Fish and aquatic news

Florida anglers are being sharply criticized after a video of them free-gaffing a Mako shark off South Florida this week was made public on the Internet.

In the video, which was uploaded to Youtube and also displayed on the website of a Florida TV station (can be seen below), the anglers can be seen trying to gaff a free-swimming shark. The shark ventured close to the boat after being attracted to a swordfish that the anglers had alongside their vessel.

Since no rods or reels appear to have been used by the anglers as they captured the 748-pound Mako shark, they may have acted in violation of state and federal law. “I’d hazard that I’m not the first to pick up on these fine points of the law but if the video does indeed tell the full tale then these laws need to be enforced,” said Luke Tipple, a marine biologist and director of the Shark-Free Marina Initiative. “If however the fishermen can provide video evidence of them using PRIMARY tackle (i.e. hook and line) to initialize the capture then they would be within their rights to have landed the shark. If this turns out to be the case then I will instead turn this report into a cautionary tale of how the media should be more responsible in reporting on shark harvests, particularly when dealing with species considered by some to be globally threatened.”

The rare Gangetic dolphin (Platanista gangetica) has been declared National Aquatic Animal of India. A few days after the formal declaration, which took place at a National Ganga River Basic Authority meeting in New Delhi earlier this week, Bihar chief minister Nitish Kumar announced that he has directed state authorities to put a halt to dolphin hunting in the Ganga.

“A close watch is being kept on the ghats of river Ganga by the magistrates, police officials and block development officers to stop hunting and fishing of the mammals,” senior officials said.

Patna District Magistrate J K Sinha said that instructions from chief minister has been passed
to senior officials, including sub-divisional officers, magistrates, police officers and block development officers to ensure close surveillance and act swiftly to stop hunting of the aquatic animal.

“Schools will take steps to aware the students about the gangetic dolphin which would

boost eco-tourism in the region,” he added.

Although the Wildlife Protection Act of India mandates dolphin conservation as a priority, little has been done at the government level to implement or enforce the law.

Where is Bihar?

Bihar is an Indian state located in the eastern part of the country. It is bordered by Nepal to the north, Jharkhand to the south, Uttar Pradesh to the west, and West Bengal to the east. The state is bisected by the Ganga River which flows through the middle of the state from west to east.

What is Ganga?

Outside India, the Ganga River is more commonly known as the Ganges River.

What is the Gangetic dolphin?

The Gangetic dolphine, also known as Ganges dolphin, Ganges river dolphin, Blind dolphin, and Side-swimming dolphin, is a dolphin endemic to the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh. Its scientific name is Platanista gangetica and it is listed as Endangered on the IUCN Red List of Threatened Species. The current population consists of 1,200-1,800 individuals, and roughly half of these are found in Bihar and Uttar Pradesh.

It is referred to as the Blind dolphin due to its poor eye-sight which is probably an adaptation to the murky waters of the Ganga River.

Lack of iron is a limiting factor for plankton growth in many parts of the ocean, especially in the southern oceans and parts of the eastern Pacific. Scientists at the University of Leeds, UK, have now showed that acid in the atmosphere breaks down large particles of iron found in dust into small and highly soluble iron naonparticles; particles which can be easily absorbed and utilized by oceanic plankton.

Since plankton absorb carbon dioxide from the atmosphere, more available iron could trigger increased movement of carbon dioxide from the air to the ocean.

“This could be a very important discovery because there’s only a very small amount of soluble iron in the ocean and if plankton use the iron nanoparticles formed in clouds then the whole flux of bioavailable iron to the oceans needs to be revised,” says Dr Zongbo Shi, lead author of the research from the School of Earth and Environment at the University of Leeds.

Polluting industries that causes a high degree of acidic particles to be present in clouds can therefore strangely enough simultaneously be combating global warming.

“Man made pollution adds more acid to the atmosphere and therefore may encourage the formation of more iron nanoparticles,” says Dr Shi.

