Fishing that starves seabirds

Industrial fishing is reducing the amount of fish available to feed seabirds, which are seeing their populations plummet. According to David Grémillet, oceanographer at the Centre d'écologie fonctionnelle et évolutive in Montpellier, this is a wake-up call for the state of the oceans.

David Grémillet

It's what you might call unfair competition. By catching more and more fish, mankind is not leaving enough for seabirds to feed on, and seabirds are in decline. To reach this conclusion, researchers have for the first time assessed the competition between industrial fishing and seabirds worldwide between 1970 and 2010.

"To map fishing catches on all oceans and know precisely how much fish is being caught, we used data from the "The sea around us" project led by Daniel Pauly at the University of British Columbia," explains David Grémillet. This colossal project, which took 20 years to complete, has produced more reliable data than the official statistics provided by theFood and Agriculture Organization of the United Nations (FAO).

A colossal project

At the same time, researchers collected data on 276 species of seabirds, representing 60% of the planet's species. In all, over a billion birds were tracked. " By studying their breeding grounds, their diet and their weight, we were able to estimate the quantity of fish consumed by seabirds", explains the oceanographer.

By cross-referencing these two databases, David Grémillet and his colleagues from theUniversity of British Columbia in Canada and theUniversity of Aberdeen in Scotland were able to assess the competition between fishermen and seabirds. And their findings are indisputable: fishing is starving seabirds in all the world's oceans. Between 1970-1989 and 1990-2010, the average annual catch of bird prey by fisheries increased from 59 to 65 million tonnes," explains the researcher. Between these two periods, birds' annual food consumption fell from 70 to 57 million tonnes."

Birds under pressure

This competition has serious consequences for seabirds. " Since 1950, seabird populations have fallen by 70%," laments the oceanographer. Penguins, terns, frigate birds and boobies are all seeing their numbers plummet. These animals are all the more vulnerable because they are already under heavy pressure. "Seabirds are suffering the destruction of their breeding habitats by human activities, they are being decimated by invasive species such as rats and cats, they are victims of accidental capture by fishing gear, and they are enduring the effects of pollution and global warming. Competition with fishermen for food adds yet another pressure," explains David Grémillet.

To alleviate this pressure and leave more fish for the birds, the researchers recommend first and foremost banning industrial fishing, which consists of harvesting small pelagic fish such as sardines and anchovies to transform them into oil and meal for feeding farmed salmon or chickens. This practice alone accounts for 25% of fish catches, "an ecological disaster but also an ethical scandal. These fish should be used to feed people in the countries where they are caught, particularly in Africa", asserts David Grémillet.

The specialists' second recommendation: enforce fishing quotas. " The dunce's cap goes to Europe in this area, where pressure from the fishermen's lobby is such that some countries, such as France, prefer to pay fines rather than enforce quotas," explains David Grémillet.

Political will

Finally, the oceanographer advocates increasing the number of marine protected areas in which fish populations can regenerate. "Studies show that if international waters were transformed into marine protected areas, fish stocks would increase and fishermen would be able to catch more."

"All these recommendations depend on political will", stresses the researcher. These solutions are all the more important as seabirds are sounding the alarm about the state of health of the entire ocean ecosystem. "Seabirds are an umbrella species, an indicator of the health of the ocean. If they are declining, it means that the health of the ocean as a whole is in peril," warns David Grémillet.