The main objective of this thesis is to quantify movement and activity of the American Lobster in order to determine implications for population ecology, structure and dynamics. The first chapter evaluates whether the current life history scheme for juvenile benthic phase American lobsters accurately describes lobster movement in the field using an ultrasonic telemetry tracking system. The second chapter expands the size range of lobsters to include adults as well as expanding the scale of ultrasonic tracking, both in area and temporal duration. Again the current life history scheme will be evaluated, and this larger study will investigate seasonal changes in movements, and questions about habitat use. The third chapter utilizes a unique data set which includes multiyear recaptures of ovigerous females which will be used to assess how behaviour limits habitat use across years, and if there is a relationship between lobster recaptures and lifetime spawning area size.