Metazoan Meiobenthos temporal fluctuations in the deep NW Mediterranean Sea (DYFAMED-BENTHOS 1993-1995). Contribution of spatial variability and disturbance

Time-series surveys to resolve metazoan meiofauna abundance fluctuations in the deep sea are scarce. Between January 1993 and October 1995, surface sediment was collected with a multicorer at an average sampling frequency of 1.3 months at the DYFAMED-BENTHOS station (43 degrees 24.62' N-7 degrees 51.68' E; 2347 m depth) in the NW Mediterranean. Total metazoan meiofauna abundance in the 170 samples collected over the three-year period ranged from 133 to 770 ind. 10 cm(-2) (mean 380 ind. 10 cm(-2)). The community comprised on the average similar to 89% nematodes, 4.7% copepods, 4.3% nauplii, 1.1% annelids and 0.5% least common taxa pooled (Others). Variability in organism abundances was analysed at three spatial- (cm, 10-cm, 100-m) and two temporal (dates, years) scales, using coefficients of dispersion, nested ANOVAs and autocorrelation statistics. All the meiobenthic groups except the annelids exhibited aggregation at the centimetre scale. The 5 sources of variation together explained similar to 95% of the variability in the nematode abundances. They explained 65% of the variability in the abundances of nauplii and