Maldives Declares All Its Territorial Waters a Shark Sanctuary

The Maldives definitely knows who's paying the bills these days... The low-lying Indian Ocean nation has declared the entirety of its 90,000 square mile Exclusive Economic Zone a shark sanctuary, banning all fishing as well as imports and exports of shark fins.

Tourism now forms the majority of the Maldives' economy, but fishing is growing in importance and competing with tourism in terms of preserving the very natural resources people come to see. In the case of sharks, the more than 30 species found in the waters around the Maldives.

Praising the move, Matt Rand, director of Global Shark Conservation for the Pew Environment Group said:

Countries are beginning to recognize just how important vibrant shark populations are to healthy ecosystems, and to their ecotourism industries. Today's announcement protects the Maldives' tourism industry from the the ravages of the shark fin trade. It is a bold and farsighted move on the part of the government of the Maldives.

Source: http://www.treehugger.com/files/2010/03/maldives-declares-all-its-waters-shark-sanctuary.php

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About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

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Leviathans may battle in remote depths

New studies suggest that great white sharks may migrate so they can dine on giant squids.

In what could be the ultimate marine smack-down, great white sharks off the California coast may be migrating 1,600 miles west to do battle with creatures that rival their star power: giant squids.

A series of studies tracking this mysterious migration has scientists rethinking not just what the big shark does with its time but also what sort of creature it is.

Few sea denizens match great white sharks and giant squids in primitive mystique. Both are the subject of popular mania; both are inscrutable. That these two mythic sea monsters might convene for epic battles in the stark expanses of the Pacific is enough to make a documentarian salivate.

For more reserved scientists, the possible link between sharks and squid, suggested by marine ecologist Michael Domeier of the Marine Conservation Science Institute in Fallbrook, is just one part of emerging research that has altered their understanding of the great whites.

The shift began eight years ago with the surprising discovery that great white sharks migrate, somewhat as humpback whales do. That and subsequent studies have demolished the iconic image of great whites lurking in relative shallows, ready to snatch an errant swimmer, as popularized in the movie "Jaws."

Domeier said he believes the animals "are not a coastal shark that comes out to the middle of the ocean. They are an ocean shark that comes to the coast. It is a complete flip-flop."

Picture them not as a dorsal fin off the beach but rather as an unseen leviathan swimming through black depths where the oxygen thins and fish glow in the dark, and maybe pouncing on a 30-foot squid.

The squid part is controversial. But Domeier's work and that of other scientists increasingly suggests that great white sharks are not randomly roving eating machines.

Instead, they obey set migration patterns, have distinct populations and return to the same locales. They are not desperadoes but dutiful migrants: Nomads but not outlaws, they yearn for home.

But this new understanding raised a question: Why would an animal so large, that grows teeth as humans grow hair, bother to go so far when it can dine on just about anything in fin's reach? The migration is especially puzzling because it means sharks miss out on coastal food supplies, said the University of Hawaii's Kevin Weng, who also tracked sharks' migration.

Determined to find the reason, Domeier and his team spent three years catching 22 great whites off Mexico's Guadalupe Island, southwest of San Diego, and bolting high-tech tags to their fins. The area, like California's Farallon Islands, is a hot spot for shark visits.

The team used hooks that could cradle a volleyball. They wrestled the sharks onto platforms, lifted them aboard their vessel and put towels over their eyes. The 4,000-pound predator is only a minor threat out of water, Domeier said. But after being thwacked off his feet, he learned to tie up their tails.

Funded by Newport Beach's George T. Pfleger Foundation and others, Domeier arranged a voyage with a National Geographic Channel television crew to follow the sharks in a 126-foot boat. The crew used the tags to track the sharks to an area of the deep Pacific about 1,500 miles east of Kauai that scientists consider an ecological desert because it is so biologically unproductive.

There, the sharks abruptly ended their migration, and satellite tags showed them milling around and diving.

Despite hours of surveys and trolling during last spring's monthlong voyage, members found barely any fish or other prey that the sharks might be eating.

