Identifying Potential Habitats From Multibeam Echosounder Imagery To Estimate Abundance Of Groundfish: A Case Study At Heceta Bank, Or, Usa

Heceta Bank is one of the largest banks off the western coast of North America, extending 55km from north to south and rising above the continental shelf to 67 m water depth. Due to heterogeneous substrate of varying relief, the bank supports a diverse assemblage of demersal fishes and is an important fishing ground off the coast of Oregon, USA. The top of the bank is comprised of boulders and cobbles eroded from outcrops of sedimentary rocks, while layers of finer grain size material cover the lower relief flanks. Using observations of fish substrate associations from 19 remotely operated vehicle dives, we identified 57 distinct substrate types and 9 habitat types. In a separate exercise, we overlaid observations of substrate types onto high-resolution multibeam imagery to delineate four potential habitat classes. Using this map of potential habitats, we estimated bank-wide abundance and variance values for a select group of resident fishes.