'Hidden' hawksbill turtles found (via Dawn Holloway)

Scientists have found hawksbill turtles "hiding" in mangrove forests of the eastern Pacific.

The team, that has been tracking the turtles for three years, also found that the critically endangered animals nested in these estuaries.

The discovery of this previously unknown sea turtle habitat was published recently in the Royal Society journal Biology Letters.

It could explain why the species went undetected in the region for so long.

Mangrove forests, which are unique coastal tree and shrub habitats, are also under threat. They could represent an important breeding and nesting site for the species, which was thought to depend on coral reefs.

Alexander Gaos, a conservation scientist with San Diego State University and the Eastern Pacific Hawksbill Initiative, led the research.

He and his colleagues tracked hawksbills in four countries - El Salvador, Honduras, Nicaragua and Ecuador - using satellite tracking tags glued to the turtles' backs.

These trackers revealed that adult hawksbill turtles in the eastern Pacific inhabited in-shore mangrove estuaries.

"For upwards of five decades sea turtle scientists thought hawksbills had [disappeared from] the eastern Pacific Ocean", Dr Gaos told BBC Nature.

"Despite hundreds of sea turtle projects and scientists focusing efforts in the region, no one had located hawksbills.

Our findings help explain this… it's hard to spot hawksbills in mangrove estuaries."

Dr Gaos said that the turtles might be spending their entire lives in these "cryptic habitats".

"Couple that with the fact that there are very few individuals left - hawksbills in the eastern Pacific are one of the world's most endangered sea turtle populations - and it's no wonder researchers didn't know about them!"

The scientists worked with local fishermen and even illegal egg collectors, in order to find hawksbill turtles to fit their tags to.

They hope their revelations about the species' habitat will inform conservation efforts.

Why the turtles were "seeking shelter" in mangroves was not clear.

The scientists think it might be a recent adaptation brought on by a lack of their more typical habitat of coral reefs in the region.

Dr Gaos said: " We now have a better idea of where to look for them, which may help us direct research and conservation of the species, upon which their survival may ultimately depend."
By Victoria Gill Science reporter, BBC Nature
http://www.bbc.co.uk/nature/14735144

New Pacific eel is a 'living fossil', scientists say

A newly discovered eel that inhabits an undersea cave in the Pacific Ocean has been dubbed a "living fossil" because of its primitive features.

It is so distinct, scientists created a new taxonomic family to describe its relationship to other eels.

The US-Palauan-Japanese team say the eel's features suggest it has a long and independent evolutionary history stretching back 200m years.

Details appear in the journal Proceedings of the Royal Society B.

The animal used as the basis for the new study was an 18cm-long female, collected by one of the researchers during a dive at a 35m-deep cave in the Republic of Palau.

But the scientists also mention other examples of the new eel species in their research paper.

At first there was much discussion among the researchers about the animal's affinities. But genetic analysis confirmed that the fish was a "true" eel - albeit a primitive one.

"In some features it is more primitive than recent eels, and in others, even more primitive than the oldest known fossil eels, suggesting that it represents a 'living fossil' without a known fossil record," write the scientists.

In order to classify the new animal, the researchers had to create a new family, genus and species, bestowing on the animal the latin name Protoanguilla palau.

The team - including Masaki Miya from Chiba's Natural History Museum in Japan, Jiro Sakaue from the Southern Marine Laboratory in Palau and G David Johnson from the Smithsonian Institute in Washington DC - drew up a family tree of different eels, showing the relationships between them.

This allowed them to estimate when the ancestors of P. palau split away from other types of eel.

Their results suggest this new family has been evolving independently for the last 200m years, placing their origins in the early Mesozoic era, when dinosaurs were beginning their domination of the planet.

The researchers say the Protoanguilla lineage must have once been more widely distributed, because the undersea ridge where its cave home is located is between 60 and 70 million years old.
By Paul Rincon Science editor, BBC News website
http://www.bbc.co.uk/news/science-environment-14547942

Aberdeen scientists discover secrets of the deep

Scientists investigating in one of the world’s deepest ocean trenches, previously thought to be void of fish, have discovered an entirely new species.


The findings by a team of marine biologists from Aberdeen, Tokyo and New Zealand, have shed new light on life in the deepest places on Earth and the global distribution of fish in our oceans.

