk of spreading disease. The second is a closed system approach, where problems of disease and effluent are eliminated in recirculation ponds behind the intertidal zone controlled by industrial scale producers. (Bush) Both require significant alterations to current plans to better control the dangers of mass production worldwide.
Governments have failed to entice producers or introduce regulations to discourage inefficient and environmentally detrimental business practices. For example, new zoning regulations should stipulate the principle of no net loss of coastal habitats as a result of shrimp farming. However, in developing countries, obvious negative impacts are ignored and governments are hesitant to enact legislation that would harm the large number of poor farmers who are engaged in shrimp aquaculture. (Lan) Protection of citizens and states rights becomes a major concern that makes outside economic pressure difficult to acquiesce.
More efficient production methodologies, like farms with smaller deeper ponds with fewer shrimp and the use of aquamats to promote larvae colonization, have proved promising. Wherever possible, domesticated local shrimp species should be used to eliminate the introduction of foreign species. (Bene) The need for domesticated shrimp might help bring a new sub industry to each region where shrimp are farmed in large quantities.
In the short term, all these proposals would increase the cost of production and force marginal producers out of the industry. Profits are high enough to absorb any additional cost associated to develop more sustainable and environmentally friendly shrimp aquaculture. These sustainability cists are estimated to offset themselves within a 2 to 3 year time span after which an environmental profitability would be attained. (Clay & Boyd)
Part 2 – Shrimp Production and the Destruction of Mangrove Forests
The world’s mangrove forests are critical to the well being of coastal wetlands everywhere. As much as 5-10% of all mangrove habitat loss is due to shrimp farming alone. This number rises to as much as 20% in some countries and even more significant losses where watershed areas are present. (Clay & Boyd) While the damaged areas grow the problems become harder to avoid and bring to mind the declining habitats worldwide. Like the rain forests, the world’s mangroves are in serious decline. This is of grave concern because mangroves are a crucial part of the lifecycle of a number of aquatic species, and are a source of raw materials for the local human inhabitants and to the global ecology because of the ecosystem services they provide.
Mangroves are a crucial part of the life cycle of a number of aquatic creatures, not just shrimp. At high tides, hundreds of species use the mangroves to feed, as do the bird and mammal species that feed on them. Before leaving the mangroves to spawn, shrimp larvae enter mangrove lined bays and estuaries on the tide to attach themselves to the tree roots to feed and mature. (Farley) Birds use the safety of the mangroves for hunting, nesting and breeding. Even India’s majestic Bengal tiger calls the Ganges River Delta and the 8000 sq. kilometer Sunderhans mangrove (literally beautiful) forest home. (Hellier) Both the Ganges and the rainforests put shrimp aquaculture in perspective in terms of potential for further damage as a motivator to reduce impacts on further implementation of aquaculture.
Mangroves provide a rich spectrum of utility for local residents. The human inhabitants use mangrove forests for building materials, fuel for their cooking fires and for fabricating dug-out canoes. The bark of some species produces dyes and tannins that are used for treating leather. (Hellier) The loss of mangroves would have a vast impact on the natural production of the inhabited regions.
Ecosystem services are the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life. (Tallis) For most of our existence, humans have taken things like clean water, nutrient recycling and soil formation for granted because they were unable to place a value upon them despite their obvious benefit to us. The case of Indonesia and low biodiversity in comparison to tropical regions give a valuable example of rich resources of many functions and uses. These ecosystems grow in value because of mangrove forests to around $10,000 per hectare when taking provisioning into account. The production of fuel, fiber, food, and water is an invaluable asset to Indonesia and also represent cultural importance presenting a sense of identity and place for residents. Photosynthesis and other chemical processes would not be readily abundant without the local mangroves and natural production. (Tallis) The value of ecosystems services for mangrove forests with biodiversity higher than those of Indonesia is estimated to be five to nine times greater.
Case studies presented and being researched now will help bring light to the potentially dire situation of shrimp fishing spiraling out of control globally. Estimates are that upwards of 100,000 sq. kilometers of mangrove forests are left in the world and they are disappearing rapidly. The Philippines, for example, have lost 80% since the 1920’s, Java almost 75% and Thailand over half of their mangrove forests in the last 30 years. (Hellier) The presumed impact of economy and environment need to be met in harmony to prevent utter destruction of the societies that aquaculture currently is benefitting from in a short sighted approach. In addition to reasons stated above just the loss of such a beautiful and irreplaceable resource is enough of a call to action worldwide.
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