The Food Web of Potter Cove (Antarctica): complexity, structure and function

MARINA, TI; SALINAS, V; CORDONE, G; CAMPANA, G; DEREGIBUS, D; TORRE, L.; SAHADE, R; TATIÁN, M.; MOMO, F

ESTUARINE COASTAL AND SHELF SCIENCE

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018 vol. 200 p. 141 - 151

0272-7714

Knowledge of the food web structure and complexity are central to better understand ecosystemfunctioning. A food-web approach includes both species and energy flows among them, providing anatural framework for characterizing species? ecological roles and the mechanisms through whichbiodiversity influences ecosystem dynamics. Here we present for the first time a high-resolution foodweb for a marine ecosystem at Potter Cove (northern Antarctic Peninsula). Eleven food web propertieswere analyzed in order to document network complexity, structure and topology. We found a lowlinkage density (3.4), connectance (0.04) and omnivory percentage (45), as well as a short path length(1.8) and a low clustering coefficient (0.08). Furthermore, relating the structure of the food web to itsdynamics, an exponential degree distribution (in- and out-links) was found. This suggests that the PotterCove food web may be vulnerable if the most connected species became locally extinct. For two of thethree more connected functional groups, competition overlap graphs imply high trophic interactionbetween demersal fish and niche specialization according to feeding strategies in amphipods. On theother hand, the prey overlap graph shows also that multiple energy pathways of carbon flux exist acrossbenthic and pelagic habitats in the Potter Cove ecosystem. Although alternative food sources might addrobustness to the web, network properties (low linkage density, connectance and omnivory) suggestfragility and potential trophic cascade effects.