CS39A Zooplankton - Feeding, Reproduction, Growth and Molecular Diversity
Date: Tuesday, June 11, 2002
Time: 4:15:00 PM
Location: View Royal
 
DutzJ, Netherlands Institute for Sea Research, Den Burg, Netherlands, jdutz@nioz.nl
Baars, M, , Netherlands Institute for Sea Research, Den Burg, Netherlands, baars@nioz.nl
 
EFFECTS OF INORGANIC MINERALS ON FEEDING, EGG- AND FECAL PELLET-PRODUCTION BY TWO MARINE COASTAL COPEPOD SPECIES
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Total suspended matter (TSM) in coastal oceans is characterized by a high fraction of non-living material. Microflocs consisting of organic matter and inorganic minerals, which originate from fluvial transport or coastal erosion, contribute significantly to TSM. The suspended minerals may affect the ability of zooplankton to locate and ingest food, because the microflocs fall well into the size spectrum of copepod food particles. In laboratory experiments, the effect of mineral additions on the feeding, egg- and fecal pellet-production of two coastal copepod species was compared (Acartia clausi, Temora longicornis). Species-specific differences in response to the additions were observed. While feeding and egg-production of A. clausi was not affected, the ingestion rate of T. longicornis was significantly reduced. A threefold increase in the number of fecal pellets produced by T. longicornis suggests that the reduction result from ingestion of microflocs. Shifts in the food particle spectrum were also observed and demonstrate that an enhanced sediment load can modify the pelagic energy transfer. Despite the reduction in total food uptake, however, negative effects on egg production of T. longicornis were not observed.