“This process is happening in clouds all over the world, but there are particularly interesting
consequences for the oceans. What we have uncovered is a previously unknown source of
bioavailable iron that is being delivered to the Earth’s surface in precipitation,” says Professor Michael Krom, the principal investigator of the research, also at the University of Leeds.

The Maldives is planning to ban shark fishing in its waters, a move which would make the Maldives the first nation in the region to enact such a protective law.

The announcement was made by the Maldives Minister of State for Fisheries and Agriculture, Dr Hussein Rasheed Hassan, at the South West Indian Ocean Fisheries Commission steering committee meeting in Mombasa.

“We have realised that it is more economically viable to leave the shark and other sea creatures unharmed because the country currently earns about $7 million annually from the diving industry,” said the minister.

In 1998, the Maldives imposed a 10-year moratorium banning shark fishing around seven atolls that received a lot of vacationers from abroad. Now, the country intends to expand the ban to include all reef shark fishing across the Maldives within a 12 nautical mile radius (22km).

During recent years, the number of sharks in the Maldives has plummeted due to overfishing for the lucrative shark fin market.

“The marine ecosystem is very fragile and that is why we have to regulate activities that coupled with the treats of climate change could adversely affect the major sources of income for the country,” Hassan explained.

The Maldives is an island country consisting of a group of atolls stretching south of India’s Lakshadweep islands. Despite having a population of no more than roughly 300,000 individuals, the Maldives receives over 600,000 tourists each year.

Compared to the record-setting low years of 2007 and 2008, the Arctic Sea ice has made a slight recovery in 2009, according to the University of Colorado at Boulder’s National Snow and Ice Data Center. Despite this positive change, the minimum sea ice extent in 2009 was the third lowest since satellite record-keeping started in 1979.

“It’s nice to see a little recovery over the past couple of years, but there’s no reason to think that we’re headed back to conditions seen in the 1970s,” said NSIDC Director Mark Serreze, also a professor in CU-Boulder’s geography department. “We still expect to see ice-free summers sometime in the next few decades.”

The standard measurement for climate studies is the average ice extent during September. This September, the average Arctic Sea ice extent was 5.36 million square kilometres, which is 1.06 million square kilometres more than September 2007 and 690,000 square kilometres more than September 2008.

According to Mike Steele, Senior Oceanographer at the University of Washington, the decrease in ice loss is probably due to cloudy skies during late summer. Sea surface temperatures in the Arctic were higher than normal this season, but slightly lower than in 2007 and 2008 – most likely due to the presence of clouds this year. Atmospheric patterns in August and September also helped spreading the ice pack over a larger area.

Arctic sea ice follows an annual cycle of melting during the warm season and refreezing in the winter, and the extent of Arctic sea ice has always varied due to changing atmospheric conditions. During the past 30 years, there has however been a dramatic overall decline in Arctic sea ice extent.

A gigantic underwater museum filled with 400 sculptures will be created in Mexico’s West Coast National Park in on the Yucatán Peninsula. The artistic director is Jason de Caires Taylor, famous for his underwater sculptures, but other artists will also be involved in the project.

The Subaquatic Sculpture Museum is designed to relieve some of the pressure placed on the regions natural reefs by divers and snorkelers; the national park currently receives almost 300,000 visitors each year and quit a few of these vacationers do not behave as careful around the reefs as they should.

“If they [the tourists] swim near the corals, the divers with little experience might kick them with a fin or hit them with the oxygen tank,” says national park director Jaime

González, adding that some tourists even climb coral reefs and walk on top of them, breaking and shattering them.

In 2005, the park administration submerged 110 hollow domes and concrete structures in layers in the Sac Bajo area in a similar effort to divert tourists from the natural reefs, and this project has already become a success story.

“At first the people of Isla Mujeres told us that they were never going to bring tourists there, but after a few years it became a must-see attraction,” says González.

The park administration is planning to launch the new underwater museum next month by submerging four sculptures in human form. All 400 sculptures in the museum will be made from pH neutral concrete to allow rapid growth of algae and incrustation of marine invertebrates, such as corals. Eventually, the new habitat will also begin to attract reef fish – just like the Sac Bajo project.

