Toxic Soup: Oil Spill Enters Bluefin Tuna's Spawning Area

"Toxic Soup" is a Change.org series focusing on how the Deepwater Horizon oil spill impacts the Gulf's seafood industry and marine life. For more posts on this issue, see here, here, here, and here.

Life keeps kicking bluefin tuna while they're down. Already, the threatened swimmers face overfishing, capture for tuna ranches, changing water conditions spurred by global warming, and rapidly depleting populations. And according to a recent study, you can now add oil to their plight.

A study published in PLoSONE outlined where Atlantic bluefin and yellowfin tuna prefer to spawn. Using electronic and fisheries catch data, researchers tracked the movements of bluefin tuna throughout the year. They found that bluefin tuna return to almost the exact same regions of the Gulf of Mexico year after year to spawn. And here's the kicker: Bluefin tuna's main spawning months are April and May, and a good chunk of their spawning habitat overlaps with the Deepwater Horizon spill zone. Talk about wrong place, wrong time.

This study is part of a growing pile of evidence showing just how profoundly this oil spill is affecting the Gulf's seafood industry and marine life. But bluefin tuna will likely be especially hard-hit given how precarious their existence is to begin with.

Sushi's growing worldwide popularity created an insatiable demand for bluefin tuna, which sent fishermen chasing after the massive fish. And while catch limits have been put in place, bluefin tuna's high market value prompts many fishermen to catch them illegally; one bluefin tuna can fetch more than $100,000. According to the Center for Biological Diversity, in 2007, fishermen reported catching 5,000 tons more than they were supposed to catch. Scientists estimate that the real figure is probably twice that.

And it's not just overfishing: Bluefin tuna often get captured accidentally through long-line fishing, and sometimes they're captured intentionally for tuna ranches. Plus, changing water conditions brought on by climate change threaten the tuna's survival. All these forces caused North Atlantic bluefin tuna's populations to dwindle by a whopping 80 percent.

It's too early to determine exactly what effect oil and dispersants will have on the tuna, but the outlook doesn't look so good. Both oil and the dispersants used to clean it up are hugely toxic, and it's all hitting bluefins right in the gills during their critical spawning months.

Sadly, short of building a time machine, there's nothing we can really do to reverse the oil spill's effects. But we can try to hit responsible parties where they don't like to be hit—their wallets. Sign our petition demanding that the EPA take away BP's federal contracts, which are worth billions of dollars.

Photo Credit: OpenCage via Wikimedia Commons