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2/18/11

Talk about a quick learner: in just 50 years, a fish has evolved a resistance to toxic chemicals polluting its Hudson River home, a new study finds. 

Between 1947 and 1976, roughly 1.3 million pounds of polychlorinated biphenyls, or PCBs, were dumped in the Hudson by two General Electric facilities. The Atlantic tomcod, a small bottom-feeding fish, quickly accumulated high levels of the toxic compounds, which caused lethal heart defects in juveniles of the species.

Then, natural selection took over. In a matter of decades, a rare genetic mutation that allowed a small number of tomcod to tolerate PCB contamination spread through the broader population, allowing the species to thrive, scientists concluded after a four-year study.

“We think of evolution as something that happens over thousands of generations,” Isaac Wirgin, a population geneticist at New York University and the study’s lead author, said in a statement. “But here it happened remarkably quickly.”

Documented instances of rapid evolution in response to environmental contamination are quite rare, Dr. Wiggin said.

The tomcod had long been known for its remarkable tolerance to PCB pollution, but the biological mechanism responsible for its survival was unclear until now. Researchers found that a mutation to just one gene effectively blunted the chemical’s toxic effects, and that fish with the mutation survived and reproduced while those without it died off.

The study appears in the journal Science this week.

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2/7/11

CRESCENT CITY, Calif.—An unexpectedly large run of salmon in the rivers of far Northern California this winter is providing an economic boost to local communities across the hard-hit region.

After years of declining fish numbers, some waterways, including the Smith River—which flows through giant redwoods into the Pacific Ocean near Crescent City—have seen their best salmon returns since the 1970s, according to the California Department of Fish and Game and local biologists.

That is jump-starting the business for guides like Ken Cunningham, who lives near this town of 7,500 and fishes for salmon from a small boat drifting downriver. The 63-year-old said he spent about 20 days guiding last October at the height of the run, compared with about 10 days in October 2009. At $250 to $350 a trip, depending on the number of people, Mr. Cunningham made more than $5,000 in October.

The revival of freshwater recreational fishing is especially important for areas like Crescent City, which 30 years ago was a booming forestry and commercial-fishing town. "It was a very different community. There was a lot of economic activity," said Richard Young, the Crescent City harbor master and a former commercial fisherman.

The Rowdy Creek Fish Hatchery on a Smith tributary, for one, counted 3,538 salmon this winter, compared with 2,775 last year and 589 in 2006. The nearby Trinity River hatchery's fall and winter salmon runs totaled 12,002, up from 9,983 a year earlier. To the south, a hatchery on the Feather River reported more than 17,000 returning adult salmon during the recent run, compared with 6,234 a year earlier.

The teeming fish runs are a turnabout from years of decline, when salmon populations were affected by dams, low rainfall and logging, which can smother salmon spawning areas with dirt. Although no one is sure why so many salmon returned this winter, some hatchery managers and others speculate heavy rain and favorable ocean conditions helped the healthy returns.

Scientists say salmon remain imperiled, and that some fish populations in California are extinct or nearing extinction. They are still trying to figure out what makes the populations fluctuate.

What is clear is that this winter's huge salmon runs have drawn legions of fishermen, creating business for fishing guides, tackle shops and motels in many small towns in the region. The U.S. Fish and Wildlife Service estimated anglers in California made $2.7 billion in fishing-related expenditures in 2006, the most recent year for which data are available.

On remote Smith tributaries, a nonprofit group this winter offered tourists trips to see spawning fish. In drought years, some of those tributaries don't have enough water for salmon to spawn.

"It's huge for us to have a big population of fish, for our economy," said Zack Larson, a local biologist who has also worked as a fishing guide.

Still, Andy Van Scoyk, who runs the Rowdy Creek Fish Hatchery, said there was reason for concern. While this winter's run was large, he said, its small proportion of juvenile fish points to a potentially weak run next winter.

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An increasingly productive way of restoring fisheries is based on the counter-intuitive concept of allowing fishermen to take charge of their own catch. But the success of this growing movement depends heavily on a strong leader who will look out not only for the fishermen, but for the resource itself.

1/31/11

When it began in the early 1970s, Southern California’s sea urchin fishery was a wide-open free-for-all. State marine managers considered urchins a pest — a threat to coastal kelp beds, which they eat — and divers were given a no-limit harvest. Japan’s robust economy was driving a thriving trade in “uni,” buttery sweet urchin gonads beloved by sushi fanciers. The good money convinced divers like Peter Halmay, then a civil engineer, to quit his day job and dive for urchins full time.

“You go down with a rake and a basket and hand pick ‘em, one by one,” says Halmay, who dives out of an old lobster boat based in San Diego. “Cleanest fishery in the world — our by-catch is zero.”

The open harvest worked all too well. By the 1990s, the sea urchin population had been reduced by 75 percent and showed no sign of leveling off. The state limited the number of urchin licenses, but still the population fell. So Halmay led his fellow divers to agree upon limits among themselves. “We realized that unless we established minimum size limits we were going to fish these things out,” he recalls.

