Estuary ecosystemWhat is an estuary? Estuary is a partially closed body of water formed where fresh water from rivers and streams flows into the ocean, mixing with salt water from the sea,” as noted by (Biomes (n.d.). The estuary is part of the marine ecosystem (ocean and lakes). The estuary is believed to be the part of the bay where fresh water mixes with salt water rivers, once this mixing has occurred it is considered brackish water which is not as salty as the ocean water. In addition, the estuary ecosystem is along the coast with thousands of birds and fish, mammals, plant life and other animals seek homes in the estuary ecosystem despite there being rapid fluctuations in temperatures from the heat to the cold (adaptation to estuaries (nd). Biotic factors are organisms that coexist in a particular habitat, such as birds the blue heron, geese, fish, bacteria and nutrients, many ocean fish depend on sustainability of the estuarine ecosystem and zooplankton is mainly produced by the estuarine ecosystem, zooplankton thrives on phytoplankton and therefore is transferred into the ecosystem....