New approaches for investigating dynamics in coastal systems: Preliminary results from Elkhorn Slough and Monterey Bay

Adina Paytan, Ph.D.
Stanford University

Wednesday, May 14, 2003
3:00 p.m. – Pacific Forum

Coastal systems represent some of the most rapidly and dramatically altered ecosystems on the globe. Among the largest human-based impacts is the increase in nutrient loading to coastal systems. The results of this eutrophication include toxic algal blooms, hypoxic events, increased sedimentation, and reductions in biodiversity. In order to understand the ecological significance of these increased nutrient loads to coastal areas, traditional nutrient concentration monitoring is not sufficient. Systematic knowledge of the sources and the biogeochemical transformations of these nutrients within the watershed and adjacent coast must be reached. New approaches for studying nutrient dynamics will be presented with examples from Elkhorn Slough and Monterey Bay. These include: estimates of subterranean groundwater input and associated nutrient load using Ra isotopes; N cycling using coupled d¹⁵N and d¹⁸O systematics; P cycling using d¹⁸O of phosphate, ³¹P-NMR, and alkaline phosphatase activities. These approaches may provide new insight into coastal nutrient dynamics and allow for better management strategies.