Visual observation of fishes and aquatic habitat [Chapter 17]

Abstract

Whether accomplished above the water surface or performed underwater by snorkel, scuba, or hookah divers or remotely operated vehicles (ROVs); direct observation techniques are among the most effective means for obtaining accurate and often unique information on aquatic organisms in their natural surroundings. Many types of studies incorporate direct observation methods, including broad-scale inventories of aquatic organism distribution and abundance (Hankin and Reeves 1988), highly specialized observations of behavior (Drew et al. 1976), evaluations of habitat use (Fausch and White 1981), estimates of population size structure (Griffith 1981), assessments of gear performance (High 1971; Jones et al. 2008), and censuses of surrogate structures such as spawning nests or redds to estimate fish abundance (Dauble and Watson 1997). Visual observation methods fall into three broad categories: direct underwater observation by divers (snorkel, scuba, and hookah), surface observation (land-based, aerial, boat-based, and viewing windows), and remote methods (cameras and ROVs).

Citation

Thurow, Russell F.; Dolloff, C. Andrew; Marsden, J. Ellen. 2012. Visual observation of fishes and aquatic habitat [Chapter 17]. In: Zale, Alexander; Parrish, Donna L.; Sutton, Trent M., eds. Fisheries Techniques, 3rd edition. Herndon, VA: American Fisheries Society.