Fish and aquatic news

After being exhibited for two months at the Monterey Bay Aquarium, a young female white shark was released back into the ocean Wednesday this week.

“I’ve always said that these animals will tell us when it’s time to put them back to the ocean. Now was clearly the time,” said Randy Hamilton, vice president of husbandry for the aquarium.

The release was prompted by a change in behaviour; she started acting aggressive towards other sharks in the million-gallon aquarium and during the Halloween weekend she received a superficial bite wound. She also injured a galapagos shark by biting it and was observed chasing the scalloped hammerhead sharks.

“We monitor the behavior of great white sharks very closely while they’re on exhibit,” Hamilton explained. “When we saw a new pattern of aggressive behavior, we decided it was best to release her.”

The young female was the fifth great white shark exhibited and successfully released back into the wild by the aquarium. Monterey Bay Aquarium is the only institution to keep a great white shark on exhibit for more than 16 days, get the shark to consistently take food from the staff, and document the animal’s successful return to the sea.

Just like this young female, the four previously released great white sharks were fitted with electronic tracking tags which make it possible to confirm the shark’s successful adaptation back into the wild. Two of the sharks travelled to the southern tip of Baja California and beyond after being released, while the third one opted for Santa Barbara waters. The fourth shark also stayed near Santa Barbara where it was caught and released by a commercial fisherman just a few days after being released from the aquarium and it was then reportedly in good health.

The female shark released this week has been fitted with two tracking devices; one that will deliver real-time data on her location and one that will collect and store information about her travels, the depths she dives to and the water temperatures she favours for about six months, before it pops free and delivers those data to scientists via satellite.

You can find the real-time data emitted by the first device on the TOPP website (Tagging of Pacific Predators): http://www.topp.org .

The shark was released in offshore waters near the southern tip of Monterey Bay shortly after sunrise.

“Her health is excellent, and we learned a lot while she was with us. Based on past experience, we have every expectation that she’ll do well after release,” said Hamilton.

During her two month long stay (69 days to be exact) in the aquarium, she grew from 5-foot 3-inches to 5-foot 5-inches and put on an extra 20 pounds. She ate mackerel only and would happily gulp down up to three percent of her body weight in a day.

The exhibit of young great white sharks is part of the Monterey Bay Aquarium’s effort to change public attitudes towards the feared white sharks and raise awareness about the threats facing them in the wild. The first white shark was exhibited in 2004/2005 and was seen by over a million visitors before being released after six months in captivity. Collectively, the four sharks exhibited before the newest addition has been seen by almost 2.5 million visitors.

“I can’t overstate the impact of this single animal on advancing our mission to inspire conservation of the oceans,” aquarium Executive Director Julie Packard said of the first white shark the aquarium had on exhibit.

The million-gallon Outer Bay exhibit will undergo renovations starting late August 2010 and it will therefore not be possible to see any great white shark at the aquarium until summer 2011 at the earliest.

Europe’s first artificial surf reef was officially launched this Monday. Around a dozen surfers and body boarders headed for the waves as soon as the Bournemouth Borough Council declared the reef open.

As reported earlier, the artificial reef – which is located in Boscom on UK’s South Coast – consists of big geo-textile bags pumped hard with sand and aids in the formation of powerful barrel waves by pushing the naturally occurring waves upwards.

Prior to the opening, surfers had expressed fears that the reef was too big, situated the wrong way around, located on the wrong side of the pier, and potentially dangerous, so many eyes are now carefully monitoring the project to see if it’s a flip or flop.

“We have now got to give it the chance to see if it [the reef] does perform against the criteria that we have agreed with them,” says Roger Brown, the council’s director of leisure services.

Sean Wade, from Sorted surf shop, said: “Longer term it will need tweaking but with any project it is finding out how it works and what the best conditions are. Yesterday it looked pretty amazing.”

