Bio 2-L35- estuaries

what are estuaries

where river meets the sea

• salinity, sediment-sulphoruous odor, dissolved oxygen

zones within estuaries and what organisms are mixed

1. Zone 1: Head- dominant river flow, freshwater- strong currents and sediments-

2. Zone 2- main mixing area- variable salinity, fine sediments- polychaetes, nematodes, crustaceans

3. Zone 3- middle reaches- tidal currents, salinity 18-25- muddy- more amphipods

4. Zone 4- lower reaches- fast tidal currents- outs- bivalve beds- mussels, oysters, salmon

5. Zone 5- mouth- meets the sea, strong, fully saline, sandy sediment

what is key about estuarine fish

usually fish arent the key organisms- only come to have babies and move in the summer- water temp is a trigger

food web in estuaries

• When drawing food web- how energy gets into- primary producers

• Primary consumers- zooplankton, plant grazers, feeders

• Second degree consumers- birds, invertebrate predators, fish

• Microbes are important- sedimentary environment and microbes are vital

what are estuarine birds

migrating birds- eat seagrass