But there was an exception: squids. Purple and neon flying squids were easy to find. There also were leaping sperm whales, a marine mammal known to feed in spawning areas for large squids. To Domeier, it was clear: The sharks had found a squid-based ecosystem with big enough prey to attract sperm whales.

Finally, the crew found a whitish carcass of a giant squid that had been chewed on, perhaps by various predators. Because of the lack of alternative food sources, and the pinging tags that traced deep and frequent dives, Domeier said, he formed a speculative conclusion: The sharks go to the area for the same reason as sperm whales: to feed on large squids, including the giant ones in the area, and on various predators the squids attract.

The weather turned bad, and the investigation ended early. The trip back was boring enough for the crew to form a band, then break up.

Domeier said he believes the sharks return to the coast to breed. His tags showed that some females stayed out at sea full-time.

The idea has set off robust debate. Some scientists argue it remains possible that the sharks mate offshore, and all agree that more research is needed to determine exactly what, and when, they eat. And it's highly unlikely anyone will ever see a shark making an easy kill of giant squid.

But Oscar Sosa-Nishizaki, a fisheries biologist in Ensenada, said the tagging effort helps researchers count sharks and plan conservation efforts.

Shark scientists face a dilemma: There is intense popular interest in their work, but some fret that it may hinder conservation. Media interest in sharks tends to be "sparse on detail, high on testosterone," said marine biologist Weng. "It's as if aliens were to visit planet Earth, and the only thing they saw of human beings was ultimate fighting on TV."

Though wary of pop biology, Domeier made the most of it. He used his time on camera to lobby against eating bluefin tuna and Chilean sea bass.

If mythic predator-mania gave him the chance, so be it, he said. "We are at a state of real disaster of our oceans," he said. "Perhaps the scientific routine . . . doesn't work."

jill.leovy@latimes.com

Source: http://articles.latimes.com/2010/mar/07/local/la-me-shark7-2010mar07

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About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

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LEMON SHARKS PROTECTED IN FLORIDA

FOR IMMEDIATE RELEASE:
OCEANIC DEFENSE: LEMON SHARKS PROTECTED
Feb 18, 2010,

We are very pleased to announce that the FWC has protected Lemon sharks from harvest in the state of Florida. We will continue to bring you more news as it becomes available. Please visit us on facebook for updates: http://www.facebook.com/OceanicDefense

The following is directly from the FWC website:

Official release from FWC:

News Release

February 18, 2010
Contact: Lee Schlesinger, 850-487-0554

The Florida Fish and Wildlife Conservation Commission (FWC) approved a rule Thursday to prohibit all recreational and commercial harvest of lemon sharks from Florida waters. The FWC took this action to protect lemon sharks, because they have a high potential to be overharvested.

Lemon sharks are often found near shore in shallow water, especially in Southeast Florida, where they aggregate in large numbers each year. This makes them easy to locate and raises the potential for large numbers of lemon sharks to be removed from the population with minimal effort by fishermen.

Lemon sharks also are susceptible to overharvest because of their life history characteristics. They are slow-growing, reaching sexual maturity at 12-15 years of age, and have a low reproductive potential, producing 6 to 18 pups per litter every second or third year. Juvenile lemon sharks experience a mortality of 40-60 percent.

Recently, some preliminary data from an ongoing tagging study found that at least 7.5 percent of tagged adult lemon sharks from a Southeast Florida aggregation succumbed to fishing mortality in one season. At that rate, the entire lemon shark aggregation could be harvested in a few years.

In addition, recent regulatory actions for other shark species might put more fishing pressure on lemon sharks in Florida waters, where 90 percent of known lemon shark aggregations occur. The harvest of lemon sharks will still be allowed in offshore federal waters adjacent to state waters.

Healthy lemon shark populations are especially important to Florida's dive charter industry which provides ecotourism trips to see lemon shark aggregations in the winter months.

The FWC's lemon shark rule takes effect on March 23. More information about recent shark-management actions is available online at MyFWC.com/Rules, click on "Fishing - Saltwater."

