Distribution of meiobenthic communities in the deep-sea floor of northeastern Pacific seafloor along a latitudinal transect

Abstract

This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of the northeastern Pacific during July 2003. The samples were collected using the multiple corer at 13 stations along the transects from 5°N to 17°N. The most abundant meiobenthos was nematodes and followed by sarcomastigophorans; these two taxa comprised more than 70% of the total abundance at all stations. For size distribution analyses showed that animals which fit into the sieve mesh size of 0.063 mm were abundant. The maximum density of meiobenthos was 147 inds./10 cm2 at station located in 7°N, and the minimum density was 6 inds./ 10 cm2 at station located in 14°N. More than 60% of meiobenthos were distributed at surface sediment layer within 1.0 cm, and the peak abundance was found at 0∼0.25 cm layer. The latitudinal distribution pattern of meiobenthos in the study area seemed to be related with the primary productivity of the surface water that is also connected to the water circulation pattern of the Pacific Ocean near the Equator, diverging at latitude of 8°N and conversing at 5°N.