The destruction of mangrove forests implies the loss of unique species. Mangroves link the tropical forests with the coral reefs, providing a critical transition between terrestrial and marine ecosystems. They also protect shorelines from erosion, capture sediments --thus protecting coral reefs-- and are the spawning grounds for the majority of tropical commercial fish. They also protect coastal lowland rainforests from tropical storms. They are critical to local biodiversity, harbouring plants and animals totally unique to mangrove ecosystems. They are also used for recreation and tourism. They are extremely biologically productive and for local communities mangroves are an important source of fuel, medicines, food, fodder, etc.
Apart from the fact that vast areas of mangroves are cut, another consequence of industrial shrimp farming is that there is a vast volume of waste produced inside the ponds by the shrimps. Feed eaten by shrimps but not retained in their body ends up as waste. As the waste piles up, bacteria flourish and consume the available oxygen. This can suffocate the shrimps and reduce their growth. Intermediate waste products --both of shrimp and microbes-- such as ammonia and nitrite, are toxic to shrimp, fish and other animals. Shrimp weakened by waste and lack of oxygen is more susceptible to disease. In order to avoid this problem, the water from inside the ponds is regularly removed out and the ponds are filled in with clean water. This system results in the pollution of the neighbouring surface waters.
This activity also provokes the salinization of coastal aquifers and agricultural lands. When the ponds are abandoned due to disease or other causes, the area is often left as a wasteland and the soils contain high levels of salinity, acidity and toxic chemicals, which make other uses practically impossible.
Another consequence of industrial shrimp farming is the use of antibiotics, pesticides, fungicides, parasiticides, and algicides. To guard against diseases farmers also use a large amount of antibiotics during production as well as toxic chemicals between harvests to sterilize the ponds. The result is that human consumers of tropical shrimps produced in this way are eating food containing high levels of antibiotics. Many of the substances used in this activity are prohibited in some countries due to their carcinogenic effects. Regarding antibiotics, some of the ones that are used in shrimp farming are the ones used in humans, which might decrease the effectiveness of antibiotics against diseases. It is important to highlight that in many of the producer countries there are no regulations limiting the amount of chemicals used.
In the quest for profits, the idea of using genetically modified shrimps is already being taken on board and Thailand --the world leading producer-- has started research in this area. The idea is to develop a super-shrimp. If this were to succeed, consumers --apart from eating antibiotics, pesticides and other chemicals-- would be also eating GM Shrimps.
Among the social and economic impacts of this activity, the destruction of mangroves entails the destruction of an ecosystem which is of great importance for local communities, which of course do not share the profits! Aquaculture is said to be a viable response to the problem of food resources especially in the poor countries. This is clearly not the case of shrimp farming. It is also said that it is a source of much needed foreign exchange, enabling shrimp producing countries to import lower cost protein thus ensuring food security. This argument present two problems. Firstly, that there is no evidence that the foreign exchange earned by shrimp farmers will be used to purchase cheap imported protein. The foreign exchange is earned not by the poor but by the rich shrimp farm owners who decide on how to spend it. Secondly, dependence on imported food reduces food security in times of currency instability.
Regarding employment generation shrimp aquaculture --due to its industrial nature-- employs fewer people than agriculture or other fishing activities.
In many cases, shrimp farming has resulted in serious human rights violations, including murder, physical injuries, eviction of villagers, detention of workers in shrimp farms, violation of shrimp farm workers’ rights, and confiscation of land, forest and water resources.
Displacement of local communities is common in shrimp exporting countries, where politically connected investors turn highly productive complex ecosystems into a single use private domain. The many poor people who depend on mangrove and coastal fisheries for their livelihoods are eventually displaced. Conflict over land tenure rights are at the core of the conflicts related to shrimp farming.
Shrimp farming is a profitable business for a small group of people, and it is profitable because liberalized trade does not take into account the so called “externalities”. This means that those who make the profits do not pay for the destruction of the ecosystem, while tremendous costs are being unwillingly absorbed by local communities at whose expense the industry makes its profits.
In sum, industrial shrimp farming is not only not a solution, but aggravates socioeconomic disparities within the framework of environmental destruction.
