Estuaries are semi-enclosed areas where fresh water and seawater meet and mix, forming one of the most productive environments on earth. They serve as protected habitat and vital breeding and feeding grounds for many species. Cities were often built near estuaries due to the abundance of seafood. There are four main types of estuaries that form from different geological processes: drowned river valleys, bar-built, tectonic, and fjords. Estuaries have varying salinity levels and substrates that influence the distribution of species and ecological processes within them.

1. Chapter 12 Estuaries Where Rivers meet the Sea

5. Cape Hatteras Estuary In N. Carolina

6. Milford Sound in New Zealand is a fjord – a finger-like inlet surrounded by sheer walls with a shallow entrance and deep basin resulting in stagnant, oxygen-depleted deep water.

9. an IDEAL ESTUARY Isohaline are the same salt content water. How many are there?

10. High Tide Low Tide The Salt wedge moves in and out with the tide

13. Types of species living in an idealized estuary in relation to salinity. The width of the bars = relative numbers of species

14. The body fluids of estuarine animals responds in various ways to the salinity of the water. Osmoregulator = blood salinity stays the same. Osmoconformer=blood salinity will change with the water salinity.

16. Look at the shallow roots of this mangrove tree reaching above the mud to get oxygen. Why does mud not have much oxygen in it?

17. Cordgrass is an important component of salt water marshes

18. Pickle Weed is a common succulent plant in salt marshes around the world.

19. The Atlantic menhaden is an important commercial fish spawn offshore and larvae drift with tides into the estuary to grow.

20. The California horn snail is abundant on mudflats

21. Mudflat animals in temperate estuaries

22. Fiddler on the Mud What is this behavior for?

24. The daily tides play a crucial role in salt marshes. They help circulate detritus and nutrients and expose mudflat organisms to predation by shorebirds and other animals

25. A salt marsh near Atlantic Beach, NC. Many of these types of marshes have been filled in and destroyed.

26. A mudskipper from the mudflats of a mangrove forest in New Guinea. Its eyes can see in air.

27. An Oyster reef formed by the eastern oyster near Beaufort, NC are exposed at low tide.