A new study has found that 42 countries or territories around the world permit the harvest of marine turtles — and estimates that more than 42,000 turtles are caught each year by these fisheries.The research, carried out by Blue Ventures Conservation and staff at the University of Exeter’s Centre for Ecology and Conservation, is the first to comprehensively review the number of turtles currently taken within the law and assess how this compares to other global threats to the creatures.All seven marine turtle species are currently listed on the IUCN Red List of Threatened Species.Frances Humber of Blue Ventures and a PhD student at the University of Exeter, who led the research, said: “This is the first study to comprehensively review the legal take of turtles in recent years, and allows us to assess the relative fisheries threats to this group of species. Despite increased national and international protection of marine turtles, direct legal take remains a major source of mortality. However, it is likely that a fraction of current marine turtle mortality take is legal, with greater threats from illegal fisheries and bycatch.”The first marine turtle harvest legislation was instigated in Bermuda in 1620 to protect “so excellent a fishe” and prohibited taking any turtle “under eighteen inches in the breadth or diameter.”But large scale commercial taking of turtles continued all over the world for centuries, with global capture peaking at over 17,000 tonnes in the late 1960s. For example, during the peak of Mexico’s sea turtle exploitation in 1968 it is estimated that the national take was over 380,000 turtles.Increased conservation awareness at an international scale has led to greater protection of marine turtles, with 178 countries now signed up to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) restricting the international trade of turtle products.The direct take of turtles has continued legally in many regions and countries, often for traditional coastal communities to support themselves or small-scale fisheries supplying local markets with meat, and sometimes shell. The fisheries are an important source of finance, protein and cultural identity, but information can be scarce on their status — despite often being listed as one of the major threats to turtle populations.The researchers collated data for all seven species of marine turtles from over 500 publications and 150 in-country experts.They estimate that currently more than 42,000 marine turtles are caught each year legally, of which over 80% are green turtles. Legal fisheries are concentrated in the wider Caribbean region, including several of the UKs Overseas Territories, and the Indo-Pacific region, with Papua New Guinea, Nicaragua and Australia together accounting for almost three quarters of the total.The data indicates that since the 1980s more than 2 million turtles have been caught, although current levels are less than 60% of those in the 1980s.Bycatch — the unwanted fish and other marine creatures trapped by commercial fishing nets during fishing for a different species — is thought to be a far higher cause of death for marine turtles, likely running into hundreds of thousands each year.Illegal fishing also continues to be a major cause of mortality, with the researchers estimating a minimum of 65,000 turtles taken from Mexico alone since the year 2000. The scale of global illegal capture is likely to be severely underreported due to the difficulties collecting information on such an activity.Dr Annette Broderick, of the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall, added: “We were surprised to find that there are 42 countries with no legislation in place that prohibits the harvest of marine turtles, although for many of these countries these harvests provide important sources of protein or income. It is however important to ensure that these fisheries are operating at a sustainable level.”Story Source:The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.Read more
Sep. 11, 2013 — Researchers have transported two endangered freshwater mussel species from Pennsylvania to Illinois in an attempt to re-establish their populations in the western part of the Ohio River Basin.The team of biologists, led by Jeremy Tiemann, of the Illinois Natural History Survey (INHS), traveled to the site of a bridge-replacement project on Pennsylvania’s Allegheny River to collect northern riffleshell (Epioblasma rangiana) and clubshell (Pleurobema clava) mussels. The INHS is a division of the Prairie Research Institute at the University of Illinois.The two mussel species historically had inhabited the Ohio River Basin, an area that stretches from Illinois to Pennsylvania and New York to Kentucky. The 2- to 3-inch-long northern riffleshells and their larger clubshell counterparts make their homes three or more inches beneath the surface of the gravel layer they live in, Tiemann said.There are more than 30,000 individual mussels of these species living under Pennsylvania’s Hunter Station Bridge. The bridge-replacement project brings with it the potential for huge losses of the already endangered species, he said.Mussels reproduce by attaching their juveniles to certain species of fish, so finding a suitable habitat for them can be a challenge. The northern riffleshell was “last seen alive in Illinois about a hundred years ago,” Tiemann said. There are sites on the Vermillion River in Illinois that serve as the perfect backdrop for the re-establishment of populations in the species’ historical range, he said.”It is a win-win situation for everybody,” Tiemann said. “We save the mussels and get a new population here in Illinois.”The team collected the mussels over a two-day period in late August, and then brought them to their lab in Illinois to be tagged with a “microchip similar to what you put in your dog or cat. (It’s) the size of a large grain of rice,” Tiemann said.Last year, the group collected and transported 1,000 northern riffleshells and 200 clubshells. The team has seen an 80 percent survivorship within this group.This year, they transported 750 clubshell and 250 northern riffleshell mussels.The benefit of the project stretches beyond simply removing these species from the endangered list. …Read more
