A group of Indian fishermen have threatened to commit suicide unless the authorities take necessary action to stop other fishermen from using prohibited purse seine and hair nets. The banned equipment can catch at least three tonnes of fish and sea food in a single trip; efficiently depriving lawful fishermen of fish.

According to the affected fishermen, roughly 300 boats continue to use prohibited fishing gear in the waters off Ramanathapuram. Since the present regulation against the practise has proven ineffective, the fishermen now demand confiscation of boats and nets from unlawful fishermen. Officials from the fisheries department have expressed powerlessness, since the unlawful fishermen enjoy political patronage.

Located in India’s south-eastern coastal region, close to Sri Lanka, Ramanathapuram is a city and a district in the Tamil Nadu state.

In May this year, hundreds of Asian swamp eels were discovered in and around Silver Lake in historic Gibbsboro, New Jersey. This was the first finding in New Jersey, Asian swamp eelbut not the first finding in the United States. Unlike Florida, Georgia, and Hawaii – the three other U.S. states where this species have been discovered – New Jersey is however subjected to harsh winters and a breeding population of Asian swamp eels in New Jersey confirms the suspicion that this Asian invader has no problem adjusting to the
chilly climate of northern North America.

The Asian swamp eels were found by a local college student checking on frogs and turtles in the Silver Lake. As he spotted snake-like heads peeking from the water, he decided to photograph them and post the pictures online. This lead to the “snakes” being identified as Asian swamp eels, Monopterus albus, and prompted a call to the local authorities.

In its native environment in Asia and Australia, the swamp eel Monopterus albus inhabits gentle hill streams, estuaries and lowland wetlands, and it is a common species in rice paddies. It has developed a long row of traits that makes it an apt survivor in many different kinds of environments. Unfortunately, these traits also make it the “perfect” invasive species and biologists fear that the Asian swamp eel may wreck havoc with existing North American ecosystems, especially if the predatory species of these systems prefer to target familiar prey rather than catching the newcomers.

– The Asian swamp eel can survive long periods of drought by burrowing in moist earth, and can therefore take advantage of seasonally appearing, short-lived bodies of water.

– If its home becomes unsuitable, e.g. because of drought, this eel simply crawls ashore and make its way to a more suitable home by slithering over land, just like a snake. This makes it hard to eradicate from bodies of water using poison or similar; there is always the risk of at least two specimens getting away over land and forming a new breeding colony in nearby waters.

– The Asian swamp eel can tolerate a wide range of oxygen levels in the water since it is capable of absorbing oxygen from the air above the surface through its skin. This skill doesn’t only come in handy in oxygen depleted waters; it is also what makes it possible for the fish to travel impressive distances over land.

– This eel prefers freshwater habitats, but can tolerate brackish and saline conditions, which increases its chances of always finding a suitable home.

– It eats all sorts of prey, not only fish, crustaceans, amphibians, and other aquatic animals, but detritus (decaying organic matter) as well. Highly specialized feeders have a much harder time adjusting to new habitats and are therefore less likely to become problematic invasive species.

– This eel is a protandrous hermaphrodite, which means that it can change its sex. All specimens are born male, but can turn into females if necessary. This means that if an aquarist releases two male specimens into a lake, one of them can turn into a female to make reproduction possible.

In Georgia, the first specimens of Asian swamp eel was discovered in 1994, and three years later eels were found in Florida as well. The Hawaiian history of combating swamp eels is much longer as the first specimens are believed to have been released in Hawaiian waters about 100 years ago. In Georgia and New Jersey, biologists blame aquarists of having caused the situation by releasing their pets into the wild. In Florida and Hawaii however, Asian food markets and fish-farmers are considered more likely sources. Asian swamp eels are typically sold fresh in food markets and can be kept alive for long periods of time as long as their skin is kept moist.

New Jersey authorities are now focusing on containing the creatures while trying to figure out a way of annihilating them. “We’re not panicking yet,” says Lisa Barno, chief of the New Jersey Bureau of Freshwater Fisheries. “It’s more that it’s just an invasive species we’d rather not have. We’re still documenting the true extent of the problem, but right now it seems to be fairly contained.” One of the immediate goals is to prevent an expansion downstream to the Cooper River and a watershed leading to the Delaware River. Since May, only one Asian swamp eel has been discovered outside the Silver Lake.

In addition to the recently proposed areas in the Pacific Ocean, (See this and this) president Bush now says he wants to find even more regions of the Pacific Ocean to protect.

