Use of the photo method in the study of the composition and abundance of soft-bottom macrobenthos

The composition and abundance of the macrobenthic fauna associated with soft-bottom beds of the large bivalve mollusks Crenomytilus grayanus and Modiolus modiolus were studied in the inner part of Vostok Bay (Sea of Japan) in spring 2010. More than 30 taxa of animals were found in the mussel beds. Comparison of the data obtained with three different methods of studying muddy-bottom mussel communities showed that 80% of their biomass and only up to 25% of the species composition and 19% of the abundance can be estimated by the photo method. Photo surveys disregard small and/or juvenile animals, as well as infaunal organisms, and thus do not give a complete picture of the species, size, and age composition and abundance of biota.