Canada and the World
Current Events with a Canadian Perspective
Last update
31 December 2010
Sea Turtles Caught in
Fishing Gear Dying by Millions
Fishers targetting other species
are accidentally decimating sea turtle species
Researchers from Duke University and San Diego State University have conducted a global survey of sea turtle populations and their findings show rapid declines. Their report was published in April 2010 in the scientific journal Conservation Letters.
Conservation International, which funded the study, says “Sea turtles are among the most migratory animals on Earth, many of them crossing thousands of miles of ocean – and international borders – in a single season.”
Sea Turtles are an Ancient Species
Turtles have been swimming the world’s oceans for at least 110 million years, so they were paddling about when dinosaurs roamed the planet.
They survived the catastrophe that killed off T. rex and the others. However, their contact with humans, lasting only a few hundred years, is having a devastating impact.
There are seven types of sea turtles in the world’s oceans and six of them are on the Red List of Threatened Species. The list is maintained by the International Union for the Conservation of Nature and Natural Resources.
Turtles Dying as By-
The researchers believe a major reason for the collapse in turtle numbers is that
they are a by-
Today’s fishing techniques include using long lines; the name is appropriate because these are strings of hooks up to 40 kilometres in length. They are used to catch tuna. Of course nets, such as gill nets and trawl nets are popular as well.
Turtles need to rise to the surface to breathe, but when they are caught in nets or impaled on a hook below the surface they drown. And, other dangers lurk out there for turtles.
Sometimes, turtles ingest plastic bags of which there are millions floating in the ocean; they mistake the bags for their favourite lunch – squid – but a shopping bag caught in the throat of a turtle is usually fatal.
Turtles Killed for Food
The animals are still caught purposely for their meat and the shells are sold to tourists as souvenirs.
Also, turtles come ashore to lay eggs in hollows they dig in beaches. Unfortunately for turtles, the eggs make for good eating.
Coastal development in the form of resorts and marinas are destroying the places
where they used to lay their eggs, and, in common with most life-
By-
The Conservation International study found the worst carnage is taking place in the Mediterranean Sea and the Eastern Pacific.
The lead researcher of the survey is Bryan Wallace, Science Advisor at Conservation
International. He says the health of the world’s turtle population is an indicator
of the wider state of the oceans. “Sea turtles are sentinel species of how oceans
are functioning,” he states. “The impacts that human activities have on them give
us an idea as to how those same activities are affecting the oceans on which billions
of people around the world depend for their own well-
In reporting on the survey for BBC News (April 6, 2010) Richard Black wrote, “Over
the period 1990-
According to Dr. Wallace the sample was just one percent of the world’s seafood industry,
and none of the small-
He also says there is massive under-
Strategies for Saving Sea Turtles
The good news is that there are strategies available to cut down on the turtle slaughter.
The bad news is that introducing them will require coordination among many national
governments, fishing companies, individual fishers in dug-
According to Conservation International solutions include:
- “the use of turtle exclusion devices (TEDs) in trawl nets, which act as trapdoors to allow turtles to escape once they are caught;
- “replacing “J” hooks on long-
lines with circle hooks, which are too large for turtles to swallow; and, - “substituting squid bait with fish bait on hooks -
research has shown that most turtles consume fish by taking smaller bites, as opposed to squid, which they swallow whole, including the hook it’s on. By eliminating squid bait, the turtles are less likely to swallow hooks.”
Sources:
“Turtles Killed ‘in Millions’ by Fishing Gear.” Richard Black, BBC News, April 6, 2010.
“Turtles in Peril.” Molly Bergen, Conservation International, April 5, 2010.
Image credit: Damien du Toit
© Canada and the World, April 2010
All rights reserved
In 2007, a leatherback turtle (right), fitted with a tracking device travelled more than 19,000 kilometres in a migration that took it from a nesting area in Indonesia to feeding grounds off the coast of Oregon.