Scientists from the U.S. Geological Survey (USGS) have revealed that largemouth bass injected with oestrogen produces less hepcidin than normally. Hepcidin is an important iron-regulating hormone in fish, amphibians and mammals, and researchers also suspect that hepcidin may act as an antimicrobial peptide. In vertebrate animals, antimicrobial peptides are the body’s first line of defence against unwelcome bacteria and some fungi and viruses, so if there’re right, a lowered amount of these compounds is certainly not good news.

“Our research suggests that estrogen-mimicking compounds may make fish more susceptible to disease by blocking production of hepcidin and other immune-related proteins that help protect fish against disease-causing bacteria,” says lead author Dr. Laura Robertson.

You can find more info in the study “Identification of centrarchid hepcidins and evidence that 17β-estradiol disrupts constitutive expression of hepcidin-1 and inducible expression of hepcidin-2 in largemouth bass (Micropterus salmoides)” by Laura Robertson, Luke Iwanowicz and Jamie Marie Marranca in the latest issue of the journal Fish & Shellfish Immunology. It is the first published study demonstrating control of hepcidin by estrogen in any animal.

Eleven suspected abalone poachers have been arrested in northern California, officials said Friday.

Since the tide was unusually low in Mendocino County, California Department of Fish & Game wardens were aware of the increased risk of poaching activity and kept their eyes on the coast line, including the coral reefs that had become exposed as the water disappeared.

At about 6.15 a.m. on Wednesday wardens noticed suspicious divers exiting waters near Caspar, south of Fort Bragg. Fish & Game Lt. Kathy Ponting, who runs the special operations unit, said her team drove to a spot near the suspicious divers and began surveillance.

Unaware of the wardens’ presence, the divers collected abalone from the reef and placed them in tall grass near the beach.

“Then a large van pulled up near the dive area and we watched them load up a bunch of abalone in plastic bags into the van,” Ponting said. The divers went back to the sea, while wardens decided to follow the van. After pulling it over, they discovered 50 abalones inside.

Abalones can sell for up to $100 dollars, but collection is strictly regulated since these molluscs need many years to develop. It can take 12 years for a specimen to reach the legal size. With a California fishing license and an abalone stamp card you are allowed to fetch 24 specimens per year, but no more than three per day. It is also illegal to collect them for sale, and anyone caught with a dozen or more will be considered possessing them with the intention of selling them.

Red Abalone. The only type that can be harvested.

When the van did not return to the divers, the alleged poachers loaded a pickup truck. The wardens followed the car to a nearby hotel and found coolers filled with abalone inside the divers’ hotel room. Most of the abalones were smaller than the legal size.

The wardens found a total of 166 abalones with the group, Ponting said. The suspects were booked on charges of felony conspiracy to harvest abalone for commercial purposes, which carries a fine of up to $40,000, said Game Warden Patrick Foy. Two vehicles also were

seized along with $6,000 in cash.

The black market for abalone is large and poaching is widespread, despite official efforts to eradicate the practise.

“We always only catch the tip of the iceberg, there is so much

abalone poaching going on because of the black market,” Ponting

explained. “We can pick almost any group and watch them poaching

abalone. It’s really unsettling.”

What is an abalone?

The abalone is a medium sized to very large edible sea snail prized for its exquisite flavour. There is roughly 100 known species world wide, all of them being gastropod molluscs belonging to the genus Haliotis. You may stumble upon a species marketed as “Chilean abalone” in the food trade, but this is not a real abalone; its name is Concholepas concholepas and it belongs to an entirely different family.

Since abalones are found in so many different parts of the world, they are known under many different names, such as abulón in Spanish, ormer in Jersey and Guernsey, pāua in

New Zealand, muttonfish or muttonshells in Australia, perlemoen in South Africa, and Venus’s-ears, ear-shells, and sea-ears in British and American English.

Abalones reach sexual maturity when they are comparatively small, but they won’t produce any significant amount of offspring until they grow bigger. A small abalone may release around 10,000 eggs at a time, which may sound like a big number but is dwarfed compared to the 11 million eggs released at a time by really large abalones. As a result of this, the removal of abalones from the sea before they have a chance to grow large is highly detrimental to the survival of the species.

Abalone has been farmed since the 1950s in Japan and China, and during the 1990s the practise spread to other parts of the world in response to dwindling wild populations. Today, it is possible to purchase farmed abalone and refrain from removing specimens from the wild. China and Japan are still major producers of abalone, but has been joined by Korea, Thailand, Australia, New Zealand, South Africa, Namibia, Iceland, Ireland, Canada, USA, Mexico, and Chile.