Aug. 16, 2013 — The number of humans on the planet has almost doubled in the past 50 years ‒ and so has global food production. As a result, the use of pesticides and their effect on humans, animals and plants have become more important. Many laboratory studies have shown that pesticides can harm organisms which they were not meant to affect. Intensive farming is also linked to collapsing populations of wild animals and the endangerment of species such as amphibians. Can the biochemical effects of pesticides upset entire ecosystems?Share This:Professor Heinz Köhler and Professor Rita Triebskorn from the University of Tübingen’s Institute of Evolution and Ecology (EvE) have published a study on the link between pesticides and changing ecological systems in the latest edition of Science. The two ecotoxicologists cite deficits in the research which have prevented recognition of the consequences of biochemical pesticide effects on a species population or on the composition of biological communities. “Although there are many indications of animal populations and ecosystems changing because of pesticides, there are few studies proving the connection without a doubt,” Köhler and Triebskorn say. The researchers point to mathematical and experimental approaches which can be used to recognize links between the effects of pesticides in individuals and ecological changes in biological communities and ecosystems in regions where intensive farming is practiced.An important role is played by number of rare studies combining experimental fieldwork and research on sections of ecosystems, as well as a broad selection of chemical and biological analyses. An interdisciplinary approach can plausibly demonstrate connections between the effects of chemicals in humans and animals and the often indirect consequences on the population, community and ecosystem levels.Köhler and Triebskorn also postulate interdependent effects between pesticides and global warming. …Read more
July 26, 2013 — In the beech groves of Navarre a team from the UPV/EHU-University of the Basque Country has analysed the influence exerted by forestry management on the fungi populations that decompose wood.There is a shortage of dead wood in forests because fallen branches and trees tend to be cleared away. This wood, if available, ought to be decomposing, as it is the habitat of many living beings like lignicolous fungi. These fungi are capable of decomposing dead wood and turning it into organic and inorganic matter. So clearing away the dead wood from the forests is ecologically harmful for the fungi. Nerea Abrego-Antia and Isabel Salcedo-Larralde, biologists in the Department of Plant Biology and Ecology of the UPV/EHU-University of the Basque Country, have recently quantified this effect on fungi populations that live off dead wood in various beech groves in Navarre. The main conclusion of the study is that forestry and classical forest management are harming the community of saproxylic fungi. What is more, the researchers have discovered that in the forests being exploited various fungi species are disappearing and in some cases even whole families are affected.The conclusion of the research is crystal clear: the clearing away of remains of dead wood is harming the populations of lignicolous or saproxylic fungi. Nevertheless, Isabel Salcedo, director of the research, has qualified this: “You see everything very clearly, but you don’t accept it that easily. The pre-hypothesis could be that as the basic matter is lost, the environment will be directly affected. But the aim of our work is to prove it. …Read more
July 22, 2013 — Scientists have for the first time traced a novel virus that infected two men from northwestern Missouri in 2009 to populations of ticks in the region, providing confirmation that lone star ticks are carrying the recently discovered virus and humans in the area are likely at risk of infection. The findings were published online today in the American Journal of Tropical Medicine and Hygiene.Dubbed Heartland virus or HRTV, the infection causes fever, headaches, and low white blood cell and platelet counts. The two men infected in 2009, who live about 70 miles apart, were sufficiently ill to require hospitalization. They eventually recovered, and no other cases have been reported. Disease experts anticipate, however, that more people could become infected. The Missouri Department of Health and Senior Services is working with the US Centers for Disease Control and Prevention (CDC) to identify additional cases and determine the role of this novel virus as a human pathogen.”Ten samples of ticks tested positive for the Heartland virus, nine of which were collected from the property of one of the patients and one that came from conservation lands nearby,” said Harry M. Savage, PhD, a research entomologist at CDC in Fort Collins, Colorado and the lead author of the paper. “It’s pretty strong evidence that the virus is persisting from season to season in tick populations and that these ticks play an important role in disease transmission.”There is no treatment available for HRTV. Unlike other tick-borne diseases like Lyme, ehrlichiosis and Rocky Mountain spotted fever, HRTV is a virus and thus does not respond to antibiotics.Disease HuntingHRTV was discovered when a doctor at the hospital treating the two infected men, who had reported being bitten by ticks, sent blood samples to a CDC laboratory in Atlanta for testing. All involved assumed the tests would reveal ehrlichiosis, the tick-borne disease that is most common in the area. …Read more
