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WEST BOOTHBAY HARBOR, ME - The inshore trawl survey conducted last fall was a success due to excellent cooperation between the industry and the Department of Marine Resources. This survey will provide much needed information for many species found in Maine waters.
This information includes:
- Estimates of current abundance of exploited age groups;
- Year-to-year and place-to-place comparisons;
- Size of recruiting year-classes (not caught in commercial catches due to mesh and size limits) ;
- Inventory of fish populations (groundfish, lobsters, crabs, sea cucumbers, dogfish, and others.) ;
- Information on distribution, biological parameters (growth rates, feeding behavior, reproduction, habitat) ;
- Efficacy of the inshore spawning closure; and
- Allow refinement of Essential Fish Habitat designations based on Maine data rather than guesstimates.
An example of how these data will be useful to fisheries in Maine is that estimates of lobster abundance and distribution used in stock assessments will come from Maine waters rather than from offshore or Massachusetts surveys.
Trawl procedures
The trawl used for the survey had a spread of about 80' (including doors); the net spread was about 35'. The tows could be made in relatively small areas and turns of less than 15° were made to avoid fixed gear. The ground gear had six inch discs that came up with very little mud indicating that the gear was set properly.
Of the 95 planned tows, 78 tows were completed. The 17 tows that were unsuccessful were primarily due to unsuitable bottom and bad weather days. Tows were between 13 and 20 minutes, with shorter tows conducted during bad weather or in the case of gear conflicts.
For each tow, the volume of total mixed catch varied from less than one to 20 baskets. Except for biological samples, all lobsters, fish, and other organisms were returned overboard.
Fishermen went on the boat a number of times to observe the operation. Future plans are to video tape the trawl lines to determine the impact.
Nearly all of the tows were videotaped as they came aboard with the exception of tows during rough weather during the first week of the survey.
Catches were sorted by species and weighed and measured, with fish samples collected for age and growth analysis, maturity and fecundity, and other analyses as needed.
Lobster report
With the assistance of the lobster industry members in moving traps, lobster gear was only caught on 14 occasions. Gear removal was a primarily matter of slipping the pot warp off the doors and returning the gear back to the water.
When gear was caught, traps were returned directly to lobstermen.
Lobsters made up anywhere from less than 1% to as much as 90% of the catch by count. Lobster mortality ranged between 5%-10%, but actual numbers of lobsters were low, even when there was a large catch.
Eggers were uncommon and, when caught, the eggs appeared to be held on tightly. The rate of cull lobsters was about 25% overall but was lower when less lobsters were caught and higher as the number of lobsters in the tow increased.
ME forum session
Department staff are currently evaluating results from the survey. To address people's questions and concerns about the survey and survey results, the Department will hold a session at the Maine Fishermen's Forum on March 3, 2001 at 2:45 pm to discuss the results from the trawl survey.
For further information or an update, contact
at the Boothbay Lab at 633-9500.