Catching abalone in California

As mentioned above, it is legal to fetch a certain amount of abalone per day and year in Californian waters if you have a California fishing license and an abalone stamp card. The abalone stamp card has 24 tags and captured abalones must be tagged immediately. The legal size is (a minimum of) seven inches (178 mm) measured across the shell. A person may be in possession of no more than three abalones at any given time. Other regulations to keep in mind are listed below. Always check with the California Department of Fish & Game before you go abalone hunting in California to find out if there have been any regulatory changes.

· Scuba diving for abalone is always prohibited; you may only pick them from the shore or use breath-hold techniques.

· Abalone may only be taken from April to November, not including July.

· You may only take Red abalones; no Black, White, Pink, or Flat abalones.

· You may not take any abalones south of the mouth of the San Francisco Bay.

· You may not sell any part of the abalone, including the shell.

· Only abalones still attached to the shell can be legally transported.

North Carolina State University engineers have created a non-toxic ship hull coating that resists the build up of barnacles.

Barnacles that colonize the hull of a ship augment the vessel’s drag which in turn increases fuel consumption. After no more than six months in salt water, the fuel consumption of a ship has normally swelled substantially, forcing the ship owner to either spend more money on fuel or to remove the ship from the water and place it in a dry dock where it can be cleaned. Both alternatives are naturally costly, and for many years ship owners fought barnacles by regularly coating ship hulls with substances toxic to barnacles. Unsurprisingly, these substances turned out to be toxic to a wide range of other marine life as well, including fish, which caused most countries to ban their use.

Ships are not the only ones colonized by barnacles. In the wild, it is common to see barnacles attached to a wide range of marine species, such as whales and sea turtles. One type of animal is however usually free of barnacles: the sharks. Unlike the smooth-skinned whales, sharks tend to have rough and uneven skin, and this might prove to be the salutation for ships as well.

The new hull coating created by Dr. Kirill Efimenko, research assistant professor in the Department of Chemical and Biomolecular Engineering, and Dr. Jan Genzer, professor in the same department, contains nests of different-sized “wrinkles” which makes the surface rough and uneven, just like the skin of a shark.

The wrinkly material was tested in Wilmington, N.C and remained free of barnacles after 18 months of exposure to seawater. Flat coatings made of the same material were on the other hand colonized by barnacles within a month.

“The results are very promising,” says Efimenko. “We

are dealing with a very complex phenomenon. Living

organisms are very adaptable to the environment, so

we need to find their weakness. And this hierarchical

wrinkled topography seems to do the trick.”

Efimenko and Genzer created the wrinkles by stretching a rubber sheet, exposing it to ultra-violet ozone, and then relieving the tension, causing five generations of “wrinkles” to form concurrently. After that, the coating was covered in an ultra-thin layer of semifluorinated material.

The inclination to end up stuck on a hook seems to be a heritable trait in bass, according to a study published in a recent issue of the Transactions of the American Fisheries Society.

The study, which was carried out by researchers DP Philipp, SJ Cooke, JE Claussen, JB Koppelman, CD Suski, and DP Burkett, focused on Ridge Lake, an Illinois lake where catch-and-release fishing has been enforced and strictly regulated for decades. Each caught fish has been measured, tagged and then released back into the wild.

Picture by: Clinton & Charles Robertson from Del Rio, Texas & San Marcos, TX, USA

David Philipp and coauthors commenced their study in 1977, checking the prevalence of Largemouth bass (Micropterus salmoides) on the hooks of fishermen. After four years, the experimental lake was drained and 1,785 fish were collected. When checking the tags, Philipp and his team found that roughly 15 percent of the Largemouth bass population consisted of specimens that had never been caught. They also found out that certain other bass specimens had been caught over and over again.

To take the study one step further, the research team collected never caught bass specimens (so called Low Vulnerability, LV, specimens) and raised a line of LV offspring in separate brood ponds. Likewise, the team collected bass specimens caught at least four times (High Vulnerability, HV, specimens) and placed them in their own brooding ponds to create a HV line.

The first generation (F1) offspring from both lines where then marked and placed together in the same pond. During the summer season, anglers where allowed to visit the pond and practise catch-and-release, and records where kept of the number of times each fish was caught.

As the summer came to an end, HV fish caught three or more times where used to create a new line of HV offspring, while LV fish caught no more than once became the parents of a new LV line.

The second generation (F2) offspring went through the same procedure as their parents; they were market, released into the same pond, and subjected to anglers throughout the summer. In fall, scientists gathered the fish that had been caught at least three times or no more than once and placed them in separate ponds to create a third generation (F3) HV and LV fish.

A following series of controlled fishing experiments eventually showed that the vulnerability to angling of the HV line was greater than that of the LV line, and that the differences observed between the two lines increased across later generations.

If this is true not only for bass but for other fish species as well, heavy hook-and-line angling pressure in lakes and rivers may cause evolutionary changes in the fish populations found in such lakes. Hence, a lake visited by a lot of anglers each year may eventually develop fish populations highly suspicious of the fishermen’s lure.

