1,400 Lbs, 15′ Long, Warm-Blooded—and Vulnerable to Overfishing

By Rebecca Horne | June 28, 2010 1:13 pm



Underwater photographer Keith Ellenbogen photographed the Atlantic bluefin tuna both inside and outside of the massive underwater cages used by purse seiner fishing boats on a recent expedition with the watchdog non-profit Oceana. On this expedition, the crew on board the Marviva Med documented the impact of bottom trawling and driftnets on marine ecosystems, and identified marine areas that need protection. Ellenbogen says, “Each year, as they have done for thousands of years, bluefin tuna migrate to the Mediterranean Sea to reproduce. At this moment, I felt a sense of urgency as I observed populations much smaller than expected. I imagined what life must have been like only a few years ago when tuna were abundant, swimming free, and able to reach their true, glorious size.”

The Atlantic bluefin can live 40 years, grow to 15 feet in length and weigh up to 1,400 lbs. They are warm-blooded and able to stabilize their body temperature as they migrate across the Atlantic Ocean, and have been recorded swimming at speeds of up to 55 mph; the word “tuna” comes from the Greek word “to rush.” Bluefin are sought after for the high prices they fetch on the international sushi market: individual Atlantic bluefin tuna have been sold for more than $100,000. Scientists and conservationists fear the Atlantic bluefin tuna is especially vulnerable to extinction due to overfishing, given its low reproduction rate and late maturity, at 3-5 years.

Ellenbogen and a team of scientists observed the tuna being caught by large purse seiner fishing boats from Turkey, France, Spain, and Italy among other countries, with some illegally using spotter planes to locate the fish. The tuna are transferred from fishing nets underwater to cages approximately 300 feet in diameter and 80 feet deep where they are towed slowly (at a speed of about 2 knots) to coastal destinations a couple of days or even weeks away, where they are fattened and then sold to market.

Images courtesy Oceana/Keith Ellenbogen

Bluefin tuna in a tuna cage, Malta, Marviva Med expedition, June 2008

  • Pingback: Tweets that mention 1,400 Lbs, 15′ Long, Warm-Blooded—and Vulnerable to Overfishing | Visual Science | Discover Magazine -- Topsy.com()

  • http://www.nicky510.com Crow

    Life in the ocean has always been one that’s fraught with risk:


  • terra incognita

    “Life in the ocean has always been one that’s fraught with risk:”

    especially when humans are the predators, since we seem as a species to have no capacity for self restraint.

    eventually there won’t be any air to breathe and nothing non-toxic to eat. but hey, you probably won’t see it happen, so it doesn’t matter, right?

  • http://the50besthealthblogs.blogspot.com/ The 50 Best Health Blogs

    Fascinating. I had no idea that they were caged and fattened.

  • http://www.nicky510.com Crow

    “eventually there won’t be any air to breathe and nothing non-toxic to eat. but hey, you probably won’t see it happen, so it doesn’t matter, right?”

    We’re already seeing the precursors and if the system degrades at the speed I find likely I suspect I’ll see a lot more of it than I’d like.

    The good news is that life on earth will recover relatively quickly. Just without us humans.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Visual Science

Science stories, beautifully told.

About Rebecca Horne

Rebecca Horne (http://rebeccahornephotography.com) is an artist, multi-platform freelance writer, and award-winning photography director. She launched Visual Science for Discover.com in March 2010. She also writes about science and photography for The WallStreet Journal. You can reach her at rh@rebeccahornephotography.com.


See More

Collapse bottom bar

Login to your Account

E-mail address:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »