El Nino (ENSO) events occur periodically and vary greatly in both intensity and spatial magnitude. ENSOs are characterized by local increases in water temperature, sea level elevation and reduce water column nutrients. Despite these biologically significant features, and especially considering their influence on pelagic assemblages and coral reef ecosystems, the impact of ENSOs on mid- to high-latitude, nearshore benthic assemblages remains ambiguous. The rocky intertidal assemblage characteristic of the exposed coast of Washington State has been experiencing ENSO conditions since at least January 1992. Dr. Paine will examine how changes in nutrients availability effect algal productivity, recruitment and growth. A relative new technique will be employed using terra cotta flower pots. In a balanced, replicated design, some pots will be filled with nutrient-rich materials, some protected from benthic grazers by anti-fouling paint and others left untreated. Comparison between treatments should allow a statistical analysis of the influences of terrestrial inputs, nutrients and grazers on algal productivity. Repetition in a non-ENSO year will identify the possible contribution of water column recruitment of three kelp species.
