Sunday, October 09, 2005
Mangroves and Aquaculture the path to Sustainability
GLOBAL VOICES OF SCIENCE:
Mangroves, Fishponds, and the Quest for Sustainability Jurgenne H. Primavera*
An insight of how aquaculture has impacted the mangrove ecosystem in the Philippines and the need for scientists to share their knowledge with the public and decision makers so that existing plots of mangroves can be preserved.
An excerpt of the article...
Mangroves at Risk
Aquaculture ranks as a phenomenal success story in global food production. In 1975, when I joined the SEAFDEC/AQD, aquaculture contributed 8% to the overall yield of the world's fish harvest; now it provides more than one-third of the yield of the world's fisheries. Total aquaculture production in 2003 was 54.8 million metric tons, valued at $67.3 billion in U.S. dollars. More than 90% of this output comes from Asia, where aquaculture has its origins.
As with land-based agriculture, all of this aquatic food production and economic activity has come with environmental problems and social conflicts. Foremost among these is the loss or modification of habitat in places where aquafarmers clear mangroves for ponds and where they install cages or pens above seagrass beds and coral reefs. Other environmental effects include the loss of bycatch (unwanted fish and invertebrate species) during the collection of wild "seed" used for stocking in ponds and of adult brood-stock for hatcheries, introduction of exotic species, spread of parasites and diseases, interactions of escapees from ponds or pens with wild populations, misuse of chemicals and antibiotics, salinization of soil and water, and coastal pollution. Many of these ecological impacts of shrimp aquaculture have brought along social problems, among them privatization of public lands and waterways, the decline of open-sea fisheries, rural unemployment, and social disruption.
Even the seemingly reasonable assumption that aquaculture is an efficient way to produce new protein is undermined by the dependence of shrimp, salmon, and other cultured aquatic carnivores on raw fish and on fish meal and oil in pelleted feeds. Careful calculations indicate that some cultured species actually are net consumers of fish...
For the whole article please visit the Science Magazine
Mangroves, Fishponds, and the Quest for Sustainability Jurgenne H. Primavera*
An insight of how aquaculture has impacted the mangrove ecosystem in the Philippines and the need for scientists to share their knowledge with the public and decision makers so that existing plots of mangroves can be preserved.
An excerpt of the article...
Mangroves at Risk
Aquaculture ranks as a phenomenal success story in global food production. In 1975, when I joined the SEAFDEC/AQD, aquaculture contributed 8% to the overall yield of the world's fish harvest; now it provides more than one-third of the yield of the world's fisheries. Total aquaculture production in 2003 was 54.8 million metric tons, valued at $67.3 billion in U.S. dollars. More than 90% of this output comes from Asia, where aquaculture has its origins.
As with land-based agriculture, all of this aquatic food production and economic activity has come with environmental problems and social conflicts. Foremost among these is the loss or modification of habitat in places where aquafarmers clear mangroves for ponds and where they install cages or pens above seagrass beds and coral reefs. Other environmental effects include the loss of bycatch (unwanted fish and invertebrate species) during the collection of wild "seed" used for stocking in ponds and of adult brood-stock for hatcheries, introduction of exotic species, spread of parasites and diseases, interactions of escapees from ponds or pens with wild populations, misuse of chemicals and antibiotics, salinization of soil and water, and coastal pollution. Many of these ecological impacts of shrimp aquaculture have brought along social problems, among them privatization of public lands and waterways, the decline of open-sea fisheries, rural unemployment, and social disruption.
Even the seemingly reasonable assumption that aquaculture is an efficient way to produce new protein is undermined by the dependence of shrimp, salmon, and other cultured aquatic carnivores on raw fish and on fish meal and oil in pelleted feeds. Careful calculations indicate that some cultured species actually are net consumers of fish...
For the whole article please visit the Science Magazine