Tiny ocean plankton hold clues to the future of Maine lobster

The future of Maine's lobster industry hinges on a microscopic creature, the Calanus finmarchicus zooplankton, discovered by University of Maine researchers. During a critical phase of their life cycle, baby lobsters, or larvae, preferentially feed on this tiny nutrient-dense zooplankton. A new study indicates that the availability of Calanus finmarchicus is declining in the Gulf of Maine, coinciding with a 40% reduction in Maine's lobster harvest since 2016.

The researchers found that 30% of larval and post-larval lobsters sampled contained traces of Calanus finmarchicus, despite it comprising only a few percent of the available zooplankton. This suggests a direct link between the dwindling food source and the survival of young lobsters. As the Calanus range moves northward into cooler waters, its availability decreases, threatening the survival of lobster larvae and potentially reducing future adult lobster populations.

The study, published in Elem Sci Anth, highlights the need to understand the diets of larval lobsters to predict fluctuations in their numbers and the overall lobster fishery.