The artificial reef is part of the £8 million Boscombe Spa Regeneration Project funded through the sale of a seafront car park to a company that will use the space to build flats. On days with good swell, the new reef is expected to provide grade five waves.

Last month, 82 Green sea turtles hatched at SeaWorld in San Diego, California.

The eggs hatched on Shipwreck Beach and the youngsters didn’t need any human aid to get out of their shells and into the water. The park had decided to let nature take its course by refraining from incubating the eggs or help the hatchlings emerge. SeaWorld are now planning to dig up the beach to check if any buried eggs failed to hatch.

At the moment, the baby sea turtles are roughly one month old and only weigh a few grams. They happily feed on squid, shrimp, krill and special pellets. Assistant curator of fishes Tim Downing says they are all in excellent health and that they will go on display before the end of the year.

“There is so much that is not known about sea turtles,” said Downing. “We are getting real good information on the growth rate of juveniles. They are all gaining weight and doing well. We have done some X-rays, and they are progressing just like we would expect them to.”

SeaWorld is home to 30 adult sea turtles, including four Green sea turtles – three females and one male. They have been living at SeaWorld since the 1960s and are sexually mature, so all three females may have buried eggs in the sand. Only genetic testing will be able to reveal the maternity of each baby turtle.

All seven species of sea turtle in the world are endangered or threatened, with the Green sea turtle being listed as Endangered on the IUCN Red List of Threatened Species. It will be up to the National Marine Fisheries Service and the U.S. Fish and Wildlife Service to determine whether the new turtles will stay at SeaWorld and whether the adult turtles will be given opportunity to mate again next year.

A new method for distinguishing between tuna species has been presented in a paper co-authored by Dr Jordi Viñas, a fish genetics specialist at Girona University in Spain and Dr Sergi Tudela, Head of Fisheries of WWF Mediterranean.

The new method is based on gene sequencing and the researchers hope that it will support fisheries management and make trade restrictions possible for endangered species of tuna, since it can be used to accurately identify the species from any kind of processed tuna issue. It works for all eight recognized species of tuna, including highly endangered species like the Southern and Pacific bluefin tuna.

The true tunas belong to the genus Thunnus and are among the most endangered of all commercially exploited fish. They are also high priced, so when you pick up some cheap tinned fish in the supermarket the box will rarely contain Thunnus; the content will in most cases have been made from fish belonging to related families such as mackerels.

The Principality of Monaco has already lodged an application before the Convention on International Trade in Endangered Species (CITES) for a trade ban on the endangered Atlantic (Northern) bluefin tuna.

The paper – “A Validated Methodology for Genetic Identification of Tuna

Species (Genus Thunnus)” - was published on October 27 in the journal PLoS ONE.

http://www.plosone.org/

The Monterey Bay Aquarium has launched a national campaign asking top U.S. chefs and culinary decision makers to take a “Save Our Seafood” pledge not to serve items listed in the “avoid” section of the Monterey Bay Aquarium Seafood Watch List.

Seafood Watch is one of the best known sustainable seafood advisory lists, compiled by the Monterey Bay Aquarium. The origin of the list can be traced back to the “Fishing for Solutions” exhibit which ran at the Monterey Bay Aquarium from 1997 to 1999.

The list consists of an avoid list and a good-alternative list and is updated twice a year. The website (http://www.montereybayaquarium.org/cr/seafoodwatch.aspx ) is updated even more frequently.

“Ocean life is still in decline and we clearly need to take urgent action to turn things around,” said aquarium Executive Director Julie Packard. “The good news is that we know what it will take, and that key players are working more closely than ever to solve the problems. I’m confident that we can and will create a future with healthy oceans.”

So far, about two dozen top culinary professionals from across the nation have agreed to adhere to the list, including Susan Spicer (Bayona, New Orleans), Rick Bayless (Frontera Grill/Topolobampo, Chicago), Suzanne Goin (Lucques, Los Angeles), Mary Sue Milliken and Susan Feniger (Border Grill/Ciudad, Los Angeles), Fedele Bauccio (Bon Appetit Management Co., Palo Alto), Rick Moonen (rm seafood, Las Vegas), Michelle Bernstein

(Michy’s, Miami), Alton Brown (Be Square Productions, Atlanta), and Michel Nischan (The Dressing Room, Westport, Conn.).

