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Friday Fishy News - February 9


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Love Those Toothpick Fish


February 2

Some people like to run around the world, but now a new, perhaps crazier guy is hitting the headlines. Slovenian Martin Strel loves to swim. He really loves to swim.

Rivers are his favorite territory. Winning records for swimming the length of the Mississippi, Danube and the Yangtze (his previous longest success, at 2,487 miles), Strel is now ready to tackle the a shop. Starting in Atalaya in Peru and heading down to Belem in Brazil, Strel plans to swim 3,375 miles. Possible problems? Well, a few of the native lifeforms:

The world's second longest river is home to piranha fish, crocodiles, bull sharks, poisonous freshwater stingrays and the toothpick fish, or candiru.

Nice. Fancy swimming along with him? Or prefer your adventure travel in a slightly safer form? Reminder: the candiru is the fish that can swim into your nether bits.

Raiders, here’s some more information about the candiru from http://www.k-state.edu/parasitology/625tut...ls/Candiru.html

“The Trichomyteridae comprise a family of over 40 genera and about 180 species of small, nearly transparent catfish termed "pencil catfish" or "parasitic catfish." Most are only a few centimeters in length and many inhabit sandy or muddy bottoms where they feed on a variety of protozoa, rotifers, and insect larvae. Some species, however, enter the gill chambers of other fish, erect a spine to hold them in place, and ingest blood for a minute or two from the gill filaments. Rarely, in the a shop, members of the genus Vandellia (and perhaps a few closely related species in other genera) accidently enter the urethra, vagina, or rectal orifices of humans. The species most commonly reported as intraurethral is Vandellia cirrhosa ("candiru," "carnero," "canero,", or "vampire catfish"). The exact reason why this fish might accidently enter a body orifice is unknown, although the presence of ammonia or urea in the water has been a popular hypothesis. Evidence by Spotte et al. (2001, Environ. Biol. Fishes, 60: 459-464) suggests this hypothesis may not be true. Surgical removal is the primary method of therapy.”

Here's a pic (looks so innocent, doesn't it?):


Fish populations reap benefits of flooding

ABC News Online

February 6

The Mackay-Whitsunday Natural Resource Management Group says last week's flooding has done great things for the region's fish populations.

Coast and marine coordinator Matt Bloor says the heavy rain triggers fish migration both upstream and downstream.

Mr Bloor says some fish move to breeding grounds in the upper reaches, while others, like barramundi, move downstream and spawn in the estuaries.

"It works both ways, it's a real trigger for fish movement, and just the extent of the flooding has meant that a number of the wetlands that have been hydrologically separated are now all being connected, so it's providing a really good role for fish to move into waterways that they haven't been able to access in the dry," he said.

300 tonnes of fish dumped, court told

By Helen Murdoch


February 3

A fishing company has been charged with dumping more than 300 tonnes of fish at sea during a commercial voyage in the Southern Ocean.

The identity of the company was suppressed by Nelson District Court Judge Margaret Lee yesterday.

It has pleaded not guilty to abandoning fish, which were subject to the quota management system (QMS).

The chartered vessel's Nelson skipper, who allegedly ordered the southern blue whiting to be dumped during a trip in September 2004, has also had his name suppressed. He has pleaded not guilty to the charge of abandoning fish.

The vessel's first mate and factory processing manager have pleaded guilty to abandoning quota management fish. The court postponed the question of forfeiting the vessel until the cases against the company and the three crew were dealt with.

Ministry of Fisheries counsel Chris Lange told the court the Fisheries Act prohibited the dumping of fish subject to the QMS system. The vessel's skipper and mate falsified catch records for the 15-day voyage.

Estimates from the crew, interviewed after the voyage, showed that between 10 per cent to 40 per cent of the vessel's total catch for the voyage had been dumped. Using this information, and catch records, the ministry estimated that between 40 to 311 tonnes of fish had been dumped.

Lange said the dumping of commercial fish, known as high grading, was the greatest threat to the QMS, but hard to prove.

In his summary to the court, Lange said the ministry had been told of the dumping by an informant who had been on the boat and videoed the dumping over several days.

The vessel sailed from Dunedin, bound for the southern blue whiting fishery in the Southern Ocean.

Southern blue whiting congregated in dense schools at that time of year and big catches were possible, Lange said. Fishermen had to take care not to catch more than could be processed.

