Mekong giant catfish under threat from new Xayaburi dam

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By damming the mainstream of the lower Mekong River in Bangkok, Thailand, there is a significant new threat to the survival of the Mekong giant catfish, according to a new study commissioned by WWF.

Being one of the world's largest and rarest freshwater fish, the numbers of catfish are already in steep decline due to habitat destruction, overfishing, and dams along the Mekong's tributaries.

The exact population size of the Mekong giant catfish is unknown, but it is thought that there could be as little as a couple of hundred adult fish left.

The new study shows the status of this elusive species, including data on its numbers, distribution, threats, and measures needed to prevent losing this fish.

Revealing that the Xayaburi dam on the Mekong mainstream in northern Laos would prove an impassable barrier for the giant cat fish, the study proves that the dam risks sending the species into extinction.

The catfish are capable of reaching up to three metres in length and weighing as much as 300kg.

Dr Zeb Hogan, the study's author and associate research professor at the University of Nevada says: "Fish the size of a Mekong giant catfish simply will not be able to swim across a large barrier like a dam to reach its spawning grounds upstream.

"These river titans need large, uninterrupted stretches of water to migrate, and specific water quality and flow conditions to move through their lifecycles of spawning, eating and breeding."

During the Mekong River commission meeting in 2011, environment and water ministers had agreed to delay a decision on building the Xayaburi dam, pending further studies on environmental impacts. Last November, this agreement was swept aside when Laos decided to forge ahead with construction.

There have been growing concerns centred on the serious gaps in data and failures to fully account for the impacts of this US$3.5-billion project, particularly concerning sediment flow and fisheries.

Pöyry, the Finnish firm advising Laos on the dam construction, argues that 'fish passages' can be built. It claims that this will enable fish to get past the dam's turbines and down the river, but this claim has never been put into practise.

Dr Eric Baran with the World Fish Centre says: "You can't expect fish ladders to work without understanding your target species, their swimming capabilities, and the water current that will attract these fish toward the pass entrance.

"Research is still needed to ensure mitigation efforts will work."

Once being widely distributed through the Mekong river basin, the giant catfish were relatively abundant up until the early 1900s. Since then, the numbers have plummeted. The species is now limited to the Mekong and its tributaries in Cambodia, Laos and Thailand. According to catch figures the numbers have dropped from thousands of fish in the late 1800's to dozens in the 1900's, and only a few in recent times.

Laws have been put into place in Thailand, Laos and Cambodia to regulate fishing for Mekong giant catfish, with a ban on fishing the species in Thailand and Cambodia. However the species is still fished illegally and caught accidentally in fisheries targeting other species.

Dr Lifend Li, Director of WWF's Global Freshwater Programme says: "The Mekong giant catfish symbolises the ecological integrity of the Mekong River because the species is so vulnerable to fishing pressure and changes in the river environment. Its status is an indicator of the health of the entire river, and its recovery is an important part of the sustainable management of the Mekong basin.

"The Mekong giant catfish can be saved, but it will take a level of commitment from all lower Mekong countries, as well as international organizations and donors, that currently does not exist."

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Published: Amy Munday Monday 24 June 2013, 3:38 pm
Views: 777 times
Filed under: catfish giant Mekong river dam Thailand Xayaburi Bangkok threat extinct WWF

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Is New Zealand&#39;s <b>Freshwater Fishing</b> Under Threat?

Could the future quality of New Zealand's world-famous freshwater fishing be under threat? The Chief Executive of Fish and Game New Zealand seems to believe so and has made a plea to local anglers to send comments on proposed changes to the Resource Management Act (RMA) and also the Freshwater Reform Proposals before the submittal deadlines of April 2nd and 8th 2013.

The below message was sent to all subscribers of 'Reel Life' - the newsletter of Fish & Game New Zealand.

25th March 2013

Future of freshwater fishing under threat 

The present government is hell-bent on wrecking the RMA. The key points are as follows:

The RMA is being dramatically changed to allow the development and degradation of sports fish and game habitat by farmers and industry.Lowland streams will have no legal recognition so will become 'farm drains'.Water Conservation Orders will ultimately go, with their previously recognised habitat protection and recreation values lost in one- size-fits-all 'regional plans'.Practically all the substantive case law that has been developed over the years around environmental protection (much of it with Fish & Game licence fees), will be lost.Current protection of the habitat of trout and salmon will be scrapped.

This is a plea for all anglers to ensure they have their say on the future of the RMA, the only real safeguard we have against rampant, unsustainable development of the freshwater resources trout and salmon rely on for survival.

You only have until 5.00pm April 2, 2013 to submit on the RMA.

Submission on the equally devastating Freshwater Reform proposals must be received by 5.00pm April 8, 2013.

Don't worry if you have never made a submission before – it can be as simple or as complex as you choose to make it, the most important thing is that you have a say.

Information on how to make a submission, suggested points to make in your submission, and where to send it are on our RMA resource page here.

Please, stand up for freshwater quality protection and the future of angling in this country – it's in your hands.

Bryce Johnson 

Chief executive 

Fish & Game NZ

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Catch <b>Bass</b> Under Bridges With These Tips from Pro Angler Aaron Martens

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If you’re not sure where to cast for bass on any given lake, head for the nearest bridge. Most bridges provide bass with deep water, shade, bridge pilings and riprap for cover, and baitfish. Current caused by the wind or a power-­generating dam boosts its desirability. But don’t take my word for it. Just ask bass pro Aaron Martens, who’s finished second twice in the Bassmaster Classic by fishing bridges exclusively.

Top of the Morning
At daybreak, largemouth bass often feed on shad near the surface around bridge pilings. Martens picks off these fish with a Megabass Giant Dog-X walking stickbait. He works the Dog-X alongside the bridge pilings and over the eddy water on the downstream side of the pilings. “I catch a lot of bass by fishing the eddy 50 to 100 feet down­current from the pilings,” Martens says. “Most fishermen overlook these bass.”

Let’s Get Cranking
Largemouths feed deeper when the sun starts to get up. Martens uses his fishfinder to see how deep the bass are suspended next to the pilings. Once he has the depth, he selects a diving crankbait that runs at or just above that depth. “Cast past the bridge pilings and retrieve the crankbait with the current,” Martens says. “Try to bump the pilings with the crankbait and hit them from different angles. Don’t sit in one spot all the time.”

Give Them the Shake
When the lunkers are refusing crankbaits, or are too deep to reach with them, Martens starts targeting the fish with a shaky-head jig dressed with a Zoom Fluke. Depending on the depth and current, Martens uses a jig that weighs from 1/8 to 3/4 ounce. “Cast upcurrent past the bridge pilings, count the jig down to the right depth, and reel it back slow and steady,” Martens says. “Try to hit the pilings with the jig.”

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