[MARINE_BIOLOGY_INTERNATIONAL] Coral could hold key to sunscreen pill


Sydney, NSW - Scientists hope to harness coral's natural defence against the sun's harmful ultraviolet rays to make a sunscreen pill for humans.

The King's College London team visited Australia's Great Barrier Reef to uncover the genetic and biochemical processes behind coral's innate gift.

By studying a few samples of the endangered Acropora coral they believe they can synthetically replicate in the lab the key compounds responsible. Tests on human skin could begin soon.

Before creating a tablet version, the team, led by Dr Paul Long, plan to test a lotion containing the same compounds as those found in coral.

To do this, they will copy the genetic code the coral uses to make the compounds and put it into bacteria in the lab that can rapidly replicate to produce large quantities of it.

Dr. Paul Long said: "We couldn't and wouldn't want to use the coral itself as it is an endangered species."

He said scientists had known for some time that coral and some algae could protect themselves from the harsh UV rays in tropical climates by producing their own sunscreens but, until now, they didn't know how.

"What we have found is that the algae living within the coral makes a compound that we think is transported to the coral, which then modifies it into a sunscreen for the benefit of both the coral and the algae.

"Not only does this protect them both from UV damage, but we have seen that fish that feed on the coral also benefit from this sunscreen protection, so it is clearly passed up the food chain."

The reef samples provide clues to how the coral protects itself from the sun This could ultimately mean that people might be able to get inbuilt sun protection for their skin and eyes by taking a tablet containing the compounds. But for now, Dr Long's team are focusing their efforts on a lotion.

"Once we recreate the compounds we can put them into a lotion and test them on skin discarded after cosmetic surgery tummy tucks.

"We will not know how much protection against the sun it might give until we being testing.

"But there is a need for better sunscreens."

Another long-term goal of the Biotechnology and Biological Sciences Research Council-funded study is to look at whether the processes could also be used for developing sustainable agriculture in the Third World.

The natural sunscreen compounds found in coral could be used to produce UV-tolerant crop plants capable of withstanding harsh tropical UV light.

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[MARINE_BIOLOGY_INTERNATIONAL] 'Landlubber' Fish Leap for Love When Tide Is Right


MICRONESIA — One of the world's strangest animals -- a unique fish that lives on land and can leap large distances despite having no legs -- has a rich and complex social life, a new study has found.

The odd lifestyle of the Pacific leaping blenny (Alticus arnoldorum) has been detailed for the first time in research findings that throw new light on how animal life first evolved to colonise the land.

The Pacific leaping blenny is a marine fish yet is terrestrial in all aspects of its daily adult life, eking out a precarious existence in the intertidal zone of rocky shores in Micronesia, according to the study published in the journal Ethology, led by Dr Terry Ord, of the UNSW Evolution and Ecology Research Centre.

"This remarkable little fish seems to have made a highly successful transition across the water-land interface, although it is still needs to stay moist to enable it to breathe through its gills and skin," says Dr Ord, who is an evolutionary ecologist with a special interest in animal behaviour.

"Our study showed that life on land for a marine fish is heavily dependent on tide and temperature fluctuations, so much so that almost all activity is restricted to a brief period at mid-tide, the timing of which changes daily. During our field study on Guam we never saw one voluntary return to water. Indeed, they spend much of their time actively avoiding submersion by incoming waves, even when we tried to capture them for study.

"I can tell you they are very hard to catch and are extremely agile on land. They move quickly over complex rocky surfaces using a unique tail-twisting behaviour combined with expanded pectoral and tail fins that let them cling to almost any firm surface. To reach higher ground in a hurry, they can also twist their bodies and flick their tails to leap many times their own body length."

Working with Tonia Hsieh, of Temple University in the US, Dr Ord found that adult blennies shelter in rock crevices at high and low tide, emerging at mid-tide to feed, breed and socialise in surprisingly complex ways -- given their brief window of opportunity.

The researchers discovered that males are territorial and use complex visual displays to warn off rivals and attract mates. Females were seen aggressively defending feeding territory at the start of their breeding season, while males displayed a red-coloured fin and nodded their heads vigorously to attract females to their closely defended rock holes. The team filmed females inspecting these holes before entering with a chosen mate.