Today the San Diego sea urchin fishery is one of the most sustainable co-managed fisheries in America. Co-management is just what it sounds like: Local divers and state officials work together to set limits, and for the most part the divers police themselves. Over the past two decades, co-managed fisheries have emerged as one of the most promising strategies — along with marine reserves and catch shares — to halt the decline of ocean ecosystems worldwide. At least 211 co-managed fisheries now exist worldwide, ranging from Alaska’s billion-dollar Bering Sea pollock fishery to smaller artisanal cooperatives like the abalone harvest along the Chilean coast.

What separates a successful co-managed fishery from a failure? It’s not strict oversight, enforcement, or harsh punishment. It’s Peter Halmay — or rather, the role that he plays.

In a study published earlier this month in Nature, researchers at the University of Washington analyzed 130 co-managed fisheries around the world, looking for the factors that made the difference between success and failure. At the top of the list: Strong, legitimate community leaders like Peter Halmay.

“Community leaders weren’t just important — they were by far the most important attribute present in successful co-managed fisheries,” says Nicolás Gutiérrez, the study’s lead researcher. That community leader usually comes from among the fishers. Like Peter Halmay, it’s someone who’s earned the respect of his competitors and peers, continues to have a stake in the fishery, but doesn’t use his position to line his own pockets. “Having the trust of peers is critical,” Gutiérrez says. “We identified some fisheries where there were leaders, but they were mostly guided by self interest, and they weren’t effective.”

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2/3/11

An article published in the journal Geophysical Research Letters this week describes a new and simple way of measuring groundwater’s contribution to small streams on the surface. 

By taking snapshots of streams with a device designed to capture, through infrared radiation images, the temperatures in various parts of the water, the approach “advances the immediate detection and quantification of localized groundwater inflow for hydrology, geology and ecology,” the article’s authors, Tobias Schuetz and Marcus Weiler of the University of Freiburg’s Institue of Hydrology, wrote.

Groundwater, they found, tends to be cooler than surface water in summer and warmer in winter; the infrared devices record the difference and produce images that show groundwater as clearly as night goggles show a human figure in the dark.

By coincidence, on Tuesday, the same day the article was officially published, the California state assembly’s committee on water, parks and wildlife held a hearing on groundwater that was part science class and part exploration about what to do to regulate the use of groundwater in the state.

More than any state in the West, California severely limits the circumstances under which groundwater can be regulated in view of its connection to both surface water and other pockets of groundwater.

Only when it is in a “known and definite channel” underground is groundwater subject to significant controls. Hard pumping of the groundwater located outside such channels over the last 60 years has caused land in the San Joaquin Valley to drop more than 25 feet.

So while the Freiburg researchers show side-by-side photographs of streams as seen by the naked eye, and the same streams with the groundwater inflow clearly visible to infrared sensors, California water law, figuratively, closes its eyes, operating under theories that are largely oblivious to the connections that the Freiburg researchers and others have been documenting for decades.

Pumping groundwater beneath one’s land is commonplace in agricultural areas, and largely unregulated. Although the state does now monitor the levels of groundwater tables, legislative efforts to establish a state system to permit wells or simply monitor the amount of water pumped have failed repeatedly over the past decade.

But, as demonstrated by the hearing called by Assemblyman Jared Huffman, chairman of the water and parks committee, the effort to manage groundwater as if it were part of the surface water system may finally be gathering momentum. (It was going nowhere when I first wrote about the issue back in 2009.)

As Thomas Harter, a hydrologist at the University of California, Davis and a witness at Tuesday’s hearing, said in an interview, “In legal terms, there are, historically, two very different doctrines on how groundwater and surface water has been allocated.”

But, he added, “to the degree that groundwater feeds streams it’s important to stream flows and stream ecosystems.” And “streams are an important component of the groundwater budget in California,” he said.

Tony Rossmann, a lawyer in San Francisco. said that the state is unlikely to abandon its current legal distinction between groundwater an surface water soon.

The major constituency for the status quo is California’s $30 billion agricultural industry. But each new study that confirms the connections between water on underground and water on the surface gives a little more ammunition to environmental groups, legislators and water lawyers who want to bring groundwater under unambiguous state control, as it is in every other state except Texas.

Barry Nelson of the National Resources Defense Council took up the issue in a blog post this week, noting that over eight years, overpumping averaged even million acre-feet each year, he noted. “The impacts of this level of unsustainable pumping are far-reaching — declining water tables, increasing pumping costs, rivers like the Cosumnes literally sucked dry from below, subsiding land and more.”

“Liquid Assets,” a report issued last year by the California legislature’s legislative analyst’s office, recommended phasing in a system of permitting groundwater withdrawals.

As the authors of the new Freiburg study, even though their methodology is currently limited to small streams, their measuring process “may well improve our ability of sustainable water management in water-scarce regions” —– maybe even regions governed by laws and court rulings that create distinctions that fly in the face of this kind of science.

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