Guest Column: Lobster stock assessment will consider climate change

This year, the American Lobster Technical Committee will begin work on the next benchmark stock assessment for lobster. The Technical Committee (TC), which is comprised of state biologists and federal scientists, is scheduled to meet in Rhode Island on May 14 to 17 to begin the stock assessment process. As a first step, the TC will review data from trawl surveys, ventless trap surveys, commercial landings, and sea and port sampling to understand what information is available for use in the assessment model. For Maine, this will include a review of data from DMR sea sampling trips, the Maine/New Hampshire trawl survey, and landings from Maine dealer reports. During the meeting, the TC also will review any new sources of data as well as data submitted by members of the public. Two new focuses for this upcoming benchmark stock assessment will be to quantify environmental/climatic drivers in the lobster fishery and evaluate the implications of habitat expansion or contraction on population productivity. The 2015 Stock Assessment concluded that warming waters are a contributing factor to the disparate stock conditions along the Atlantic coast. Specifically, the 2015 Stock Assessment showed that the Gulf of Maine is experiencing more days of optimal temperature conditions (12-18oC or 53o-64o F.), promoting recruitment and increased stock abundance. In contrast, southern New England is experiencing more days above optimal temperature conditions (>20oC or 68o F.), negatively impacting population dynamics. This upcoming stock assessment seeks to build from these findings by quantifying environmental impacts to better inform management. In addition, the assessment will investigate how these climatic changes are impacting the habitat available to lobster. Settlement surveys in the Gulf of Maine have shown declines over the last five years; the stock assessment will examine to what degree changes in habitat are contributing to changes in the movement of lobster and/or their reproduction. The stock assessment process is expected to continue over two years, with a completion date of 2020. Following the May TC meeting, the group will focus on evaluating new information regarding lobster life history (i.e. growth rates, size at maturity, migrations) and associated modifications to the assessment model. Much of this work will take place throughout 2019. Information regarding upcoming meetings can be found on the calendar tab of the ASMFC website (www.asmfc.org/calendar/). In addition, information regarding submission of data sources for the upcoming stock assessment can be found here: http://www.asmfc.org/uploads/file/5a70cf3bpr02LobsterDataWorkshop.pdf.