Monterey Bay Aquarium is also working with 14 nonprofit organizations across the United States and Canada as part of the Conservation Alliance for Seafood Solutions (www.solutionsforseafood.org). Participating organizations have crafted a Common Vision for Environmentally Sustainable Seafood to help seafood buyers and suppliers develop comprehensive, corporate policies on sustainable seafood. Since the debut of the Common Vision in 2008, more than 20 major companies across North America have pledged their support.

The amazing eyes found on the mantis shrimp may inspire a new generation of CD:s and DVD:s, according to a new study from the University of Bristol.

Odontodactylus scyllarus, a species of mantis shrimp living on Australia’s Great Barrier Reef, has the most complex vision system known to science and can see in twelve colours as opposed to the human eye which only sees in three. As if this wasn’t enough, Odontodactylus scyllarus can also distinguish between different forms of polarized light.

The eyes of this mantis shrimp are equipped with special light-sensitive cells that work like the quarter-wave plates found in CD and DVD players; they can rotate the plane of the oscillations of a light wave as it travels through. Thanks to this feature, the mantis shrimp is capable of converting linearly polarized light to circularly polarized light and vice versa.

The design and mechanism of the quarter-wave plate in the mantis shrimp’s eye outperforms anything manmade. While the quarter-wave plates found in CD and DVD players tend to work well for one colour of light only, the mantis shrimp can convert light across the whole visible spectrum, i.e. from infra-red to nearly ultra-violet.

“What’s particularly exciting is how beautifully simple it is,” said Dr Roberts, lead author of the article. “This natural mechanism, comprised of cell membranes rolled into tubes, completely outperforms synthetic designs. It could help us make better optical devices in the future using liquid crystals that have been chemically engineered to mimic the properties of the cells in the mantis shrimp’s eye.”

How the mantis shrimp benefits from having this ability remains unknown, but polarization vision is sometimes used by animals to secretly communicate within their own species without catching the attention of predators. Also, it might make it easier for the mantis shrimp to see under water, which would come in handy when hunting for prey.

The research was carried out at the University of Bristol’s School of Biological Sciences in the UK in collaboration with researchers at the University of Queensland, Australia and the University of Maryland, Baltimore County, USA.

The paper was published in Nature Photonics on October 25.

http://www.nature.com/nphoton/

http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2009.189.html

The fossilised skull of a gigantic predator has been found off the English Channel coast of southern England.

The skull is 2.4 meters long and scientists believe it once belonged to a 16 meter long pliosaur which probably weighed an impressive 12 tons.

The pliosaurs were a type of ocean dwelling reptiles that dominated the seas roughly 150 million years ago.

The man behind the discovery is fossil hunter Kevin Sheehan from Dorset who gradually uncovered the remains of the fragmented skull over a number of years.

“In 40 years of collecting, I have often been green with envy at some of the finds other people have made“, said Sheehan. “But now when someone shows me a find, I can say ‘That’s not a fossil, this pliosaur, that’s a fossil’.”

The fossilised skull is 90% complete and clearly shows the jaws of a powerful predator.

“These creatures were monsters”, says Dr David Martill, a palaeontologist from the University of Portsmouth. “They had massive big muscles on their necks, and you would have imagined that they would bite into the animal and get a good grip, and then with these massive neck muscles they probably would have thrashed the animals around and torn chunks off. It would have been a bit of a blood bath.”

Martill suspects that the skull may belong to a species of pliosaur that haven’t been unearthed until now.

“This is one of the largest, if not the largest, pliosaur skull found anywhere in the world and contains features that have not been seen before“, he explains. “It could be a species new to science.”

