Turtles killed 'in millions' by fishing gear

Millions of marine turtles have been killed over the past two decades through entrapment in fishing gear, according to a global survey.

Described as the first global synthesis of existing data, the study found especially high rates of "bycatch" in the Mediterranean and eastern Pacific.

Six of the seven sea turtle types are on the Red List of Threatened Species.

Writing in the journal Conservation Letters, researchers advocate much greater use of gear safe for turtles.

These include circular hooks rather than the conventional J-shaped hooks on long fishing lines, and hatches that allow the reptiles to escape from trawls.

Turtles must come to the surface to breathe.

When they are caught in a net or on a fishing hook, they cannot surface, and drown.

Lead researcher Bryan Wallace said the state of the world's turtles was an indicator of the wider health of the oceans.

"Sea turtles are sentinel species of how oceans are functioning," he said.

"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-being."

Dr Wallace works in the global marine division of Conservation International and at Duke University in the US.

Off target

The raw material from the study came from records of bycatch - incidental catches in fishing gear - from different regions of the world.

Over the period 1990-2008, records showed that more than 85,000 turtles were snared.

However, those records covered a tiny proportion of the world's total fishing fleets.

"Because the reports we reviewed typically covered less than 1% of all fleets, with little or no information from small-scale fisheries around the world, we conservatively estimate that the true total is probably not in tens of thousands, but in the millions of turtles taken as bycatch in the past two decades," said Dr Wallace.

Three types of fishing gear are identified in the survey - long-lines, gillnets and trawls.

Modern long-line boats trail strings of hooks that can be 40km long, usually in search of high-value species such as tuna and marlin.

Gillnets are usually stationary, and use mesh of a set size in an attempt to target certain species of fish.

The researchers suggest that several areas of the world account for particularly high levels of bycatch - the Mediterranean Sea and the eastern Pacific Ocean for all types of gear, together with trawling operations off the west coast of Africa.

Catches cut

Modifying fishing gear can have a dramatic impact on the size of bycatch.

Shrimp trawls fitted with turtle excluder devices (TEDs) catch markedly fewer of the reptiles.

A grid prevents anything large from entering the back portion of the net, and a hole above the grid allows accidentally snared animals such as turtles to escape.

A number of countries now require that shrimp boats must use nets fitted with TEDs.

The circular long-line hooks also reduce bycatch of birds such as albatrosses.

However, some fleets have resisted adopting selective gear because fishermen believe it will reduce their catch.

In many parts of the developing world, the gear is not available.

Marine turtles face other significant threats.

Debris in the oceans, such as plastic bags, can also cause drowning, while development in coastal regions can affect nesting and reproduction.

Some turtles are still targeted for meat, and their shells used for tourist souvenirs.

Numbers of adult leatherbacks - the largest species, growing to more than 2m long and capable of journeys that span entire oceans - are thought to have declined by more than 75% between 1982 and 1996.

Commercial Fishing Estimated to Kill Millions of Sea Turtles
ScienceDaily 6 Apr 10;

The number of sea turtles inadvertently snared by commercial fishing gear over the past 20 years may reach into the millions, according to the first peer-reviewed study to compile sea turtle bycatch data from gillnet, trawl and longline fisheries worldwide.

The study, which was published online April 6 in the journal Conservation Letters, analyzed data compiled from peer-reviewed papers, government reports, technical reports, and symposia proceedings published between 1990 and 2008. All data were based on direct onboard observations or interviews with fishermen. The study did not include data from recreational fishing.

Each dot on the map represents a previous study that was included in this analysis. (Credit: Conservation International)

Six of the world's seven species of sea turtles are currently listed as vulnerable, endangered or critically endangered on the IUCN Red List of Threatened Species.

"Direct onboard observations and interviews with fishermen indicate that about 85,000 turtles were caught between 1990 and 2008. But because these reports cover less than one percent of all fleets, with little or no information from small-scale fisheries around the world, we conservatively estimate that the true total is at least two orders of magnitude higher," said Bryan Wallace, lead author of the new paper.

Wallace is the science advisor for the Sea Turtle Flagship Program at Conservation International and an adjunct assistant professor at Duke University's Nicholas School of the Environment. Most of his co-authors are researchers at Duke's Center for Marine Conservation.

Their global data review revealed that the highest reported bycatch rates for longline fisheries occurred off Mexico's Baja California peninsula, the highest rates for gillnet fishing took place in the North Adriatic region of the Mediterranean and the highest rates for trawls occurred off the coast of Uruguay.

When bycatch rates and amounts of observed fishing activity for all three gear types were combined and ranked across regions, four regions emerged as the overall most urgent conservation priorities: the East Pacific, the Mediterranean, the Southwest Atlantic, and the Northwest Atlantic.

"Although our numbers are estimates, they highlight clearly the importance of guidelines for fishing equipment and practices to help reduce these losses," Wallace said.

