Comparison of fish assemblages recorded by visual census and video census
Introduction: Underwater visual census is the basis of many studies on fish ecology, however, a series of limitations and error pathways have been reported that influence the estimation of the richness and abundance of ichthyofauna, for which video techniques have been proposed. Objective: Traditional census was compared with video census using the technique known as diver-operated video to characterize the fish community of two bays of Huatulco, Oaxaca. Mexico. Methods: Sampling points were established in each bay, in which the traditional census and the video census using the diver-operated video technique were carried out. The number of species, abundance and diversity were calculated by type of census for each locality and by sampling point. To compare the richness, abundance and diversity of each census by locality, comparison tests and analysis of similarity (ANOSIM) were performed. To compare richness, abundance and diversity at the same sampling point, permutation tests were used. Results: It was found that both censuses provide similar estimates regarding the number of species, abundance, and diversity by locality and by sampling points. The composition and structure, as well as the abundance, number of species, and diversity did not show differences between census in each locality and the sampling points. Conclusion: Video census using the diver-operated video technique can be used as a complement or as an alternative to traditional census. Its use can provide a more complete assessment, increase data acquisition, and implement long-term monitoring programs in areas where there are economic limitations for its operation.