The skull has been purchased by the Dorset County Council and will be displayed in the county museum.

The Zoological Society of London (ZSL) has announced their plans to create a cryobank for corals. Corals will be collected from tropical areas and placed in liquid nitrogen at the Whipsnade zoo in Bedfordshire.

“Carbon dioxide emissions are rising fast and are already above the safe level for corals,” said Dr Alex Rogers, head of marine biodiversity at the ZSL. “Some reefs are already beginning to fail and many will die within a few decades. We need a plan B, and freezing them is the best option.”

The idea of creating a coral cryobank stems from similar projects concerning seeds, such as the Svalbard Global Seed Vault where seeds from all over the world are preserved inside a cool cavern on Spitsbergen, north of mainland Norway.

Storing coral for prolonged periods of time without killing them was made possible quite recently thanks to a new method developed by researcher Craig Downs of the Haereticus Environmental Laboratory.

“We can take 1mm-2mm biopsies from coral, freeze them at -200C and thaw them out to regenerate back into a polyp,” says Downs, who is now working with the ZSL. “We are proposing to do this for every species of coral on the planet.”

Roughly 3,350 cold-water corals and about 1,800 tropical coral species are currently know to science. Downs proposes keeping 1,000 samples of each at the zoo.

The Smithsonian Institution in Washington is now discussing setting up their own coral sample facility to alleviate the risks of having just one coral sample storage in the world.

Charlie Veron, former chief scientist of the Australian Institute of Marine Science, said he supported the efforts but warned it was no consolation for the eradication of reefs. According to Veron, endeavours such as cryobanks, genetic make-up preservation, and coral aquariums aren’t meaningful.

“These are not solutions,” says Veron. “Because Australia is home to the biggest coral reef in the world, it should concentrate all its efforts into helping the Great Barrier Reef survive. Personally, I feel it’s no compensation to know that the genetic information of corals is kept in machines.”

An algae bloom stretching from the Olympic Peninsula in Washington state to the northern parts of Oregon has killed thousands of seabirds by stripping them of the natural oils that keep them waterproof. Without these oils, seabirds quickly get wet and succumb to hypothermia.

“This is huge,” says Professor Julia Parrish, a marine biologist who leads a seabird monitoring group at the University of Washington. “It’s the largest mortality event of its kind on the West Coast that we know of.”

Similar mass-deaths have taken place along the coast of California before, but this is the first time it is reported from the states of Oregon and Washington. Also, as far as we know, the California die-offs affected hundreds of seabirds, not thousands.

The so called algae “bloom” consists of tiny single-celled algae of the species Akashiwo sanguinea.

Marine biologists have not been able to determine the reason for the sudden appearance of up to a million Akashiwo sanguinea cells per litre seawater, but recent storms in the area may have contributed to the severity of the problem by breaking up the algae.

When the algae get whipped, it turns into what can best be described as a bubbly soap which sticks to the seabirds.

“It looks like they’re [the seabirds] lying in a sea of bubble bath,” said Greg Schirato, regional wildlife program manager for the Washington Department of Fish and Wildlife.

The Indonesian Navy (TNI AL) has officially announced that they are deploying five warships and one reconnaissance plane to protect the Natuna waters from illegal fishing and poaching.

“The five warships and reconnaissance plane have conducted routine patrols in the Natuna waters as part of efforts to reduce the number of fish thefts,” S.M. Darojatim, Commander of the Main Naval Base IV Commodore, announced Tuesday.

He also stated that the Natuna waters and the South China Sea were vulnerable to a number of criminal offences, including fish and coral thefts.

“The Pontianak naval base has so far secured the West Kalimantan waters well so that it sets a good example to other naval bases to safeguard the Indonesian waters,” said the commander.

Natuna Sea Facts

The Natuna Sea is a part of the South China Sea and home to an archipelago of 272 islands, located between east and west Malaysia and the Kalimantan (the Indonesian portion of the island Borneo). The islands form a part of the Indonesian Riau province and is the northernmost non-disputed island group in Indonesia.

