CS29 Phytoplankton & Primary Production
Date: Tuesday, June 11, 2002
Location: Poster Session - VCC
 
NewtonJA, Washington State Dept Ecology & Univ Washington, Olympia, WA, USA, newton@ocean.washington.edu
Reynolds, R, A, Washington State Dept Ecology & Univ Washington, Olympia, USA, 
Nakata-Van Voorhis, K, , Washington State Dept Ecology, Olympia, USA, 
Bos, J, , Washington State Dept Ecology, Olympia, USA, 
Dowty, P, , Puget Sound Water Quality Authority, Olympia, USA, 
 
REGIONAL ESTIMATES OF PHYTOPLANKTON PRODUCTION AND NUTRIENT SENSITIVITY IN GREATER PUGET SOUND: ARE WE SEEING CHANGES?
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Puget Sound is a large (2,330 km2) estuarine system in northwest Washington State, USA, linked to the northeast Pacific Ocean via the Strait of Juan de Fuca. Much development has occurred in its watersheds, with associated nutrient input. Deep bathymetry, sills, and tidal forcing afford strong mixing in places, while other reaches are highly stratified. To assess current levels of primary production and nutrient sensitivity, C-14 uptake experiments were conducted adding N and P in the Strait, Central Basin, Hood Canal, and South Puget Sound. Strong diversity was observed both in magnitude and nutrient addition response. Productivity ranged 0.5, 0.8, 1.0-1.5, and 0.7-1.1 kg C m-2 y-1, respectively. Our value for the Strait compares with an earlier estimate by Harrison et al., 1983 of 0.3-0.5 kg C m-2 y-1; however, our value for the Central Basin is higher than the ~0.5 kg C m-2 y-1 of Winter et al., 1975. Nutrient sensitivity was highest in Hood Canal, a highly stratified sub-estuary. South Puget Sound, and to less extent, the Central Basin, showed strong spatial and temporal variation in nutrient response.