Friday Fishy News - Happy Easter!

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Australian fish heading south

By Michael Byrnes

Reuters

April 4

SYDNEY, Australia — Global warming is starting to have a significant impact on Australian marine life, driving fish and seabirds south and threatening coral reefs, Australia's premier science organization said on Wednesday.

But much more severe impacts could occur in coming decades, affecting sea life, fishing communities and tourism.

In particular, warmer oceans, changes in currents, disruption of reproductive cycles and mass migration of species would affect Australia's marine life, particularly in the southeast.

Already, nesting sea turtles, yellow-fin tuna, dugongs and stinging jellyfish are examples of marine life moving south as seas warm, the report by the government-backed Commonwealth Scientific and Industrial Research Organization said.

"It's not a disaster for the ones that can move south. It is for the ones that can't move south," lead author of the report, Dr Alistair Hobday, told Reuters.

"If you're at the tip of Tasmania, you've got nowhere else to go," he said, referring to Australia's southern island state, the last major part of Australia before the Antarctic.

Atlantic salmon, which are farmed in Tasmania, face a bleak future. Salmon-farming businesses would become largely unviable as the ocean warmed the predicted one to two degrees over the next 30 years, Dr. Hobday said.

Fisheries and aquaculture are worth more than $2.5-billion (Australian) a year the report, "Impacts of Climate Change on Australian Marine Life," says. It is the first major study in the Australian region to combine the research of climate modelers, ecologists and fisheries and aquaculture scientists.

Coral in the Great Barrier Reef off Australia's northeast coast may be hit by more frequent bleaching events, every two or three years compared with five or six years at present.

"You would basically get hit with a hammer every couple of years. Nobody responds well to that," Dr. Hobday said.

Worse, oceans are becoming more acidic as carbon dioxide increases in the atmosphere. This will adversely affect many organisms that use calcium carbonate for their skeletons and shells, including corals and mollusks.

Turtles under threat

Turtles are especially vulnerable to warming, with warm weather causing increased female hatchlings, the report said.

Changing ocean food production because of warming could also affect other species already battling low numbers by restricting their food supply, the CSIRO report, which was prepared for the Australian government, said.

Its release comes two days before the UN Intergovernmental Panel on Climate Change adopts a major report on the impacts of global warming.

Australia's southeast will be hit hardest, with the Tasman Sea suffering the greatest ocean warming in the southern hemisphere, the CSIRO report, citing the UN climate panel, said.

The result is likely to be a decline in fish along Australia's eastern seaboard.

"These species have become adapted to a particular set of conditions and the speed at which the ocean is changing is faster than they have experienced," Dr. Hobday said.

One result would be that Australian fishing industries would have to move south.

Tourism was also likely to be hard hit, the report said, highlighting the multibillion-dollar economic value of the nation's reefs.

An expected increase in human migration to the Australian coast over the next 10 to 20 years because of warming temperatures would also add to pressure on the oceans, Dr. Hobday said.

This would be accompanied by rising sea-levels and ensuing greater coastal erosion.

"You'll have cliff-side mansions crashing into the ocean," he said, adding that Australia needs to reduce its greenhouse gases and pollution and to better protect coastal areas.

The great escape -- fleeing fish fall in line

physorg.com

March 31

With the unappealing prospect of being eaten, one might imagine that during a predator attack it is a case that all fish escape at once in the desperate hurry to escape as quickly as possible. However, new research indicates that this is not the case, and in fact fish in schools escape using a relatively fixed chronological order. This research was carried out at the International Marine Centre (IMC) in Sardinia, Italy, and will be presented at the Annual Meeting of the Society for Experimental Biology in Glasgow.

Scientists mimicked an aerial predator attack by mechanical stimulation and used a high speed camera to record responses in schools of ten grey mullet each. Individuals within a school were then ranked according to the timing of their escape. The experiment was performed ten times at 10 minute intervals on a total of seven separate schools of grey mullet. Interestingly, results suggested that there is a trend for individual fish to maintain a given rank, indicating that the chronological order of escape responses within a school is maintained in successive startle events.

Head of the research group Dr Paolo Domenici stated, “Our work is the first to show that fish maintained under the same conditions, with no differential treatment, show a tendency for keeping a relatively fixed chronological order of escape. This implies that in a given school certain individuals may have a greater influence on the escape strategies of the whole school.”

Researchers are keen to explore whether the tendency to keep a fixed chronological order of escape corresponds to a leadership maintained over a relatively long period of time.