“The underwater museum will draw many tourists, allowing us to give a rest to the natural reefs. It’s like a restoration process,” says González.

If everything goes according to plan, some 250 sculptures will have been submerged by April 2010. Each sculpture will be human sized and rest on a four square meter base. Some parts of the museum will be theme based, such as the “Coral Collector” gallery and the “Dream Catcher” section which features bottles filled with messages sent by castaways. There will also be a series of sculptures depicting Maya warriors.

A marine park will be formed at Camden Sound, Australia, in an effort to protect the Humpback whale (Megaptera novaeangliae). Once hunted to the brink of extinction, the humpbacks have already bounced back considerably thanks to conservation efforts and they are now much sought after by whale-watchers, particularly off parts of Australia, Canada, and the United States.

“The Government recognises the Kimberley as one of Australia’s special places,” said Premier Colin Barnett as he unveiled the plans for the park. “That is why we are protecting Camden Sound, making it a marine park, and developing and implementing our Kimberley Science and Conservation Strategy. This strategy will balance the need to develop industry and create wealth with the expectation that the environment and special places will be protected. This remarkable area warrants protection as a first step in the broader conservation of the Kimberley.”

Environment Minister Donna Faragher added that Camden Sound is the largest calving area for humpbacks in the southern hemisphere.

“More than 1000 humpback whales can be found in the Camden Sound ‘maternity ward’ during the calving season,” Faragher said. “They are part of the biggest population of humpback whales in the world - numbering about 22,000 - that migrate from Antarctica every year to give birth in the waters off the north of our State.”

Faragher said the park will be created in consultation with the local indigenous community and all stakeholders with an interest in the area.

Allowing for consultation, including a public comment period of three months, a marine park could be established as early as mid-2010.

Camden Sound

Camden Sound is a bay in the Indian Ocean situated in the Kimberley region of Western Australia. The sound is a highly bio-diverse region; home to animals such as dugongs, crocodiles, sea-snakes, sharks, rays, and three species of sea turtle. Indo-Pacific humpbacked dolphins, Bottle-nosed dolphins, and the newly recognized Snub-fin dolphin can all be found within the borders of the proposed marine park. The sound is also visited by several species of whale, including False Killer whale, Bryde’s whale, Minke whale, and Dwarf Sperm whale. The corals reefs in the region are still fairly unharmed and varied the extensive mangrove forests found along the shores acts as nursery areas for fish and invertebrates.

Humpback whales born in Camden Sound stay there for several months after birth to grow big and strong enough to survive the long journey to the chilly Arctic waters where the humpbacks feed during the summer.

An international team of researchers have shown how one single gene mutation is capable of making the medaka, a Japanese killifish, loose its attractive colours and display a drab grey colour which renders them significantly less attractive to medakas of the opposite sex – unless that potential mate is grey too.

In the wild, medakas come in a wide range of colours, including orange, brown and drab grey.

“We observed that the grey medaka were often rejected in favor of their brown or orange rivals“, says lead author Shoji Fukamachi. “This is the first demonstration of a single gene that can change both secondary sexual characteristics and mating preferences“.

As mentioned above, you don’t have to fear ending up without a mate just because you happen to be a grey medaka – you just have to go out looking for another grey specimen since the study showed greys to be preferentially selective for each other. This preference for choosing a member of your own colour suggests that sympatric speciation could occur in medakas as the colour determining gene is mutated, i.e. new species may form as the medakas choose to mate with specimens of their own colour.

The research is a collaborative effort by researchers from the University of Konstanz, Germany and from the University of Tokyo, Japan. The study has been published in the open access journal BMC Biology.

Telling a wild salmon from a farmed one can be tricky, especially if you don’t want to kill or injure the fish in question. To solve this problem, Dr Elizabeth Adey of the Scottish Association for Marine Science (SAMS) have developed a way of using fish scale analysis to determine the origin of a salmon.