The islands are populated with roughly 100,000 people, most of them farmers and fishermen. The beaches are important nesting sites for sea turtles and the surrounding waters are filled with biodiverse coral reefs. The archipelago is also famous for its rich avifauna with over 70 different described species of bird, including rare ones like the Natuna Serpent-eagle and the Lesser Fish-eagle. The islands are also home to primates, such as the Natuna Banded Leaf Monkey which is considered one of the 25 most endangered primates in the world.

According to geologist James W. Castle and ecotoxicologist John H. Rodgers, both of the Clemson University in South Carolina, toxin-producing algae caused or contributed to the mass extinction of dinosaurs.

After spending two years analyzing data from ancient algal deposits, so called stromatolite structures, the researchers have found evidence that blue-green algae where present in sufficient quantities to kill off countless numbers of plants and animals living in the ocean or on land at the time. Blue-green algae may not seem very harmful, but they produce toxins and deplete oxygen.

Other researchers have suggested that phenomena such as volcanic activity, climate change, sea level changes or asteroids are responsible for the five major extinctions and a number of other significant die-offs during the part of Earths history during which life with skeletons or shells have existed. According to Castle and Rodgers, all these phenomena contributed to the mass deaths but algae was the most important factor.

“The fossil record indicates that mass extinctions… occurred in response to environmental changes at the end of the Cretaceous; however, these extinctions occurred more gradually than expected if caused solely by a catastrophic event,” Castle and Roger argue in their work.

The part of the study that has caused the most debate so far is the warning that current global warming may cause similar die-offs, since our current environmental conditions show significant similarity to times when mass die-offs have occurred.

“This hypothesis gives us cause for concern and underscores the importance of careful and strategic monitoring as we move into an era of global climate change,” Castle and Roger writes, adding that the level of “modern toxin-producing algae is presently increasing, and their geographic distribution is expanding… “

The paper has already gained a lot of attention within the scientific community.

“Scientists from around the world have been sending us data that support our hypothesis and our concern about the future,” says Rodgers. “I look forward to the debate this work will generate. I hope it helps focus attention on climate change and the consequences we may face.”

You can download the entire “Hypothesis for the role of toxin-producing algae in Phanerozoic mass extinctions based on evidence from the geologic record and modern environments” from Clemson University.

http://www.clemson.edu/media-relations/files/articles/2009/2336_295_mass_extinctions.pdf

The work has also been published in the March 2009 issue of the journal Environmental Geosciences.

In order to survive until it becomes a skilled hunter, a shark pups is born with an enlarged “super liver” that functions as a food source for several months.

This new finding have surprised marine scientists, because shark pups were believed to suffer from a high mortality rate because they had to find food immediately after being born.

“They’re much more likely to survive when they’re born than we previously thought,” says Australian Institute of Marine Science researcher Aaron MacNeil.

Unlike live-bearing sea mammals like dolphins and whales, live-bearing shark mothers do not produce milk for their offspring. Until know, researchers assumed that the shark mothers didn’t invest much energy into keeping the offspring alive once it was born, but the new finding changes this perception radically. The shark mother is effectively sending her young off with a liver so packed with energy and nutrients that it keeps the baby fed for several months.

“It is likely that the liver reserves enable the newborn sharks to acclimatize themselves to their environment and to develop their foraging skills,” says lead researcher Nigel Hussey, “We know that large sharks use their livers as an energy store, but we had no idea that the mother provisions her young with additional liver reserves to enhance their survival.”

The research that led to the discovery was carried out by an international team of researchers headed by the Bangor University in Wales.

The annual whale expedition off the Japanese port city of Kushiro ended this weekend after having caught 59 minke whales, the Japanese Fisheries Agency said in a statement.

The whales where caught as a part of a research program that whaling opponents claim is just a cover for commercial whaling. A maximum capture of 60 whales is allowed under this research program, which is authorised by the International Whaling Commission (IWC).