Effective measures to reduce turtle bycatch include the use of circle hooks and fish bait in longline fisheries, and Turtle Excluder Devices (TEDs) in trawling. Many of the most effective types of gear modifications, Wallace noted, have been developed by fishermen themselves.

Wallace said the Hawaiian longline fishery and the Australian prawn fishery have significantly reduced bycatch through close working relationships between fishermen and government managers, use of onboard observers, mandatory gear modifications and innovative technologies. TurtleWatch, a real-time database that provides daily updates on water temperatures and other conditions indicating where turtles might be found, has guided fishermen to avoid setting their gear in those areas.

Other approaches, such as the creation of marine protected areas and use of catch shares, also reduce bycatch, preserve marine biodiversity and promote healthy fish stocks in some cases, he said.

"Fisheries bycatch is the most acute threat to worldwide sea turtle populations today. Many animals die or are injured as a result of these interactions," Wallace said. "But our message is that it's not a lost cause. Managers and fishers have tools they can use to reduce bycatch, preserve marine biodiversity and promote healthy fish stocks, so that everyone wins, including turtles."

The study stems from work Wallace began in 2005 as a postdoctoral research associate at the Duke University Marine Lab, where he helped develop the first global bycatch database for longline fisheries. That work was part of a three-year initiative called Project GloBAL (Global By-catch Assessment of Long-lived Species).

Co-authors on the new study -- all of whom were part of the Project GloBAL team -- are Rebecca L. Lewison of San Diego State University; Sara L. McDonald of Duke's Center for Marine Conservation; Richard K. McDonald of the Center for Marine Conservation and the University of Richmond; Connie Y. Kot of the Center for Marine Conservation and the Marine Geospatial Ecology Lab at Duke's Nicholas School of the Environment; and Shaleyla Kelez, Rhema K. Bjorkland, Elena M. Finkbeiner, S'rai Heimbrecht and Larry B. Crowder, all of the Center for Marine Conservation. Crowder is director of the center and the Stephen Toth Professor of Marine Biology at the Nicholas School. Lewison formerly was a research associate at the Duke Marine Lab.

For Sydney's sea turtles, survival still hangs in the balance

http://www.blogger.com/post-create.g?blogID=7964186368159THE green turtles of Sydney Harbour tell a tale of two cities.

That these endangered reptiles regularly visit to graze on seagrass meadows in the middle of a big city, and some have even made the harbour their home, attests to the improving health of Sydney's main waterway.

This week, the Herald delves into the state of our harbour, and its changing life both above and below the waterline.

The turtles - with the mussels that crowd on to channel markers and the seahorses that wrap themselves around shark nets - are a good sign the estuary is becoming cleaner.

Yet for a 13-year-old sea scout, Julia Spragg, her first encounter with a green turtle was far from a good experience.

With one flipper entangled in fishing line that had cut to the bone, another flipper severed, and deep tackle wounds to its neck, the animal had little chance of survival.

When fellow members of the 1st Sailors Bay Sea Scouts found its mangled body while kayaking in the beautiful reaches of Middle Harbour, they were sad to see how much it had suffered.

''It was not nice,'' said Julia.

This young guardian of the harbour wishes more people, particularly those fishing, could see the devastating results of leaving bottles, bait bags and tackle around.

''If you see rubbish, just pick it up. It's not a big job,'' she said.

Geoff Ross, a wildlife management officer with NSW National Parks, said the entangled turtle might have been a long-time harbour resident, and its recent death was a concern.

''The loss of just one breeding-sized individual can have an impact on the species,'' he said.

Although remedies such as waste-retention traps on stormwater outlets had significantly decreased the amount of debris entering the harbour, individuals could do more, he said.

The pollution we can see in the harbour is just one of the many man-made threats to the estuary. These range from an industrial legacy of dumping toxic metals in its sediments to the future effects of global warming.

An increase in sightings of sea turtles, which prefer warmer climes, could be a sign conservation strategies were having an effect but it could also be linked to climate change, Mr Ross said.

Archaeological material from middens at Balmoral Beach and Cammeray suggests Aborigines might have eaten turtles, although Val Attenbrow, of the Australian Museum, said the evidence was not conclusive, with only some bone fragments found. The East Australian Current, a conveyor belt from the tropics on which the turtles ride, is strengthening, with warmer, saltier water found 350 kilometres further south than 60 years ago.

An influx of tropical fish has made the harbour even more of a wonderland for underwater photographers, bringing rare species such as a pair of ornate ghost pipefish that were recently spotted in Chowder Bay.

While more than 570 kinds of fish have been identified - many more than the 350 types found in the whole of Europe - for fishing guide, Craig McGill, it is not the fish, or the the visiting dolphins and whales, or even the fairy penguins, that epitomise the big improvements he has seen in water quality in the past 20 years.

It is the filter feeders on the marinas, pylons and piers. Middle Harbour has an abundance of oysters, he said.

''And the channel markers in the main harbour have had a growth of mussels we've never seen before.''

A ban on anti-fouling paint containing tributyltin was a large contributor. And improvements in the management of sewage and stormwater have reduced other microscopic pollutants.