Little is known of their breeding and development of the young, but it seems that females lay their eggs in a chosen rock hole then play no further role in parenting, leaving the male to guard the eggs.

"The Pacific leaping blenny offers a unique opportunity to discover in a living animal how a water-land transition has taken place," says Dr Ord.

"We know that our ancient ancestors evolved originally from lobe-finned fish but, today, all such fish are fully aquatic. Within the blenny family, however, are species that are either highly terrestrial, amphibious or entirely aquatic. Remarkably, representatives of all these types can be found on or around Guam, making it a unique evolutionary laboratory."

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NORWAY — An underwater "field" as big as a Norwegian county could provide two billion litres of kelp-based fuel a year. SINTEF is currently establishing a centre of expertise that will enable us to cultivate seaweed and kelp on a large scale.

Kelp cultivation will mean that we can produce bioethanol fuel in addition to biogas for heating and fuel, without the need to use food crops as a raw material, and without having to utilise agricultural land or freshwater resources.

This is among the reasons behind SINTEF's decision to establish the Norwegian Centre for Seaweed and Kelp Technology, which was opened in Trondheim on August 15 by State Secretary Kristine Gramstad of the Ministry of Fisheries and Coastal Affairs

There are even more potential uses of kelp and seaweed beyond applications as sources of energy.

As well as being an energy resource, macroalgae such as kelp and seaweed are used in food production and as agents that bind water, in biological purification systems, the reestablishment of kelp cultures in fjords that have suffered high rates of kelp mortality, as soil improvers and in the hunt for new compounds for medical and industrial applications (bioprospecting).

"Macroalgae cultivation lies at an exciting interface between better resource utilisation, new marine-based products and potential renewable energy production. Although the process of establishing new industry can be demanding, I believe that a maritime land such as Norway, with its major offshore and marine supply industries, solid research base and a world-beating aquaculture industry should be quite capable of achieving success in this field," says State Secretary Gramstad.

Today, some 15 million tonnes of seaweed and kelp are cultivated all over the world, mostly in Asia, and are used in foods, animal feedstuffs, chemicals, medicines, health foods, cosmetics and fertilisers.

"The Norwegian coastline, including all its islands, is twice as long as the Equator. In other words, we possess huge areas that are suitable for cultivating seaweed and kelp. However, manpower is more expensive here than in Asia. This means that the greatest challenge lies in cultivating large volumes at sufficiently low cost, and research-based knowledge will be essentlal if we are to manage this,"says chief scientist Trina Galloway of SINTEF Fisheries and Aquaculture.

Galloway says that SINTEF has already been cultivating kelp on a trial basis, on behalf of Norwegian industrial interests and with financial support from the the Research Council of Norway.

"We ourselves have a good deal of competence, but there are also inportant sources of knowledge elsewhere in the world. The aim of the centre is to gather all such sources of expertise into a single team, so we are inviting both Norwegian and overseas research gropups into the centre.

The competence centre will offer industry and the authorities its knowledge, which will cover everything from controlled production of seed plants and cultivation in the sea to harvesting and processing the raw material for a wide range of applications.

Seaweed and kelp take up nutrient salts (fertilisers) and CO2 from the sea. The plants can be cultivated in dedicated macroalgae systems, or side by side with farmed fish. The plants can thus be fertilised by the fish and thus help to cleanse the water around the sea-cages.

At present, seaweed and kelp are not cultivated commercially in Norway. But we already have a major industry based on an annual harvest of around 150,000 tonnes of kelp from which alginates are extracted. These are substances that have the ability to thicken and stabilise liquids, and are therefore used in a large number of food products. Grisetang is also used to produce kelp meal, which is used as a soil improver and in animal feed and health-food products.

"Although harvesting removes less than one percent of Norway's standing seaweed and kelp biomass, we do not recommend taking out more than this amount, as kelp forests are actually important nursery and feeding grounds for a wide range of invertebrates and fish. If we want to expand our kelp-based industry, we will have to cultivate kelp on a large scale," says Galloway.

