Berkeley Scientific Journal

nutrients from anthropogenic pollution can degrade water quality and alter the balance of marine food webs. lying at the base of the trophic pyramid, plankton quickly respond to nutrient changes in the water, which can have repercussions throughout both pelagic and benthic food webs, and thus they serve as a good bioindicator of water quality. In early november 2009, we evaluated sediment pollution, water pollution, and plankton abundance at four shoreline sites in the San Francisco Bay. We tested the sediment for nitrogen, phosphorus, potassium, and pH levels, all factors that can affect growth of primary producers. In the water, we tested nitrate, phosphate, and pH levels. lastly, we sampled shoreline plankton abundance both morning and evening. Sediment phosphorus and water phosphates were strongly correlated with one another, but water nitrates remained relatively constant, at low levels, across sites. daytime plankton abundance showed a positive trend with water phosphate. these trends suggest nitrogen is quickly taken up by plankton, making nitrogen the limiting factor for them. the relationship between plankton and phosphorus is influenced by more complex factors.