The Fisheries Agency says the goal of the hunt was to study the feeding patterns of the whales and their effect on fish stocks. Initial examination of the stomach contents of the killed mink whales revealed mostly pollack, krill and anchovy. The complete results of the study will be presented at next year’s IWC meeting.

Japan also catches about 1,000 whales in the Antarctic Ocean and the northwest Pacific Ocean each year under another IWC research programme.

Minke Whale Facts

· Once perceived as asingle species, the minke whale population has quite recently been recognized as consisting of two distinct species: the Northern Mink Whale, Balaenoptera acutorostrata, and the Southern Mink Whale, Balaenoptera bonaerensis.

· Also known as Little Piked Whales or Lesser Rorquals, Mink Whales prefer icy waters but are found world-wide.

· Balaenoptera acutorostrata is listed as Least Concern on the IUCN Red List of Threatened Species, while Balaenoptera bonaerensi is listed as Data Deficient since it was recognized as a separate species so recently.

· Together, the two species are believed to form a population of over 1 million Minke Whales world-wide.

Researchers from Emory University have identified the first fish to have switched from ultraviolet vision to violet vision, i.e. the ability to see blue light. This fish in question – a type of scabbardfish – is also the first example of an animal where a deleted molecule has resulted in a change in visual spectrum.

Many species, including humans, have violet vision but our common vertebrate ancestor had UV-vision and could not sense the blue colour spectrum.

All fish studied before the scabbardfish have been found to have UV vision. The scabbardfish is believed to have switched from UV vision to violet vision by deleting the molecule at site 86 in the chain of amino acids that makes up the opsin protein.

“Normally, amino acid changes cause small structure changes, but in this case, a critical amino acid was deleted,” Yokoyama explains.

Vision is of particular interest to evolutionary geneticists since it is a comparatively straight-forward sensory system with a low number of genes involved. Human vision is for instance made possible by no more than four genes.

“It’s amazing, but you can mix together this small number of genes and detect a whole color spectrum,” says evolutionary geneticist and research team leader Shozo Yokoyama. “It’s just like a painting.”

In their study, the Emory researchers linked molecular evolution to functional changes and the possible environmental factors driving them.

“This multi-dimensional approach strengthens the case for the importance of adaptive evolution,” says Yokoyama. “Building on this framework will take studies of natural selection to the next level.”

The Scabbardfish spends most of its life at a depth of 25-100 meters and at these depths UV light is less intense then violet light, something which may have prompted the change in vision. Living deep down in the ocean will however not necessarily make you benefit from a vision switch; the Lampfish has for instance retained its UV vision – most likely because it swims up to the surface at night to feed on translucent crustaceans that are easier to locate if you have UV vision.

“The finding implies that we can find more examples of a similar switch to violet vision in different fish lineages,” says Yokoyama. “Comparing violet and UV pigments in fish living in different habitats will open an unprecedented opportunity to clarify the molecular basis of phenotypic adaptations, along with the genetics of UV and violet vision.”

The article has been published in the October 13 issue of Proceedings of the National Academy of Sciences.

http://www.pnas.org

In addition to evolutionary geneticist Shozo Yokoyama, the research team also included post-doctoral fellow in biology Takashi Tada and post-doctoral fellow in biology and computational chemistry Ahmet Altun.

A research team from the National University of Singapore announced this week that they have created the world’s first semi-cloned fish – a female medaka fish named Holly.

Holly is the result of so called semi-cloning; an approach that leads to the formation of a new and unpredictable combination of genetic traits from both parents, similar to normal fertilization.

The research team also announced that Holly has produced normal offspring that carry a genetic marker also found in her and her parents. According to the team, this indicates that the new technique retains genetic stability.

Holly may aid researchers working with reproductive medicine and technology to find new ways of helping people with infertility problems.

The findings will be published in the October 16 issue of Science Journal.

www.sciencemag.org