Brazil's Shrimp Farm Industry: Not For The Birds

Mangroves are the rainforests by the sea, appearing on coastlines throughout the tropical and sub-tropical regions of the world.  They are comprised of salt-tolerant trees and other plant species which thrive in inter-tidal zones of sheltered tropical shores, “overwash” islands, and estuaries.  Mangrove forests and their associated wetlands support an immense variety of marine, plant, and bird life.  Hundreds of bird species utilize the mangrove wetlands as prime nesting and migratory sites.

These unique coastal tropical forests are among the most threatened habitats in the world.  And the threat goes beyond the continued loss of the forests to the related loss of associated tidal wetlands, such as mud flats, salt marshes, salt flats, and apicuns or salinas, which are often targeted for shrimp farming. These tidal and mud flats are critical habitat for shorebirds.

Mangrove Action Project (MAP) was formed in 1992 to specifically address the problems of shrimp farm  expansion and the related loss of mangrove forest wetlands.  Since its formation, MAP has made some progress in convincing the international shrimp aquaculture industry to stay out of the mangrove forests. However, the industry has increasingly taken the approach that the mud flats and salt flats are NOT valuable coastal wetlands, and in places such as Ecuador and Brazil, are rapidly converting these wetlands to shrimp aquaculture ponds with immunity from laws meant to protect the mangrove forest zones. In Ecuador alone, nearly 80% of these areas have been lost in the last 10 years.

Brazil contains the second largest mangrove area in the world —  more than one million hectares of mangrove forests are found along Brazil's long and curving coastline. In 2000, the Brazilian government released an ambitious three-year  plan to expand its shrimp aquaculture industry’s area of production six fold — from 5,000 ha to 30,000 ha.  In 2002, Brazil had over 10,000 ha of shrimp farms that produced about 60,000 tons of farmed shrimp; ponds are expected to cover 25,000 ha of important coastal wetlands by 2005.

The north-central coast of Brazil is the most important wintering area in South America for Black-bellied Plovers, Ruddy Turnstones, Whimbrels, and Willets, and is regionally important for Sanderlings, Semipalmated Sandpipers, Short-billed Dowitchers, and Red Knots.  In the spring, some Red Knots likely use Brazilian coastlines as their final fueling stopover before departing for Delaware Bay.  Because of its importance to migratory shorebird populations, coastlines of the Maranhão have been designated a Western Hemisphere Shorebird Reserve Network site of hemispheric importance — hundreds of thousands of shorebirds use the region each year. 

For many years, the mangrove forests were seen and actually often officially designated as wastelands, not fit for anything but mosquitoes and smelly swamp. Fortunately, this view of the tidal forests is changing, influenced by recent scientific studies and public awareness campaigns. Mangroves are now seen for their unique natural characteristics supporting high levels of biodiversity, immensely important for the health of wild fisheries and marine ecology.

Unfortunately, the mangrove forests are now viewed by many as somehow separate or isolated from their associate wetlands found on the tidal flats--the mud and salt flats, the salinas and salt marshes which are themselves really part of a greater, integrated tidal ecosystem. These are not really separate ecosystems, but are instead variations on a common theme--the tidal wetlands. Where there is now a mangrove forest, in the future there could be a salt marsh or salina, depending on changes in hydrology, sea level, or other factors. The mud flat of today may well become the mangrove forest of tomorrow. In fact, with the rising sea levels reportedly caused by global warming, existing mud flats and salinas may offer the only place of refuge for the natural progression of the mangroves. If the tidal wetland areas directly behind the mangrove are lost to development, this natural progression of mangrove forest will be thwarted or stymied.

Further information is needed to evaluate the direct and indirect effects that loss of these wetlands are having on migratory shorebird habitats. Without proper planning, strict enforcement, and an effective coastal zone management plan, the shrimp industry in Brazil could follow the same destructive path the industry has taken elsewhere, and leave in its wake the extinction of many species of migratory shorebirds. 

We must correct previous popular misconceptions of what constitutes the mangrove coastal wetlands ecosystem. We must  recognize the intricacies of this quite complex and  interconnected ecosystem. If we can integrate these concepts into our defense of the mangroves against such industries as shrimp farming, we might make more headway in halting further expansion of such unsustainable industries into these fragile and valuable wetlands which now must be seen to include the mud flats and salt marshes, the apicuns and salt flats within this broader definition. This clearer appreciation of the true nature of the tidal flats, along with its biological variance, will help us incorporate these ideas into our stronger defense of the mangroves!