George Chamberlain, GAA president, rejected the statements on shrimp farming effect. (Photo: GAA/integratedaquaculture/FIS)
GAA refutes ecologist's figures on carbon footprint of shrimp farming
Tuesday, March 13, 2012, 02:50 (GMT + 9)
The Global Aquaculture Alliance (GAA) is arguing that a presentation at the 2012 meeting of the American Association for the Advancement of Science has bred “sensationalized and misleading articles about the impacts of shrimp farming.”
GAA noted that it does not dispute the presentation by ecologist J Boone Kauffman of Oregon State University regarding the carbon footprint of converting mangroves to other uses, but it does challenge his assumptions about the role of shrimp aquaculture in those conversions. GAA President George Chamberlain claimed that Kauffman’s carbon footprint values are not applicable to the vast majority of the industry.
Only about 3 per cent of the current global farmed shrimp production is raised under the conditions Kauffman used for his calculations, GAA maintains.
Kauffman's paper said that 50-60 per cent of shrimp farms are built in former mangrove areas, have annual productivity of 50-500 kg per ha and are abandoned in just three to nine years. All these erroneous assumptions led him to believe the release of carbon dioxide through conversion of mangrove land to shrimp ponds yields a 198-kg footprint per 100 g of edible shrimp, GAA said.
"It is important to understand how far off those numbers are," Chamberlain stressed.
Aquaculture scientist Claude Boyd did research with World Wildlife Fund's (WFF) Jason Clay and estimated that less than 10 per cent of historic mangrove loss resulted from shrimp farm construction – a practice which essentially stopped almost 20 years ago.
The low-density culture methods described by Kauffman are today confined to limited areas of Bangladesh, Indonesia and southern Vietnam, thus representing only a small portion of the total global shrimp harvest, GAA highlighted.
Further, it is inaccurate to assume that shrimp ponds have a lifespan of three to nine years, Dan Lee, GAA Best Aquaculture Practices standards coordinator, said. In Ecuador and Honduras, they are still in operation after 40 years and traditional "tambak" ponds have produced fish and shrimp in Indonesia for centuries.
"[Kauffman’s] assumptions bear little relation to today's shrimp-farming industry, which has long since moved away from the mangrove zone. It's akin to calculating soil erosion for US agriculture based on the Dust Bowl practices of the 1930s," Chamberlain accused.
GAA also noted that Kauffman's numbers were quickly disseminated by various media entities and often carrying “anti-shrimp headlines.” Moreover, “inattentive editors” incorrectly reported that only 1 kg of shrimp is produced in 13.4 sqkm of pond – “an absurd statistic.”
"“It is very unfortunate that these misleading messages are being circulated," Lee said. "GAA sincerely hopes that when consumers and others read such material, they can recognise how outdated and distorted it is."
By Natalia Real