Sedimentation rates were determined daily over a 2 wk period (late April -early May 1992) under post spring bloom conditions at a permanent station in the Bjernafjorden, Norway. Samples collected using floating sediment traps deployed at 50 and 100 m depth showed that sedimented seston, particulate organic matter, carbonate and lithogenic + opal fractions were, on average, twice as high at 100 m (221, 99, 51 and 76 mg m-2 d ', respectively) as at 50 m (119, 62. 27 and 34 mg m-2 d ' l , respectively). Faecal pellets made up the bulk of sedimenting matter, accounting for 87 and 92% of the average total organic carbon recorded at 50 and 100 m, respectively. The remaining sedimented matter consisted mainly of tintinnids. Diatoms cells and resting spores, coccolithophorids and flagellates contributed a minor fraction. It is postulated that the vertical flux of faecal pellets was determined by a combination of 3 factors: (1) relatively high standing stock of actively grazing mesozooplankton dominated by calanoid copepods and appendicularians, which are known for t h e ~r high faeces production rates; (2) a relatively high abundance of the cyclopoid copepod Oithona s~rnllls, which is reported to feed on faecal pellets produced by calanoid copepods, suggesting that coprophagy in the water column was high; (3) a phytoplankton community dominated by diatoms and coccollthophorids, whose mineral skeletons accelerate sinking rates of faecal pellets.
No takes yet. Share an insight, caveat, or question.
González et al. (1994) studied this question.