Portland

Conservationists are accusing the US government of ignoring its own scientific advisers over its decision to import tuna fish from Mexico.

In December 2002, the Department of Commerce agreed that tuna from Mexico could be labelled ‘dolphin safe’ and so be imported and sold in the United States.

But a conservation organization last week revealed a cache of documents that suggest this decision was taken against scientific advice.

Biologists want the imports banned because Mexican fishermen target and chase dolphins in order to catch the underlying tuna. They argue that this is contributing to the decline in dolphin numbers in the Pacific Ocean.

The papers were circulated by the Earth Island Institute, a conservation group in San Francisco and one of several plaintiffs suing the government over the issue, after they were released by a district court judge in San Francisco towards the end of last year. They are a “smoking gun”, according to the institute's director, David Phillips.

The documents list talking points for briefings prepared by officials for the commerce secretary, Donald Evans. One states: “We've all seen the science. We know that dolphins aren't recovering.” Another says that “a determination of ‘no significant adverse impact’ is not supported by the science”.

The issue was analysed by the Southwest Fisheries Science Center, a San Diego-based research arm of the National Marine Fisheries Service (NMFS). Its report, released in August 2002, said that indirect effects of tuna fishing such as stress could explain declining dolphin populations in the Pacific.

A five-member independent expert panel unanimously agreed with these findings, and the current lawsuit is backed by three members of this panel.

But the commerce department got different advice from the Inter-American Tropical Tuna Commission, which is funded by governments to maintain maximum sustainable tuna catches in the Pacific. It contends that if Mexican fishermen adopted new fishing methods, it would damage marine ecosystems further.

NMFS director William Hogarth maintains that the initial import decision was justified, but neither he nor the chief scientist from the Southwest Center would comment further pending the district court hearing on 29 March.