Source: Society for Experimental Biology

Rare marine fish caught in Cox's Bazar

By Muazzem Hossain Shakil

The Daily Star

April 6

A very rare species of fish, captured from 60 to 80 feet deep sea water around 50-70 km southwest of the St Martin's Islands on April 2, is now kept at the museum of under-construction Panowa Bay Park at Cox'a Bazar.

Raguib Uddin Ahmed, a biologist of the park, identified the rare fish at Cox's Bazar fish harbour and took immediate steps for its preservation.

Generally called ocean sunfish or slender sunfish, the fish's scientific name is Ranzania laevis that belongs to family Molidae.

The coral reef dependent species of fish, two and a half feet in length and weighing about 6 kg, has got an amusing tube-like mouth opening to suck algae.

The sluggish creature moves with the help of cartilaginous tail, appearing as though somebody has cut it into halves.

Several elderly fishermen of the area said seeing the fish is a new experience for them.

Raguib said he observed the same species of fish nearly 130 feet below sea surface in coral-reef habitat of Tulamben Bali, Indonesia in October 2002.

A NAUI (National Association of Underwater Instructors, USA) licence holder deep sea SCUBA (Self Contained Underwater Breathing Apparatus) diver, Raguib dives at the Bay of Bengal and other seas and oceans for about ten years.

Over-fishing, destruction of coral-reef around the St Martin's Islands and further down, use of environment unfriendly fishing gears have now become threats to the existence of fishes, especially the rare ones.

The research cell of the proposed marine museum and park aims at providing better information about such creatures and help conservation of valued natural treasures of the Bay of Bengal.

Seafood Poisoning Rises With Warming

sfgate.com - Philippines

By Michael Casey

April 1

Bowls of piping hot barracuda soup were the much-anticipated treat when the Roa family gathered for a casual and relaxing Sunday meal.

Within hours, all six fell deathly ill. So did two dozen others from the same neighborhood. Some complained of body-wide numbness. Others had weakness in their legs. Several couldn't speak or even open their mouths.

"I was scared. I really thought I was going to die," said Dabby Roa, 21, a student who suffered numbness in his head, tingling in his hands and had trouble breathing.

What Roa and the others suffered that night last August was ciguatera poisoning, a rarely fatal but growing menace from eating exotic fish. All had bought portions of the same barracuda from a local vendor.

Experts estimate that up to 50,000 people worldwide suffer ciguatera poisoning each year, with more than 90 percent of cases unreported. Scientists say the risks are getting worse, because of damage that pollution and global warming are inflicting on the coral reefs where many fish species feed.

Dozens of popular fish types, including grouper and barracuda, live near reefs. They accumulate the toxic chemical in their bodies from eating smaller fish that graze on the poisonous algae. When oceans are warmed by the greenhouse effect and fouled by toxic runoff, coral reefs are damaged and poison algae thrives, scientists say.

"Worldwide, we have a much bigger problem with toxins from algae in seafood than we had 20 or 30 years ago," said Donald M. Anderson, director of the Coastal Ocean Institute at the Woods Hole Oceanographic Institution in Massachusetts.

"We have more toxins, more species of algae producing the toxins and more areas affected around the world," he said.

Although risk of ciguatera has soared recently, the phenomenon is ancient. Fish poisoning shows up in Homer's Odyssey. Alexander the Great forbade his armies to eat fish for fear of being stricken, according to University of Hawaii professor Yoshitsugi Hokama.

Capt. James Cook and his crew probably suffered ciguatera poisoning in 1774 after eating fish near Vanuatu in the South Pacific, according to crew journals and correspondence studied by Dr. Michael Doherty of the Swedish Epilepsy Center in Seattle, writing in the scientific review Neurology. Cook recorded that they "were seized with an extraordinary weakness in all our limbs attended with a numbness or sensation like ... that ... caused by exposing one's hands or feet to a fire after having been pinched much by frost."

Ciguatera has long been known in the South Pacific, the Caribbean and warmer areas of the Indian Ocean. Some South Pacific islanders use dogs to test fish before they eat.

But in the past decade, it has spread through Asia, Europe and the United States, where more restaurants are serving reef fish, prized for their fresh taste and exotic cachet.

In the United States, ciguatera poisonings are most frequent in Florida, Texas and Hawaii, which has seen a fivefold increase since the 1970s to more than 250 a year.

Hong Kong, which imports much of its seafood, went from fewer than 10 cases annually in the 1980s to a few hundred now.

Still, Hong Kong diners pay a premium for the risky fish. Rare species like the Napoleon wrasse fetch nearly $50 a pound. The fish are increasingly shipped live from Southeast Asia and as far away as the South Pacific, raising concerns from the World Conservation Union that many species, especially groupers, could be fished out of existence.

