The deep scattering layer (DSL) of Indian EEZ

Abstract

The deep scattering layer is a trophic network that carry numerous food chains, some of which end up in species of high economic value, such as oceanic squids, tunas, other scombroids, pelagic sharks etc. These diurnally and vertically moving bioacoustic layers are assemblages of mostly negatively phototropic zooplankton and micronekton. The paper examines their characteristics, sampling methods, ecosystem, bio composition and future lines of research and management priorities and reviews all works done in India on the DSL. The major database for this study is drawn from the results of the initial surveys and samplings of FORV Sagar Sampada in the Indian EEZ since 1985.