Twenty-four of 28 swimming sites in the harbour complied 100 per cent of the time with bacterial guidelines between October 2008 and April 2009.

But February this year was a very different story, as the sea scouts of Sailors Bay well know. When any of them fell into the water, they were quickly ushered out to have a shower.

The heavy rains washed debris and road run-off into the harbour, said scout leader, Adrian Spragg . ''It smelt and it was oily.''

In February, only three swimming sites - Redleaf Pool, Nielsen Park and Watsons Bay - passed safety tests, according to Harbourwatch.

This run-off is why the sediments in Sydney Harbour remain some of the most contaminated in the world.

Stuart Taylor, an expert on the harbour bed, said there are almost 21 million tonnes of contaminated sediments, containing thousands of tonnes of copper, lead and zinc, as well as pesticides and other chemicals.

''This is where the detritus of civilisation ends up. Everyone living in the catchment contributes,'' Dr Taylor said.

When there is low rainfall, the contaminants settle quickly and when the sediments are disturbed, they tend to fall back in much the same area, rather than spread.

About 1.5 centimetres of sediments are deposited each year, but rather than providing a fresh top layer, worms and shrimps burrow into the mud and mix it up, he said.

More than 90 per cent of the harbour contains contaminants in surface sediments that exceed guidelines based on US studies. This could be having adverse ecological effects, said Dr Taylor of Geochemical Assessments, who carried out his studies with Associate Professor Gavin Birch at the University of Sydney's School of Geosciences.

Some hot spots, like Homebush Bay, have undergone remediation, but others, where there is no industrial culprit to pay for a risk assessment and clean-up, and where any evidence of effects on human health is lacking, remain untouched.

One of the first studies on the effects of the sediments has been done by Nathan Knott and Emma Johnston of the University of NSW and Sydney Institute of Marine Science.

Surprisingly, being repeatedly doused in heavily contaminated sediments from Rozelle Bay for 10 days had no effect on a range of creatures, including sea squirts and sponges.

But ''further research is required to assess the potential impacts of long-term exposure,'' the scientists said.264062

One dead, dozens treated after consuming turtle meat in West Sumatra

A 57-year-old man died and 139 residents of South Pagai Island, in Mentawai, West Sumatra, have been treated for food poisoning after consuming the meat of a leatherback turtle.

Tiolina Saogo, chief of South Pagai public health center, told The Jakarta Post 30 residents had been put under intensive care.

“We had to treat the others at their homes because of insufficient facilities on the island,” Tiolina said.

Residents of Maonai and Mapinang coastal hamlets caught the 40-kilogram turtle two weeks ago and split the meat between the hamlets.

“A few days later, all the residents that ate the meat suffered dizziness, nausea and vomiting. A man named Osael died four days after he had eaten the meat,” Tiolina said.

The health official only became aware of the mass poisoning earlier in the week after a number of residents came to the health center for treatment.

There are frequent deaths from turtle-meat poisoning on the islands off the West Sumatran coast.

Three have died in a village on South Pagai Island and two others on Siberut Island in the past two months.

Local authorities have repeatedly warned residents about their turtle-consuming habit. Aside from pork, turtle meat is the main cuisine at local traditional feasts.

Phuket leatherback sea turtle eggs fail to hatch

MAI KHAO, PHUKET: Hopes that two clutches of eggs could spell a reversal of fortune for Phuket’s endangered leatherback sea turtle population were dashed last month when the eggs failed to hatch.

Mai Khao Sea Turtle Conservation Group member Somporn Anupun said the 130 eggs, laid in mid-January, failed to hatch as expected in March.

The two clutches, thought to have been laid by the same female, were the first in several years at Mai Khao Beach, once famed nationwide for the scores of enormous leatherback turtles that came to nest there. Little remains of that legacy apart from tourist attractions with turtle-themed names.

The eggs appeared to be viable, but after the expected hatching period, a look inside revealed the albumen was watery. This indicated they had never been fertilized, Mr Somporn said.

Kongkiet Kittiratanawong, a researcher at the Phuket Marine Biological Center (PMBC), agreed with this assessment.

The failure of the eggs to hatch had not been caused by volunteers moving them to a safe location on the beach after they were discovered, he said.

The PMBC often incubates and raises hatchlings at its facilities at Cape Panwa, but not the highly pelagic leatherback, which does not do well in captivity, he told the Gazette earlier.

A similar clutch of unfertilized leatherback eggs was found at Mai Khao in 2004, he said.

Despite the disappointment in Phuket, it has been a good year for leatherback nesting along other parts of Thailand’s Andaman coastline.

More eggs were laid this nesting season than over the last five, with clutches reported at Thai Muang Beach and Koh Phrathong in Phang Nga, and Koh Lanta in Krabi.

Only the eggs at Thai Muang were viable however, with a 70% to 80% hatching rate.

Leatherbacks typically lay clutches of around 80 fertilized eggs together with 30 smaller unfertilized eggs. The incubation period is about 65 days.