Aquaculture 2022

February 28 - March 4, 2022

San Diego, California

COMPARATIVE STUDY OF SMAST DROP CAMERA SURVEY TECHNIQUES ON ATLANTIC SEA SCALLOP Placopecten magellanicus BIOMASS AND DENSITY ESTIMATES IN THE GULF OF MAINE

Kyle S. Cassidy* and Kevin D.E. Stokesbury

University of Massachusetts Dartmouth – School for Marine Science and Technology

836 South Rodney French Blvd, New Bedford, MA 02744

Email: kcassidy@umassd.edu

 



The University of Massachusetts Dartmouth School for Marine Science and Technology (SMAST) has historically used a centric systematic survey design to assess Atlantic Sea scallop population from Canada to the United States southern Mid-Atlantic, however the argument has been made as to how this design compares to a stratified random design.  In 2020 SMAST was funded to examine such differences as part of a two-year research project focused on the Gulf of Maine. In year one we conducted the traditional systematic survey to gather baseline data which was then used to develop strata for sampling in the subsequent year.  In year two, we surveyed each of the identified banks (Figure 1) with both sampling techniques simultaneously as to avoid any discrepancies which could results from fishing pressure or seasonality.  Strata were derived from 2020 station level density data which was interpolated through hot spot analysis and inverse distance weighted (IDW) analysis in ArcGIS.  The number of sampling stations required within each stratum were estimated using methods outlined in Ecological Methodology (Krebs, 2013) where we utilized the coefficient of variation from the mean density of scallops in each identified area from the previous year’s survey.  When the survey analysis was completed, researchers compared the derived results to determine if there was any significant difference between the sampling techniques.