| Popis: |
The Antarctic has often been considered a paradox in terms of primary productivity. That is, the rich water masses in this region, with their elevated nutrient concentrations, are rarely matched by correspondingly high phytoplankton standing stocks and productivity. Exceptions to this general condition are the productive coastal areas and frontal systems that are considered as productive as most regions in temperate latitudes. The Ross Sea may be another exception to this general scenario of low plankton productivity. As of the early 1980s, there has been increasing evidence that this area may represent one of the most productive regions in the Antarctic. Elevated phytoplankton biomass and productivity have, in fact, been measured both in situ (Smith and Nelson 1985; Wilson et al. 1986; Innamorati et al. 1990, 1992; Smith et al. 1996; Saggiomo et al. 1998; Lazzara et al., this Vol.) and via satellite images (Arrigo and McClain 1994). Further, there is also evidence of elevated flux of biogenic material accumulated over the continental shelf (Dunbar et al. 1985; DeMaster et al. 1992; Fabiano et al. 1996; Nelson et al. 1996; Langone et al. 1997; Ceccaroni et al. 1998; Frignani et al., this Vol.). The elevated productivity of this region has also recently been confirmed for its top predators such as krill, birds, seals and whales (Saino and Guglielmo, this Vol.; Azzali et al., this Vol.). |