---

About Oceanic Defense
We are an international non-profit organization with members in over 60 countries, spanning 6 continents with 1 mission; healthy aquatic ecosystems free from human abuse and neglect. Oceanic Defense teaches people to protect our oceans by acting responsibly as consumers and by making smart decisions in our daily lives. Whether we are buying groceries, commuting to work, planning a vacation or advocating within our own communities; each action we take or decision we make either helps or hurts our oceans. We empower people to be part of the solution rather than part of the problem and work together to protect our blue planet.

Join us on Facebook:
www.facebook.com/OceanicDefense
Visit our official website:
www.oceanicdefense.org
Follow us on Twitter:
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Scientists Shed New Light On Behavior Of Shark 'Tweens' And 'Teenagers'

ScienceDaily — A long-term field and DNA study by the Institute for Ocean Conservation Science at Stony Brook University, University of Miami, Field Museum of Chicago and others has shown that young lemon sharks born at the Bimini islands, Bahamas, tend to stay near their coastal birthplace for many years. While shark research and conservation typically focuses on baby sharks confined to shallow habitats, or ocean-roaming adults, less is known about these intermediate-aged animals, which are the breeders of tomorrow and are roughly similar in development to human ‘tweens’ and teenagers.

Tropical island-nations that sacrifice their nursery habitats to coastal development are therefore likely to lose not only babies but also much older sharks from their local areas, with potentially dire effects on the surrounding ecosystem. The study, conducted over a 14-year period at the Bimini Biological Field Station, is the cover article in the August issue of Molecular Ecology, a leading international scientific journal.

“It takes some sharks more than a decade to reach reproductive age, so we set out to better understand the phase of their development from when they are a couple of years old until they are on the verge of sexual maturity,” said lead author Dr. Demian Chapman, shark scientist with the Institute for Ocean Conservation Science at Stony Brook University (SBU) in New York, and an assistant professor at SBU. “We were very surprised to see that many lemon sharks lingered for years around the island where they were born -- often more than half of their development to adulthood.”

Fear of deep waterand the bigger predators that live there combined with abundant prey in the mangroves around Bimini probably keeps these island-born sharks in safer waters near home for several years after their birth. “This means that using marine reserves and other local conservation measures may help protect sharks born around tropical islands for much longer than we thought,” Dr. Chapman explained. He suspects that future research could show that these stay-at-home behavior patterns are common among many shark species that live and breed around tropical islands. “If island communities develop all of their shark nursery habitats, like mangroves, or overfish baby sharks in local waters, then they will subsequently lose a big chunk of the older sharks as well,” he said.

Love them or not, sharks are essential to healthy oceans. Removing these top-level ocean predators will disrupt the local food web and cause negative consequences for other species and the ecosystem at large. Moreover, many tropical islands generate substantial revenue from shark-dive tourism, which this new research suggests will be heavily reliant on sharks born in local nursery areas.

During the course of the Bimini study, from 1995 to 2007, over 1,700 immature lemon sharks were caught, tagged and released. The implanted tags, plus subsequent recaptures and DNA analysis, showed that more than half of the 3- to 7-year-old sharks caught off Bimini were born locally and had lingered near their birthplace for years. Full results are described in the study, entitled, Long-term natal site-fidelity by immature lemon sharks (Negaprion brevirostris) at a subtropical island.

“In general, the survival of these intermediate-aged sharks is critical for sustaining shark populations,” said study co-author Dr. Samuel Gruber, Professor at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science and Director of the Bimini Biological Field Station, who has been leading the overall lemon shark research program at Bimini since 1978. “Our study suggests that local conservation efforts can help many lemon sharks born at islands like Bimini survive through roughly half of their development to adulthood. Broader scale, sometimes international, management is needed to protect them after they’ve left their birthplace as adolescents and adults.”

Detailed information on how sharks disperse from their birthplace could be very useful for conservation efforts throughout the tropics, given that many tropical shark species are threatened by overexploitation to supply the trade for shark fin soup, for which demand is especially high in Asia. Between 22 and 73 million sharks are killed each year to supply the fin trade, and international management agencies are scrambling for solutions to stem severe shark population declines.

“Our study suggests that many tropical island nations may not have to wait for complex international shark regulations to be established in order to act,” said Dr. Chapman. “Their local management efforts could give immature sharks a chance to grow up in relative safety until they are big and ‘bad’ enough to roam deeper habitats far from home, where broader scale protection becomes more important.”