July 10, 2013 — A new species of rare and beautiful plant has been described from the biodiversity rich Peninsular Malaysia. Ridleyandra chuana is endemic to the region and only known from two small montane forest populations. The conservation status of this recently described delicate flower is assessed as Endangered due to its restricted distribution.The new species was described and illustrated in the open access journal PhytoKeys.Ridleyandra chuana is a perennial herb with a woody usually unbranched stem crowned by an asymmetrical rosette of dark green leaves covered in fine hairs. The beautiful and delicate cone-like flowers are white with dark maroon purple stripes. They rarely appear in more than two in one go usually flowering in succession. Ridleyandra chuana grows on moss-covered granite rock embedded in soil or on low moss-covered granite boulders, in extremely damp, deeply shaded conditions on steep slopes in valleys.Although the species is only formally described now, it was in fact first encountered as early as 1932 at Fraser’s Hill, Pahang. However, it was only in 1999 when another population was discovered by L.S.L. Chua on Gunung Ulu Kali, Pahang, that sufficient material was available for its description. Since then, both these localities have been revisited and the Gunung Ulu Kali population is now the focus of conservation.The new species is named in honour of Dr Lillian Swee Lian Chua, botanist and conservationist, who first discovered this species on Gunung Ulu Kali while making an ecological inventory of the summit flora. Under the IUCN criteria, this species is assessed as Endangered because it is known from two localities, one of which is threatened, and only 130 known individuals.”The population at Fraser’s Hill falls within a Totally Protected Area and consists of about 30 plants that grow in an undisturbed site away from tourist trails and is too remote to be affected by development. …Read more
June 17, 2013 — Amphibian populations are declining worldwide and a major cause is a deadly fungus thought to be spread by bullfrogs, but a two-year study shows they can also die from this pathogen, contrary to suggestions that bullfrogs are a tolerant carrier host that just spreads the disease.When researchers raised the frogs from eggs in controlled experimental conditions, they found at least one strain of this pathogen, Batrachochytrium dendrobatidis, also called Bd or a chytrid fungus, can be fatal to year-old juveniles. However, bullfrogs were resistant to one other strain that was tested.The findings, made by researchers at Oregon State University and the University of Pittsburgh, show that bullfrogs are not the sole culprit in the spread of this deadly fungus, and add further complexity to the question of why amphibians are in such serious jeopardy.About 40 percent of all amphibian species are declining or are already extinct, researchers say. Various causes are suspected, including this fungus, habitat destruction, climate change, pollution, invasive species, increased UV-B light exposure, and other forces.”At least so far as the chytrid fungus is involved, bullfrogs may not be the villains they are currently made out to be,” said Stephanie Gervasi, a zoology researcher in the OSU College of Science. “The conventional wisdom is that bullfrogs, as a tolerant host, are what helped spread this fungus all over the world. But we’ve now shown they can die from it just like other amphibians.”The research suggests that bullfrogs actually are not a very good host for the fungus, which first was identified as a novel disease of amphibians in 1998. So why the fungus has spread so fast, so far, and is causing such mortality rates is still not clear.”One possibility for the fungal increase is climate change, which can also compromise the immune systems of amphibians,” said Andrew Blaustein, a distinguished professor of zoology at OSU and international leader in the study of amphibian declines. “There are a lot of possible ways the fungus can spread. People can even carry it on their shoes.”The average infection load of the chytrid fungus in bullfrogs, regardless of the strain, is considerably lower than that of many other amphibian species, researchers have found. Some bullfrogs can reduce and even get rid of infection in their skin over time.While adult bullfrogs may be carriers of some strains of Bd in some areas, the researchers concluded, different hosts may be as or more important in other locations. International trade of both amphibian and non-amphibian animal species may also drive global pathogen distribution, they said.The findings of this study were published in EcoHealth, a professional journal.Read more
May 1, 2013 — Amphibian populations living close to agricultural fields have become more resistant to a common insecticide and are actually resistant to multiple common insecticides, according to two recent studies conducted at the University of Pittsburgh.Amphibian populations living close to agricultural fields have become more resistant to a common insecticide and are actually resistant to multiple common insecticides.