Fish scales grow like tree rings and preserves a chemical record of the water in which the fish lived as each new section of the scale was formed. The new method, which was developed in collaboration with the National Oceanography Centre in Southampton, checks the amount of manganese present in the fish scale. During her work, Dr Adey discovered that the scales of farmed salmon have a very high manganese content compared to the levels found in scales coming from their wild counterparts.

“This is probably caused by manganese supplements in fish food, and also because conditions underneath the fish cages promote recycling of manganese in the water column,” Dr Adey explains. Using the new method, Dr Adey and her team was able to distinguish between farmed and wild salmon with 98% accuracy.”Because of its non-destructive nature, this technique could be used to assess the proportion of farmescape salmon present in any river, and therefore identify where additional conservation and wildlife protection measures are needed,” says Dr Trueman, a geochemist with the University of Southampton’s School of Ocean and Earth Science, based at that National Oceanography Centre. “Salmon farming is a big, intensive business. In 2006, around 130,000 tonnes of salmon were farmed in Scotland for the table. Wild populations of Atlantic salmon are in serious decline across their whole range and the total wild population returning to Scottish rivers in the same year is estimated at less than 5000 tonnes. Wild fish are rare and expensiveso there is a strong incentive for fraudulent labeling. Farmed fish also escape into rivers, harming the wild population. Unfortunately, it can be difficult to distinguish between farmed and wild fish.“

In the future, the new technique may also be able to point out which individual fish farms that need to implement more efficient methods for keeping their salmons in. In some Norwegian rivers, more than 50 percent of the salmon are now escapees. Escaped fish can carry disease to wild populations, and there is also a risk of genetic pollution since farmed fish haven’t gone through the same natural selection process as wild fish.

Fancy, a four-year-old Chihuahua, survived for more than 24 hours under water after being left inside a capsized riverboat. She was onboard a houseboat that sunk in the river near Toledo, USA after hitting a stump.

As the 44 foot houseboat went under, none of the four passengers remembered to take the Chihuahua with them to dry land. When she was missed, they thought it was too late to save her and didn’t return to the wreck until 24 hours.

But Fancy wasn’t dead, she was stuck in an air-pocket with her body – but not her head – submerged under water.

“Over to my right side I heard her little feet go too,too, too, too. I was almost like a whale going offthe side of the boat,” said Rebel Barrett, the owner of the dog. “I just got in the water and I grabbed her and I was crying, and screaming, and hugging her and kissing her and shewas happy to see her mama.”

The owner of the houseboat, who happened to be a scuba diver, went down and rescued Fancy from the air wreck.

“I just turned my head slightly, and I looked in and I saw her sitting there with her head on her paws, just shaking and quivering,” said the astounded boat owner. “The air pocket was maybe two or three inches, just a little bitty pocket, but she was sittin up there in it. It’s a miracle.”

A previously unknown field of endangered Staghorn coral has been found in Florida waters by scuba divers belonging to the non-profit group Palm Beach County Reef Rescue.

“We’ve found the largest field (of the coral) in the county,” says Reef Rescue’s director Ed Tichenor. “We’re really surprised by this.”

The field, which is located roughly a mile east of Palm Beach island, is significant since Palm Beach town officials have objected to federal protection of the area.

Last year, the National Marine Fisheries Service designated roughly 1,300 square miles of ocean floor – ranging from the Florida Key to the Boynton Beach Inlet – as critical habitat for staghorn. This prompted the Palm Beach County Reef Rescue to petition the government to extend the protected area northwards to the Lake Worth Inlet, thereby including the coast off Palm Beach.

The Palm Beach County Reef Rescue estimates the newfound staghorn field to be between 100 and 300 feet long.

“I was expecting to see it but not as much,” said Connie Gasque, a Palm Beach resident who led the dive group. “My reaction was ‘Wow!

Everywhere you looked, there it was.”

Before this discovery, only small pockets of staghorn coral was known to exist in the waters off Palm Beach.

