Many aquaculture practices, particularly coastal net cage and shrimp farming, come at the expense of sensitive coastal habitat. Where and how fish are farmed can make all the difference.
Farming at the Ocean's Edge
In Thailand, Ecuador and other tropical nations, coastal mangrove forests once sheltered large numbers of wild plants and animals that local people used to feed their families. Mangroves can protect the coast against storm waves. But many mangrove forests have been cut down and replaced with farms that supply shrimp to Europe, Japan and America. After a few years of intensive farming, the accumulation of waste products and chemical pollution force the farmers to abandon their farm ponds, clear a new section of mangrove forest and rebuild—an unsustainable cycle that impacts local people and their ability to live in these areas.
Young Fish Need Shelter
Coastal habitats are important for wild plants and animals—including fish—providing food and protection. Many kinds of fish rely on wetlands as nursery areas for their young and without these protected waters, these fish may never mature and venture to sea. By locating shrimp farms inland, away from these sensitive areas, coastal habitats are recovering and, along with them, the plant and animal populations that call them home.
Smaller is Better
Large aquaculture operations are likely to have a greater impact on sensitive habitats. Often, smaller is better.
A Closed Case
Farms that are open and allow surrounding water to flow through the enclosures—or those that divert wastes and chemicals into the environment—pollute adjacent waterways and habitats. This includes floating net cages or ponds that exchange water with the ocean.
Some fish farmers are working to develop closed systems to manage wastes. For instance, shrimp pond farmers in Thailand are beginning to "close" their systems, filtering their ponds and composting wastes to keep them out of neighboring waters.