Tuesdays with Turtles – Wednesday Edition

Where I’m a day late and a dollar short. It turns out that the Mediterranean sea is awash with plastic and most of the loggerheads there have swallowed plastic bags. So, the next time you’re out looking for loggerhead nests and find one in which all the eggs have been double bagged, do not be surprised! Now. if they start swallowing egg cartons…

Mediterranean drowning in a hidden sea of plastic rubbish – Independent Online Edition > Europe

A recent study of the endangered loggerhead turtle off Spain’s Mediterranean coast found that 75 per cent of them had swallowed plastic bags. Mr Rodriguez said: “We have to understand the sea is not a tip; it will constantly return to us what we throw in.”

Seriously, plastic bags need to go away.

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  • Tuesdays with Turtles – Outback Edition

    flatback-kp.jpgWell, since this blog gratuitously takes its name from a sea turtle, it’s only fair that there needs to be a turtle post at least once a week! Why Tuesday? Because it alliterates. Why not Thursday? Because apparently, Tuesday’s the day that you do things with other things, ask Morrie.

    I confess to knowing very little about the flatback. It’s only found around Australia and is listed as threatened. This news item caught my attention (for obvious reasons)

    Turtles may fall victim to Australian gas project – International Herald Tribune

    The peak nesting season is just drawing to a close for the flatbacks, a threatened species of sea turtle found only in Australia, when thousands of palm-sized hatchlings emerge from eggs buried under the sand and race to the sea. Every second counts: Between them and the ocean lies an army of hungry predators: lizards, dogs, foxes and gulls. Most of the turtles will never taste saltwater.

    Development is another threat. Until now, the flatbacks could find some respite off the coast west of here, on Barrow Island, one of the country’s oldest nature reserves. But now environmentalists say that Barrow’s flatbacks may be among the victims of a plan by the oil giant Chevron to use Barrow Island for a roughly $8.6 billion project meant to supply natural gas to Japan and other energy-hungry nations.

    “The environment is being made to pay for a poor business development model,” said Chris Tallentire, director of the Conservation Council of Western Australia in Perth.

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    Turtles, Arribadas, Science, Policy and Implementation

    turtle Read stuff like this (hat tip to my mom for telling me about this report she’d seen on TV in Madras), and you begin to doubt your utility as a scientist.
    IBNLive : Orissa turtles neck-deep in danger

    Nearly 3,000 Olive Ridley turtles have died off the Orissa coast this season. Beaches have become turtle graveyards.

    Orissa is one of the three places in the world where the Olive Ridleys come for their annual mass nesting.

    Mechanised trawlers are the biggest culprits for this slaughter. When the trawlers go to the sea, turtles are trapped in their fishing nets. The turtles are unable to disentangle themselves and suffocate to death.

    See the video report too. In her own breathlessly indignant style, the reporter explains the science behind turtle excluder devices (well known and established), the regulation expressely forbidding shrimp trawling close to the coast, especially during the arribada, the money set aside in the budget to purchase a few speed boats for the coast guard, who are well aware of the problem, so wot’s, uh, the deal?

    The investigative reports contradict each other, the first one linked said there was no patrolling, the second one gushingly praises the coast guard for vigorous enforcement and patrolling, so which is it? I need to find out, call on some old friends… But clearly, there are issues if net catch mortality is on the rise.

    The three pillars of any regulatory action are the science, the policy, and the implementation. The science here is very clear (though the US administration seems to not think so any more?), shrimp nets with turtle excluder devices cause decrease in mortality. The policy is clear, use these nets when shrimp fishing, and completely ban fishing activity during the arribada (the number of turtles in an arribada, 50000 in a night and perhaps 300000-400000 over the course of a week is staggeringly large, so, shrimp net or not, you’ll kill a lot of turtles just by being there).

    So, like anything else in India, where is the implementation? The people running the trawlers know they are illegal anyway, so they don’t bother with the TEDs. The owners of the trawling boats never face the consequences, only the poor hapless fishermen running the boats. No attempt is made to coopt the people being regulated, it is a top down “we tell you what to do” kind of situation where the law is selectively enforced, no explanations are given, the regulation may just be an excuse to get some kickbacks. The fishermen see the excluder device as an inconvenience as they are not shown how to use it. Some low level bureaucrat in charge of buying high speed boats for the state’s forest service either does not realize the importance of getting this policy on the road, or is on the take. You can pick any, or all of these reasons and you’ll see why just like most other things in India, the road to hell is paved with good intentions 🙁

    Why be a scientist and come up with cool new techniques to do things when you don’t pay equal attention to the implementation of techniques invented 20 years back? As a responsible scientist, I must look at policy and implentation with as much interest and passion as I look at the science – New career paths?

  • Tuesdays with Turtles – Archie Carr Edition

    Archie Carr is considered the father of modern sea turtle research. And now, there’s a book about him about to come out. It’s called “The Man who Saved Sea Turtles”.

