TWELVE YEARS OF OBSERVED SPRING NUTRIENT LEVELS IN THE NORTHERN GULF OF ALASKA: 1998-2010
This study presents observational results from a retrospective analysis of 12 years of ocean chemistry data collected along the Seward Line transect in the Northern Gulf of Alaska (GOA). For this report, we focus on inter-annual variability in spring nutrient levels going into the annual phytoplankton bloom. This subarctic region is highly productive and supports several major fisheries and significant levels of primary production. Despite year-round down-welling, winter overturning replenishes nutrients to the surface each spring. We examine the correlation between spring macro-nutrient levels and physical oceanographic parameters such as temperature and salinity to determine if these more readily observed variables are good proxies for nutrient levels. Initial results indicate that although nutrient stratification trends mirror physical stratification trends due to changing climate, the actual concentration of spring nutrients varies significantly from year to year and is not well correlated with current-year physical parameters. Other likely factors impacting spring nutrient levels include prior year biological drawdown and poorly characterized deep water transport processes. Implications for primary production are discussed.
Trahanovsky, K. A., University of Alaska Fairbanks, USA, firstname.lastname@example.org
Whitledge, T. E., University of Alaska Fairbanks, USA, email@example.com
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: Yes