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[MARINE_BIOLOGY_INTERNATIONAL] Saving the oceans' marine mammal hot spots



Preserve 4% of oceans to save mammals
"The next 2 billion people we're going to add to the planet are going to do much more damage to the ocean than the previous 2 billion did," says study co-author Paul Ehrlich. "Humans reach for the low-hanging fruit first, so to speak, but for the ocean that's gone now." The Hawaiian monk seal (above) is a conservation-reliant endangered species. (Credit: NOAA)
STANFORD (US) — Set aside some carefully chosen marine preserves, and marine mammals such as otters and whales may survive the damage to the oceans caused by humans, a new study finds.
Preserving just 4 percent of the ocean could protect crucial habitat for the vast majority of marine mammal species, according to researchers at Stanford University and the National Autonomous University of Mexico. Their findings were published in the Proceedings of the National Academy of Sciences.
Of the 129 species of marine mammals on Earth, including seals, dolphins, and polar bears, approximately one-quarter are facing extinction, the study notes.

Setting aside nine critical ocean conservation sites would protect habitat for the vast majority of marine mammal species on Earth, including humpback whales. (Credit: NOAA)
Straight from the Source
Read the original study
DOI: 10.1073/pnas.1101525108
"It's important to protect marine mammals if you want to keep the ocean's ecosystems functional," says study co-author Paul Ehrlich, professor of biology and senior fellow at the Woods Institute for the Environment at Stanford. "Many of them are top predators and have impacts all the way through the ecosystem. And they're also beautiful and interesting."
Mapping marine mammals
To pinpoint areas of the ocean where conservation could protect the maximum number of species and the ones most vulnerable to extinction, the researchers overlaid maps of where each marine mammal species is found. Their composite map revealed locations with the highest "species richness"—the highest number of different species.
"This is the first time that the global distribution of marine mammal richness has been compiled and presented as a map," says co-authors Sandra Pompa and Gerardo Ceballos of the National Autonomous University of Mexico. "The most surprising and interesting result was that all of the species can be represented in only 20 critical conservation locations that cover at least 10 percent of the species' geographic range."
The researchers identified the 20 conservation sites based on three main criteria: how many species were present, how severe the risk of extinction was for each species and whether any of the species were unique to the area. The scientists also considered habitats of special importance to marine mammals, such as breeding grounds and migration routes.
Nine key sites
It turned out that preserving just nine of the 20 conservation sites would protect habitat for 84 percent of all marine mammal species on Earth, the scientists found. That's because those nine locations have very high species richness, providing habitat for 108 marine mammal species in all.
These nine sites, which make up only 4 percent of the world's ocean, are located off the coasts of Baja California in Mexico, eastern Canada, Peru, Argentina, northwestern Africa, South Africa, Japan, Australia, and New Zealand, the study reports.
The researchers also looked at how pollution, local climate disruption and commercial shipping overlapped with species richness in or near the nine key sites. "At least 70 percent of the richness areas coincide with regions highly impacted by humans," according to Pompa and Ceballos. "This is powerful information that obliges us to enhance marine conservation."
Factoring in other impacts, such as overfishing and global climate change, would likely reveal even more negative effects on the nine conservation sites, the authors said.
"The next 2 billion people we're going to add to the planet are going to do much more damage to the ocean than the previous 2 billion did," says Ehrlich. "Humans reach for the low-hanging fruit first, so to speak, but for the ocean that's gone now."
Unique creatures
While nine of the conservation sites harbor numerous marine mammal species, the remaining 11 sites boast species found nowhere else. Preserving these areas is important, because species that live exclusively in one place may be at especially high risk for extinction, the authors said. For example, the critically endangered vaquita, or gulf porpoise, lives only in the upper northern Gulf of California, and only a few hundred individuals remain, the researchers note.
"We need to conserve what's left of the biota of the planet, both on land and in the sea," says Ehrlich. "We need to know where the biodiversity is before we can take many of the necessary steps to conserve it. This is just a start on the mammals of the sea."
The study was supported by grants from the National Autonomous University of Mexico, EcoCiencia Sociedad Civil, Mexico's National Council for Science and Technology, and the Cetacean Society International.
More news from Stanford University: http://news.stanford.edu/

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[MARINE_BIOLOGY_INTERNATIONAL] Blue Whales sighted off King Harbor


Redondo Beach, CA - "They're coming in fast," Captain Brad Sawyer recently shouted to his crew. "Their speed is a good 10-15 knots, and we only go 8!"