In a study published today in Evolutionary Applications, the Pitt researchers demonstrate, for the first time, that tadpoles from populations close to farm fields are more resistant to chlorpyrifos — one of the most commonly applied insecticides in the world, often sold as “Dursban” or “Lorsban.” In addition, a related study published in February shows that tadpoles resistant to chlorpyrifos are also resistant to other insecticides.
“While we’ve made a lot of progress in understanding the ecological consequences to animals that are unintentionally exposed to insecticides, the evolutionary consequences are poorly understood,” said study principal investigator Rick Relyea, Pitt professor of biological sciences and director of the University’s Pymatuning Laboratory of Ecology. “Our study is the first to explore how amphibian populations might evolve to be resistant to insecticides when they live in places that have been sprayed for many years.”
The Pitt researchers used newly hatched tadpoles collected from nine populations of wood frogs living at different distances from agricultural fields. They tested the frogs’ resistance when exposed to chlorpyrifos, which is used against insects, and Roundup Original MAX®, which is a common herbicide used against weeds.
Relyea and his Pitt collaborators exposed the tadpoles from each of the nine populations to environments containing either no pesticides, chlorpyrifos, or Roundup®. After 48 hours, they measured how well the populations survived.
“Wood frogs living close to agricultural land were more likely to have been exposed to pesticides for many generations compared to those living far from agriculture; the latter frog populations likely experienced little or no exposure to pesticides,” said Rickey Cothran, the lead author of the study and a postdoctoral researcher in Relyea’s lab. “Although populations differed in their resistance to Roundup®, populations closer to fields were not more resistant to the herbicide.”Wood frogs living close to agricultural land were more likely to have been exposed to pesticides for many generations compared to those living far from agriculture.
“Because chlorpyrifos kills in a way that is similar to many other insecticides, higher resistance may have been favored each time any insecticide was sprayed,” said Pitt alumnus Jenise Brown (A&S ’09), a coauthor of the study and a former undergraduate researcher in Relyea’s lab. “In contrast, herbicides have a variety of ways that they kill organisms, which may make it harder for animals to be resistant when exposed to different herbicides over many years.”
In a related study, published online Feb. 21 in Environmental Toxicology and Chemistry, Relyea’s Pitt research team examined whether wood frog populations that were resistant to chlorpyrifos might also be resistant to other insecticides. This phenomenon, said Relyea, happens commonly in pest species when farmers switch pesticides from year to year, but little is known about how this switching of pesticides affects amphibians.
Using three commonly applied pesticides that have similar chemical properties — chlorpyrifos, carbaryl, and malathion — the Pitt researchers exposed 15 populations of wood frog tadpoles to high concentrations of each insecticide. They found that wood frog populations with resistance to one insecticide also had resistance to the other insecticides.
“This has a beneficial outcome,” said Jessica Hua, the lead author of the second study and a graduate student in Relyea’s lab. “While it doesn’t mean that pesticides are beneficial to amphibians, our work does suggest that amphibians can evolve to resist a variety of pesticides and therefore improve their survival.”
As they hypothesized in the study published today, the researchers suspect that the reason for this cross-resistance is that chlorpyrifos kills in a way that is similar to many other insecticides. Thus, evolving higher resistance to one insecticide may provide higher resistance to others.
“This finding may buffer an amphibian population from suffering the consequences of exposures to new, but similar-acting chemicals,” said Aaron Stoler, a coauthor of the second paper and a graduate student in Relyea’s lab.
In the future, Relyea and his team plan to study the genetic mechanisms that underlie increased resistance in amphibians and determine whether increased resistance occurs in additional animal species that are not the targets of pesticides.