The expedition to the Peru-Chile trench in the south-east Pacific Ocean revealed a new species of snailfish living at 7000m, never before caught or captured on camera.

Mass groupings of cusk-eels and large crustacean scavengers were also discovered living at these depths for the first time.

During the three week expedition on the research vessel Sonne, the team of scientists employed state-of-the-art deep-sea imaging technology, including an ultra-deep free-falling baited camera system, to take a total of 6000 images between 4500 and 8000 metres deep within the trench.

The expedition is the seventh to take place as part of HADEEP – a collaborative research project between the University of Aberdeen’s oceanlab and the University of Tokyo’s ocean research institute, with support from New Zealand’s national institute of water and atmospheric research institute.

The HADEEP team has been investigating extreme depths across the globe for three years. Their findings to date have included capturing the world’s deepest fish on camera for the first time.

These latest discoveries provide a new insight into the depths at which fish survive and the diversity of populations which could exist in the deepest points of oceans across the globe.

Dr Alan Jamieson from the University of Aberdeen’s oceanlab, who led the expedition said: “Our findings, which revealed diverse and abundant species at depths previously thought to be void of fish, will prompt a rethink into marine populations at extreme depths.

“This expedition was prompted by our findings in 2008 and 2009 off Japan and New Zealand where we discovered new species of snailfish known as liparids - inhabiting trenches off Japan and New Zealand at depths of approximately 7000m – with each trench hosting its own unique species of the fish.

“To test whether these species would be found in all trenches, we repeated our experiments on the other side of the Pacific Ocean off Peru and Chile, some 6000 miles from our last observations.

“What we found was that indeed there was another unique species of snailfish living at 7000m – entirely new to science, which had never been caught or seen before.

“A species of cusk-eel - known as ophidiids - also gathered at our camera and began a feeding frenzy that lasted 22 hours - the entire duration of the deployment.

“Further research needs to be conducted to decipher whether this is also an entirely new species of cusk-eel that we have discovered.

“Our investigations also revealed a species of crustacean scavengers - known as amphipods - which we previously did not know existed at these depths in such great numbers.

“These are large shrimp-like creatures of which one particular group, called eurythenes, were generally far larger and occurred much deeper in this trench than has ever been found before.”

Dr Niamh Kilgallen, an amphipod expert from NIWA said: “The sheer abundance of these big amphipods was overwhelming, particularly at 7000 and 8000m, which is much deeper than they have been found in any other trench. It begs the question of why and how they can live so deep in this trench but not in any other.”

Dr Toyonobu Fujii, a deep-sea fish expert from the University of Aberdeen said: “How deep fish can live has long been an intriguing question and the results from this expedition has provided deeper insight into our understanding of the global distribution of fish in the oceans.”

Dr Jamieson added: “These findings prompt a re-evaluation of the diversity and abundance of life at extreme depths. Furthermore, it is now apparent that each of the deep trenches across the globe hosts a unique assembly of animals which can differ greatly from trench to trench. The immense isolation of each trench draws parallels with island evolution theory popularised by Darwin’s finches.”

Aberdeen scientists discover secrets of the deep

Scientists investigating in one of the world’s deepest ocean trenches, previously thought to be void of fish, have discovered an entirely new species.


The findings by a team of marine biologists from Aberdeen, Tokyo and New Zealand, have shed new light on life in the deepest places on Earth and the global distribution of fish in our oceans.

The expedition to the Peru-Chile trench in the south-east Pacific Ocean revealed a new species of snailfish living at 7000m, never before caught or captured on camera.

Mass groupings of cusk-eels and large crustacean scavengers were also discovered living at these depths for the first time.

During the three week expedition on the research vessel Sonne, the team of scientists employed state-of-the-art deep-sea imaging technology, including an ultra-deep free-falling baited camera system, to take a total of 6000 images between 4500 and 8000 metres deep within the trench.

The expedition is the seventh to take place as part of HADEEP – a collaborative research project between the University of Aberdeen’s oceanlab and the University of Tokyo’s ocean research institute, with support from New Zealand’s national institute of water and atmospheric research institute.

The HADEEP team has been investigating extreme depths across the globe for three years. Their findings to date have included capturing the world’s deepest fish on camera for the first time.