Palm Beach County Reef Rescue now hopes that the discovery will convince the National Marine Fisheries Service to include the region in the protected coral zone.

What is Staghorn?

Staghorn (Acropora cervicornis) is a branching coral that can reach a length of up to 2 meters (almost 7 feet). It is the fastest growing species of all West Atlantic corals and can grow 10-20 cm per year in favourable conditions. The natural range for Staghorn coral stretches from Florida, USA through the Bahamas and the Carribbean Sea, down to Venezuela in South America.

Acropora cervicornis was placed on the U.S. Endangered Species List in 2006, and it is also listed as Critically Endangered on the IUCN Red List of Threatened Species.

According to the U.S. National Oceanic and Atmospheric Administration, staghorn is not found north of Boca Raton.

Researchers at Woods Hole Oceanographic Institution (WHOI) and the University of South Carolina has managed to solve a conundrum that’s been puzzling marine scientists for roughly a decade – where does all the oceanic phosphonate come from?

Roughly a decade ago, phosphonate – a rare form of organic phosphorus – was discovered in marine organic matter. Not only were researchers baffled to find this rare form of phosphorus in the ocean; they were also flummoxed by the high concentrations in which it was found throughout the sea. No one could explain where it came from and why it could be found in such abundance.

That is, no one could explain it until now.

In 2006, biologist Sonya Dyhrman and her WHOI team commenced a field and laboratory study on a group of phytoplankton called Trichodesmium. Trichodesmium is a microscopic marine microbe found in ample amounts throughout warm tropical and subtropical waters where nutrients are scarce. The WHOI team were able to show that Trichodesmium uses phosphonate to support carbon and nitrogen fixation, and that a special set of genes have given them this capacity. This triggered Dyhrman’s curiosity – where did Trichodesmium get its phosphonate from in the first place?

To solve the mystery, Dyhrman partnered up with Claudia Benitez-Nelson, a marine geochemist with the University of South Carolina, and started analyzing various phytoplanktons using nuclear magnetic resonance.

“We’ve been fascinated by these phosphonate compounds for a while,” said Benitez-Nelson. “Sonya and I decided that something had to be producing them, and we had to start looking at all these organisms to figure out who it was.”

“After culturing several different kinds of phytoplankton and analyzing them using nuclear magnetic resonance (NMR) spectroscopy, we found high concentrations of phosphonate in cultures of a specific Trichodesmium species – in fact an average of 10 percent of the cellular phosphorus is in the form of phosphonate“, explained Dyhrman. “Ten percent may not sound like much, but this is the most phosphonate ever detected in a marine microbe.”

“When we first saw the phosphonate peak in the Trichodesmium culture, we were stunned, after a 10-year mystery it seemed ironic for Trichodesmium to both consume and produce this compound“, said Benitez-Nelson. “We ran it again. We grew them under different nutrient conditions and, sure enough, the results were the same.”

Since nitrogen is scarce in the open ocean, nitrogen fixing organisms like Trichodesmium are imperative to the marine food web. Trichodesmium phytoplankton will not only bring carbon into the food chain by absorbing it from the atmosphere like other phytoplankton; they will also provide the food chain with essential nitrogen due to their ability to absorb nitrogen gas from the air and transform it into a compound that other organisms can use.

“Not only does this solve a mystery about where these forms of phosphorus are coming from, but the fact that it is Trichodesmium has ramifications for how the phosphorus cycle is linked to the cycling of carbon and nitrogen and how those cycles will function in the future ocean,” said Dyhrman.

The Dyhrman and Benitez-Nelson study was recently published in the journal Nature Geoscience.

The gar family, famous for containing the largest fresh water fishes in Mexico, is currently at risk of becoming extinct – something which Mexican researchers are working hard to prevent.

“This fish is native to our country and the United States”, Doctor Eduardo Mendoza Alfaro explains. “Currently, its populations are threatened due to excessive hunting, — for there are no rules that regulate its fishing — urban expansion, pollution, and particularly the dams´ construction, which caused the destruction of their breeding grounds. These factors led this species to reduce to only forty adult specimens in the country — in inventory and considered national patrimony.”