This Friday, Bush made public that he has asked the secretaries of the Interior, Commerce and Defense to identify additional areas of the Pacific Ocean that could be eligible for conservation. He also revealed that the Monterey Bay National Marine Sanctuary will be expanded by 585 square nautical miles and come to include the Davidson Seamount. Davidson Seamount is a 42 km long underwater mountain located roughly 120 km southwest of Monterey, California. The seamount rises 2400 meters off the ocean floor, but its highest point is still more than a kilometre below the surface.

The Caspian Sea has traditionally been the world’s main source of caviar, but pollution and overfishing has caused serious problems for the fish in this enormous lake and yields are dwindling at a worrisome pace. The Caspian crisis is now prompting an increasing number of restaurants and importers to switch to Israeli caviar instead.

Sturgeon in pond – Not the facility talked about in the article

In Israel, Ossetra sturgeon (Acipenser persicus / Acipenser gueldenstaedtii) is commercially farmed at the Kibbutz Dan close to the Lebanese border, using eggs imported from the Caspian Sea. Compared to caviar from the Beluga sturgeon (Huso huso), Ossetra caviar – also known as Osetra or Asetra caviar – is firmer in texture and has the most variety in terms of size, color and flavor.

Kibbutz Dan began their Ossetra project in 2003, when caviar prices skyrocketed and made sturgeon roe even more expensive than before. The idea was not primarily to export caviar, but to satisfy the demands of the large Russian-Israeli population, according to Ben Tzvi at Kibbutz Dan. The location of the sturgeon fish farm is well chosen since it can use water from the snow-fed river Dan, a principal source of the river Jordan.

Under normal conditions, a female Ossetra sturgeon will not become sexually mature until she is around 15 years old, but Israeli biologist Avshalom Hurvitz has managed to make female sturgeons commence egg-laying at an age of just 8 or 9 years.

So, is sturgeon roe really kosher? Since the sturgeon is considered a scale-less fish, it is seen as forbidden food according to traditional Jewish dietary laws. However, according to Berta Levavi-Sivan, a scientist at the Hebrew University and a participant in the sturgeon-rearing project, the sturgeon fish is actually equipped with tiny scales – it is has only been considered a scale-less fish because the scales are too small to bee seen with the naked eye.

In a new study on Tanganyika cichlids, three scientists[1] [2] [3] from Uppsala University in Sweden have shown that intricate rearing behaviour varies with brain size in females. The only previously published study showing similar patterns concerned predatory animals.

Tropheus moori – one of the species used in the study. – Picture www.jjphoto.dk

How the vertebrate brain has developed throughout the course of evolution is still not clear, and we are still not certain if brain functions in a specific species develop to match a demanding environment. One way of learning more about this is to compare brain size and structure in closely related species living under dissimilar circumstances.

“It is important to look at differences between males and females since females often distinguish themselves from males, both in behaviour and appearance”, says Niclas Kolm, lead-author of the study.

The study looked for correlations between brain size and ecological factors in a large number of specimens from 39 different species of Tanganyika cichlid. Lake Tanganyika is especially suitable for this type of study since it is inhabited by cichlid groups exhibiting significant dissimilarities in both brain structure and ecology, and whose ancestry is well known. Tanganyika cichlids varies dramatically from species to species when it comes to factors such as body size, diet, habitat, parental care, partner selection, dissimilarities between the sexes, mating behaviour, and brain structure.

The result of the study showed a correlation between brain size and the two factors diet and parental care behaviour. Species where only the female fish cares for egg and fry turned out to have bigger brains than species where both parents engage in parental care. The brain was however only larger in females; there was no difference in brain size between males of the two groups.

The largest brains of all were found in algae-eating cichlids. These fishes live in environments characterized by a high level of social interaction. “This indicates that social environment have played a role in brain development”, says Kolm.

The study was published in the web version of “Proceedings of the Royal Society of London Series B” on September 17. You can find it here (http://journals.royalsociety.org/content/j114062824820l76/).

According to a new study from Uppsala University, the origin of fingers and toes can be traced back to a type of fish that inhabited the ocean 380 million years ago. This new finding has overturned the prevailing theory on how and when digits appeared, since it has long been assumed that the very first creatures to develop primitive fingers were the early tetrapods, air-breathing amphibians that evolved from lobed-finned fish during the Devonian period and crawled up onto land about 365 million years ago.

Lead author Catherine Boisvert[1] and co-author Per Ahlberg[2], both of Uppsala University in Sweden, used a hospital CT scanner to investigate a fish fossil still embedded in clay. “We could see the internal skeleton very clearly, and were able to model it without ever physically touching the specimen,” says Ahlberg. The scan revealed four finger-like stubby bones at the end of the fin skeleton. The bones were quite short and without joints, but it was still very clear that they were primitive fingers. “This was the key piece of the puzzle that confirms that rudimentary fingers were already present in the ancestors of tetrapods,” Catherine Boisvert explains.

