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Feature Articles
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American lobster: Setting research agenda
A monthly newsletter by the Maine Department of Marine Resources
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This article is reprinted with permission of Commercial Fisheries News, the Northeast's fishing newspaper for over 30 years, ©2003 Compass Publications Inc. Commercial Fisheries News is published monthly; annual subscriptions are $21.95. To subscribe or request a sample issue: call (877) 263-4496; fax (207) 367-2490; e-mail (cfoster@fish-news.com); or click on the hot link.
WEST BOOTHBAY HARBOR, ME - In May 2000, the Department of Marine Resources (DMR) undertook a research agenda-setting effort for five of Mainešs major commercial species: clams, lobsters, scallops, sea urchins, and shrimp. The following is the fourth in a DMR page series that will summarize the results of meetings with industry on each of the species. (Contact CFN for copies of the clam, sea urchin, and northern shrimp research priority summaries.)
The American lobster (Homarus americanus) fishery is Mainešs signature fishery. It dwarfs all other fisheries in numbers of participants and value to the state. In 1999 the dockside value of the catch was a record $185 million, with an estimated economic impact on the state economy of $500 million. There were 5,930 commercial lobster/crab licenses in 1999. Of those, 3,457 are estimated to be full-time and 2,000 are estimated to be part-time harvesters.
Lobster abundance, landings, and value have steadily increased since the late 1980s. Prior to that, the long-term average landings had been in the range of 20 million pounds. Landings topped 40 million pounds in 1994 and were 53.5 million pounds in 1999. In this respect, it is recognized worldwide as one of the few fishery management success stories.
Nonetheless, the federal government includes lobster on its list of overfished species based on the estimates of fishing mortality rate from the lobster stock assessment. The discontinuity between this long-term increase in landings and concerns about overfishing during the last 10-15 years have resulted in research into some of the basic dynamics of the lobster population.
The change to co-management with the statešs lobster management zones is starting to create a demand for local research, at least at the scale of the seven zones. Lobstermen are now responsible for certain management decisions and they are starting to generate research questions for their local area and to seek monitoring, such as settlement test sites, in their zones. There is potentially interest and energy in the zones for collaborative information collection and monitoring.
Sixty-six people attended the two lobster public meetings that were held in April of 2000 in Rockport and Ellsworth. Topics and presenters included:
Oceanography - Dr. Lew Incze, Bigelow Laboratory for Ocean Sciences;
Spawning/Life History - Dr. Rick Wahle, Bigelow Laboratory;
Assessment - Carl Wilson, DMR, and Dr. Paul Rago, NMFS; and
Socio-economics - Dr. James A. Wilson, University of Maine.
Lobster research priorities are driven by the tension between the federal/ASMFC determination that the lobster fishery is overfished and the increase in abundance and landings in the last 20 years.
Simultaneous predictions of stock collapse and record abundance result in fundamental questions: Why do we have this abundance? Where are the bottlenecks for this population? Does the population really have egg production that is too low? What is driving recruitment? What effect do large- and fine-scale oceanographic events have on the population? At both meetings participants stressed the need to integrate Canadian research efforts and findings into our own.
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Oceanography.
The source and sink for lobster larvae remains the dominant research question for the lobster industry. This is an area that has had considerable research attention in the last 15 years and that work has yielded new insights that in turn are producing new areas of research. Management questions about the relationship of the inshore and offshore lobster stocks and the value given in the assessment to the v-notched and oversize lobsters off the Maine coast continue to make this research directly pertinent to the future of the Maine lobster industry.
Priority research needs are: determine the lobster broodstock source for larval settlement and harvest areas and the relationship and relative contributions of the inshore and offshore broodstock; study nearshore oceanography to understand its impact on larval transport and settlement for lobsters; study the effect of water quality on lobster reproduction, growth, and health including chlorine, herbicides and pesticides, and nutrients; and determine if there are large-scale oceanographic or climatic influences causing the reduced lobster larval settlement in the last five years, and if so, through what factors or mechanisms are those influences operating.
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Assessment.