Doctor Eduardo Mendoza Alfaro*, a member of the ‘Eco-physiology Group,’ from the Universidad Autonoma de Nuevo Leon’s (UANL) School of Biological Sciences Ecological Department, is currently researching gar reproduction and diet in order to find ways of efficiently raising gars in captivity. The team also works with several other types of endangered fish, but the gar – which can reach a length of three meter and is highly esteemed by sport fishers – is arguably the most iconic.

Lepisosteus platostomus - Shortnosed gar, Copyright www.jjphoto.dk

One of the hurdles that must be overcome to ease gar raising in captivity is how to distinguish males from females. In a reproductive facility you want to keep an ideal sex ration – with gars this is four males for each female – but this is difficult to accomplish without reliable sexing methods.

“We could not identify females and males, because, morphologically, they are

Identical”, says Dr Alfaro. “Even though most of the fish can be cannulated in order to know their gender and maturation status, for gar is not the same process, that is what represents

the first obstacle for scientifics when they were carrying out the reproduction

studies and establishing fish’s gender. Most of the fish can be cannulated by introducing them a catheter in the oviduct in order to take the oocytes (ovules). However, this process cannot

be carried out with the gar. They are so primitive fish, which date since 189 million years ago and their urinal tract which ends with the oviduct in a kind of sewer that cannot allow the

cannulation.”

To overcome the problem, Dr Alfaro and his team devised a new technique based on a molecule known as vitelogenine. Vitelogenine is present only in females from puberty and onwards, and can be used as a biochemical marker.

First, the team purified the molecule. Then, they created antibodies against the molecule for recognizing and quantifying it.

“Currently, we got an extremely sensitive method which allows us to dose this molecule with only a small sample of fish’s skin mucus, says Dr Alfaro. “So, we not only identified if it is a female or a male, but we can follow up females’ sexual maturation.”

Gar facts

· The gar family evolved during the cretaceous.

· A gar can weigh up to 220 lbs.

· The gar is a predatory fish with an elongated jaw. It is sometimes referred to as alligator fish due to its resemblance to the predatory reptile. It has numerous sharp teeth and a body protected by hard scales.

· Gars spawn in swamps during the wet season and destruction of wetlands poses a problem for them.

· In the wild, several males follow the female wanting to fertilize her eggs as she deposits them.

· Mexico is the world’s leading gar specimen producer.

*Roberto Eduardo Mendoza Alfaro is a professor at the UANL´s School of Biological Sciences Ecology Department in Leon, Mexico.

The world’s first shark sanctuary will be created by Palau, a small island nation in the Pacific Ocean. The sanctuary will measure 240,000 square miles and be a haven for vulnerable shark species like Leopard shark, Hammerhead, and Oceanic Whitetip. Over 135 different species of shark and ray is known to live in this biological hotspot.

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

Unfortunately, this tiny nation with a population of 20,000 people has only one patrol boat to protect the immense sanctuary from fishermen.

While acknowledging the difficulties, the president still hopes that others will respect Palauan territorial waters - and that the shark haven will inspire more such conservation efforts globally.

“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.”

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

We have updated the crocodillian section of the site and it is now possible to find info about most crocodillians in it.

American Alligator
American Crocodile
Black Caiman
Broad Snouted Caiman
Brown Caiman
Chinese Alligator
Cuban Crocodile
Dwarf Crocodile
False Gavial
Freshwater Crocodile
Gavial
Mexican Crocodile
Mugger Crocodile
New Guinea Crocodile
Nile Crocodile
Orinoco Crocodile
Philippine Crocodile
Rio Apaporis Caiman
Saltwater Crocodile
Siamese Crocodile
Slender-snouted Crocodile
Smooth-fronted Caiman
Spectacled Caiman
Yacare Caiman

Crocodile Facts
American Crocodile facts
Nile Crocodile facts
Saltwater Crocodile facts