Assessing the size selectivity of capture gears for reef fishes using paired stereo-baited remote underwater video

All methods used to sample fish populations exhibit some degree of size selectivity, whether due the physical properties gear, behavioral responses or spatial distribution targeted population. In most stock assessments, selectivity functions are assumed and their parameters estimated a paucity empirical data necessary estimate selectivity. However, incorrect assumptions about can impart significant bias, ultimately affecting assessment outcomes. 2016, study was conducted assess three fishery-independent survey for reef in U.S. South Atlantic: (1) chevron trap survey, (2) standardized repetitive timed drop hooked-gear (3) an unstandardized designed mimic industry fishing practices. Each method paired with stereo-baited remote underwater video (S-BRUV) camera, which treated as comparative reference, considering that it is least selective four gears used. A total 93 stations were sampled all gear types, analyzed managed fishes: red snapper, Lutjanus campechanus (all gears), black sea bass, Centropristis striata vermilion Rhomboplites aurorubens except traps). For capture showed dome-shaped doming being more pronounced traps evidenced by decreasing probability individuals over ~500 mm FL. Despite largest snapper (> 800 FL) observed often on S-BRUV, mean generally smaller S-BRUV than either indicating hooked-gears proportionally fewer snapper. there evidence flat-topped but captured average did hooked gears. both exhibited Given these results it’s clear improper lead poor Therefore, when function particular type not explicitly known, studies directly should be reduce applied assessments. This demonstrates utility non-destructive surveys complement evaluate standard fisheries methods. Furthermore, efforts broaden scale this study’s methods, expand species examined, validate collected life history data, determine potential influence interannual recruitment variability patterns better understand processes fishes assessed region.