The research team is now extending its study to answer one of the great mysteries of shark biology: do sharks home back to their birthplace as adults? Co-author Dr. Kevin Feldheim of the Field Museum in Chicago, who led the genetics part of the study, said: “This research showed that most of the young sharks left the island by the time they were mature. Now we want to find out if they end up coming back to the place where they were born to breed, much like salmon and sea turtles do.”

Source: http://www.sciencedaily.com/releases/2009/08/090824141047.htm

Florida considers protection for lemon sharks

Lemon sharks are being considered for protection. (Walt Stearns, Florida Fish and Wildlife Conservation Commission / November 19, 2009)

Undersea predators called vital to health of reefs
By David Fleshler, Sun Sentinel

They are the lords of the reefs, powerful 10-foot sharks that prowl shallow coastal waters, snatching stingrays, crabs and mullet.

But while lemon sharks can hold their own in the undersea jungle, they face a tougher time against the predators equipped with powerboats, baited hooks and satellite tracking devices.

The Florida Fish and Wildlife Conservation Commission this month is considering a ban on the catch of lemon sharks, hoping to protect a species that plays an important role in maintaining the health of coral reefs.

The proposal for the ban came from a group of scientists and environmentalists clustered around University of Miami professor Samuel Gruber, the world's foremost lemon shark expert. They fear that restrictions on catching other shark species over the past couple of years are leading fishermen to turn their attention to lemon sharks. Since 2004, the Florida lemon shark catch has risen more than 400 percent.

Because these sharks take years to mature and bear few young, they have difficulty recovering from heavy fishing pressure. In the 1980s in the Florida Keys, for example, where Gruber was tagging sharks, the entire population had virtually disappeared by 1986.

"It was targeted by commercial fishermen," he said. "They set huge gill nets and everything they caught went to the fish house for 10 cents a pound."

Adding to the lemon shark's vulnerability is the species' bizarre habit of assembling in large, stationary groups on the ocean floor. A couple of miles off Jupiter, for example, lies the biggest known aggregation of lemon sharks, with groups of up to 100 visible during the winter.

"They're lying on the sand, nose into the current, basically shoulder to shoulder like cars in a parking lot," said Walt Stearns, a professional undersea photographer from Palm Beach Gardens, who brought the assemblage of sharks to the attention of scientists.

Gruber describes this as the largest known congregation of lemon sharks on the East Coast of the United States, and he said it highlights the danger to the sharks from people.

"They could target and catch them and wipe them out in a matter of weeks," Gruber said.

Fort Pierce shark fisherman Joe Klosterman takes his 37-foot boat Gale Mist II up to 25 miles out to sea, where he deploys a longline baited with mullet, bluefish and bits of shark. He says he hasn't noticed a decline in lemon sharks and that a catch ban won't do the sharks much good.

Although he would be required to throw back any banned sharks he catches, he said that doing so will do little for the shark since at that point it would probably be dead.

"Some sharks die real quick on the lines," he said. And throwing one back would cost him the $300 or so he could have earned for the shark's fins alone, which are exported to East Asia for shark fin soup, a delicacy.

"Most fisherman are all for conservation," he said. "You want to see a sustainable fishery. But I don't see where this is going to save more sharks."

Lemon sharks, named for their yellow-brown color, live in coastal waters from the mid-Atlantic states to southern Brazil. They rank 13th in attacks on people, far below the "big three" for shark attacks: the great white, tiger and bull sharks, according to the International Shark Attack File at the Florida Museum of Natural History. There have been no known fatal attacks by lemon sharks.

The sharks play an important role in maintaining the health of shallow ecosystems, such as coral reefs, by preventing lesser predators from multiplying out of control, Gruber said. They hold down the population of stingrays, for example. Without this service, the stingrays would devastate the lobsters, with further consequences down the food chain.

"The lemon shark is one of the largest predators on the reef," Gruber said. "If you were to take away the predator pressure, you will cause an ecological disruption in the balance of species."

The wildlife commission will decide whether to approve a draft ban on lemon shark catches at its Dec. 10 meeting in Clewiston.

