인도양 서부 해역의 유광대 내 동물플랑크톤 군집 구조 특성

Abstract

We investigated the mesozooplankton community and environmental characteristics in the euphotic zone at the 67°E latitude of the western Indian Ocean. Mesozooplankton was collected from the upper 200 m between 5°N and 16°S at 1° latitudinal intervals along 67°E transect in the Indian Ocean during July 2017. Multiple opening/closing net and environmental sensing system (MOCNESS 1 m2 opening, 200 &micro m) were towed behind the research vessel ISABU. Warmer water (>29°C) was observed at northern latitudes and the temperature gradually decreased towards the southern latitudes (average 27 °C). The upwelling zone was located between 2°N-4°N, and 7°S-9°S, which caused a shoaling of the thermocline depth (~50 m). The thermocline (2°N-4°N) coincided with high chlorophyll-a (chl-a) concentrations. The total abundnace of mesozooplankton ranged 890-2,296 inds.m-3 (average 1,641 inds.m-3) at 5°N to equator and ranged 487-1,858 inds.m-3 (average 942 inds.m-3) at 1°S to 16°S. ). The mesozooplankton community was mainly composed of foraminiferans, dinoflagellates (Noctiluca scintillans), ostracods, copepods (calanoida, cyclopoida, poecilostomatoida, harpacticoida), amphipods, euphausiaceas, decapods, polychates, echinoderms, urochordates (appendicularians, salps) and chaetognaths.inal intervals along 67°E transect in the Indian Ocean during July 2017. Multiple opening/closing net and environmental sensing system (MOCNESS 1 m2 opening, 200 &micro m) were towed behind the research vessel ISABU. Warmer water (>29°C) was observed at northern latitudes and the temperature gradually decreased towards the southern latitudes (average 27 °C). The upwelling zone was located between 2°N-4°N, and 7°S-9°S, which caused a shoaling of the thermocline depth (~50 m). The thermocline (2°N-4°N) coincided with high chlorophyll-a (chl-a) concentrations. The total abundnace of mesozooplankton ranged 890-2,296 inds.m-3 (average 1,641 inds.m-3) at 5°N to equator and ranged 487-1,858 inds.m-3 (average 942 inds.m-3) at 1°S to 16°S. ). The mesozooplankton community was mainly composed of foraminiferans, dinoflagellates (Noctiluca scintillans), ostracods, copepods (calanoida, cyclopoida, poecilostomatoida, harpacticoida), amphipods, euphausiaceas, decapods, polychates, echinoderms, urochordates (appendicularians, salps) and chaetognaths.