More information can be found in the paper published in Transactions of the American Fisheries Society: Philipp, DP, SJ Cooke, JE Claussen, JB Koppelman, CD Suski and

DP Burkett (2009) Selection for vulnerability to angling in Largemouth Bass. Transactions of the American Fisheries Society 138, pp. 189–199.

The Snubfin dolphin (Orcaella heinsohni), recognized as a species as recently as 2005, have been spotted while utilizing a rare hunting technique previously only noted in the Irrawaddy dolphin (Orcaella brevirostris), a close relative of the Snubfin.

The unusual group hunting technique involves chasing the prey fish to the surface of the ocean and rounding them up by spitting jets of water at them. Once the fish is packed together in a reasonably small “cylinder”, the dolphins move in to devour them.

According to WWF Australia’s marine and coasts manager Lydia Gibson, the behaviour was first noticed in Australia off the Kimberley Coast.

We still know very little about the Snubfin dolphin, which lives along Australia’s northern coast in a number of locations off the Queensland and Northern Territory coasts, as well as the Kimberley region of Western Australia. It is listed as Near Threatened on the IUCN Red List of Threatened Species, chiefly due to habitat destruction. Since Snubfin dolphins live close to shore, they are also more likely to end up in gill nets and drown compared to more pelagic species of dolphin.

The juvenile Hawksbill turtle found near-dead 8 months ago with a plastic shopping bag lodged inside her belly has made a remarkable recovery and has now been released back into the ocean. The Hawksbill turtle is listed as Critically Endangered on the IUCN Red List of ThreatenSped ecies, so each specimen that can be rescued is important for the population.

Eight months ago the young female, who has been dubbed Alva by her caregivers, was found halfway up the beach, upside down, with her head buried in the sand, slowly dying in the sun. She was rushed to Townsville’s Reef HQ turtle hospital where x-rays revealed that a large piece of plastic stuck inside her had caused a severe gut blockage.

In addition to receiving treatment for the blockage, Alva was bathed, scrubbed and hand-fed by the turtle hospital staff who gradually nursed her back to life from the near-death experience.

“We brought it back from brink of death”, said Reef HQ aquarium acting director Fred Nucifora. “That is the miracle.”

On May 21, Alva was deemed healthy enough to return to the sea and was released into the water in the Australian Great Barrier Reef Region.

“It was emotional to say goodbye,” said Nucifora. “We’d like to think Alva turned back and gave us a heartfelt look, but it was barely a glance and, with a flick of the flipper, she was off.”

A company named Ghost Pros is currently exploring the ship wrecks of Florida in search not of gold, silver or precious stones but of ghosts. The company is using the latest underwater ghost-detection technology, including submersible high powered sonar listening devices. Ghost Pro divers have also teamed up with Tampa’s Sea Viewers, the makers of high definition studio cameras which will be used to develop under water rovers.

“We’re listening to everything and anything we can down there,” says Ghost Pros’ Lee Ehrlich, explaining that you have to know what is not a ghost before you can find one. “[…] before you can tell you need to know what that ship sounds like alone,” he says.

Unlike Ghost Busters, Ghost Pros doesn’t get paid to hunt ghosts, but the search does generate a lot of attention from ghost aficionados and ghost critics, as well as from the general media. Hunting for the para-normal has proven to be an excellent way of creating some very normal buzz for Ehrlich and his companions, who – when not hunting down the ghosts of voyages past – are developing advanced submersibles for search and rescue operations.

As a diver, I would like to recommend any readers of this blog to leave the deep sea ghost hunting to professionals like Ehrlich and his crew. If you start seeing ghosts while scuba diving, make a safe ascendance and wait for the nitrogen poisoning to wear off.

Thanks to a system of underwater hydrophones, scientists have been able to document the presence of North Atlantic Right whales in an area where they were believed to have gone extinct.

The North Atlantic Right whale (Eubalaena glacialis), where even the name is a reference to it being the “right” whale to hunt, was heavily targeted by whalers during the 19^th and 20^th century and the entire species was on the brink of extinction when the moratorium on whaling was implemented in the 1960s.

Being an important whaling area throughout the 19^th century, Cape Farewell Ground off the southern tip of Greenland was believed to have no surviving population of Right whales, but when scientists from Oregon State University (OSU) and the National Oceanic and Atmospheric Administration (NOAA) begun investigating the area using hydrophones, they recorded a total of 2,012 Right whale “calls” from July through December 2007.

“We don’t know how many right whales there were in the area,” says David Mellinger, assistant professor at OSU’s Hatfield Marine Science Center in Newport and chief scientist of the project. “They aren’t individually distinctive in their vocalizations. But we did hear right whales at three widely space sites on the same day, so the absolute minimum is three. Even that number is significant because the entire population is estimated to be only 300 to 400 whales.”