For the second year in a row, the biggest mammals in the world, the blue whales, were moving through Redondo Canyon in search of krill, a type of crustacean and one of the main sources of food for the whales.

It is not abnormal for the blue whales to be found this far north. However, Craig Stanton, a local skipper and part owner of the Voyager, believes the whales have been seen in this area because of the change in weather and currents, pushing colder water inshore and bringing the krill and subsequentually the blues with it. Redondo Canyon is the perfect feeding grounds for the blues, trapping the krill and creating the perfect all-you-can-eat buffet.

"The more food they have the longer they stay," said Sawyer. "When we're whale watching, it's the blues that put on a show. The grays are on a migration mission, but it's the blues that swim in circles feeding and allow people to see them."

Only 1 percent of people have ever seen a blue whale, making it a unique experience and an exciting adventure.

Bramwell Burrows, 7, saw his first whale ever on the Friday expedition. "I thought it was cool," he said. "I didn't think they would be so big."

Sawyer watched the water and adjusted his ship, Voyager, to the appropriate distance from the gigantic creatures. His ship is about 65 ft long and weighs approximately 42 tons. He estimated the blue whales he was following to be about 85 ft. long and 80 tons.

"That's why you definitely don't want to get in their way," Sawyer explained.

Nichole Beckman, a 26-year-old deck hand from Torrance, scanned the water. "We're looking for the light blue color they get their name from before they crest the surface."

They were scanning the water's surface for "fluke prints," which is what indicates a blue whale is cresting the water. At such times it appears flatter and a light blue color can be seen coming to the surface.

Once passengers realized what they were looking for, they scanned the water hoping to see the majestic creatures. Water spouted about 40 feet into the air from the surface, and cameras and eyes turned to the disturbance.

"Three o'clock!" Sawyer shouted, and most of the passengers on the ship ran to the right side to see two whales breaching and exhaling through their blowholes, sending spouts of water and vapor into the air.

Peggy Gillian, a veteran naturalist in the CMA/ASC-LA volunteer program and whale enthusiast, talked to a group of passengers about the whales, explaining their eating habits and migration tendencies.

"The blue whale," she explained, "is the largest mammal to ever inhabit the earth. Their blowholes have a splash guard and they can grow to be 90-100 feet long. Females are larger than males and they live almost exclusively on krill."

It is not entirely known how long blue whales live. Some people suggest 30-40 years while others estimate that they can live to 100.

"Just being outside on the ocean is great," said marine biology student Carina Salazar, "especially when we can see them up close — it's amazing."

Passengers on this day's outing frequently lost sight of the whales when the Voyager had to yield to passing sailboats. Passengers would sit down and snap photos as the crewmen watched for the whales.

They would wait for a few minutes, the boat in idle, until they knew where to move next. Once someone shouted from the front of the boat as passengers saw a bubbling surface just meters from the front of the ship.

One of the whales emerged but the location of the other leviathan was unknown.

"Where's the other one…holy cow… find the other one!" Sawyer shouted to the crew. Several deck hands quickly moved about the boat, watching the water for signs of the other whale, hoping it wouldn't come up under the ship.

Off in the distance they saw the other whale blow water at least 20 feet into the air. Both whales were now spotted. Sawyer turned the engines back on and followed the pair, allowing people more time for photographs.

Blues are often found in pairs and can be found in all oceans of the world — now surprisingly showing up 5 miles offshore from Redondo Beach's King Harbor.

"We saw so much wildlife today," said April House volunteer activist with Sea Shepherd Conservation Society as well as a whale-watch naturalist with the American Cetacean Society's Los Angeles chapter and Cabrillo Marine Museum. "When they were charging through so quickly we saw behavior we normally don't get to see. They were moving so fast for such big creatures."

