Hypotheses & Objectives

The size frequency distribution of offshore lobsters captured in traps is different from inshore lobsters, with more large lobsters and fewer small lobsters.

Catch per unit effort will be correlated with water temperature, with greatest catch occurring in areas around 16C, which is the preferred temperature of the American lobster.

The sex ratio of certain areas offshore will not be 1:1 because of aggregation of reproductive females in some locations.

Berried females will exhibit a seasonal abundance, with egg stages suggesting an inshore migration to allow eggs to be released closer to shore.

Shell disease will be more severe and prevalent in the most southern study sites and may show some tendency to move north during the course of the project.

The size at maturity of female lobsters will differ according to bottom temperature, with lobsters reaching sexual maturity at smaller size classes in more southern warmer waters.

The overall goal of this project was to develop a monitoring program for the offshore lobster fishery, which would cover an area extending from waters off the Gulf of Maine to Hudson Canyon. The protocol and methodology outlined below were developed so that we could test the aforementioned hypotheses. The specific scientific goals of this project were to:

Determine the size frequency distribution of lobsters caught in offshore lobster traps.

Map the distribution and abundance of berried females captured offshore.

Map the temporal and spatial patterns of shell disease in lobsters captured offshore.

Measure the size at maturity of female lobsters captured offshore and determine if there is a spatial pattern that is correlated with water temperature.

Make management recommendations at the end of the study, based upon the data obtained.