During the last 50 years no more than two Right whales have been sighted at Cape Farewell Ground, so even a figure as low as three during the same day is good news.

The project has been using five hydrophones engineered by Haru Matsumoto at OSU, configured to continuously record ambient sounds below 1,000 Hz over a large region of the North Atlantic. These underwater hydrophones are sensitive enough to record sounds from hundreds of miles away. The scientists used previous recordings of Atlantic and North Pacific Right whales to identify the species’ distinct sounds, including a type of vocalization known as “up” calls.

“The technology has enabled us to identify an important unstudied habitat for endangered right whales and raises the possibility that – contrary to general belief – a remnant of a central or eastern Atlantic stock of right whales still exists and might be viable,” says Mellinger.

Results of the 2007 study were presented this week at a meeting of the Acoustical Society of America in Portland, Oregon.

In addition to Mellinger and Clapham, scientists involved in the project include Sharon Nieukirk, Karolin Klinck, Holger Klinck and Bob Dziak of the Cooperative Institute for Marine Resources Studies – a joint venture between OSU and NOAA; Phillip Clapham, a right whale expert with NOAA’s National Marine Mammal Laboratory, and Bryndís Brandsdóttir of the University of Iceland.

The Turkish government has set their own very high catch limit for endangered Mediterranean bluefin tuna without showing any regard for internationally agreed quotas and the survival of this already severally overfished species. By telling the Turkish fishermen to conduct this type of overfishing, the Turkish government is effectively killing the future of this important domestic industry.

Turkey currently operates the largest Mediterranean fleet fishing for bluefin tuna, a commercially important species that – if properly managed – could continue to create jobs and support fishermen in the region for years and years to come. Mediterranean societies have a long tradition of fishing and eating bluefin tuna and this species was for instance an appreciated food fish in ancient Rome. Today, rampant overfishing is threatening to make the Mediterranean bluefin tuna a thing of the past.

Management of bluefin tuna is entrusted to the International Commission for the Conservation of Atlantic Tunas (ICCAT), an intergovernmental organisation. Last year, the Turkish government objected to the Bluefin tuna quota that was agreed upon at the ICCAT meeting in November and is now ignoring it completely.

The agreed tuna quota is accompanied by a minimum legal landing size set at 30 kg to make it possible for the fish to go through at least one reproductive cycle before it is removed from the sea, but this important limit is being widely neglected as well. Catches below the 30 kg mark have recently been reported by both Turkish and Italian media.

To make things even worse, Mediterranean fishermen are also involved in substantial illegal catching and selling of Mediterranean bluefin tuna. This year’s tuna fishing season has just begun and Turkish fishermen have already got caught red-handed while landing over five tonnes of juvenile bluefin tuna in Karaburun.

According to scientific estimations, Mediterranean blue fin tuna fishing must be kept at 15,000 tonnes a year and the spawning grounds must be protected during May and June if this species shall have any chance of avoiding extinction in the Mediterranean. This contrasts sharply against the actual hauls of 61,100 tonnes in 2007, a number which is over four times the recommended level and twice the internationally agreed quota. The crucial spawning grounds are also being ravished by industrial fishing fleets.

By blatantly ignoring international quota limits, the Turkish government is in fact threatening not only the tuna but also the future livelihood of numerous Mediterranean fishermen, including the Turkish ones.

U.S. and Canadian scientists have documented the first known migration of blue whales from the coast of California to areas off British Columbia and the Gulf of Alaska since the 1965 ban of commercial whaling.

Researchers identified 15 separate cases where Blue Whales were spotted in the waters off British Columbia and the Gulf of Alaska. Four of the observed animals were identified as Blue Whales previously seen swimming in Californian waters, which suggests that Blue Whales are re-establishing their old migration pattern.

The identifications were made by comparing pictures of Blue Whales photographed in the northern parts of the Pacific Ocean since 1997 with photographs of Blue Whales taken off the southern U.S. West Coast. The identity of individual Blue Whales was determined based on dorsal fin shape and pigmentation patterns in skin colour.

The Blue Whale was almost hunted to extinction during the 20^th century and even though commercial whaling has been prohibited (albeit not strictly enforced) since 1965 the populations are having a hard time recovering. Blue Whales are still listed as endangered on the IUCN Red List of Threatened Species and no more than roughly 5,000 to 12,000 Blue Whales are believed to remain in our oceans, with 2,000 of them living of the U.S. West Coast.

The migration research was conducted by scientists from Cascadia Research Collective in Washington State, NOAA’s* Southwest Fisheries Science Center in California, and Canada’s Department of Fisheries and Oceans. You can read the full article in the most recent issue of the journal Marine Mammal Science.

* The United States National Oceanic and Atmospheric Administration (NOAA)