The Voyager departs daily from Redondo Beach Marina in search of whales. Crew and passengers often see dolphins, sharks, sea lions and the good-luck fish, mola mola. So far this year, the Voyager crew has had sightings on every recent outing, and last year they had a similar success rate. If more blue whales migrate to the area, the Voyager will potentially have multiple excursions daily until early October if history repeats itself.

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[MARINE_BIOLOGY_INTERNATIONAL] Scientist Creates New Hypothesis on Ocean Acidification


Honolulu - A Researcher at the Hawai`i Institute of Marine Biology, an organized research unit in the University of Hawai`i at Mânoa's School of Ocean and Earth Science and Technology has come up with a new explanation for the effects of ocean acidification on coral reefs.

Since the beginning of the Industrial Revolution, the concentration of carbon dioxide in the atmosphere has been rising due to the burning of fossil fuels. Increased absorption of this carbon by the oceans is lowering the seawater pH (the scale which measures how acidic or basic a substance is) and aragonite saturation state in a process known as ocean acidification. Aragonite is the mineral form of calcium carbonate that is laid down by corals to build their hard skeleton. Researchers wanted to know how the declining saturation state of this important mineral would impact living coral populations.

Much of the previous research has been centered on the relationship between coral growth and aragonite levels in the surface waters of the sea. Numerous studies have shown a direct correlation between increased acidification, aragonite saturation, and declining coral growth, but the process is not well understood. Various experiments designed to evaluate the relative importance of this process have led to opposing conclusions. A recent reanalysis conducted by Dr. Paul Jokiel from the Hawaii Institute of Marine Biology (HIMB), suggests that the primary effect of ocean acidification on coral growth is to interfere with the transfer of hydrogen ions between the water column and the coral tissue. Jokiel re-evaluated the relevant data in order to synthesize some of the conflicting results from previous ocean acidification studies. As a result, Jokiel came up with the "proton flux hypothesis" which offers an explanation for the reduction in calcification of corals caused by ocean acidification.

In the past, scientists have focused on processes at the coral tissues. The alternative provided by Jokiel's "proton flux hypothesis" is that calcification of coral skeletons are dependent on the passage of hydrogen ions between the water column and the coral tissue. This process ultimately disrupts corals' ability to create an aragonite skeleton. Lowered calcification rates are problematic for our coral reefs because it creates weakened coral skeletons leaving them susceptible to breakage, and decreasing protection.

Dr. Jokiel is excited about this work; he states that "this hypothesis provides new insights into the importance of ocean acidification and temperature on coral reefs. The model is a radical departure from previous thought, but is consistent with existing observations and warrants testing in future studies". In general, this hypothesis does not change the general conclusions that increased ocean acidification is lowering coral growth throughout the world, but rather describes the mechanism involved.

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[MARINE_BIOLOGY_INTERNATIONAL] Great White Sharks 'could be in British waters'


LONDON - Great white sharks could be "occasional vagrant visitors" to waters around the British Isles, according to an expert.

Richard Peirce, chairman of the Shark Trust, said the conditions and availability of prey made British waters an ideal hunting ground for the feared predator.

Mr Peirce said: "The real surprise is that we don't have an established white shark population, because the conditions here mirror those in parts of South Africa, Australia and northern California.

"Research has shown that white sharks tolerate water temperatures in a range which would make British waters perfectly suitable for this species."

British waters are home to many species of predatory sharks including blue and mako sharks which have been spotted off southwest England in the summer and threshers and porbeagles which are year-round residents.

There have also been sightings of other sharks in British waters over the summer. Earlier this month fisherman Jim Millar spotted a 15ft (4.5m) thresher shark off Dartmouth in Devon, where they are very rarely seen.

Another fisherman caught a 300lb (21 stone) porbeagle shark off the coast of Donegal, Republic of Ireland, last month.

And there were two separate sightings of what was believed to have been an oceanic whitetip shark, a species also known to attack humans, in St Ives, Cornwall, in June, although very few shark experts believe the sightings were oceanic whitetips.

