Death at sea

Pollutants are killing whales near Mexico

Published: Thursday 15 April 1999

large numbers of whale deaths off Mexico's coasts were most likely caused by humans polluting the seas, but the real answer may never be known due to government foot-dragging, environmentalists said. Mexico has recorded at least four massive die-offs of whales and other marine mammals since 1993, the latest occurring in recent weeks in the Gulf of California between the Baja California peninsula and the mainland coast.

Environment pressure group Greenpeace said 29 g rey whales and at least 200 sea lions died a couple of weeks ago. Last week, another environmental organisation, Group of 100, reported 50 grey whale deaths, but it considered a larger area, including the Pacific coast. "Without a doubt, if an in-depth study was done, we would find that the Gulf of California is a real cocktail of pollutants," Roberto Lopez, a Greenpeace spokesperson, told a news conference recently.

Since chemicals such as agricultural fertilisers and pesticides were passed to mammals through the food chain, humans were also at risk from eating seafood, Greenpeace officials said. The government environmental prosecutor, Profepa, is investigating the deaths. Past necropsies showed that they were caused by natural causes or from a fluorescent chemical called nk -19 used by drug traffickers to mark spots at sea where they drop cocaine packets.

However, Greenpeace said that Profepa failed to consider the impact of tonnes of pesticides and industrial chemi cals poured into the oceans, many making their way to the sea as run-off. The Gulf of California, also known as the Sea of Cortes, is bordered by a number of agricultural states whose fields are bombarded with chemical fertilisers and pesticides. Profepa spokesperson Eduardo Canto dismissed the Greenpeace claim, saying his office was motivated strictly by science and would not conceal evidence. "Never. We have no reason to," he said, speaking to Mexican news agencies.

Juan Carlos Cantu, who heads the biodiversity programme for Greenpeace in Mexico, said toxins were accumulated in the body fat of whales, dolphins and sea lions. During food shortages, the animals draw on their fat reserves, poisoning themselves with chemicals that damage their immune systems. The result is that much like humans with acquired immuno deficiency syndrome ( aids ), the animals die of diseases they could otherwise fend off. The problem, Greenpeace says, is that Profepa has failed to uncover the underlying cause.

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