Sonar-like project brings new precision to fish counts

NAHANT — Scientific research for the U.S. Navy inadvertently discovered that low frequency acoustic waves can be sent over considerable distances — much of the Gulf of Maine or Georges Bank, for example — in a matter of seconds and produce a real-time picture showing the status of stocks in America's oldest fishery.

But officials at the National Oceanic and Atmospheric Administration have not included any money to further test or utilize it despite widespread questions around the credibility of their own science — and despite the consternation of two Massachusetts federal lawmakers.

The experimental approach — known as Ocean Acoustic Waveguide Remote Sensing, or OAWRS — expands by a factor of "roughly one million," according to a peer-reviewed article in Science Magazine, the effectiveness of traditional trawl surveys, now the starting point for regulatory controls.

Those trawls have come to be considered so unreliable and imprecise that allocations or catch limits extrapolated from the trawl surveys are typically reduced by a sizeable fraction, denying the fishing economy significant revenues because of "scientific uncertainty."

As a result, the limits of the present approach to fish finding, identifying and counting are held by critics of the regulatory system — and many government fishery scientists, too — as a weak link in calculations leading to the catch limits mandated by the federal Magnuson-Stevens Act.

The limits of fish stock census-taking and the implications of those limits were highlighted recently when the National Oceanic and Atmospheric Administration decided to adjust upward by 600 percent the total allowable catch of pollock, based on a number of factors including a new trawl survey.

The announcement came after months of complaints by fishermen and their political advocates that the 2008 trawl survey of pollock, a semi-pelagic wanderer, had badly missed the fish, leading to false conclusion that pollock were in need of emergency protection and an allocation for 2010 that was barely one third the size of the previous year's landings.

Last Wednesday, in an old World War II bunker converted into a lecture hall on the campus of the Northeastern University's Marine Science Center here, lead scientists in the OAWRS project briefed a prestigious audience that included U.S. Sen. John Kerry and Congressman John Tierney on the evolution of the science and its potential for reducing uncertainty in fishery regulation.

"What you've got yourself," said Kerry, summing up, "is a fish-finder on steroids."

He and Tierney, however, seemed nonplused when told the research team, led by Nicholas C. Makris of Massachusetts Institute of Technology and Northeastern's Purnima Ratilal, did not have funding to return to the field for a third time to validate their belief that the OAWRS technology can distinguish between species.

"NOAA (the National Oceanic and Atmospheric Administration) should put this in their budget," said Tierney.

"This makes me so angry," said Kerry. "We're going straight to the top."

In the first two field surveys, in 2003 and 2006, OAWRS' was tested only on herring, a pelagic and a mid-column swimmer.

OAWRS' acoustics for the mixed stocks at and near the sea floor, which make up the core of the New England fishing industry, pose what the scientists acknowledge to be an untested challenge.

"We should be able to see individual cod," said Makris during the discussion that followed the lecture.

The OAWRS project, which began with funding from the Office of Naval Research, discovered the acoustic fish identification capabilities of the technology while trying to figure out what was creating background "clutter" in the testing of sonar.

By using low frequency sound waves, such as whales and elephants do to communicate over vast distances, the OAWRS system uses the ocean bottom and surface to push the waves horizontally whereas conventional acoustic fish finding using higher frequency waves plumb only vertically, according to the research papers.

The first field study in 200, — reported in the Feb. 3, 2006 Science — took place south of Long Island, N.Y., and found and described a shoal or super school of herring.

"It was a 200 million shoal of herring, about the size of Manhattan," Ratilal told the federal lawmakers and about two dozen invited guests.

Hosted by Northeastern University President Joseph E. Aoun, the invited guests included Roger Berkowitz, president and CEO of Legal Seafoods, representatives of the Gloucester fleet and the Gloucester Seafood Display Auction, and Gloucester's state legislative team of Sen. Bruce Tarr and Rep. Ann-Margaret Ferrante.

Ferrante credited Berkowitz with seeing OAWRS' potential for improving the accuracy of stock surveys that produce more confident and therefore larger allocations leading to a stronger industry. Berkowitz has longstanding ties to Gloucester, and Legal Seafoods does much buying via the Gloucester Seafood Display Auction.

After Berkowitz learned about the research from a fellow Northeastern scientist (working with mine-sweeping robotic lobsters), Ferrante said, "Roger called me."

In May, Ferrante, Attorney General Martha Coakley and state Sen. President Therese Murray got a briefing by Ratilal, and soon Kerry and Tierney were involved and a $200,000 earmark was inserted into the Senate version of the state budget.

Gov. Deval Patrick vetoed the item, but since then, after a meeting with Ferrante and Tarr, they said he has agreed to approve the appropriation.

The state's $200,000 would not fully fund the crucial test, whether the OAWRS' technology can indeed make the essential distinctions between the mixed stocks of bottom fish — cod, haddock, flatfish and hake and the others landed primarily in Gloucester and New Bedford, and lesser ports.

To go back into the Gulf of Maine this year to test whether the OWARS' technology can distinguish between species, would cost about $1 million the conference was told.

The work is well known in NOAA science circles. NOAA's Redwood W. Nero worked on the 2003 and 2006 field studies and J. Michael Jech of the Northeast Fisheries Science Center worked on the 2006 project which studied Georges Bank herring and compared OAWRS' findings with traditional trawl survey material.

Reported in the March 27, 2009 issue of Science, the 2006 research was funded primarily by the Alfred P. Sloan Foundation and the National Oceanographic Partnership Program, a partnership of federal agencies including NOAA.

The work centered on monitoring the activities of super schools so large that conventional technologies were inadequate to cover the scale and scope of the activities, and produced a new understanding of how shoals of herring congregate in the night but disperse during the daylight hours.

This insight also bears on the findings of traditional trawl surveys, Ratilal told the conference last Wednesday, and indicates that "conventional surveying leads to severe undersampling."

Russell W. Brown, the supervisory research fishery biologist at NOAA's Northeast Fisheries Science Center, said, the OWARS' project is well known and considered promising.

"We see potential in this," Brown said, "... but the technology is in the research and development phase." He said it needs to prove capable of distinguishing between species.

Makris agrees with Brown, but adds that the problem has been drawing the interest of the budget-decision makers at the administrative level, not the scientists.

"The system is sort of working," Makris said, while acknowledging it's "maybe a little slow."

Richard Gaines can be reached at 978-283-7000, x3464, or rgaines@gloucestertimes.com.

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