The commission's ban would apply only to state waters, which extend three miles off the east coast and nine miles off the west coast. But the federal government, which regulates fishing up to 200 miles off the coast — except where that zone would run into the Bahamas — may follow Florida's lead if the state requests it. Karyl Brewster-Geisz, fishery management specialist for the National Marine Fisheries Service, said states normally request comparable regulations in federal waters for consistency.

Staci-lee Sherwood, a Lighthouse Point animal rights activist who filed comments with the commission in support of the ban, said lemon sharks have far greater economic value if they remain in place to be seen by dive boats full of tourists, rather than killed for a few hundred dollars worth of fins and meat. But beyond that, she said, they have value beyond any use by human beings.

"I'm against any kind of cruelty to animals," she said. "I wouldn't justify killing any animal just for its fins or ivory or fur."

David Fleshler can be reached at dfleshler@SunSentinel.com 954-356-4535.

Source: http://www.sun-sentinel.com/news/local/florida/fl-lemon-shark-20091203,0,3793198,full.story

Wide Heads Give Hammerhead Sharks Exceptional Stereo View

Scalloped hammerhead, Sphyrna lewini. (Credit: Courtesy of Flickr, via Wikimedia Commons)

ScienceDaily — Hammerhead sharks are some of the Ocean's most distinctive residents. "Everyone wants to understand why they have this strange head shape," says Michelle McComb from Florida Atlantic University. One possible reason is the shark's vision.

"Perhaps their visual field has been enhanced by their weird head shape," says McComb, giving the sharks excellent stereovision and depth perception.

However, according to McComb, there were two schools of thought on this theory. In 1942, G. Walls speculated that the sharks couldn't possibly have binocular vision because their eyes were stuck out on the sides of their heads. However, in 1984, Leonard Campagno suggested that the sharks would have excellent depth perception because their eyes are so widely separated. "In fact one of the things they say on TV shows is that hammerheads have better vision than other sharks," says McComb, "but no one had ever tested this."

Teaming up with Stephen Kajiura and Timothy Tricas, the trio decided to find out how wide a hammerhead's field of view is and whether they could have binocular vision and publish their results on November 27 2009 in the Journal of Experimental Biology.

Hammerheads come in all shapes and sizes so McComb and Kajiura, opted to work with species with heads ranging from the narrowest to the widest. Fishing for juvenile scalloped hammerheads off Hawaii and bonnethead sharks in the waters around Florida, the team successfully landed the fish and quickly transported them back to local labs to test the fish's eyesight.

The team tested the field of view in each shark's eyes by sweeping a weak light in horizontal and vertical arcs around each eye and recorded the eye's electrical activity. Comparing the hammerheads with pointy nosed species, the team found that the scalloped hammerheads had the largest monocular visual field, at an amazing 182 deg., and the bonnethead had a 176 deg. visual field, which was bigger than that of the pointy nosed blacknose and lemon sharks, at 172 deg. and 159 deg., respectively.

Having collected the animals' monocular visual fields, the team plotted the visual fields of both eyes on a chart of each fish's head to see whether they overlapped. Amazingly, they did. The scalloped hammerhead had a massive binocular overlap of 32 deg. in front of their heads (three times the overlap in the pointy nosed species) while the bonnet head had a respectable 13 deg. overlap. And when the team measured the binocular overlap of the shark with the widest hammerhead, the winghead shark, it was a colossal 48 deg. The hammerheads' wide heads certainly improved their binocular vision and depth perception.

Finally, the team factored in the sharks' eye and head movements and found that the forward binocular overlaps rocketed to an impressive 69 deg. for the scalloped hammerheads and 52 deg. for the bonnetheads. Even more surprisingly, the team realised that the bonnethead and scalloped hammerheads have an excellent stereo rear-view: they have a full 360 deg. view of the world.

"When we first started the project we didn't think that the hammerhead would have binocular vision at all. We thought no way; we were out there to dispel the myth," says McComb. But despite their preconceptions, the team have shown that the sharks not only have outstanding forward stereovision and depth perception, but a respectable stereo rear view too, which is even better than the TV shows would have us believe.

