Faecal pellets, carbonate

Urban-Rich J, Nordby E, Andreassen H, Wassmann P (1999) Contribution by mesozooplankton faecal pellets to the carbon flux on Nordvestbanken, North Norwegian shelf 1994. Sarsia 84 253-264 Veldhuis MJW, Wassmann P (2005) Bloom dynamics and biological control of a high biomass HAB species in European coastal waters a Phaeocystis case study. Harmful Algae 4 805-809... 

We hypothesize therefore that the observed low 234Th flux in traps is associated to the composition of settling material. Faecal pellets did not dominate the vertical export in April 1997 in fact phytoplankton, mainly diatoms and Phaeocystis, comprised a major fraction of the sinking particles (Reigstad et al. 2000). The high PPC (total phytoplankton carbon)/POC ratios... 

Morales, C. E. (1987). Carbon and nitrogen content of copepod faecal pellets Effect of food concentration and feeding behavior. Mar. Ecol. Prog. Ser. 36, 107—114. 

Carbonate particles embedded in the faecal pellets of planktonic crustaceans are protected from dissolution by an organic capsule. This mechanism is lEirgely responsible for the presence of remains of calcareous nannoplemk-ton in deep ocean sediments below the compensation level for carbonate (Honjo, 1976). Similarly, carbonate particles suspended in sea water are apparently coated by a layer of organic matter. After this layer is experimentally removed by a strong oxidant (e.g. hypochlorite or H2O2), the rate of carbonate dissolution increases significantly (Chave and Suess, 1967,... 

Destruction of carbonates by organisms also involves translocation of material from the site of biological corrosion or abrasion, and its redistribution in the environment. Carbonate particles which are mechanically removed by gastropods and echinoderms are transported through their digestive tracts and distributed via faecal pellets. Sponges remove the chips of car-... 

Carbonate sedimentary rocks are dominantly of marine origin. Many limestones are composed of fossilised shell debris in various states of comminution, some fine grained carbonates such as chalk (q.v.) may be entirely composed of sub-microscopic phytoplankton. Algal mats secrete aragonite particles and coral reefs are CeiCO structures which may be preserved, fossilised, intact or degraded to produce other limestones. As discussed above, allochems such as faecal pellets and ooliths may be... 

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