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by Madeleine Hall-Arber
DURHAM, NH - With funding from the Northeast Consortium, commercial fishermen and researchers from the University of New Hampshire (UNH) are engaged in an intensive 16-month effort to tag cod.
Under the supervision of Dr. Hunt Howell, graduate student Michael Morin has been focusing this tagging effort on two 30-minute squares in the Gulf of Maine - Areas 132 and 133 - with some additional work in adjacent areas.
The fishing trips are dedicated to tagging, with Morin going on board to place the tags and the fishermen being reimbursed for their time. By December 2001, some 12,000 fish had been tagged and 790 tags had been returned. The project is expect to run through February 2002.
Like other cod-tagging projects, this one is examining the distribution of cod over time and space, but its principal focus is on the rolling closure areas and surrounding waters.
The scientists are trying to determine if the biomass is increasing in the closed areas. If there are many cod in the rolling closure areas, it may indicate the strategy is effective. But if there are few cod in the closed areas, it may suggest that the closures are either poorly timed or ineffective.
Areas 132 and 133 off New Hampshire are the focal points, but to determine whether the cod are using their touted fins and tails to move in and out of the closed areas, the group is also tagging in areas 124 and 125 off Massachusetts and areas 139 and 140 off southern Maine.
Five boats
Five vessels have been involved in the project:
- Vincent Balzano's North Star out of Portland, ME;
- Carl Bouchard's Stormy Weather out of Hampton, NH;
- David Goethel's Ellen Diane out of Hampton, NH;
- Jim Ford's Lisa Ann out of Newburyport, MA; and
- Russell Sherman's Captain Dutch, which made one tagging trip out of Gloucester before being sold.
"If we had more boats or more space, we could have tagged more fish," Goethel noted.
Five commercial fishing vessels have been participating in the UNH cod tagging project, including the Ellen Diane out of Hampton, NH, pictured above.
Lots of fish
Perhaps the first surprise for project participants was the sheer number of cod available to be tagged.
Between March and November, they tagged 12,000 cod, handling as many as 900 fish during a few trips. Exhaustion, more often than cod availability, limited the numbers of cod tagged in season.
"It's like wrestling your teenager onto a table to measure him," Goethel joked. "The cod we're tagging is usually a lively 20 pounds or so. By the end of the 900-fish day, you've tossed around 18,000 pounds!"
Normally, just three men participate on a given day - the captain, one crewmember, and a graduate student. The participating vessel makes 15- to 30-minute tows with a net configured to catch just cod. Haul back is very slow to insure the fishes' survival.
In high concentrations of cod, 15-minute tows have yielded 10,000-20,000 pounds of fish, but only 800-1,000 pounds are brought onto the deck after a tow. That's because the point is to get the fish back into the water fast so they will survive.
Since this project places tags during fishing trips dedicated to tagging, extra care is taken to insure the survivability of the fish, above, including keeping a flow of running water to the holding tank.
Insurance challenges
Another surprise to both fishermen and scientists was the paperwork gauntlet.
Obtaining the federal experimental fishing permit required to fish in closed areas turned out to be extremely arduous and time consuming. In addition, insurance has proved to be a problem for some.
Universities require vessels taking out students or faculty to have personal injury (P&I) insurance. As a cost-saving measure, some boats no longer carry hull insurance, so they are unable to obtain P&I. Unless the project is able and willing to pay for insurance on top of the other project costs, these boats are disqualified from participation.
Given that one of the goals of the collaborative research effort is to allow fishermen hurt by the management measures to access alternative funds, this is a potential "Catch-22" situation.
Results to date
Out of 12,000 tagged fish in 2001, 790 tags had been recovered by year's end. At a little over 6% in nine months, the return rate was good news for the scientists.
"Past multiyear cod-tagging projects have typically had 7%-10% returns," Michael Morin said, "so we are confident that we will have enough returns at the end of the year-and-a-half of research to be able to draw some interesting conclusions."
The movement of about 500 fish has been plotted to date, but not yet correlated with dates of closures and other information. So far, Morin said that there did not seem to be a single pattern of movement, but at least four or five.
As expected, there are cod moving in and out of the closed areas, to the northwest and southeast. Tags have been recovered near closed areas by commercial fishermen and by recreational fishermen inside closed areas. While one tag was recovered south of the 42° line and one off southwest Nova Scotia, not a lot of interaction among the stocks has been demonstrated so far.
Traditional cycle?
Fishermen have long maintained that the traditional cod cycle features movement from the Great South Channel to Massachusetts Bay to Ipswich Bay to Wells. Then they "disappear."
In May, Goethel caught a cod tagged by the University of Massachusetts Dartmouth School of Marine Science and Technology (SMAST) project off Provincetown. That fit the traditional cod cycle, he noted - except that the cod had moved in the wrong direction.
The tagging so far has also confirmed that the fish tend to congregate by size. The fish in Massachusetts Bay, for example, tend to be smaller than the fish off New Hampshire.
Rarely do scrod congregate with larger fish. However, there are apparently some exceptions. Fishermen suspect that some small fish go along with the larger fish to learn the migration routes, similar to geese and other birds.
That might explain why eastern Maine has lost some of its spawning populations, Goethel speculated. Where fishing was once very heavy on spawning aggregations, insufficient numbers of cod were left to lead the way.
Measure of success
The UNH scientists anticipate being able to identify patterns of cod movement that will enable them to draw conclusions about the effectiveness of the rolling closures. However, they do not expect to have publishable results until the end of summer 2002.
For the fishermen participating in the cod-tagging projects, success will be the demonstration that they can successfully tag, map distribution, learn about basic biology, and get scientists out measuring fish again, rather than sitting in front of a computer.
Those, like Goethel, who have been fishing since they were children and have a good sense of what's going on, believe that these collaborative projects provide them with the opportunity to prove their observations and provide information that will be taken more seriously since it will have a "PhD attached."
