Kelp beds as habitat for American lobster Homarus americanus

Examined how American lobster uses Laminaria longicruris and L. saccharina beds and habitat along the Gulf of Maine. Lobster population density and biomass were significantly higher in both real and artificial kelp treatments than in non-kelp control plots. The change in lobster density was apparent the day following placement of the experiment, so a secondary trophic effect such as attracting prey into treatments is unlikey to have occurred. Thus, kelp beds can affect local lobster population densities by providing shelter for lobsters. Lobster density was significantly greater in the smallest kelp patches. Lobsters typically occupied the edges of kelp beds, and their abundance within kelp patches correspond to the patch's perimeter-to-area relationship. This suggests that edge effects influence the local carrying capacity for lobsters by influencing the lobsters' choice of kelp beds as habitat. -from Authors