The aim of the vessel's voyage was to fillet and freeze the fish and process the waste into fishmeal, he said.

However, processing could not keep up with the catch sizes and older unprocessed fish, and small fish, were dumped at night when new catches were made.

When a patrolling New Zealand Air Force Orionflew over the vessel the skipper ordered fish dumping to halt, Lange said.

On or about September 15 the informant estimated 60 tonnes of fish had been caught by trawl. However, ministry examinations of the returns for the day showed a maximum catch of 25 tonnes, Lange said.

"Examination of all the records showed maximum trawls of 25 tonnes on eight occasions and one record catch of 40 tonnes," he said.

When the mate and the factory manager were interviewed they denied any knowledge. But the manager later made a second statement confirming the offending and identified the skipper as the decision-maker behind it, Lange said.

The company and the three men will reappear in the Nelson District Court on March 22.

Plant-grazing fish boost resilience of coral reefs facing stress


February 8

By using cages to experimentally control the access of fish to coral reefs, researchers have assessed the role of fish "grazing" in the ability of reefs to successfully recover from potentially devastating coral-bleaching events related to rises in ocean temperatures. The findings, reported by a group led by Terry Hughes of James Cook University in Australia, will appear in Current Biology online on February 8th.

Pollution and overfishing have for some time been major threats to the health of coral-reef ecosystems, but additional environmental stress caused by warming of ocean waters has recently become a key factor in coral-reef stability. The importance of this kind of stress is illustrated by the massive coral-bleaching event of 1997–1998, which impacted 16% of the world's reefs and was particularly damaging in regions of the Pacific and Indian Oceans.

In the new work, the Australian researchers took an innovative approach to studying the recovery of coral reefs after the 1997–1998 event. Instead of simply observing and describing effects of the event and subsequent trajectories of reef health, the authors of the study experimentally tested the ability of reefs to recover under two different conditions: the presence of abundant predatory and herbivorous (plant- and algae-eating) fish, and the absence of significant numbers of these fish. The latter condition, which was achieved by placing large cages over coral reef stands to keep large fish away, mimicked the conditions under which coral reefs would recover from a bleaching event in areas also experiencing chronic overfishing.

The experiment assessed coral recovery in a region of the Great Barrier Reef Marine Park that is strictly protected from fishing, such that only coral stands under experimental cages experienced the depletion of large predatory and herbivorous fish. The researchers found that the two groups of coral underwent very different courses of recovery from the bleaching event: Whereas reefs subjected to grazing by large herbivorous fish species exhibited resilience in recovery, recruiting new corals to the reef and keeping algal growth in check, the reef areas from which large fish were excluded showed a distinct erosion in reef quality, with assemblages of algae and plant life overgrowing the reef and preventing the recruitment of new coral.

The study's findings indicate that grazing by large herbivorous fishes plays a key role in the ability of coral reef ecosystems to recover from bleaching events and maintain resilience in the face of thermal stress due to rises in ocean temperatures. On a practical level, the work strongly suggests that local management efforts aimed at preventing chronic overfishing may not only help ensure reef health under stable conditions, but may also significantly boost the resilience of coral reefs in the face of bleaching events and, potentially, other aspects of environmental thermal stress. -Cell Press

Study: An endangered fish species recovers

Science Daily

February 6

ITHACA, N.Y., Feb. 6 (UPI) -- Scientists say for the first time in U.S. and probably global history a fish identified as endangered has been shown to have recovered.

The population of shortnose sturgeon has increased by more than 400 percent in the Hudson River since the 1970s, Cornell University Assistant Professor Mark Bain and colleagues report.

However, researchers note shortnose sturgeon is still endangered in other rivers and will not necessarily be removed from the U.S. endangered species list.

During the past 100 years, 27 species of fish have died off in North America and four have become extinct. The U.S. government currently protects 149 fish species and subspecies and a total of 1,311 species.

"Endangered and threatened U.S. fish outnumber mammals, reptiles, birds, etcetera," said Bain. Since 1966, when the federal government started identifying threatened species, only 16, including the American alligator, American peregrine falcon and brown pelican, have recovered.

"Recovery is very rare," said Bain. "The nature of this species, its habitat and evidence for a large and secure population are an example of successful protected species management."


Edited by Flattieman
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