These latest discoveries provide a new insight into the depths at which fish survive and the diversity of populations which could exist in the deepest points of oceans across the globe.

Dr Alan Jamieson from the University of Aberdeen’s oceanlab, who led the expedition said: “Our findings, which revealed diverse and abundant species at depths previously thought to be void of fish, will prompt a rethink into marine populations at extreme depths.

“This expedition was prompted by our findings in 2008 and 2009 off Japan and New Zealand where we discovered new species of snailfish known as liparids - inhabiting trenches off Japan and New Zealand at depths of approximately 7000m – with each trench hosting its own unique species of the fish.

“To test whether these species would be found in all trenches, we repeated our experiments on the other side of the Pacific Ocean off Peru and Chile, some 6000 miles from our last observations.

“What we found was that indeed there was another unique species of snailfish living at 7000m – entirely new to science, which had never been caught or seen before.

“A species of cusk-eel - known as ophidiids - also gathered at our camera and began a feeding frenzy that lasted 22 hours - the entire duration of the deployment.

“Further research needs to be conducted to decipher whether this is also an entirely new species of cusk-eel that we have discovered.

“Our investigations also revealed a species of crustacean scavengers - known as amphipods - which we previously did not know existed at these depths in such great numbers.

“These are large shrimp-like creatures of which one particular group, called eurythenes, were generally far larger and occurred much deeper in this trench than has ever been found before.”

Dr Niamh Kilgallen, an amphipod expert from NIWA said: “The sheer abundance of these big amphipods was overwhelming, particularly at 7000 and 8000m, which is much deeper than they have been found in any other trench. It begs the question of why and how they can live so deep in this trench but not in any other.”

Dr Toyonobu Fujii, a deep-sea fish expert from the University of Aberdeen said: “How deep fish can live has long been an intriguing question and the results from this expedition has provided deeper insight into our understanding of the global distribution of fish in the oceans.”

Dr Jamieson added: “These findings prompt a re-evaluation of the diversity and abundance of life at extreme depths. Furthermore, it is now apparent that each of the deep trenches across the globe hosts a unique assembly of animals which can differ greatly from trench to trench. The immense isolation of each trench draws parallels with island evolution theory popularised by Darwin’s finches.”

Fearsome giant turtles found in Pacific cemetery (via Chad Arment)

Emma Young August-17-2010

WITH THEIR HORNED HEADS and spiked shells, giant turtles that once lived on the Pacific island of Efate in Vanuatu may have looked fearsome, but they were easy prey for settlers, says a new study.

People shared the island with these giant land-dwelling turtles for at least two centuries, but eventually wiped them out, according to research published today by researchers at the University of New South Wales in Sydney.

"I don't think the people would ever have contemplated that the resource was limited - subsistence hunters eat whatever they encounter if they can catch it the world over," says lead author Dr Trevor Worthy. "Many peoples in the Pacific still have little concept of conservation, which is something only the wealthy first-world nations have recently embraced."

Macabre practice
People first arrived on Efate, the main island in Vanuatu, about 3000 years ago. Matthew Spriggs and Stuart Bedford of the Australian National University, Canberra, who worked with Worthy, found middens - mounds of waste - dating from about 200 years after that. These middens contained the remains of at least 30 of the giant turtles, dumped, somewhat macabrely, on top of the graves of the first settlers.

"It is the first time this family of turtles has been shown to have met with humans and there are many turtle bones in the middens," says Trevor. "Initial excavations in 2004 by the ANU team revealed that the first use of the site was as a cemetery and provided the first real opportunity in more than 50 years of research to describe a group of Lapita people and glean insights into their ritual and mortuary practices."

This particular species of land turtle is new to science, but the remains very closely resemble those of other extinct giant turtles (known as meiolaniid turtles) from Lord Howe Island, NSW, for example.

While the team don't have skulls from Vanuatu, they think the new turtle probably shared the horns, as well as the knobby tail, of its close relatives. The beasts were big, with shells up to one metre long. However, their horns meant they were unable to retract their heads into the shells, making them more vulnerable to hunters.

Systematic killing
The team don't know how many of the turtles lived on the island before people arrived, but the settlers probably systematically killed and ate the animals, says Trevor. While this is the first evidence that people ever overlapped in time and space with giant turtle species, other giant turtle fossils have been found in New Caledonia and Viti Levu in Fiji, showing the animals were widespread in the Pacific.