Mr Peirce believes it is only a matter of time before proof is found that the species at the top of the marine food chain, the great white shark - Carcharodon carcharias - is occasionally present in British waters.

"Great whites are highly nomadic in movement around the north Atlantic so it's reasonable to say there's a good chance they may stray into British waters.

"I do suspect we do get the occasional vagrant visitor."

Mr Peirce claims he almost proved there is a great white occurrence in the UK with a photograph of a shark caught off the north east coast of Scotland.

"I sent the photo to some of the world's leading experts but as soon as they heard it was caught off Scotland they started looking at what else it could be."

Mr Peirce has investigated more than 80 reported sightings of great whites in British waters over the last 14 years but only seven were found to be credible.

A fisherman in Cornwall reported a great white sticking its head out of the water, known as "spy-hopping" in the 1970s and fishermen onboard three different boats, also off Cornwall, described a sighting of a great white within three weeks of one another in 1999.

Mr Peirce said: "The reason the evidence is so compelling is that it's from independent witnesses who do not know each other on different boats.

"The problem is these things happen in a flash. Unless the shark jumps right out of the water or is caught, all we'll see is a dorsal fin sticking out the water.

"The closest capture of a great white was off La Rochelle (in western France) about 200 nautical miles from UK shores which is no distance to them."

In 5,000 hours of observing Seawatch SW has only seen one predatory shark However Dr Russell Wynn, co-ordinator of the SeaWatch SW project and a senior marine scientist at the National Oceanography Centre in Southampton, said the odds of a great white being found in British waters were extremely low as the creatures are very rare in the northeast Atlantic.

The SeaWatch SW survey team has spent more than 5,000 hours scanning the seas off southwest England in the past five years but the only predatory sharks seen have been single blues and threshers.

"The only large shark the public are likely to see is the harmless plankton-feeding basking shark, which can grow to over 10m long and is occasionally seen leaping out of the water," he said.

But Dr Wynn accepted there was a small chance of a great white sighting off the British coast.

"It's certainly not impossible that a great white could be seen or caught in British waters one day, as we know they occur off southwest Europe in very low numbers."

But despite the recent sightings, the opportunity of seeing sharks is decreasing year on year.

Research carried out by Dalhousie University, Nova Scotia, Canada, in the Western Atlantic indicate serious depletions of more than 50% for many shark species.

Mr Peirce said: "Unless we do something about shark mortality in the Atlantic we won't be having this conversation in 50 years time."

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A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>

Date: 25 Aug 2011
Source: Baden Online [in German, machine-trans. summarised, edited] <http://www.baden-online.de/news/artikel.phtml?page_id=67&db=news_lokales&table=artikel_ortenau&id=16878>

Since the beginning of August 2011, fish have been dying in the Wolf river in Oberwolfach. The cause is not yet clarified, and the fishermen are completely clueless. Meanwhile, the fish kill has extended to a length of several kilometers in the Oberwolfach-Kirche/Oberwolfach-Walke area [south western Germany].

Initially, the event affected only grayling and trout; currently, additional fish species are involved. The fish mortality is now shifting further upstream.

Industrial monitoring and environmental protection are being undertaken by the Offenburg police, who have been investigating this event since it began. Several samples of water and fish have been obtained and are being examined in the Chemical and Veterinary Investigation Office in Freiburg. Fish diseases were not detected in the samples so far; toxicological investigation is continuing.

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[The town of Oberwolfach, in Baden-Wurttemberg, south west Germany, lies between 270 and 948 meters above sea level in the central Schwarzwald (Black Forest) on the river Wolf, a tributary of the Kinzig; map at <http://healthmap.org/r/1bbV>.

Information on the outcome of the epidemiological/laboratory investigation would be appreciated. - Mod.AS]

ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material.

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[MARINE_BIOLOGY_INTERNATIONAL] Selective Trawl Catches Norway Lobster but Allows Cod to Escape


NORWAY — Researchers from DTU Aqua in Denmark have decoded the behaviour of Norway lobsters and cod and used the results to develop a selective trawl. This so-called SELTRA-trawl ensures that fewer cod end up as by-catch in the Norway lobster fishery in the Kattegat.

