Document Type

Statistical Report

Publication Date



The amount of phytoplankton present in Tampa Bay waters can be estimated from measurements of the green plant pigment chlorophyll-a. Phytoplankton is one of several major forms of plants that exist in Tampa Bay and most other estuaries. Other major plant types are submerged seagrass, macro-algae and benthic micro-algae. The different plants can be viewed as being in competition with each other for required resources, such as light and nutrients. Studies conducted in urbanized estuaries have shown that excessive loading of nitrogen generally is accompanied by an increase of phytoplankton and macro-algae, including epiphytic and drift macro-algae, and by a reduction of seagrass. Relatively little is known about the response of benthic micro-algae to changes in nutrient availability. From a resource perspective, the loss of seagrass means a loss of essential habitat for a multitude of marine animal species. Therefore, the amount of chlorophyll-a present in the water column not only measures phytoplankton biomass, but the amount present also gives a general understanding of resource competition within the Tampa Bay ecosystem.