Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France)

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

6

Scientific paper

In situ benthic chamber experiments were conducted in the Thau Lagoon that allowed the simultaneous determination of the benthic exchanges of trace metals (Cd, Co, Cu, Mn, Pb and U) and mercury species (iHg and MMHg). Fluxes of organotin compounds (MBT, DBT and TBT) were also investigated for the first time. The benthic incubations were performed during two campaigns at four stations that presented different macrobenthic and macrophytic species distribution and abundance (see [Thouzeau, G., Grall, J., Clavier, J., Chauvaud, L., Jean, F., Leynaert, A., Longpuirt, S., Amice, E., Amouroux, D., 2007. Spatial and temporal variability of benthic biogeochemical fluxes associated with macrophytic and macrofaunal distributions in the Thau lagoon (France). Estuarine, Coastal and Shelf Science 72 (3), 432 446.]). The results indicate that most of the flux intensity as well as the temporal and spatial variability can be explained by the combined influence of microscale and macroscale processes. Microscale changes were identified using Mn flux as a good indicator of the redox conditions at the sediment water interface, and by extension, as an accurate proxy of benthic fluxes for most trace metals and mercury species. We also observed that the redox gradient at the interface is promoted by both microbial and macrobenthic species activity that governs O2 budgets. Macroscale processes have been investigated considering macrobenthic organisms activity (macrofauna and macroalgal cover). The density of such macroorganisms is able to explain most of the spatial and temporal variability of the benthic metal fluxes within a specific site. A tentative estimation of the flux of metals and organometals associated with deposit feeder and suspension feeder activity was found to be in the range of the flux determined within the chambers for most considered elements. Furthermore, a light/dark incubation investigating a dense macroalgal cover present at the sediment surface illustrates the role of photosynthetic activity in controlling benthic exchanges. Significant changes in benthic flux intensity and/or direction were reported for all redox sensitive elements (Cd, Co, Cu, Mn, Pb, U, and iHg). For MMHg and organotin species, other complimentary processes such as photodegradation/uptake and hydrophobic absorption/desorption need to be considered. This work demonstrates that the processes governing benthic exchanges are complex and that benthic organisms play a major role in the significant seasonal, diurnal and spatial variability of trace metals and organometals benthic fluxes in the lagoon.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France) will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1079193

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.