Despite the fact that the cod fishery in the Kattegat is subject to strict fishing quotas, a substantial amount of cod have ended up as by-catch in the Norway lobster fisheries. But after July 15, 2011, more cod have escaped the lobster trawl. From this date, the Danish Ministry of Food, Agriculture and Fisheries has decided, that all Norway lobster fishing in the Kattegat is to be conducted using a selective trawl, called the SELTRA-trawl.

"The Norway lobster population in the Kattegat is doing well, and the Norway lobster fishery is the most economically important fishery in the Kattegat. In 2010 alone, 1700 tonnes of Norway lobsters were caught here. The cod population, on the other hand, has declined severely in the last 20-30 years. If it had not been possible to reduce the by-catch of cod by implementing the SELTRA-trawl, the Norway lobster fishery would have to be reduced significantly in order to protect the cod," says senior research scientist Niels Madsen from the National Institute of Aquatic Resources (DTU Aqua) in Denmark. He has been in charge of developing and testing the SELTRA-trawl during a project funded by the Ministry of Food, Agriculture and Fisheries and the EU.

A trawl is a funnel-shaped net, which distends when it is pulled after a vessel. When it is pulled along the bottom of the sea, it catches Norway lobsters and bottom-dwelling fish on its way. The catch then falls back towards the rearmost end of the trawl and ends up in the so-called codend.

The challenge for the researchers at DTU Aqua has been to design a trawl that selectively catches Norway lobsters while letting cod and other unwanted by-catch escape through the meshes. Norway lobsters are relatively small, and a small mesh size is thereby required to retain them in the codend. These small meshes also retain fish the size of or larger than the Norway lobsters which is the reason that previously there has been a great deal of by-catch when fishing Norway lobsters.

The researchers came up with the idea of replacing the traditional round codend with a codend shaped like a square box. This square-shaped box proved to be more stable in the water enabling the researchers to take advantage of the cods' and Norway lobsters' behaviour.

When using this codend, the researchers discovered that the Norway lobsters were passive and preferred the bottom part of the codend, while the cod were more active and had a preference for the upper part of the codend and tried to swim against the current to escape.

Based on the knowledge of the differences in behaviour, the researchers at DTU Aqua created the so-called sorting box that has a larger mesh size and is placed in the front end of the SELTRA-trawl allowing the cod to escape. Thereby, they had come up with the basic idea for the SELTRA-trawl.

In order to keep the costs of the SELTRA-trawl relatively low, the SELTRA-trawl was developed to be added to the fishermen's own trawl:

"The fishermen fishing for Norway lobsters has their own trawl already, and all they need to do is to place the seven meter long SELTRA-trawl with the sorting box and the square codend instead of the rearmost part of their own trawl. In this way, the fishermen do not have to buy a complete new trawl," explains Niels Madsen.

Project SELTRA was initiated in 2005 and completed in the end of 2008. Since then, the SELTRA-trawl has been tested in the Norwegian company SINTEF's flume tank at the North Sea Science Park in Hirtshals.

"Through the co-operation with the Danish Fishermen's Association, fishermen and net makers we got ideas on how to design the SELTRA-trawl, so that it is convenient and useful for the fishermen and easy to construct for the net makers," says Niels Madsen.

The SELTRA-trawl has been used on commercial fishing vessels in the so-called closed areas in the Kattegat. The closed areas are areas, in which the Danish Ministry of Food, Agriculture and Fisheries has prohibited cod fishing in order to protect spawning cod.

"In some places in the closed areas, the fishermen have been required to use the SELTRA-trawl when fishing for Norway lobsters. The fishermen, who have now used the SELTRA-trawl for a couple of years, say that they have not experienced significant reductions in the amount of Norway lobsters that they catch," says Niels Madsen and continues:

"Furthermore, the SELTRA-trawl has proved to allow the main part of the cod to escape. During the development work and the following tests we have seen up to 90 % of the cod escape from the SELTRA-trawl."

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