Source: http://www.sciencedaily.com/releases/2009/11/091127101034.htm

Palau to create world's first shark sanctuary

The tiny Pacific nation of Palau is creating the world's first shark sanctuary, a biological hotspot to protect Great Hammerheads, Leopard Sharks, Oceanic Whitetip Sharks and more than 130 other species fighting extinction in the Pacific Ocean.

But with only one boat to patrol 240,000 square of Palau's newly protected waters - including its exclusive economic zone, or EEZ, that extends 200 miles from its coastline - enforcement of the new measure could be almost like swimming against the tide.

Palau's president, who is to announce the news to the U.N. General Assembly today, acknowledges the difficulty of patrolling ocean waters nearly the size of Texas or France with a single boat. But he hopes others will respect Palauan territorial waters - and that the shark haven inspires more such conservation efforts globally.

"Palau will declare its territorial waters and extended economic zone to be the first officially recognized sanctuary for sharks," Palauan President Johnson Toribiong said.

Shark fishing has grown rapidly since the mid-1980s, driven by a rising demand - mainly in China - for shark fin soup, a highly prized symbol of wealth. Because of their long life spans and low fertility rates, sharks are vulnerable to overfishing.

Within its EEZ, a nation may regulate fisheries and scientific research and develop other economic efforts. The U.N.'s Food and Agriculture Organization estimates more than half of highly migratory sharks are overexploited or depleted.

Toribiong said a recent flyover by Australian aircraft showed more than 70 vessels fishing Palau's waters, many of them illegally.

"We'll do the very best we can, given our resources," he said. "The purpose of this is to call attention to the world to the killing of sharks for commercial purposes, including to get the fins to make shark fin soups, and then they throw the bodies in the water."

Palau is one of the world's smallest countries, with about 20,000 people scattered over a 190-square-mile archipelago of lush tropical landscapes in the Western Pacific.

Its shark sanctuary will shelter more than 135 Western Pacific species of sharks and rays considered endangered or vulnerable, or for which there is not enough data to determine how the species is faring.

Source: San Francisco Chronicle

Scientists Shed New Light On Behavior Of Shark 'Tweens' And 'Teenagers'

ScienceDaily — A long-term field and DNA study by the Institute for Ocean Conservation Science at Stony Brook University, University of Miami, Field Museum of Chicago and others has shown that young lemon sharks born at the Bimini islands, Bahamas, tend to stay near their coastal birthplace for many years. While shark research and conservation typically focuses on baby sharks confined to shallow habitats, or ocean-roaming adults, less is known about these intermediate-aged animals, which are the breeders of tomorrow and are roughly similar in development to human ‘tweens’ and teenagers.

Tropical island-nations that sacrifice their nursery habitats to coastal development are therefore likely to lose not only babies but also much older sharks from their local areas, with potentially dire effects on the surrounding ecosystem. The study, conducted over a 14-year period at the Bimini Biological Field Station, is the cover article in the August issue of Molecular Ecology, a leading international scientific journal.

“It takes some sharks more than a decade to reach reproductive age, so we set out to better understand the phase of their development from when they are a couple of years old until they are on the verge of sexual maturity,” said lead author Dr. Demian Chapman, shark scientist with the Institute for Ocean Conservation Science at Stony Brook University (SBU) in New York, and an assistant professor at SBU. “We were very surprised to see that many lemon sharks lingered for years around the island where they were born -- often more than half of their development to adulthood.”

Fear of deep water and the bigger predators that live there combined with abundant prey in the mangroves around Bimini probably keeps these island-born sharks in safer waters near home for several years after their birth. “This means that using marine reserves and other local conservation measures may help protect sharks born around tropical islands for much longer than we thought,” Dr. Chapman explained. He suspects that future research could show that these stay-at-home behavior patterns are common among many shark species that live and breed around tropical islands. “If island communities develop all of their shark nursery habitats, like mangroves, or overfish baby sharks in local waters, then they will subsequently lose a big chunk of the older sharks as well,” he said.