The scanned fossil was that of a meter-long Panderichthys, a shallow-water fish from the Devonian period. Panderichthys is an “intermediary” species famous for exhibiting transitional features between lobe-finned fishes and early tetrapods, while still clearly being a fish and not a tetrapod. The specimen used was not a new finding; it had just never been examined with a CT scan before.

So, why have researchers for so long assumed that digits were something that evolved in tetrapods without being present in their fishy ancestors? The main reason is the Zebra fish (Danio rerio), a commonly used model organism when vertebrate development and gene function is studied. If you examine a Zebra fish, you will find that genes necessary for finger development aren’t present in this animal. Researchers therefore assumed that fingers first appeared in tetrapods and not in fish.

It should be noted that similar rudimentary fingers were found two years ago in a Tiktaalik, an extinct lobe-finned fish that lived during the same period as Panderichthys. Tiktaalik is however more similar to tetrapods than Panderichthys.

The Panderichthys study was published in Nature on September 21.

This week, Science published the study “Can Catch Shares Prevent Fisheries Collapse?” by Costello[1], Gaine[2] and Lynham[3], which may be used as a road map for federal and regional fisheries managers interested in reversing years of declining fish stocks.

The study has already received a lot of praise from environmental groups, including the Environmental Defense Fund (EDF) who says that the study shows how the overfishing problem can be fixed by implementing catch shares. “We can turn a dire situation into an enormous opportunity to promote better food security, create jobs and revive ecosystems,” says David Festa, vice president and director of the oceans program at EDF.

Catch share programs is intended to replace complex fishing rules and hold fishermen directly accountable for meeting scientifically determined catch limits. In a catch share program, fishermen are granted a percentage share of the total allowable catch, individually or in cooperatives. They can also be given exclusive access to particular fishing zones, so called territorial use rights. As long as the fishermen do not harvest more than their assigned share, they will retain a comparatively high flexibility and decide for themselves when to carry out the fishing, e.g. depending on market fluctuations and weather conditions.

“The trend around the world has been to fish the oceans until the fish are gone,” says Festa. “The scientific data presented today shows we can turn this pattern on its head. Anyone who cares about saving fisheries and fishing jobs will find this study highly motivating.”

As the fishery improves, each fisherman will find that the value of his or her share grows. This means that fishermen will be financially motivated to meet conservational goals.

In January 2007, a catch share system for red snapper went into effect in the Gulf of Mexico, causing the 2007 commercial snapper season to be open 12 months a year for the first time since 1990. According to EDF, fishermen in the area now earn 25% more and wasteful bycatch has dropped by at least 70%.

Hundreds of new animal species have been discovered by marine researchers studying Australian reefs as a part of the Census of Marine Life, an international effort to catalogue all life in the oceans. The findings include such curious creatures as tongue-eating isopod parasites living on fish and several new species of tanaid crustaceans, some with claws longer than their bodies. The team also found about 150 species of soft coral thought to be new to science, scores of tiny amphipod crustaceans of which an estimated 40 to 60% will be formally described for the first time, and dozens of small crustaceans likewise believed to be unknown to the scientific community. Researchers actually suspect that one or even several new families of species are to be found among the sampled crustaceans.

The investigated locales are the Lizard and Heron Islands (part of the Great Barrier Reef), plus the Ningaloo Reef off north-western Australia. All locations are considered well known and popular among scuba divers, and the research team was therefore quite surprised when they stumbled upon such a prolific collection of species unknown to science. This shows how little we still know about the species that inhabit our planet; even the ones living in habitats frequented by hundreds or even thousands of people each year.

Map of locations

“People have been working at these places for a long time and still there are literally hundreds and hundreds of new species that no one has ever collected or described,” says Julian Caley, a scientist from the Australian Institute of Marine Science who is helping to lead the research. “We were all surprised and excited to find such a large variety of marine life never before described – most notably soft coral, isopods, tanaid crustaceans and worms – and in waters that divers access easily and regularly. Compared to what we don’t know, our knowledge of marine life is a proverbial drop in the ocean. Inventorying the vast diversity and abundance of life across all ocean realms challenges both science and the imagination.”

In order to aid future explorations, researchers left several “houses” – formally known as Autonomous Reef Monitoring Structures (ARMS) – for marine creatures to colonize on the ocean floor. The houses consist of layered plastic structures and have been designed to appeal to a variety of sea life. Over the next one to three years, the houses will be collected and their tenants investigated.