Professor Yvonne Sadovy, of the University of Hong Kong, predicted that high demand and cash-hungry fishermen mean that "ciguatoxic fish entering markets around the world is going to increase."

Should global warming and pollution worsen and boost ciguatera poisonings, as most experts predict, health officials will face a daunting challenge.

Currently, there is no reliable way to detect whether a fish has ciguatera. The molecule is extremely complex and differs markedly from region to region.

There also is no antidote.

Furthermore, doctors are often ill-equipped to diagnose ciguatera, which has a range of symptoms and is sometimes misdiagnosed as chronic fatigue syndrome or other maladies.

Those challenges faced Dr. Edgar Portigo at Doctors General Hospital in Iloilo, about 265 miles southeast of Manila, when the Roa family and others arrived. The emergency room was filling with patients yelping in pain, vomiting, or, in the case of Dabby Roa, so paralyzed that he had to be carried in by a security guard.

"Normally, you have one or two emergency cases. Here we had 30 plus all at once," from ages 4 to 65, Portigo said.

At first, Portigo surmised the patients had heavy metal poisoning. But when he learned of the common thread — the barracuda dinners — he sent a sample of the fish to Manila for testing. It came back positive for ciguatera.

Portigo gave his patients intravenous drips and a diuretic to relieve their suffering. Most like Roa were released from the hospital in a week, he said, and fully recovered.

"Although this is quite rare, it can happen anytime," said Portigo, noting this was the first ciguatera outbreak in the city.

A relatively quick recovery is the norm, but some have lingering symptoms.

Dennis McGillicuddy, a 65-year-old retired cable television company owner from Sarasota, Fla., fell sick a few hours after eating a mutton snapper he caught off the coast of Bermuda in 2000. Within hours, his vomiting and diarrhea were so severe that he became delirious and was "reduced to crawling," he recalled.

The digestive symptoms lasted two weeks. After that, McGillicuddy became so sensitive to temperature extremes that it was hard to take a shower. Numbness in his extremities lasted for almost a year.

"I've never had anything like this," said McGillicuddy, who still occasionally feels tingling in his left arm. "You feel terrible all over your body."

The U.S. Food and Drug Administration and others who monitor ciguatera say they are hampered by the lack of a reliable test. Bans on certain fish or "hot spots" can help, but they often are impractical.

"It's very hard to manage," said professor Richard Lewis, of the University of Queensland in Australia, who has studied ciguatera. "Unless you don't eat the fish, you have a risk of getting ciguatera."

Poorer countries often lack even rudimentary measures to protect consumers. Those precautions that do exist are undermined by government corruption or lack of enforcement.

Hong Kong has refused to enact mandatory measures to prevent ciguatera despite increased outbreaks. It argues that educating consumers and traders is the answer, rejecting calls to crack down on traders or ban fish from suspect areas.

"Given the fact we eat so much seafood in Hong Kong, this should be one of the priorities in protecting the population," Sadovy said. "I just hope we don't have to wait for someone to die before something is done."

In Iloilo, fear has done what the Philippine government has not. Consumers stopped buying barracuda after the ciguatera outbreak. Vendors have switched to less risky varieties.

Tuna ‘ranches’ feed appetite for bluefin

Underwater feed lots off Mexican coast find ready buyers in Japan

MSNBC.com

April 2

RANCHO SANTA FE, Calif. - Pacific bluefin tuna leave Japan’s coast and swim east at breakneck speed to school in North American coastal waters. Many of them return on nonstop flights from Los Angeles as slabs of fresh toro, the “foie gras of the sea,” fattened, refrigerated and ready for the sashimi knives.

The transformation happens in underwater pens that are 150 feet wide and 45 feet deep, where wild-caught bluefin are fattened on fresh sardines to develop the buttery texture prized in Japan.

Bluefin “ranches,” which offer a reliable source of toro sushi that is higher in oil than lean fish straight off the boat, have popped up in waters from Spain to Australia. In the last decade, Mexico’s Baja California and Southern California emerged as a chief source to the lucrative Japanese market.

“It’s basically an underwater feed lot,” said Philippe Charat, who runs a Mexican bluefin operation from his home in chi-chi Rancho Santa Fe, north of San Diego. “We take something that has very little value when it’s in a can and turn it into a very high-quality product.”

Bluefin, or toro, is richer than the yellowfin, or ahi, tuna typically scarfed in American sushi bars. Top-grade cultivated bluefin regularly fetches more than $10 a pound for wholesale buyers at Tokyo’s famed Tsukiji fish market. One wild specimen once fetched $395 a pound.