Love them or not, sharks are essential to healthy oceans. Removing these top-level ocean predators will disrupt the local food web and cause negative consequences for other species and the ecosystem at large. Moreover, many tropical islands generate substantial revenue from shark-dive tourism, which this new research suggests will be heavily reliant on sharks born in local nursery areas.

During the course of the Bimini study, from 1995 to 2007, over 1,700 immature lemon sharks were caught, tagged and released. The implanted tags, plus subsequent recaptures and DNA analysis, showed that more than half of the 3- to 7-year-old sharks caught off Bimini were born locally and had lingered near their birthplace for years. Full results are described in the study, entitled, Long-term natal site-fidelity by immature lemon sharks (Negaprion brevirostris) at a subtropical island.

“In general, the survival of these intermediate-aged sharks is critical for sustaining shark populations,” said study co-author Dr. Samuel Gruber, Professor at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science and Director of the Bimini Biological Field Station, who has been leading the overall lemon shark research program at Bimini since 1978. “Our study suggests that local conservation efforts can help many lemon sharks born at islands like Bimini survive through roughly half of their development to adulthood. Broader scale, sometimes international, management is needed to protect them after they’ve left their birthplace as adolescents and adults.”

Detailed information on how sharks disperse from their birthplace could be very useful for conservation efforts throughout the tropics, given that many tropical shark species are threatened by overexploitation to supply the trade for shark fin soup, for which demand is especially high in Asia. Between 22 and 73 million sharks are killed each year to supply the fin trade, and international management agencies are scrambling for solutions to stem severe shark population declines.

“Our study suggests that many tropical island nations may not have to wait for complex international shark regulations to be established in order to act,” said Dr. Chapman. “Their local management efforts could give immature sharks a chance to grow up in relative safety until they are big and ‘bad’ enough to roam deeper habitats far from home, where broader scale protection becomes more important.”

The research team is now extending its study to answer one of the great mysteries of shark biology: do sharks home back to their birthplace as adults? Co-author Dr. Kevin Feldheim of the Field Museum in Chicago, who led the genetics part of the study, said: “This research showed that most of the young sharks left the island by the time they were mature. Now we want to find out if they end up coming back to the place where they were born to breed, much like salmon and sea turtles do.”

Source: http://www.sciencedaily.com/releases/2009/08/090824141047.htm

Sharks In Peril: Ocean's Fiercest Predators Now Vulnerable To Extinction

(Thresher Shark Supervalu and Affiliates continue to kill with no regard for their customers wishes or the plight of the species or the aquatic environment.)

ScienceDaily — Sharks are disappearing from the world's oceans. The numbers of many large shark species have declined by more than half due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and swordfish fisheries, where millions of sharks are taken as bycatch each year.

Now, the global status of large sharks has been assessed by the World Conservation Union (IUCN), which is widely recognized as a highly comprehensive, scientific-based information source on the threat status of plants and animals.

"As a result of high and mostly unrestricted fishing pressure, many sharks are now considered to be at risk of extinction," explained Julia Baum, a member of the IUCN's Shark Specialist Group who will be speaking at the American Association for the Advancement of Science Annual Conference in Boston on February 17.

"Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red List as globally 'endangered' due to overfishing and high demand for its valuable fins in the shark fin trade," added Baum, who is an NSERC Postdoctoral Fellow at Scripps Institution of Oceanography.

Baum pointed out that fishing for sharks in international waters is unrestricted, and she supports a recently adopted United Nations resolution calling for immediate shark catch limits as well as a meaningful ban on shark finning (the practice of removing only a shark's fins and dumping the still live but now helpless shark into the ocean to die).

Research at Dalhousie University over the past five years, conducted by Baum and the late Ransom Myers, demonstrated the magnitude of shark declines in the northwest Atlantic Ocean. All species the team looked at had declined by over 50 per cent since the early 1970s. For many large coastal shark species, the declines were much greater: tiger, scalloped hammerhead, bull and dusky shark populations have all plummeted by more than 95 per cent.

