Nutrient dynamics in the Western Canadian Arctic. I. New production in spring inferred from nutrient draw-down in the Cape Bathurst Polynya

作者：Simpson Kyle G^*; Tremblay Jean Eric; Price Neil M

来源：Marine Ecology Progress Series, 2013, 484: 33-45.

DOI：10.3354/meps10275

• Phytoplankton production
• Nutrient consumption
• New production
• Polynya
• Nitrate
• Phosphate
• Silicate
• Amundsen Gulf
• Arctic Ocean

Ice-retreat from the Cape Bathurst Polynya occurred in late May and early June 2004, and was quickly followed by a decrease in dissolved nutrient concentration at the sea surface. Concentration plots of NO3- versus PO43-, and Si(OH)(4) versus NO3- showed the ratios of nutrient uptake in the surface layer were in proportions expected for diatom growth (N:P 13.1:1; Si:N 1.8:1) and that water-column NO3- was depleted before PO43- and Si(OH)(4). The temporal changes in integrated nitrate, phosphate and silicate concentrations were well described by logistic models that showed maximum consumption rates of 11.8, 0.82, and 17.8 mmol m(-2) d(-1), respectively, and a total seasonal draw-down of 210 +/- 19 mmol NO3- m(-2). If we include estimates of NO3- supply by advection, nitrification and freshwater dilution, then the amount of NO3- consumed could be 25-33% higher. Uptake of NO3- above the 1% isolume was balanced by an equivalent (94%) increase in particulate N over a 15 d period beginning at ice break-up. Thus, the amount of particulate spring new production associated with NO3- disappearance was estimated to be 16.1 +/- 1.5 g C m(-2).

• 出版日期2013