Traits and Drivers: An integrative approach to benthos dynamics on the continental shelf off the Antarctic Peninsula.
Supervisors: David Barnes, Enrique Isla, C. Held (British Antarct. Survey, AWI & CSIC)
The Western Antarctic Peninsula is undergoing rapid environmental change in response to climate forcing. The current study collected high precision underwater imagery of epibenthos to investigate biological dierences between inner (Marian Cove fjord) and outer (Marguerite Trough) continental shelf benthic assemblages and to identify key environmental drivers. The fjord exhibited signicantly higher benthic mega and macrofaunal densities, reecting productive and diverse ecosystems. Both taxonomic and functional richness increased with distance from the (retreating) glacier terminus within the study fjord and were generally higher in the inner compared to the outer shelf. Furthermore, benthic assemblages transitioned from stress-tolerant taxa near the glacier to more mature communities resembling those of the outer shelf as habitat age (exposure since glacial retreat) increased and environmental conditions became more constant. Overall, suspension feeders numerically dominated along the study shelf, underscoring their role in pelagic-benthic coupling and importance in carbon pathways within polar marine ecosystems. Temperature emerged as a primary predictor for multiple functional groups in the fjord, whilst hard-bottom substrate was a significant driver on the outer shelf. These findings emphasize the complex interplay between environmental conditions and benthic functional structure in this physically and biologically dynamic region.

Key words: Benthic assemblages, Functional traits, Continental shelf, West Antarctic Peninsula