Source: http://www.sciencedaily.com/releases/2008/02/080217083422.htm

'Sobering' Decline Of Caribbean's Big Fish, Fisheries: Overfishing Deemed Most Likely Cause

ScienceDaily — Sharks, barracuda and other large predatory fishes disappear on Caribbean coral reefs as human populations rise, endangering the region's marine food web and ultimately its reefs and fisheries, according to a sweeping study by researcher Chris Stallings of The Florida State University Coastal and Marine Laboratory.

While other scientists working in the Caribbean have observed the declines of large predators for decades, the comprehensive work by Stallings documents the ominous patterns in far more detail at a much greater geographic scale than any other research to date.

"Seeing evidence of this ecological and economic travesty played out across the entire Caribbean is truly sobering," said Associate Professor John Bruno of the University of North Carolina at Chapel Hill, who served as the PLoS One academic editor for Stallings' new paper.

"I examined 20 species of predators, including sharks, groupers, snappers, jacks, trumpetfish and barracuda, from 22 Caribbean nations," said Stallings, a postdoctoral associate at the FSU Coastal and Marine Laboratory. "I found that nations with more people have reefs with far fewer large fish because as the number of people increases, so does demand for seafood. Fishermen typically go after the biggest fish first, but shift to smaller species once the bigger ones become depleted. In some areas with large human populations, my study revealed that only a few small predatory fish remain."

Stallings said that although several factors -- including loss of coral reef habitats -- contributed to the general patterns, careful examination of the data suggests overfishing as the most likely reason for the disappearance of large predatory fishes across the region. He pointed to the Nassau grouper as a prime example. Once abundant throughout the Caribbean, Nassau grouper have virtually disappeared from many Caribbean nearshore areas and are endangered throughout their range.

"Large predatory fish such as groupers and sharks are vitally important in marine food webs," Stallings said. "However, predicting the consequence of their loss is difficult because of the complexity of predator-prey interactions. You can't replace a 10-foot shark with a one-foot grouper and expect there to be no effect on reef communities. Shifts in abundance to smaller predators could therefore have surprising and unanticipated effects. One such effect may be the ability of non-native species to invade Caribbean reefs."

A case in point, said Stallings, is the ongoing invasion by Pacific lionfish, which were introduced by aquarium releases.

"Lionfish are minor players on their native Pacific reefs, yet they are undergoing a population explosion and overeating small fishes in the greater Caribbean region," said Professor Mark Hixon of Oregon State University, Stallings' doctoral advisor at OSU. "Preliminary evidence suggests that lionfish are less invasive where large predatory native fishes are abundant, such as in marine reserves," Hixon said.

The study also demonstrates the power of volunteer and community research efforts by non-scientists. Stallings used data from the Reef Environmental Education Foundation's (REEF) online database, which contains fish sightings documented by trained volunteer SCUBA divers, including more than 38,000 surveys spanning a 15-year period.

"Chris was completely undaunted by the lack of fisheries data and essentially adopted the 'Audubon Christmas Bird Count' approach in a marine system to find strong evidence for a native fisheries effect," said Felicia Coleman, director of the FSU Coastal and Marine Laboratory and Stallings' postdoctoral advisor.

Given that about half the world's populations live near coastlines and that the world population is growing, demands for ocean-derived protein will continue to increase, Stallings warned. He said meeting such demands while retaining healthy coral reefs may require multiple strategies, including implementation of marine reserves, finding alternative sources of protein, and increased efforts to implement family-planning strategies in densely populated areas.

Journal reference:

1. Stallings et al. Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities. PLoS ONE, 2009; 4 (5): e5333 DOI: 10.1371/journal.pone.0005333

Adapted from materials provided by Florida State University, via EurekAlert!, a service of AAAS.

Are You Man Enough Shark Challenge Still Promotes Killing of Sharks

Last week we heard about a shark fishing tournament in Fort Myers called the "Are You Man Enough Challenge"

Due to public outcry the organizers were forced to change the format of the tournament to 100% catch and release.

A BIG thank you goes to Lee County Commissioner Ray Judah of district 3 who was instrumental in spearheading this movement.

However the website for the tournament still promotes the fact that sharks can be landed and brought back to the docks.

The organizers of this event must now change their audio advertisement on their website and any other advetising materials that publicize or promote the landing and killing of sharks.

click here to listen to their ad.