BRETTON WOODS, N.H. — Catch shares are a double-edged sword to be used with caution and a good deal of forethought, expert participants agreed yesterday at the start of a high-level workshop on the preferred tool of the Obama administration to modernize the regulation of fisheries across America.

A partial conversion of the $64 million New England groundfishery to a catch share system welded to a business model of voluntary cooperatives called "sectors" was approved by the New England Fishery Management Council this summer at the urging of Jane Lubchenco, named in April as the new chief administrator of the National Oceanic and Atmospheric Administration.

The New England council is also writing a catch share system designed to restructure the uniquely successful $372 million scallop fishery that has made New Bedford the nation's No. 1 sales value port for a delicacy that federal officials concede is fully recovered and well managed.

Converting fisheries to catch shares implies turning commonly held wealth into tradeable private harvesting quotas. And from witnesses to earlier examples on the West Coast, British Columbia and Alaska yesterday came stories of safer, more rational and profitable fishing, albeit done by a much smaller group of boats.

But while the industries were strengthened in the transformation of public resources into tradeable abstract assets, communities have suffered, a point made by Ecotrust Canada in a written report last summer.

To Ed Backus, vice president of fisheries for Ecotrust, a West Coast nonprofit agency that innovates capital strategies for fishing communities, the distinction is between economic "efficiency" — a goal of catch share advocates — and economic "effectiveness" — a broader measure of the social impact — is everything.

The West Coast experiments have produced inflated values in quota, eight times dock value, with multiple harmful social effects including sale of equity to nonfishing outsiders and discouraging generational continuity in fishing, Backus reported.

"When quota becomes a mobile asset, it may be well and good for the asset's value," he said in an interview. But that's not so good for the community where the asset had been based, he emphasized.

At the morning session of a two-day retreat to the west side of Mount Washington, in the elegant Mount Washington Hotel, Backus joined two others from the Pacific coast experiments in catch shares, which began in the 1990s and continue.

His co-group leaders were Wes Erikson, a fourth-generation British Columbian fisherman, and Steve Minor, an Alaskan industry veteran and leader.

Erikson described the pre-catch share halibut industry as a wild and dangerous "derby," the proverbial race to the last fish that catch share advocates like to invoke.

"We were overharvesting, landing all the fish at once," he said, before the commonwealth was divided up. He said the impetus was a government order to "clean up or we'll shut you down."

So well behaved and organized did the British Columbian fishermen become that "now all species are accounted for, and we trade quotas at the dock," he added. He said they practice "avoidance fishing" of undesired species, adding that fishermen's logbooks turned so reliable that they are used by scientists.

Since 1990, the crazy, pre-catch share world of the British Columbian ports have become sane but also much smaller, and culturally weaker.

In answer to a question, Erikson said catch shares have meant the size of the fleet has been more than halved — the 435 halibut vessels are down to 200.

More to the point, he said, "Communities have shrunk and not as prosperous as they used to be."

Minor's story working in Alaska crab fisheries was much the same as Backus' perspective from Oregon's.

There, he said, about 260 boats and high lease rates on quota — the stuff of catch shares — "became barriers to entry" into the fishery. He, like Backus, urged the catch share makers of New England to look carefully at preserving community access to catch shares.

At another seminar a few doors down the corridor, officials from the Pacific Fishery Management Council said they were in the sixth year of a seven-year process of converting the groundfishery to catch shares and that the transformation was easier said than done.

Merrick Burden, a government economist, developed models to put smaller boats into co-ops and larger vessels into a quota system. Burden, too, said the idea was fleet consolidation — from 100 to 50 vessels — but annual wages would rise from $45,000 to $300,000. He said the expected effects included such "nonmarket mechanisms" as set-asides, commercial fishing associations and adaptive management.

"Market efficiencies can lead to social consequences," Burden said, adding that the fleet consolidation results in a high cost of entry into the fishery for the second generation.

Don Hansen, a former high official of Pacific fisheries, said that in reaching the goals, the problems included that "some ports could be wiped out."

"That's a mistake," he said.

"From the boat level," said Tom Ancona, a California fisherman and fisheries manager, "there are many concerns of the fleet regarding catch shares. What we envisioned then is different now. We were sold the idea on equal sharing with the buyback (of boats) and the reduced fleet."

"You need to get the information out fast on allocation formulas and costs," he said. "We're in the 11th hour of getting the groundfish catch share process going. And some of these groundfishermen could wind up out of business in 90 days. They have big concerns."

The New England Council is partnering in this series of workshops with the Nicholas Institute at Duke University and the Environmental Defense Fund, one of the environmental giants leading the charge for catch shares. EDF placed a 130-page catch share design manual on the table outside the main assembly room at the resort.

Although Amy Schick Kenney of the Nicholas School, who made introductory remarks, averred that the purpose of the seminar was to examine catch shares without bias, the package of documents prepared for participants included a July statement from Lubchenco in which she states that "there is increasing scientific evidence that catch shares are an effective method of fisheries management that produces better results than many current management systems."

"Well-designed catch shares reduce overfishing, decrease bycatch and promote environmental stewardship," she wrote.

The meeting concludes today. The featured speaker is Monica Medina, a former official in the Pew Environment Group and the Clinton administration who has been conducting a quick study of catch shares for Lubchenco. The report was expected at mid-month.

Pew has joined with EDF and other, lesser environmental non-governmental organizations in arguing that overfishing has made catch shares a necessary adaptation.

Richard Gaines can be reached at rgaines@gloucestertimes.com