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INTERPRETATION OF CATCH DATA

According to the most recent stock assessment summary SAW-22 (NEFSC 1996) total landings have more than doubled since 1978, reaching an all-time high of nearly 32,000 metric tons (over 66 million pounds) in 1994. This increase in landings has occurred over a wide geographic area, covering a wide range of habitats and extending throughout many fisheries and management regimes. Lobster size is decreasing, with the mean size of lobsters landed within one or two molts of the minimum size regulation. This indicates that the fishery is still dependent on newly recruited animals, which have just grown into legal size. These are general concerns for lobster management.

From a habitat point of view several trends are particularly alarming:

Firstly, the data shows an over-reliance on statistics and modeling with little or no spatial information. The result is that while average trends in overall productivity may be compared by region, there is virtually no monitoring of changes occurring on a sub-regional scale. This means that a local stock could collapse due to habitat degradation and possibly create a cascade effect, which would not be recognized until it is too late.

Secondly, landings are concentrated in a few areas. Landings in Maine constitute about half of the total, with about 25% occurring in Massachusetts. Overall, the coastal fisheries accounted for 86% of US landings in 1993. The inshore lobsters are competing for a limited number of coarse substrates for their protection. This very heavily fished inshore population also depends critically on the larval subsidy provided from the offshore and canyons areas. The recent expansion of fishing into the offshore area could prove a continuing threat to the entire population. It is therefore prudent that the level and pattern of offshore exploitation should be controlled.

Furthermore, some areas are being particularly hard hit by a concentration of traps. For example, in 1996, Boston Harbor and its surrounding area supplied nearly 2 million lbs. (approx. 22% of commercial landings in territorial Massachusetts). Not enough has been done to monitor sensitive habitats in these vital areas or determine the long-term effects of pollution on lobsters in the harbors.

Thirdly, landings are increasingly being concentrated during a critical few months of the year. In 1996, approximately 82% of landings within the territorial waters of Massachusetts occurred between July and November with concentrated landings in September and October. This is the critical time period after the lobsters have molted and just before females extrude their eggs (which then affords them protection against fishing). If similar compression of the season are occurring in other regions, this places an additional burden on the habitats and the resource to recover before the next disruption.

Lastly, it is well known that a significant proportion of lobsters are landed before they reach sexual maturity. This compresses spawning potential into an increasingly narrow size range and presumably age range as well. The SAW 22 panel cautions that "at low levels of egg production Ö stock collapse could come quickly and without warning."

All of these warnings have been heard before. What is not fully appreciated is the fact that we are placing ever more reliance on a shrinking size range, which increases the competition for particular environments. Other heavily fished species may become equally compressed which compounds the problem of available shelters. If these laterally restricted habitats do not currently represent an ecological bottleneck, they soon will. The rapid changes that are occurring in these sensitive and complex ecosystems create an ever-shrinking safety zone for the American lobster. If we do not begin to identify, delineate, and preserve these habitats, we may find that we are trying to save a species which has nowhere left to hide.