Surficial Substrate Complexity of the Central Gulf of Maine as Observed Through Video Observation During a Fisheries Survey

ABSTRACT

The Gulf of Maine is a geologically complex environment that supports a high diversity of plankton, invertebrates, and fish, including commercially important species. Its substrate heterogeneity is well known though existing high‐resolution substrate data are limited, hindering effective fisheries management. This study utilized a video drop camera system to characterize surficial substrate during the NOAA Northeast Fisheries Science Center's Bottom Longline Survey from 2014 to 2021. Video footage was collected from 577 stations and proportional substrate presence was calculated. Principal Component Analysis (PCA) visualized similarities of substrate composition among stations, and five kriging interpolation methods were tested to predict PC scores across unsampled areas. Regression Kriging incorporating depth and the terrain ruggedness index provided the most detailed interpolations. Results confirmed the complex and heterogeneous nature of the Gulf of Maine seafloor, showing high proportions of gravel and cobble in shallower, rugose areas and high proportions of mud in deeper basins. This research offers an improved dataset and approach for ecosystem‐based fisheries science, characterization of essential fish habitat, marine spatial planning, and complements existing broad‐scale efforts for habitat association studies.