Do visual transects provide true population density estimates for deepwater fish?

• DOI: 10.1016/j.icesjms.2004.06.002
• Publication Date: 2004-10-05T15:36:57Z
• Authors: V.M. Trenkel; P. Lorance; S. Mahévas
• Keywords: Population density

Abstract This study assesses the impact species ecology, fish reactions, and natural behaviour have on visual strip transect counts of deepwater carried out with an ROV (remotely operated vehicle). Two terraces one canyon were visited continental slope Bay Biscay. Species such as rabbit (Chimaeridae) North Atlantic codling (Lepidion eques) appear to avoided ROV. The vertical distance off bottom provided evidence that some individuals, in particular slickheads (Alepocephalidae) might been missed by being above GLM modelling showed importance depth, current speed, relative surveying direction counts. Natural reaction deep-sea will lead variable biased population density estimates.