PADRE ISLAND NATIONAL SEASHORE, Texas – almost hidden by brownish sand, the Kemps ridley sea turtle digging furiously with his dorsal fins, as she has dug a hole in the shape of bottle to lay its eggs was unaware of the excitement, it was generating among scientists, volunteers and beach-goers look remote.
They included Donna Shaver, who works for more than two decades save endangered reptiles. Each spring, she has their nests and collects safe hatching eggs before releasing the tiny progeny of turtles in the sea. Shaver knows this year each nest, she sees added importance: the turtle that created survived the offshore oil spill more important in the history of the United States.
While scientists in several States are studying the effects of the tide on loggerhead and other sea, the ridley turtles Kemps were particularly worrying. The Deepwater Horizon explosion on April 20, 2010 arrived when they would normally have been in the region. Most visibly oiled turtles 456 rescued by the U.S. Fish and Wildlife Service last year were Kemps ridleys.
At the height of the nesting season, their numbers looked good. May 24 155 Kemps ridley nests had been identified on the shores of Texas - more than all last year and more had been counted by this day here in 2008 and 2009. This is true for other species of sea turtles, although they have just begun nesting so it could be too early to have confidence in these figures.
And because sea turtles reach the age of childbearing at least ten years, all the effects of the tide may not be known for years.
"There is concern that some of the turtles which took the year off the coast of nesting or after that turtles have made nesting in 2010, they entered the waters where the oil had been present," said Shaver, explaining that reptiles forage often offshore coasts of Louisiana, Alabama and Mississippi hit before or after the nesting along the coast of Texas.
"There is concern that perhaps these turtles have been affected oil and could then have problems with their reproduction", she added.
Nesting season has long been used to estimate the size of the populations of sea turtles, and for species recovery plans are based on recorded figures where women come ashore to lay their eggs. The objective for the ridleys Kemps is to have 10,000 breeding season by 2020. At that time, the turtle of the smallest sea and endangered could be upgraded to threatened.
Shaver and its volunteers patrolled the beaches of Texas since 1980, SUVs and vehicles off-road through the heat and humidity to collect turtle eggs in foam plastic boxes and bring it to the laboratory of the National Park Service at Padre Island National Seashore of conduct. When begins to hatch, Shaver sleeps on a bed in his Office, deal for tiny turtles as if they were her babies, by ensuring that release them into the sea at the right time.
The turtle population has long been on the road to recovery. Supervised incubation protects the eggs of coyotes, raccoons, ants fire, vultures and other predators, and the nets covering silver dollar-size infants as they make their way to the beach at water guard from birds. Tiny turtles are left to deal with the items on their own only after that they reach the water.
The program was very successful, some believed that the goal of 2020 could be achieved at the beginning.
And so, the spill of oil and its potential effects were even more heartbreaking. Shaver is concerned about a severe drought that has dried sand of Texas and made turtle tracks disappear quickly will make it harder for her and his aides to find and protect the eggs of this year. It thinks if oil contamination can decrease the rate of survival for infants.
To get an idea of what may come, scientists collect additional information this year. With counting nests, they are collecting blood of nesting females and dead embryos and infants of the samples of fabrics to see if oil contamination is transmitted from mother to offspring. Contaminants experts and toxicologists will help biologists analyze the information.
Scientists also are keeping tabs on habitat of turtles, noting that if the crabs or herring they consume is fatally injured by oil, it will be in turn injured turtles.
Blair Witherington, a marine biologist and an expert of the sea turtle with the Fish and Wildlife Conservation Commission in Florida, noted these effects are sometimes so subtle that they are not detected for years. In Chesapeake Bay, for example, the Horseshoe Crab population was seriously depleted that the loggerhead now eat fish dumped overboard by shrimpers and other fishing vessels - a diet biologists appears less nutritious and slowdown in growth, he said.
"We know well what will be the impact of oil long term," said Witherington.
While scientists collect information on the turtle nesting, they said, it is difficult to assess the total population, because animals are difficult to follow at sea and some of them, such as young people, rarely docking.
"It takes 20 years so that they reach sexual maturity." It may take long to determine if the population has been affected, ", said Roger Zimmerman, Director of the laboratory National Marine Fisheries Service in Galveston." "Unfortunately, future scientists can be to make these determinations."
The turtles covered oil concluded last year have been cleaned and rehabilitated. A group of some 30 young people came out a boat in late may in an area of approximately 50 miles south of Venice, Louisiana) - right around where they were found swimming in oil, Witherington said. Others are still to be treated.
Andre Landry, Director of sea turtle and the research laboratory of fisheries ecology at Texas A & M in Galveston, concerned juveniles, whom he knows were in search of food, living and playing in Grand Isle, Louisiana), just as oil washed ashore.
Their fate has not yet been determined - or documented.
"It's a vacuum," said Landry.
___
http://Twitter.com/RamitMastiAP
没有评论:
发表评论