    Well, I guess saved is going a little too far. I would have said “postponed the extinction of”, given the imminent extinction of the Pacific leatherback. But hey, forget about the title, I am sure it’s going to be a good book to read.

    Oxford University Press: The Man Who Saved Sea Turtles: Frederick R. Davis

    Archie Carr, one of the greatest biologists of the twentieth century, played a leading part in finding a new and critical role for natural history and systematics in a post-1950s world dominated by the glamorous science of molecular biology. With the rise of molecular biology came a growing popular awareness of species extinction. Carr championed endangered sea turtles, and his work reflects major shifts in the study of ecology and evolution. A gifted nature writer, his books on the natural history of sea turtles and their habitats in Florida, the Caribbean, and Africa entertained and educated a wide audience. Carr’s conservation ethic grew from his field work as well as his friendships with the fishermen who supplied him with many of the stories he retold so engagingly. With Archie Carr as the focus, The Man Who Saved Sea Turtles explores the evolution of the naturalist tradition, biology, and conservation during the twentieth century.

  • Tuesdays with Turtles – Why Adult Turtles Die so You Can Eat Fish

    An interesting paper featuring a North Carolinian turtle researcher Larry Crowder from Duke University:

    Blackwell Synergy – Conservation Biology, Volume 21 Issue 1 Page 79 – February 2007 (Full Text)

    Abstract: Although some sea turtle populations are showing encouraging signs of recovery, others continue to decline. Reversing population declines requires an understanding of the primary factor(s) that underlie this persistent demographic trend. The list of putative factors includes direct turtle and egg harvest, egg predation, loss or degradation of nesting beach habitat, fisheries bycatch, pollution, and large-scale changes in oceanographic conditions and nutrient availability. Recently, fisheries bycatch, in particular bycatch from longline fisheries, has received increased attention and has been proposed as a primary source of turtle mortality. We reviewed the existing data on the relative impact of longline bycatch on sea turtle populations. Although bycatch rates from individual longline vessels are extremely low, the amount of gear deployed by longline vessels suggests that cumulative bycatch of turtles from older age classes is substantial. Current estimates suggest that even if pelagic longlines are not the largest single source of fisheries-related mortality, longline bycatch is high enough to warrant management actions in all fleets that encounter sea turtles. Nevertheless, preliminary data also suggest that bycatch from gillnets and trawl fisheries is equally high or higher than longline bycatch with far higher mortality rates. Until gillnet and trawl fisheries are subject to the same level of scrutiny given to pelagic longlines, our understanding of the overall impact of fisheries bycatch on vulnerable sea turtle populations will be incomplete

    Adult sea turtle killing by humans occurs due to

    1. Harvest, killing them deliberately for food
    2. Incidental bycatch in fishing nets
    3. Habitat loss

    The paper focuses on long line fishing and its effects on turtle mortality. So, if like me, you’re not a fisherperson, what is long line fishing and what are some other kinds of fishing techniques that have effects of sea turtles? Well, the Duke Project GloBal research team on studying bycatch has a nice primer. Some highlights:

    1. Longlines: As the word suggests, longlines are very long (>10 km) lines of 2000+ individually baited hooks that drift close to the surface and are used to catch tuna, swordfish, halibut, etc. Crowder’s paper suggests that while each individual longline hook has low probability of catching a turtle, because of their number and ubiquitousness, they catch many many turtles.
    2. Gillnets: These are giant rectangular mesh nets, either stationary or drifting, that catch marine life indiscriminately. There’s not much that can be done by way of reducingsea turtle catch in gillnets, except monitoring, observation and just using less of them
    3. Trawls: Big funnel shaped bags that catch fish. Bottom trawling fishing boats used to, and still catch turtles at an alarming rate. Trawls are now (at least in the U.S and other “developed” countries) required to be outfitted with Turtle Excluder Devices (TEDS) to let turtles swim to safety.
    4. Purse Seines: These are weighted on the bottom and float at the corners. They are indiscriminate, and especially hard on dolphins. It appears that mitigation efforts aimed at reducing dolphin mortality have the unintended effect of increasing sea turtle catch. Battle of the cute species!!

    Take home message? Catching fish causes a lot of turtles to die. While trawl fishing is the worst culprit, it is also the most studied and the technique for which a viable mitigation strategy exists. THe other kinds of fishing are less studied, and there is precious little that can be done to avoid sea turtle bycatch.

    Happy fishing!

  • Bonus Turtle Coverage – The Great Turtle Race

    Great Turtle Race

    Follow eleven turtles as they sprint from Costa Rica to near the Galapagos. Each of them has a corporate sponsor, and at 20 miles an hour, they will get there in a couple of weeks! I think Billie’s going to win, but the leatherback turtle is in bad shape, endangered due to poaching, adult mortality and habitat loss. They may be gone very soon.

    Here’s the flickr page for the race, some beautiful pictures already.