Combined video–hydroacoustic survey of nearshore semi-pelagic rockfish in untrawlable habitats

Abstract New survey technologies are needed to untrawlable habitats in a cost-effective and nonlethal manner with minimal impacts on habitat nontarget species. Here, we test the efficacy of integrating data from suspended underwater camera acoustic generate population estimates for nearshore Black (Sebastes melanops), Blue mystinus), Deacon Rockfish diaconus). We surveyed Seal Rock Reef near Newport, Oregon, compared our results derived mark–recapture study conducted at same reef. fish density video deployments those calculated applying published target strength length regression models acoustics data. Densities acoustics, using generalized physoclist model, were significantly different densities video; conversely, rockfish-specific model generated that not statistically densities. To assess whether, how, behaviour was influenced by presence an camera, deployed under transducer. No statistical difference observed before, during, or after deployment. Our work suggests combining stereo provided similar estimate historic results, but accurate dependent proper target–strength model. contend hydroacoustic is effective surveying rockfish habitats.