Meiobenthic biodiversity and fluxes within the Antarctic biogeochemical environment
This project studies the role of the coastal zone and deep sea ecosystems in the productivity and energy fluxes in the Southern Ocean. In the Antarctic, where the availability of food sources - produced as well in situ as imported - strongly depends on the seasonal variations in the environmental conditions, spatial and temporal fluctuations in the various relations between the different communities are of fundamental importance. The structure and functioning of Antarctic biota are also determined by typical phenomena resulting from the dynamics of the sea ice. Here one thinks of the recovery capacity of the biota subjected to disturbances due to iceberg activity in the coastal zone and at the edge of the ice cap.
Special attention is devoted to the association between meiofauna, interstitial nutrients, organic material (both dissolved and particulate), pigments, sediment texture and bacteria.
Central themes in this study of the meiobenthos are seasonal, annual and long-term changes, biogeochemical interactions and carbon fluxes, feeding strategies and life cycles. These topics are dealt with in a general framework of benthic-pelagic coupling, abiotic/biotic interactions and biodiversity within the Antarctic ecosystem.
The general objective of this project is to improve our understanding of the structure and dynamics of the Antarctic coastal and shelf ecosystems from the perspective of the meiofauna. One is attempting to determine the complex but productive patterns among the Antarctic meiobiota as a function of the specific characteristics of an ice-dominated ecosystem.
Specific objectives are:
- monthly evaluation of the seasonality of the meiobenthos in response to the pelagic supply of the primary production;
- determination of the short-term effect (days) on the benthos of supply of organic material from the water column;
- comparison of the seasonal variations in benthic activity between a low-Antarctic site (Signy) and a high-Antarctic (Rothera) site;
- study of the interactions between the composition and the structure of the meiobenthos, on the one hand, and the biotic and abiotic South Pole environment, on the other;
- improvement of knowledge about the role of the meiofauna in the recycling and transport of biogenic matter by determining a carbon balance;
- identification of life form and feeding strategies of the dominant meiobenthic groups (nematodes) over a complete annual cycle;
- determination of reciprocal coupling and uncoupling mechanisms of benthic strategies (feeding, reproduction);
- description of the structural biodiversity of benthic communities in specific polar biotopes (mats of sponge spicules, bryozoan structures, ´fluff´, algae residues, etc.);
- evaluation of the succession of benthic communities in the process of recolonisation (recovery) after disturbances caused by iceberg scouring;
- determination of the temporal variability of meiobenthic diversity in Antarctic coastal ecosystems.