Differential uptake of dissolved and particulate organic carbon by the marine musselPerna viridis

Abstract

We used radiotracers in laboratory experiments to determine the organic carbon uptake by the marine mussel Perna viridis from different diets (phytoplankton and detritus) and from the dissolved phase (colloidal and low molecular weight organic carbon). Standard compounds (glucose, arginine, and leucine, and the carbohydrate macromolecular dextran with sizes ranging from 3-2,000 kDa) were used to study organic matter flux into the green mussels. Carbon absorption was significantly affected by the food type and quality. The highest absorption efficiency (AE, 80%) was from the diatom Thalassiosira pseudonana, while the AE from Chlorella autotrophica was comparable with those from three types of algal detritus (20-30%). Mussels were able to directly ingest macromolecular dextran colloidal materials. Significant accumulation of these compounds was found both in the gills and the digestive glands of the mussels within the 12-17-h exposure period. Similarly, a significant accumulation of biogenic colloidal organic carbon (COC) and low molecular weight ultrafiltered organic carbon (UOC) was found. Uptake of UOC and COC resulting from the decomposition of different algal sources was comparable, with an uptake rate constant of 6.08 ϫ 10 Ϫ4 L g Ϫ1 dry wt h Ϫ1 and an absorption efficiency of 0.0053%. A kinetic model was subsequently applied to quantitatively evaluate the carbon contribution from dissolved and particulate sources to general organic carbon uptake by the mussels. Mussels accumulated organic carbon predominantly from the particulate phase, with very little (Ͻ0.2%) coming from the DOC. However, the apparent ingestion and accumulation of colloids suggest that they can actively participate in the food chain dynamics in marine systems.

Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes

“…This is in line with reports of high 210 Po accumulation by phytoplankton cells, with 210 Po/ 210 Pb ratios much higher than 1, and transfer to mussels (Wildgust et al, 1998(Wildgust et al, , 2000Stewart and Fisher, 2003). Organic particles in sea water, and especially the phytoplankton cells, are filtered and ingested by mussels being their main organic carbon source and this seems also to be the major pathway for radionuclide absorption by mussels (Wildgust et al, 1998;Pan and Wang, 2004).…”

Land–Ocean Coupling of Carbon and Nitrogen Fluxes on Sandy Beaches

“…(3) assimilation of carbon originally delivered in dissolved form and subsequently converted to particulate form in the prominent microbial loop of the surf zone and interstitial sediments (Cockcroft and McLachlan 1993); and (4) direct uptake of DOC, although this pathway may be inconsequential for marine species (Pan and Wang 2004). Based on the multiple roles that bivalves play in the processing of matter in benthic systems, we predict that the isotopic shifts of clams measured in this study will be detectable in other consumers and that they will propagate through most of the food web on sandy beaches impacted by river plumes.…”

Utilization of Spartina- and Phragmites-Derived Dissolved Organic Matter by Bacteria and Ribbed Mussels (Geukensia demissa) from Delaware Bay Salt Marshes

“…In salt marshes, G. demissa, the ribbed mussel, appears to use the plant matter indirectly, mediated through the microbial loop and presented to mussels as fine particles in the form of bacterioplankton and microheterotrophs (Kreeger et al 1988, Kreeger and Newell 1996 and likely also as aggregated organic flocs (Alber and Valiela 1994, Huang et al 2003, Pan and Wang 2004. In New England marshes, Spartina-derived material has been estimated to contribute up to 80% of the diet of mussels (Peterson et al 1985) and 30-50% in mid-Atlantic marshes (Langdon and Newell 1990).…”