Current carbon and nitrogen production rates in the Chukchi Sea

Abstract

The current carbon and nitrogen production rates of phytoplankton in Bering Strait and the Chukchi Sea were obtained from 2002 to 2004. The mean annual carbon production of phytoplankton from this study was 55 g C m-2 for the whole Chukchi Sea and 122 g C m-2 for the central Chukchi Sea which has been shown as the highest productivity in the Chukchi Sea. In contrast, the averages of annual total nitrogen production were 13.9 g N m-2 (S.D. = ± 16.2 g N m-2) and 33.8 g N m-2 (S.D. = ± 14.1 g N m-2) for the whole and the central Chukchi Sea, respectively. These rates were consistently 2 or 3 fold lower than those from previous studies. Moreover, compared to previous studies, lower chlorophyll-a biomass in the regions was founded in this study. We suggest that the lower carbon and nitrogen production rates in the Chukchi Sea from this study were caused by lower phytoplankton biomass from 2002 to 2004 which might be related to current warming and freshening of the water passing through the Bering Strait. However, it is not known whether the lower rates from this study is a general decreasing trend or simply temporal variation in the Chukchi Sea, since temporal and geographical variations are large and presently unpredictable.