Assessing the impacts of fishing on Vulnerable Marine Ecosystems (VMEs) in the Southern Ocean is hampered by the paucity of information on the resistance and resilience of these ecosystems to disturbance. Both resistance and resilience of individual VME-forming taxa are related to their life-history characteristics. A global database of life-history characteristics, including growth rate, age, maximum size and reproductive parameters, was established for benthic, habitat-forming taxa and associated physical and chemical variables, including depth, temperature, oxygen concentration, salinity and nutrients. Meta-analyses revealed that there were strong, consistent relationships among life-history characteristics and with physical and chemical variables. Where records for the Southern Ocean exist, they fall within general global patterns. To demonstrate how these relationships might be used to assess vulnerability to fishing data are presented for the phylum Cnidaria, an important group of habitat-forming organisms that are known to occur in the Southern Ocean. These data show significant relationships between growth, age with temperature and/or depth suggesting that these taxa will show low resilience to disturbance in the Southern Ocean. Furthermore, many deep or cold-water species brood their offspring, a trait correlated with low dispersal capability. Recovery trajectories in the orders of many decades or centuries are predicted.
Document Number:
WG-EMM-09/35
Agenda Item(s)
Abstract