Pacific bluefin spawn in Japan’s warm coastal waters and journey east a few years later, arriving off Big Sur and running 1,500 miles south to the tip of Baja California.

The fish are caught several hundred miles offshore and then towed to pens that dot the sapphire bays around the Coronado Islands in Mexican waters near San Diego and Ensenada, Mexico, 70 miles south of the border. The pens are tended by crews who guard against poachers, sharks and sea lions.

Months later, the bluefin are harvested. Divers wrestle the flailing silver-blue tuna onto the tarp-covered deck of an outfitted boat. They are rapidly brained, gutted and bled before being suspended in near-freezing saline water to prevent “burn,” or the buildup of stress-triggered lactic acid that can ruin the fish’s firm, translucent flesh.

Wholesale buyers in Japan, who get the bluefin as little as 72 hours after it’s pulled from the sea, call the Mexican shipments “laxfish” after the initials “LAX” stamped on the manifests from Los Angeles International Airport.

“The Mexican fish has a very good reputation in Japan,” said James Joseph, a tuna fisheries consultant and former head of the San Diego-based Inter-American Tropical Tuna Commission, an international body that regulates tuna fishing in the eastern Pacific. “The water is cool, and they’re feeding them fresh sardines all the time, which gives the fish a sweet taste.”

The key to Mexico’s success lies in the abundant supply of sardines, which has long lured a variety of tuna species to the Pacific coastline, from the relatively rare dark-meat bluefin to the more common white-meat albacore and yellowfin that end up in tins.

San Diego and Baja California became hubs for tuna fishing and canning in the early 1900s, when white-fleshed tuna was marketed as an alternative to chicken. Rising labor costs and the development of tuna-industry dolphin-safe standards in the 1980s decimated the region’s commercial fleet, sending boats to the far western Pacific waters of American Samoa and Guam.

Enter Charat, 67, a French-born Mexican citizen who left a shrimping business on Mexico’s Gulf Coast and began fishing tuna out of Ensenada in 1983.

Unlike the more common yellowfin species, bluefin don’t run with dolphins, exempting them from catch restrictions. In 1997, after a tour of Australian ranches, Charat went into the bluefin business in the San Diego area, facing a lone competitor who soon bailed out.

In its first year, Charat’s privately held, Ensenada-based company, Maricultura del Norte, netted 30 tons of bluefin. The following season, they took in 60 tons. This winter, Maricultura fattened more than 1,500 tons of fish in two dozen pens anchored in a hidden cove tucked around a point of land south of Ensenada harbor.

The ranches are a lifeblood for the $350-million-a-year bluefin market in Japan, generating waterfront jobs in Ensenada and San Diego. Charat thinks growing worldwide demand for bluefin can help San Diego and northern Baja California regain luster as a tuna capital.

Bluefin stocks in the Atlantic have fallen 80 percent in the past 30 years, prompting the chief European Union fisheries official earlier this year to press for cuts in worldwide catch quotas. Australian authorities imposed new limits on bluefin catches last October amid concern about dwindling supplies.

A handful of Japanese-owned operators have followed Charat into Ensenada, anchoring pens just north of the harbor. Baja Aqua Farms, which is managed by Australians, keeps pens off the Coronado Islands and brings harvested tuna by boat to a packing facility in San Diego, avoiding long waits at truck crossings on the U.S.-Mexico border.

“They said it could not be done in Mexico because the water was too cold, the area of the fish migration too big,” said Charat. “Now it’s by far the most active thing going on in the region as far as fishing goes.”

Health Canada revises assessment of mercury in fish

SpiritIndia.com

March 29

Health Canada has completed a review of the science on mercury in fish, and is putting additional measures in place to protect Canadians while encouraging them to follow the fish consumption advice contained in the new Food Guide.

Health Canada's standards for mercury in fish were already some of the most stringent and protective in the world.

They are now being strengthened even further to focus on certain predatory fish, which tend to have higher levels of mercury because of their relative size, lifespan and diet.

These fish, which had previously been exempted from Health Canada's standard, will now be subject to a 1.0 parts per million mercury limit. This new standard will apply to fresh and frozen tuna, shark, swordfish, escolar, marlin and orange roughy. Other fish, including canned tuna, will still be required to meet the existing 0.5 parts per million standard.

