ECOMARGE: Flux of particulate matter in the northwestern Mediterranean (golfe du Lion)

As part of the multidisciplinary programme ECOMARGE (ECOsysteme des MARGEs continentales) an experiment to measure vertical flux of particles was carried out in the golfe du Lion off Banyuls-sur-Mer (Lacaze-Duthiers canyon) over a period of 17 days in autumn 1983. Sediment traps were deployed at depths of 100, 200 and 315 m in a water column 350 m deep. The trapped material appeared to consist of fine muddy sediment and numerous biogenic debris. Total mass flux increased linearly with depth from 4 g m super(-2) day super(-1) at 100 m to 13 g m super(-2) day super(-1) at 315 m. The lithogenic fraction was predominant at all depths (55 to 60% of total mass flux). Trap-collected fecal pellets were categorized by different shape classes and enumerated. Mass calculations showed that intact pellets accounted for only a small proportion (5%) of the total mass flux at the 3 depths. Sequential leaching of trapped particles showed that Cu was essentially associated with the organic phase.