See pictures of some of the creatures here

The Census of Marine Life (www.coml.org) is a global network of researchers in more than 80 nations engaged in a 10-year initiative to assess and explain the diversity, distribution, and abundance of marine life in the oceans – past, present, and future. The network will release the first Census of Marine Life in 2010.

As you probably know already, many sea living creatures are capable of emitting their own fluorescent light. Turning yourself into a living light bulb comes in handy when you live at depths where no sunlight or only very little sun light is capable of reaching you, and the glow can for instance be used for communication, as camouflage, or to lure in prey.

Up until now, most fish experts have assumed that marine fish living below a depth of 10 metres (30 feet) could not be red since the type of sunlight necessary for the colour red to be visible to the eye isn’t capable of travelling so far down into the ocean, and why would an animal develop a red pigmentation that nobody could see in its natural habitat?

New light has now been shed on the situation and – according to a study published on September 15 by researchers at the University of Tubingen in Germany – fish living at these depths have managed to circumvent the problem of light scarcity by emitting their own red fluorescent light instead of relying on sun beams to display their colours. According to the study, a lot of marine species are capable of emitting a fluorescent red light which can be seen even at depths below 10 meters.

“The general consensus, which dominated fish literature for 20 or 30 years, was that fish don’t see red very well or at all,” says Nico Michiels, one of the researchers behind the study. “We have been blinded, literally, by the blue-green light that is available on reefs in the daytime.”

The scuba diving research team made their discovery when looking through a filter that blocked out the brighter green and blue light waves. While using the filter – which leaves only red light waves – the scientists realised that their dive spot was inhabited by a long row if different marine creatures capable of emitting their own red light. In addition to fish, they saw fluorescent red coral, algae and other small organisms.

Further investigation revealed that the red glowing organisms use guanine crystals to produce their light. Guanine is one of the five main nucleobases found in DNA and RNA and guanine crystals are commonly used by the cosmetics industry to give products such as shampoo, eye shadows and nail polish a shimmering lustre. As early as 1656, a Parisian rosary maker named François Jaquin extracted crystalline guanine forming G-quadruplexes from fish scales – so called pearl essence. Guanine crystals are rhombic platelets composed of multiple transparent layers and the pearly lustre appears when light is partially reflected and transmitted from layer to layer.

The red fluorescent light emitted by the organisms studied by Michiels and his colleagues is only visible at a close distance, at least to us humans. More research is now needed to investigate why so many sea dwellers have developed this capacity and how the red colour benefits them in their daily life.

According to Korean scientists, brass can be used to make shellfish a safer choice at the dinner table. “We showed that copper ions diffuse out from a brass plate into a fish tank filled with seawater, and within 40 hours the copper killed 99.99% of the Vibrio food poisoning bacteria contaminating the living fish and shellfish,” says Dr Jeong-Weon Huh from the Department of Health Research at the Gyeonggi-do Institute of Health and Environment.

When a brass plate is placed in a tank filled with seawater, copper ions will diffuse out from it and be absorbed by the Vibrio bacteria, causing them to die and fall of infested fish and shellfish. The copper will not only kill bacteria present on the outside of the animal, it will also get into the internal organs and kill Vibrio bacteria there. The dead bacteria will then be flushed out of the animal and sink to the bottom of the tank.

So, is this a safe method? According to Dr Huh¸ any remaining copper ions in the saltwater will be absorbed by sand and polyester filters and leave fish and shellfish suitable for consumption. “By being able to remove the copper ions, we can prevent people from consuming excess copper themselves, but let them safely enjoy any kind of fish, either raw or cooked.”

Raw fish and shellfish forms a major part of traditional Korean cuisine and finding a way of reducing the risk of food poisoning is high on the agenda for the Gyeonggi-do Institute of Health and Environment. Between 2003 and 2006, roughly 12 percent of food poisoning cases in Korea were caused by Vibrio bacteria. According to Korean tradition, the safest way to serve food is in a so called bangzza bowl – a bowl made from a 78% copper and 22% tin mixture. The researchers have now managed to show that this metal mixture emits enough copper ions to kill off nasty microbes like Vibrio bacteria. Using this traditional type of kitchenware might be a feasible way to prevent serious gastrointestinal infections in situations when it is difficult to uphold a high level of hygiene and sanitation.

Dr Jeong-Weon Huh revealed his findings at the Society for General Microbiology’s autumn meeting at Trinity College, Dublin.