Dammed if we do, dammed if we don't: New World's biggest freshwater fish at risk

Two of the world's biggest freshwater fish are in big trouble, come reports from scientists in North and South America.

First up, the genetically distinct Kootenai River population of white sturgeon (Acipenser transmontanus), North America's largest freshwater fish. This massive monster has been known to reach almost six meters in length and weigh half a metric ton, but its size hasn't offered it any protection. In fact, it has made it more attractive, and the species has historically been heavily overfished.

The problem in the Kootenai River isn't overfishing, although it is man-made: Montana's Libby Dam, built in 1974. The dam prevents the river from the very flooding that used to tell the sturgeon it was time to spawn. Before the dam was built, an estimated 10,000 white sturgeon lived in the river. Now, just 500 remain, and they have not spawned in the wild in 35 years. Oops.

Despite the lack of wild spawning, the fish have not died out, and that's also thanks to human intervention. The Kootenai Tribe of Idaho periodically restocks the river with farm-raised sturgeon.

The U.S. Fish and Wildlife Service has been trying to save the Kootenai River white sturgeon from extinction for years by adjusting the amount of water that flows through Libby Dam, but last Thursday they announced that all of their recent attempts have failed. They'll keep trying, though, and will send even more water through the dam this year. But they can't send too much or they'll flood local towns.

Amazonian arapaima

Meanwhile, in South America, another of the world's largest freshwater fishes—in fact, the largest species with scales—is also in danger of extinction, if it even still exists. A paper in the December issue of the Journal of Applied Ichthyology reports that the giant Amazonian arapaima (Arapaima gigas) are threatened by weak and unenforced fishing regulations in Brazil, despite the species's protected status under the Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES).

Arapaima can reach more than four meters and weigh more than 180 kilograms. The fish actually comes to the surface to breathe, leaving it vulnerable to fishing with spears and nets.

Part of the problem with preserving the arapaima is that it has never really been studied, until now. Authors Leandro Castello and Donald Stewart examined several arapaima samples in museums and found that only one of them was actually the Arapaima gigas. "Our new analyses indicate that there are at least four species of arapaima," Castello told BBC News. "So, until further field surveys of appropriate areas are completed, we will not know if Arapaima gigas is extinct or still swimming about."

Castello and Stewart recommend increased monitoring and tighter controls over harvests to protect the multiple arapaima species from extinction.

And tuna, too

As long as we're talking about giant fish, let's not forget the endangered bluefin tuna (Thunnus thynnus), which also remains heavily overfished, and as a result commands incredibly high prices on the open market. Last week, a single, 232-kilogram tuna sold for an all-time high of $175,000 to two Japanese restauranteurs—60 percent higher than last year's record. That breaks down to $21.38 an ounce—almost three dollars more per ounce than the cost of silver. (And by the time it reaches the dining table as sushi, it will be more like the cost of gold.)

But even at those prices, bluefin won't be on the menu (or maybe anywhere) for very long.

http://www.scientificamerican.com/blog/post.cfm?id=dammed-if-we-do-dammed-if-we-dont-n-2010-01-13
 
 

EPA Proposes Freshwater Nutrient Limits for Fla., a National First

U.S. EPA proposed pollution standards for nutrients in Florida waters, the first such proposal for any state.

The EPA proposal sets limits on nitrogen and phosphorous for freshwater lakes, rivers, streams, springs and canals. The agency said it would propose a rule for estuaries and other coastal waters in January 2011.

The nutrient proposal would also let Florida set interim water quality targets, a mix of standards for runoff and discharge pipes, an EPA spokeswoman said. "This works where a standard cannot be met in the short term, but can be met in the longer term," she said.

Environmental groups praised the proposal aimed at curbing nutrients that can foul drinking water and fuel algal blooms that deplete dissolved oxygen necessary for aquatic life. "The numbers are pretty good," said David Guest, an attorney for Earthjustice, which sued EPA for the standards last year.

But industry groups say complying with the standards will cost billions of dollars and disrupt work already under way in the state to curb nutrient pollution.

The American Farm Bureau Federation, National Association of Clean Water Agencies and Florida Water Environment Association met with the White House Office of Management and Budget to discuss the proposal last week, presenting documents that argue the criteria would double charges for water and sewer services in parts of the state. Both environmental and industry groups said they met with EPA last year as the agency was drafting the proposal.

Susan Bruninga, spokeswoman for NACWA, expressed objections to EPA's methodology for setting the nutrient criteria.

"EPA essentially sets criteria for broad eco-regions based on a statistical analysis of what the concentration of the nutrients are in a particular water body, and then applies it to all the water bodies," Bruninga said. "Our concern is they're kind of doing a one-size-fits-all approach and not linking concentrations to impacts."

Though EPA said the methodology it used to set the nutrient standards was specific to Florida, Guest said the proposed limits could serve as a template for nutrient standards in other states.

"I think this is a prototype that will be followed by other states," Guest said. "And if some states don't follow, EPA will be able to do this rather quickly, because they've done the hard work now."

EPA's Office of Inspector General found in August that the agency failed to follow through on its pledge to enforce federal nutrient pollution standards if states did not develop their own by 2004 (E&ENews PM, Aug. 27, 2009).

A coalition of environmental groups is now pressing the agency to set nutrient criteria for Wisconsin waters, threatening to sue EPA if it does not promptly do so (Greenwire, Nov. 24, 2009).

http://www.nytimes.com/gwire/2010/01/15/15greenwire-epa-proposes-freshwater-nutrient-limits-for-fl-21732.html