Frank, K.T. et al. (2007: Trends Ecol. Evol. 22, 236–242) provide interesting analysis, after compiling information from 19 subregions, on how the exploited shelf ecosystems of the North Atlantic are structured, either by predation (top down) or resource availability (bottom up), depending on their biodiversity and climate (cold vs warm). By the ecological ‘rules’ laid out, the Ross Sea should be structured by predation. Analysis has shown, however, that some portions of the Ross Sea follow the rules but others do not. This is apparent, though, only because the Ross Sea, unlike the remaining Southern Ocean and other portions of the World Ocean, remains at least for now, intact. If its whales, flightless seabirds, seals and large predatory fish had been severely reduced, as in the North Atlantic, bottom-up structuring likely would prevail.
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