The article published today in Evolutionary Applications is titled “Proximity to agriculture is correlated with pesticide tolerance: Evidence for the evolution of amphibian resistance to modern pesticides.” The article published Feb. 21 in Environmental Toxicology and Chemistry is titled “Cross-tolerance in amphibians: Wood frog mortality when exposed to three insecticides with a common mode of action.”
Funding for both studies was provided by a National Science Foundation grant to Relyea. Funding for the second study was also provided by Pitt’s G. Murray McKinley Research Fund to Hua and Stoler. The experiments were conducted at Pitt’s Pymatuning Laboratory of Ecology from 2009 to 2012.Read more
May 18, 2013 — By day, insects provide the white noise of the South, but the night belongs to the amphibians. In a typical year, the Southern air hangs heavy from the humidity and the sounds of wildlife. The Southeast, home to more than 140 species of frogs, toads and salamanders, is the center of amphibian biodiversity in our nation. If the ponds and swamps are the auditorium for their symphonic choruses, the scientists of the U.S. Geological Survey’s Amphibian Research and Monitoring Initiative, or ARMI, have front-row seats.
Amphibians, which rely on water for part or all of their life cycle, must adjust to often atypical weather. Some years bring heavy deluges, such as the region’s notorious hurricanes, and others bring the transformations that come with drought. Amphibians around the world seem to be experiencing the worst declines documented among vertebrates. While habitat loss is the number one reason for population declines, research suggests that disease, invasive species, contaminants and perhaps other factors contribute to declines in protected areas.
And then there’s climate change, another stressor for amphibians to contend with. Climate change projections indicate that rainfall will increasingly come in pulses, with greater deluges and longer periods of drought. Scientists have long suspected that climate change is an important factor in amphibian declines, and resource managers are asking whether conservation measures might help species persist or adapt in a changing climate. Three recent U.S. Geological Survey studies offer some insight into the issue.
Amphibians, which are declining throughout the world, play an important role in ecological systems. They eat small creatures, including mosquitos, and they are food themselves for larger creatures, such as birds and snakes. Because amphibians are the middle of the food chain — and sensitive to environmental disruption because of their aquatic or semi-aquatic lives — their existence is often used as an indication of ecosystem health.
Scientists in ARMI, a program started by Congress in 2000 in response to concerns about amphibian declines, have been working to unravel the ups and downs of amphibian populations to support effective conservation and resource management decisions. To do this, ARMI scientists and field crews monitor the status of amphibians, research the causes of declines, and scientifically evaluate projects undertaken to sustain these species and their habitats across the country.
Pond life — it’s not easy being green!
ARMI scientists looked at a range of amphibian species found in the Southeast and posed the question, “What will happen to their populations under a scenario of changes in rainfall patterns — more deluges alternating with droughts — which is being predicted by current climate models?”
It turns out that understanding how climate affects amphibians requires “thinking like the ponds” in which they live. Amphibians have unique life cycles — most alternate between living in water as juveniles, to maturing and dispersing on land, then returning to water again as adults to mate and lay eggs.
When USGS scientists reviewed what was known about amphibian responses to rainfall, it turned out that both extremes in rainfall — drought and heavy rainfall events — can decrease the number of amphibians. The amphibians’ response depends on a balance between these two key factors. If ponds dry up while aquatic juveniles are developing, survival of the next generation is lowered. However, if a deluge occurs at that time, nearby pools that often contain fish will be physically connected with the pools containing juvenile amphibians, and the fish will eat the juveniles.
In essence, the study showed that extreme rainfall events are key to predicting amphibian responses to climate, because such events affect the amount and timing of water in ponds that they depend on. The full review of species’ responses was published in March 2013 edition of the journal Biology.
Drought and declining salamanders
Knowing that each species responds to droughts and deluges based on the particulars of their biology, scientists set out to test just how these dynamics played out in the southeastern U.S. by looking at larval mole salamanders in small isolated ponds in St. Mark’s National Wildlife Refuge, Florida.
Larval mole salamanders have a similar life cycle to the flatwoods salamander, a federally threatened species found on the refuge. Because it is difficult to study the flatwoods salamander directly, and mole salamanders are ecologically similar, scientists study the mole salamander instead, knowing that whatever affects them will likely impact the flatwoods salamander as well.
