Tracking Lobsters in Their Natural Habitat
The American lobster, Homarus americanus, is one of the most well studied marine invertebrates in the world, as well as the basis of one of the most valuable fisheries in New England. Yet, despite the intense interest in this species, we still know little about its normal behavior in its natural habitat. This lack of knowledge is primarily due to our inability to conduct long-term observations in an aquatic environment.
In the summer of 2002 we created a large in situ mesocosm near the UNH Coastal Marine Laboratory (CML), within which we can continuously track the movements of up to 5 lobsters at a time, while simultaneously collecting time-lapse video recordings of lobsters in the same area.
Over the next few years we completed a number of experiments that combined lobster traps, diver observations, underwater video cameras and ultrasonic telemetry (Fig. 1, lobster with sonar tag attached). These resulted in several publications that can be found in the Publication section of this website.
What Did We Discover?
- The 44 lobsters we tracked tended to be nocturnal; residing in shelters during the day, and taking excursions during the night. During these excursions they walked about 40-70m/hour before returning to their shelter.
- Many of the lobster expressed clear homing behavior, returning to the same shelter they left earlier in the evening. It is still unclear what cues they use to find their "homes" especially since they do it at night and likely cannot see the moon or stars.
- Underwater videos revealed that when lobsters changed shelters it was often because they were "evicted" by another lobster.
Further details about our findings can be found in the following publications:
Watson, W.H. III, W. Golet and D. Scopel. 2009. Use of ultrasonic telemetry to determine the area of bait influence and trapping area of American lobster, Homarus americanus, traps. New Zealand J. of Marine and Freshwater Biol. 43: 411-418.
Scopel, D.A., W.J. Golet and W.H. Watson III. 2009. Home range dynamics of the American lobster, Homarus americanus. Marine Freshwater Behavior and Physiol. 42: 63-80.
Goldstein, JS and WH Watson III. 2015. Seasonal movements of American lobsters in New Hampshire coastal waters: Patterns, environmental triggers and implications for larval hatch. Mar. Ecol. Prog. Series 524: 197-211. doi.org/10.3354/meps11192
Carloni, J., J. Goldstein and W.H. Watson III. 2021. Movements and daily patterns of activity expressed by egg-bearing American lobsters, Homarus americanus. Mar. Ecol. Prog. Series 661: 163-173. doi.org/10.3354/meps13629.