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CONCLUSIONS

Most of the early work on lobsters involved mortality and lobster tolerances and not optimum environmental conditions and preferences.

Lobster habitat preferences are generally dictated by their biological drive to maximize growth, survivability, and reproductive potential. Environmental preferences control their selection of habitat much more than their tolerances to various conditions. Lobsters frequently change habitats as they grow in order to utilize the full range of available shelters and environmental niches.

It has generally been thought that a lobster's dependence on shelter decreases as it grows, but this is true only with regard to predators in shallow inshore regions. Shelter is an essential part of the mating ritual; it is also an essential escape from predation by larger, offshore fishes. Mature lobsters rely heavily on shelters for protection during the molt period and for establishment and maintenance of dominance and for courtship.

Although American lobsters can be located in any habitat at any stage of their life cycle, they are not equally likely to be found in a given habitat during a particular period. There are vast areas where lobsters are rarely captured in trawls.

Published trawl surveys are inadequate to accurately delineate the distribution of the American lobster. Every effort should be made to utilize satellite positioning information with these surveys and to supplement these data with reports from lobstermen.

Bottom temperatures appear to determine habitat preferences and migration patterns of the American lobster. Preliminary work indicates that the mean bottom temperature in the Gulf of Maine is increasing. Fluctuations in the volume of slope water entering the Northeast Channel may be partly responsible for the general temperature trend.

Marine habitats are made up of a near infinite variety of oceanographic, biologic and geographic factors. Estuaries and continental margins (especially canyons) are complex ecosystems that combine a number of known lobster habitats. These environments are fragile and subject to rapid changes due to human impacts

Mature females normally lose 30-50% of a clutch during the long brooding interval of 9-16 months. Poor environmental conditions or stress may lead to significant further losses. Thus identification and protection of brooding habitats should be a priority.

Optimum habitats are much more limited in aerial extent than previously thought. There is some evidence to suggest that lobsters prefer the boundaries of two different habitats in order to maximize food and shelter opportunities, as well as to maintain maximum flexibility under changing environmental conditions. If this is the case, then it further reduces the amount of optimum real estate on the sea floor.