NT-23-X13: Zooplankton Ecology of the western Gulf of Maine: trends in abundance and diversity

Offshore renewable energy development currently is underway in the north Atlantic and is in the planning stages in the Gulf of Maine (GoMe).  BOEM must evaluate the cumulative effects of offshore wind on marine species, including the highly endangered North Atlantic right whale (NARW).  The GoMe currently is designated as critical feeding habitat for NARW, which feed primarily on copepods, specifically Calanus finmarchicus.  The objective of this study is to understand the long-term variability of C. finmarchicus and impacts to their populations in the GoMe and north Atlantic.This proposed study will collect and analyze plankton data at Wilkinson Basin and in the Maine Coastal Current.  The Wilkinson Basin Time Series (WBTS) and Coastal Maine Time Series (CMTS) stations are strategically located in the western Gulf of Maine to monitor planktonic ecosystem characteristics in the Maine Coastal Current, a regional production driver, and in Wilkinson Basin, the primary overwintering habitat for C. finmarchicus.  Observations of summer abundance of C. finmarchicus at the CMTS station show approximately a 30 percent decline from 2008 to 2021, consistent with the WBTS.  Data collected in 2022 at both the CMTS and WBTS stations indicate a rebound in C. finmarchicus abundance.  Whether this is a singular event or the start of a longer-term increase in C. finmarchicus abundance awaits future observations.  Funding for 2023 sampling was provided through the Marine Biodiversity Observation Network, but this funding ends in January 2024.  Moving forward, BOEM considers additional funding imperative to continue this long-term data collection to detect climatological or other effects on NARW food availability in this critical habitat area.The study will measure total zooplankton dry weight; abundance of C. finmarchicus life stages (the Calanus Index) and other zooplankton taxa; and changes in biomass, C. finmarchicus abundance, and zooplankton community composition.  The study also will conduct DNA metabarcoding analysis and microscopy (for phytoplankton species composition).