Estuaries The water in an estuary is brackish. This means that it is a mixture of fresh and salt water. But where does the fresh and salt water come from? Insert Pic of river Insert Pic of ocean Estuaries – How does the water mix? The salty water flows in from the ocean and because it is heavier (more dense) it runs underneath the fresher water from rivers. In most estuaries, the saltier water forms a tongue shape because the fresher water is flowing out of the estuary along its sides. Tidal forces cause salt water from the ocean to flow up and into an estuary. As this occurs, the salty ocean water mixes with the fresh river water. Resulting in brackish water or brine. Blue Heron Estuaries – Who lives there? Mangroves Sandpiper Snowy Egret www.skyenet.net/~wcas sady/gallery/lesa.htm www.inhs.uiuc.edu/chf/pub/ifwi s/birds/great-blue-heron.html Pelican www.nhptv.org/naturew orks/snowyegret.htm www.poelking.com/gal eriegp/index_e.htm Manatees Snook Seagrass http://www.tbep.org/por trait/birds.html www.nal.usda.gov/awic/new sletters/v6n2/6n2manat.htm Dolphins http://www.tbep.org/ portrait/critters.html Ghost Crab Roseate Spoonbill http://www.floridaenvironment.c om/programs/fe91227.htm www.exzooberance.com/virtual%20zo o/they%20swim/dolphin/dolphin.htm http://www.tbep.org/ portrait/critters.html http://www.camacdonal d.com/birding/PeterWa llack/Spoonbill3.html Facts about Tampa Bay www.tbep.org/portr ait/fastfacts.html Tampa Bay is the largest open-water estuary in Florida, encompassing nearly 400 square miles and bordering three counties -- Hillsborough, Manatee and Pinellas. The bay's sprawling watershed covers a land area nearly five times as large, at 2,200 square miles. Tampa Bay is the largest open-water estuary in Florida, encompassing nearly 400 square miles and bordering three counties -- Hillsborough, Manatee and Pinellas. The bay's sprawling watershed covers a land area nearly five times as large, at 2,200 square miles. A single quart of bay water may contain as many as 1 million phytoplankton -- microscopic, single-celled plants that are an essential thread in the "who eats who" marine food web. More than 200 species of fish are found in Tampa Bay, including the popular snook, redfish and spotted sea trout. Mangrove-blanketed islands in Tampa Bay support the most diverse colonial waterbird nesting colonies in North America, annually hosting 40,000 pairs of 25 different species of birds, from the familiar white ibis and great blue heron to the regal reddish egret -- the rarest heron in the nation. Each square meter of bay sediment contains an average of 10,000 animals -- mostly tiny, burrowing worms, crustaceans and other mud-dwellers that are known as benthic invertebrates. The most numerous creature in the bay sediment is a primitive, fish-like invertebrate about two inches long called branchiostoma. On average, Tampa Bay is only 12 feet deep. Because it is so shallow, manmade shipping channels have been dredged to allow large ships safe passage to the Port of Tampa and other bay harbors. The largest of these, the main shipping channel, is 43 feet deep and 40 miles long. The Port of Tampa is Florida's largest port and consistently ranks among the top 10 ports nationwide in trade activity. It contributes billions annually to the region's economy. More than 4 billion gallons of oil, fertilizer components and other hazardous materials pass through Tampa Bay each year.