Larvae of the American lobster Homarus americanus H. Milne Edwards, 1837 (Decapoda: Astacidea: Nephropidae) in midcoast Maine USA from 2018–2023: density, seasonality, and carapace lengths.

This article focuses on a six-year study (2018–2023) of the planktonic larval stages of the American lobster (Homarus americanus) in midcoast Maine, conducted by the Maine Department of Marine Resources (MEDMR). The study addresses a longstanding data gap by consistently monitoring larval lobster density, seasonality, carapace lengths, and environmental factors such as temperature, salinity, and zooplankton community composition, including the key prey species Calanus finmarchicus. Results indicate an earlier seasonal peak in Stage I larvae compared to historical data, multiple seasonal peaks in postlarval abundance, and significant correlations between early-stage larval food availability and later postlarval densities. The study also finds that salinity positively correlates with postlarval carapace length, while temperature and prey abundance show no significant direct effect, highlighting the complex environmental influences on larval development in the warming Gulf of Maine.