The lobster stock assessment is the focal point of all of the disagreement about lobster population dynamics. As a result, for the lobster industry, the assessment provides the lens through which it sees lobster science questions. There is interest in both improving the data and assumptions that go into the model and developing new models.
In the process of improving data, there is interest in developing new ways to monitor the health of the lobster population. New indices that were discussed included larval surveys, post settlement surveys, and ventless trap juvenile surveys.
Fishery independent data is meant to provide an index of abundance and normally comes from a trawl survey. Maine and New Hampshire have been the only New England states without an inshore trawl survey. Furthermore, the federal survey does not come very far inshore in the eastern Gulf of Maine because of the bottom topography.
As a result, fishery independent information has been missing from the most productive area for lobster in the Gulf of Maine. Maine initiated an inshore trawl survey in November 2000.
Priority research needs are: document lobster abundance in Maine fishing areas through fishery independent means such as a trawl survey; study lobster stock structure and migration patterns so that management areas can be made consistent with stock structure; explore new models for lobster assessment and incorporate into models multiple indicators of stock health including results of new collaborative monitoring; and systematically improve research on inputs to the lobster assessment model such as natural mortality, growth rates and age, size composition of population and catch, measurement of fishing effort, lobster behavior and migration.
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Life history and behavior.
As with all crustaceans, there is no established technique to age lobster. This puts a premium on studies of lobster growth because without better understanding of growth rates, there is no way to link the settlement survey information to later harvest information.
Research in the last five years has demonstrated a strong positive relationship between the number of lobster post larvae in the water, and the number of juvenile lobsters on the bottom in that area. That work, and another time series that started in 1989, has shown a downturn in abundance starting in 1996.
Does this predict a downturn in the fishery in the next few years? If so, why is it occurring?
Priority research needs are to: improve the understanding of lobster growth rates, particularly of juveniles, in order to be able to link strength of post settlement year classes to future catch; improve/develop better fishery-independent and dependent sampling procedures to monitor juvenile lobster abundance; and understand migration and movement of lobster post larvae, juveniles, and especially broodstock.
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Socio-economic issues.
If lobster landings fall even to the long-term average, they will be reduced by more than 50% of current landings. This situation will pose serious social and economic problems for the coastal communities that are now so dependent on lobstering.
Economic contingency planning for an almost guaranteed eventual downturn received highest priority from the group. A first step in this planning process is information gathering about debt load in the industry, since that will determine the capacity of the industry to respond to lower landings. The industry wants documentation of the profound changes in lobstering since the 1950s. Those changes include the shift from making a living to seeking the good life, and dramatic changes in technology from haulers to wire traps to electronics.
The democratic zone process is a huge experiment in democratic resource management decision-making. Much of the discussion was about zone issues, but the group did not identify types of socio-economic work that could assist the process.
Priority research needs are: prepare a comprehensive response plan in the event of a sharp decrease in lobster landings and recommend actions to prepare the industry and coastal communities prior to a downturn, with particular analysis of the impact of current debt load; strengthen industry input and participation in science from the lobster management zones so that it becomes a continuous, ongoing process; describe the lobster fishery including economics, the many different businesses and fishing strategies that exist within the industry, effect of loss of alternative fisheries, and changes since 1950s; and provide social and economic descriptive material about the lobster fishery to support state interests in federal and interstate management arenas.
Two issues that were not part of the planned discussion but were given high priority by the participants included lobster health and disease issues; and research into the hypothesis that lobsters are being "farmed," fed by the high number of baited traps on the bottom.
Finally, two ideas were discussed that could serve as organizing principles for a major research project: Year of the Lobster: a bilateral, one-year, intensive, sampling project that would involve many researchers and industry members in both United States and Canada; and the role of technology, an expanded study of the quantitative and qualitative issues, such as the impact of changed fishing patterns, in documenting lobster fishing effort.
A copy of the research priorities can be found on the DMR page at
http://www.state.me.us/dmr/ or by contacting Naomi Petley,
DMR Laboratory, PO Box 8, West Boothbay Harbor, ME 04575;
call (207) 633-9525; or e-mail Naomi.Petley@state.me.us.
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