In the four years of the study, drought consistently decreased salamander occupancy in ponds. To support young salamanders, rain has to fill a pond during the breeding season and then the pond has to stay filled long enough for larvae to transform into the next life stage. Therefore, scientists confirmed that drought did indeed cause short-term declines in mole salamanders — suggesting that the listed flatwoods salamander may face a similar fate under climate change.
The results of the mole salamander study are published in the April 2013 edition of the journal Wetlands.
Can habitat conservation make a difference for frogs and toads?
To answer this question, USGS scientists examined whether the U.S. Department of Agriculture’s Natural Resources Conservation Service Wetlands Reserve Program was helping address the problem. The Wetlands Reserve Program is a voluntary USDA program offering landowners the opportunity to protect, restore, and enhance wetlands on their property. To assess the potential benefit of WRP restoration to amphibians, in this case, frogs and toads, USGS scientists surveyed 30 randomly selected WRP sites and 20 nearby agricultural sites in the Mississippi Delta in northwest Mississippi.
The scientists found that WRP sites had more kinds of species and was home to more numbers of amphibians than the agricultural sites studied. The restoration of wetland hydrology appeared to provide the most immediate benefit to the animals.Read more
May 22, 2013 — Translocation — or moving animals to safer places — is a vital tool for saving species from extinction. Many factors influence the success of these new populations, including habitat quality, predators, capture and release techniques, the number and sex of individuals, and their genetic diversity. Now new research, the first of its kind, published in the British Ecological Society’s Journal of Applied Ecology suggests bird song could also be important.
Ecologists from the University of Waikato and Lincoln University in New Zealand studied the North Island kōkako, an iconic bird with a haunting, organ-like song. Once widespread in the North Island, loss of habitat by deforestation and predation by rats, possums and stoats decimated the population. By 1999, fewer than 400 pairs remained, and between 2001 and 2007, several pairs were moved from Te Urewera National Park to two other reserves: Boundary Stream Mainland Island and Ngapukeriki.
To find out how moving the kōkako has affected their song, the researchers made hundreds of recordings in the three populations and analysed differences in song using sonograms. They then used playback experiments to discover how birds from one population reacted to another populations’ song.
They found the songs of translocated birds had diverged substantially from the source population, becoming less diverse with shorter and higher-pitched elements. According to Dr Laura Molles from Lincoln University: “Not only how kōkako sing in translocated populations, but also what they sing differs from kōkako in the source population.”
The greatest changes were found in the population that had been translocated for longest, indicating the songs may become more different over time. But despite the divergence between each population’s song, the playback experiments showed that the birds could not yet tell them apart.
“The songs diverge because birds such as kōkako learn their songs from parents, siblings and neighbours. As translocation usually involves only a small number of indivuals, they will take with them only a small portion of all the song elements in the larger source population. Subsequent variation in small populations will depend on that subset of songs and will then differ from the larger song pool in the source population,” Dr Molles explains.
The study has important implications for conservation. Although in this study the kōkako populations have not been separated for long enough to cause song incompatibility, it will occur in time, the authors say. Once that happens, releasing additional birds into these populations could be problematic because song incompatibility could make interbreeding difficult.
As a result, says Dr Molles, conservationists should consider song variation as part of bird reintroductions: “We need to be aware that behavioural factors like song can also affect translocation success and recovery of endangered birds, and adapt our management of these populations accordingly. This means that we may have to work harder but the good news is that if we consider one more factor that we now know may also affect translocation, we will be more likely to succeed in conserving birds.”
The North Island kōkako is one of New Zealand’s most iconic bird species. The size of a common pigeon, both males and females have blue-grey plumage with black masks and striking bright blue wattles. Both sexes sing, and pairs duet, with a haunting voice and the birds’ astonishingly varied organ-like notes can be heard over 1km away.
They have limited flying power, instead moving like squirrels through the branches and gliding from hill tops to valleys. They live in the temperate rainforest, feeding mainly on fruit and leaves. Once widespread, their numbers collapsed due to deforestation and predation by rats, stoats and possums, and by 1999 fewer than 400 pairs remained. Thanks to translocation to safe offshore islands, numbers have increased to around 800 pairs today.Read more