Health Canada's updated advice reflects the new standard being put in place, stresses the important nutritional benefits of eating fish and reflects advice provided in Canada's Food Guide. For the large predatory fish now subject to the new standard, the general population can eat up to 150 g per week of these fish species combined. However, women who are or may become pregnant and breastfeeding mothers can eat up to 150 g per month. Young children between 5 and 11 years of age can eat up to 125 g per month. Very young children between 1 and 4 years of age should eat no more than 75 g per month of these fish species.

Health Canada's review also identified the need for advice to specific Canadians related to canned albacore tuna. This advice was released in February 2007 and applies to women who are or may become pregnant, breastfeeding mothers and children. This information is available on the Health Canada Web site.

These changes are the result of a major review that considered the latest scientific information about fish consumption and mercury. It looked at the risk of negative health effects for Canadians of all ages from exposure to mercury through commercial fish, and also considered the health benefits of fish consumption in general. It is the most comprehensive national assessment on mercury in fish done to date, the results of which are now available on the Health Canada Web site.

Fish and seafood can be an important part of a healthy balanced diet and most Canadians do not need to be concerned about mercury exposure from eating fish. However the types of fish available for sale in Canada has changed over the years and science is regularly updated as new information is discovered. As a result, and based on the most recent information about mercury levels in retail fish, some changes are being made to Health Canada's standards and advice on mercury in fish to help Canadians incorporate the right kinds and amounts of fish into their diets with confidence.

Canada's Food Guide recommends that Canadians eat at least two Food Guide servings (of 75 grams each) of fish each week. Canadians are encouraged to choose fish that are high in Omega-3 fatty acids such as salmon, herring, sardines, char, Atlantic mackerel and rainbow trout. These fish also tend to be low in mercury.

Apples and fish reduce allergies of babies in the womb

Maternal diet found to affect asthma and eczema

By Judith Duffy, Health Correspondent

SundayHerald.com

April 6

WOMEN WHO eat apples and fish during their pregnancy could reduce the chances of their children developing asthma or allergic diseases.

Researchers discovered that the children of mothers who ate the most apples were less likely to to be diagnosed with asthma by the age of five. A similar association was found in the development of eczema in the children of women who ate fish once or more each week.

Yet the study also found that many other healthy foods - including kiwi fruit, vegetables, whole-grain products and fruit juice - did not appear to have an impact. And the children's own dietary intake of fish or apples also did not have an effect on whether they were likely to develop symptoms of the conditions.

The researchers suggest that the beneficial "apple-specific" effect could come from powerful antioxidants called flavanoids which are found in the fruit and from omega-3 fatty acids which are present in fish.

The findings add to evidence that maternal diet may have a pronounced effect on determining whether children develop asthma. Previous studies have also revealed protective effects associated with the mother's intake of vitamin D and vitamin E.

Study co-author Dr Graham Devereux, a senior lecturer at Aberdeen University, said the mother's diet could play a crucial role in the development of the baby's lungs in the womb. "The way your airways develop is basically by when you are born, that is the airways you have got for the rest of your life," he said. "So you can imagine that small changes in the way your airway develops could have a big effect later in life."

The study, which has just been published online by the journal Thorax and will be presented later this year at the American Thoracic Society conference, is the latest follow-up on women who were recruited between 1997 and 1999 at Aberdeen Maternity Hospital and kept food diaries while pregnant.

For the new research, 1212 of the mothers filled out a questionnaire about the children's allergies and respiratory symptoms, as well as giving details about their children's current diet.

Children of mothers who ate the most apples were around 50% less likely to develop asthma symptoms, compared to those with the lowest consumption of the fruit. A similar effect was also seen in relation to eczema in the children of those mothers who consumed fish at least once a week, compared with those who never ate it.

There has been a dramatic increase in asthma in recent years, with one in 10 children in the UK now suffering from the condition. Other allergic conditions, such as hayfever and eczema, are also on the rise, but scientists have so far been unable to pinpoint the reasons why.

The study noted that apple consumption in the UK has fallen to around 173g per person per day, compared to 207g in 1974. However, Devereux cautioned against recommending that pregnant women eat a certain amount of apples or fish, saying that more research would have to be done to establish exactly what the association is.

Dr Victoria King, research development manager at charity Asthma UK, which funded the research, also stressed that it was important for mothers to follow a generally healthy diet. She added: "This study suggests a simple modification that can be made to a pregnant mother's diet may help protect her child from developing asthma before the age of five."

Judy More, a spokeswoman for the British Dietetic Association, said there was much research which showed that eating well during pregnancy has a positive effect on a child's long-term health.

"I think the increase in allergies is multifactorial, and several studies have found associations between diet and allergies and asthma," she said. "In the end it is probably going to be several different factors that have changed in our lifestyle that have caused allergies and asthma to increase."

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