February 2013 Aquatic Ecosystem Function An ecosystem can be defined as “all the organisms in a given area as well as the abiotic factors with which they interact” (Reece et al. 2010). Common aquatic ecosystems range from the largest oceans to the smallest creeks, but each aquatic ecosystem plays a pivotal role in global ecology. Each ecosystem consists of important aspects including nutrients cycling, biodiversity, and energy flow that contribute to the overall state of the ecosystem. However, the limited nature of aquatic ecosystems provides distinctions from terrestrial ecosystems (Reece et al. 2010). The limiting nature of light in nutrients of an aquatic ecosystem has an overall effect on biodiversity, nutrients cycling, and energy flow. Biodiversity plays a major role in aquatic ecosystem success. It can be explained as the sum total of life on Earth and provides a balance of species (Mittermeier et al. 2002). Not only does biodiversity affect the immediate ecosystem, but it also has an extensive impact on the interdependent biosphere because biodiversity is directly intertwined with the nonliving components of the Earth (Mittermeier et al. 2002). Aquatic ecosystems have a large biodiversity of species such as phytoplankton, cyanobacteria, zooplankton, insects, fish, birds, and mammals (Reece et al. 2010). Each species makes a unique contribution to the function of the ecosystem, and adding or removing species from an ecosystem can have a measurable impact unless lost contributions can be offset by a similar species; however, the effect that removal or addition of a species will have on an ecosystem is dependent on the conditions of the ecosystem. Research suggests that increased biodiversity in aquatic ecosystems causes a global increase in CO2, ecosystem stability, and a decreased susceptibility to invasion (Humbert et al. 2002). Some events that could disturb biodiversity are pollution, damage or loss of habitat, or an introduction of a
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