As they went extinct only recently, studies of middens or recent beach deposits on other islands might unearth more species, says Trevor. "We are likely to be able to learn much more about this enigmatic family if we explore the palaeofaunas of islands similar to Efate," he says.

"This is a remarkable find, and adds the horned tortoises to the list of charismatic megafauna that has gone extinct in Australasia and the Pacific during the Holocene," comments Dr Arthur Georges, an expert on the evolution of turtles at the University of Canberra.

It's hard to know exactly what drove the turtles to extinction, say the researchers. The settlers also cleared land, and brought pigs with them, both of which could have helped speed the turtles' demise.

On other islands, such as Fiji, rising sea levels seem to have contributed to the extinction of horned turtles, adds Gilbert Price, who researches extinctions at the University of Queensland in Brisbane. Gilbert says the research is "one of the few studies that have shown a significant crossover between humans and extinct megafauna, not just for Vanuatu, but the southwest Pacific more broadly."

The research is published today in the Proceedings of the National Academy of Sciences.

http://www.australiangeographic.com.au/journal/fearsome-giant-turtles-found-in-pacific-cemetery.htm

Deep sea fish 'mystery migration' across Pacific Ocean (via Lindsay Selby)

Deep sea fish species found in the north Pacific Ocean have mysteriously been caught in the southwest Atlantic, on the other side of the world.

Deepwater travellers: A) deepwater slipskin and B) gonate squid

Photos: A Arkhipkin

It is unclear how the animals, a giant rattail grenadier, pelagic eelpout and deep sea squid, travelled so far.

Their discovery 15,000km from their usual home raises the possibility that deep sea currents can transport animals from one polar region to another.

An out of place rattail

Details are published in the journal Deep Sea Research part I.

"These findings were completely unexpected," says Dr Alexander Arkhipkin of the Falkland Islands Fisheries Department, based in Stanley, on the Falkland Islands in the southwest Atlantic Ocean.
Since 1987, the Falkland Islands Fisheries Department has performed surveys of fish caught by commercial and research fishing trawlers travelling above the Patagonian Shelf and slope around the islands.

Commercial longline catches of Patagonian toothfish have also been examined.

Recently, these catches have brought to the surface animals previously unknown in the southwest Atlantic.

For example, Dr Arkhipkin and colleagues Dr Vladimir Laptikhovsky and Dr Paul Brickle report a 81cm-long grenadier fish belonging to the genus Albatrossia caught by the longline fishery set to catch Patagonian toothfish.

Another deepwater trawl caught a small 15cm-long pelagic eelpout at a depth of 1000m.

Experts have identified this fish as being a member of the slipskin species Lycodapus endemoscotus.


Previously both species were only known from the deepwaters of the north Pacific Ocean.

A small immature 11cm-long north Pacific gonate squid Gonatopsis octopedatus was also recovered from a trawl south of the Falkland Islands.

Genetic analyses confirmed the identification, which is the first time any member of this squid genus has been recorded in the southern hemisphere.

The catches are the first time that such deepwater species have been caught so far from their natural habitat.

All three species habitually live in the deep waters of the north Pacific, at depths greater than 600-1000m.

That makes it extremely unlikely that the fish and squid could have become trapped in ballast water used by ships, and transported around the world.

"We would not expect that relatively slow deepwater fish and squid might travel so far from their common habitats," says Dr Arkhipkin
All three species live above the seafloor, and none of the three are known to habitually migrate, just as tuna and whales do.


Far more likely is that each animal was transported thousands of kilometres by deepwater currents.

These flow south, across the equator, moving past South America underneath another northbound flow called the Humboldt Current.

Finally, this flow mixes with another called the Upper Circumpolar Deep Water to pass through the Drake Passage, whcih separates South America and Antarctica, to the Southwest Atlantic.

Such deep water currents flow slowly, so it may take a few years for a long-lived fish, or even several generations of short-lived fish or squid to migrate the whole way.


Dr Arkhipkin says the catches may force scientists to reevaluate their ideas about the distribution and movements of deepwater species.

Though there is no evidence to support the idea, Dr Arkhipkin speculates that climate change may be influencing the deepwater currents, facilitating the novel spread of such animals.