Quantitative estimates of the meiofauna from the deep sea off North Carolina, USA

In 1974 the authors collected, sorted and enumerated meiofauna from 400,800 and 4000 m off North Carolina, USA. Samples were replicated respectively with 4 boxcores and 21 subsamples, 2 boxcores and 7 subsamples and 2 boxcores and 8 subsamples. Total meiofaunal numbers were highest in fine silt sediment at 800 m (x = 891.9 10 cm Super(-2)) and lowest in very fine silt at 4000 m (x = 73.5 10 cm Super(-2)). Fine sand at 400 m yielded a mean of 442.4 10 cm Super(-2). At all depths, most fauna were located in the upper 3 cm of sediment (x depth distribution = 2.2 cm), and typically only nematodes and foraminiferans were found below 4 cm. Total community abundances significantly differed with depth; however, there were no differences among replicate boxcores at particular depths. Since most (85.7%) of the variance was associated with subsamples from a boxcore, it appears that meiofauna densities are homogeneous within large areas at particular depths, and that patchiness is a small scale phenomenon at the level of the 10 cm Super(2) subsampler. Comparisons of sorting efficiencies of live and preserved samples indicated that to accurately enumerate foraminiferans, samples must first be fixed and stained, while turbellarians and oligochaetes must be sorted live.