At last count, the population of endangered Hawaiian monk seals hovered around a pitiful 1,300. So biologist and diver Kyle Koyanagi was thrilled to liberate one that had become snared in an abandoned fishing net in 2007.

Koyanagi, a 35-year-old National Oceanic and Atmospheric Administration (NOAA) scientist, spends a lot of his time thinking about nets – and not because he fishes.

Abandoned commercial fishing nets have emerged as one of the larger threats to ocean habitat. Not only do so-called "ghost nets" entangle and kill wildlife such as monk seals, green sea turtles and humpback whales, but they also act as heavy-duty tumbleweeds that bulldoze delicate coral reefs to death.

They are also a hazard to boaters – including fishermen – who can tangle their props. Until more commercial fishermen worldwide begin practicing appropriate "netiquette," the coral reefs and wildlife of northwest Hawaii and elsewhere will continue to need underwater monitors like Koyanagi.

NOAANot only do ghost nets entangle and kill wildlife such as monk seals, green sea turtles and humpback whales, but they also act as heavy-duty tumbleweeds that bulldoze delicate coral reefs to death.NET GAINS

Each year, an estimated 50 tons of marine litter washes ashore along the Hawaiian Archipelago, which extends from the southernmost island of Hawaii 1,500 miles northwest to Kure Atoll. Shores of the northwest islands are soiled by the southern edge of what's called the Garbage Patch, a watery cemetery of flotsam and jetsam that sullies a swath of species-rich waters that former President Bush protected as a marine national monument two years ago.

Nets are a massive part of the problem. But unlike plastics and other pollutants that pose scientific conundrums, there are also some solutions already in action.

Koyanagi, a marine debris specialist who learned to swim before he could walk, is an integral player in an extensive public-private partnership spearheaded in 2006 called "Nets to Energy." Collaborators concentrate on harvesting thousands of discarded nets polluting Hawaii's waters. A trash-to-energy company then transforms the sea rubbish—along with heaps of municipal garbage—into electrical power for homes and businesses at a Honolulu facility on the island of Oahu.

NOAA, Covanta Energy and the National Fish and Wildlife Foundation recently expanded the initiative to the U.S. mainland. Recalibrated as "Fishing for Energy," it gives New England fishermen a free means to dispose of worn-out and outdated nets, ropes, lobster traps and buoys.

Pilot programs in the Massachusetts fishing port communities of New Bedford, Gloucester and Scituate have yielded 58,000 pounds of derelict gear during a six-month period beginning in February. Most of it is burned into energy at Covanta's facility in Haverhill, Massachusetts, where a ton of nets can power one household for five months. The enterprise has also been tested with Long Island lobster fishermen, part of an effort to extend the program from Maine to Florida. Covanta manages 34 trash-to-energy facilities nationwide.

"I am a longtime fisherman, and I hate to see debris when I'm out on the water," says Derek Porter, vice president of external affairs for Fairfield, New Jersey-based Covanta. "I saw this program in Hawaii, and thought it was a great idea. We get almost no revenue from this. We're doing this as environmental stewards and to keep the nets out of landfills."

DEBRIS AS DISEASE

Harbormasters are enlisted as educators who encourage fishermen to turn in their own used gear and to haul in any abandoned fishing debris they find in open water. NOAA specialists suspect most of what's floating off the New England coast comes from the U.S.

NOAATrained divers remove nets that have become tangled in underwater habitats.

But the same Is not true in Hawaii. Fishermen there use long lines, not nets. And ocean currents don't lie. Tracking an enormous clockwise circuit of currents known as the North Pacific Subtropical Gyre proves that the nets Koyanagi and his cohorts pluck from the seas are swirling in from Southeast Asia, where fishermen face few consequences for dumping gear overboard.

NOAA experts are encouraged by ecological experiments in South Korea and Japan that restrict sloppy boating behavior and pay fishermen for turning in old gear.

"We think of marine debris as a disease," says Megan Forbes, a spokesper son for NOAA's Marine Debris Program, launched in 2005. "You can't cure the disease until you understand the true nature of it. We study the sources of it and its impact on habitats. We're not just doing removal. We also want to understand the size and scope of marine debris."

The Marine Debris Research, Prevention, and Reduction Act signed by President Bush authorizes $10 million to NOAA annually for fiscal years 2006 through 2010. Actual budget appropriations by Congress, however, have been less generous, with $5.2 million provided in 2007, $3.2 million in 2008, and $4 million in 2009.The same legislation also directs dollars to U.S. Coast Guard cleanup efforts.

760 TONS OF GEAR

In Hawaii, Koyanagi and other highly trained divers venture into Hawaii's most remote waters for weeks or months at a time on a giant research ship. At sea, they split into crews on smaller vessels that haul the nets back to the mother ship. Their labors have evolved into sophisticated sleuthing involving satellite imaging, computer mapping and aerial surveys.

Add the fledgling "Nets to Energy" to the mix and the long-term arithmetic shows NOAA has cobbled together sufficient dollars and partners to pull roughly 760 tons of derelict fishing gear from Hawaii's waters since 1996. That's enough trash to light up, heat and cool 328 Hawaiian homes for a year. Oahu-based Schnitzer Steel voluntarily chops the nets into easy-to-digest pieces for the municipal trash-to-energy facility operated by Covanta.

Porter points out that skyrocketing oil prices and awareness about greenhouse gases are a boon for his growing business. By converting some 5 percent of the nation's trash into electricity each year, Covanta claims it saves the equivalent of 15 million barrels of oil. Nets make up a mere 1 percent of the 15-million-ton waste stream directed to Covanta annually, but this "net gain" saves on hefty per-ton landfill tipping fees and preserves ever-diminishing landfill space.

Though Koyanagi and his ocean-cleansing colleagues have registered significant gains, they don't expect Covanta's net power supply to dry up until international fishing mandates are passed and enforced.

"This type of work offers instant gratification, and it is making a difference," Koyanagi says. "I was raised surrounded by water. This is a way for me to give back to this water what it has given me all of these years."

NOAAIn Southeast Asia, fishermen face few consequences for dumping gear overboard.