Estuaries and Coasts

1. Estuaries and Coasts Notes Series for Oceanography John P. Wnek

2. Coastlines and Productivity oceanworld.tamu.edu Coastal diagram with the area of nearshore and offshore productivity

3. Beaches http://www.usa-chamber.com/gulf-beaches/home.html

5. High Productivity Coastal Areas from NASA (SeaWIFS)

6. Northeast Coast Habitats /www.epa.gov/owow/estuaries/programs/se.htm

8. Estuary Types: Classified by Geology • Lagoon – parallel to coast (i.e. Indian River Lagoon, Florida) – Bar-Built Estuaries • Coast Plain Estuary– erosion (i.e. Chesapeake Bay and Pamlico Sound) • Tectonic Estuary– faults (i.e. San Francisco Bay) • Fjord – glacier formation (i.e. Alaska, British Columbia, Norway, Chile)\ • Delta- formed at mouth of a river (i.e. – Mississippi Delta)

9. Coastal Types Rocky Coasts Mountain Coasts Northern Boreal Coasts Western Coasts U.S. Barrier Island Coast

10. Sandy Hook, N.J.

12. San Francisco Bay Estuary – a tectonic estuary

14. Basic Definition of Estuary – A water body where salt & freshwater mix Technical Definition - “A standing water body within the coastal region where there is a greater net inflow of freshwater than an influx of sea water” J Wnek

15. Factors influencing an estuary • Temperature • Salinity • Nutrients Anthropogenic effects • Increased runoff • Development causing habitat fragmentation • Global Climatic Changes

16. Temperature • Highly subjected to seasonal variations • Shallow estuaries are prone to wide ranges in temperatures (i.e. Barnegat Bay) with variations from below -2 to 30 oC • Temperatures may change with shifting tidal regimes • There can be temperature inversions during the evenings, especially in the fall when cooler temperatures may be at the surface.

17. http://waterdata.usgs.gov/usa/nwis/uv?site_no=01409125

18. Salinity • Salinity can vary in estuaries based upon the amount of salt water inflow and freshwater inputs. • Estuaries can be classified according to the layering of salt water based on density - well-mixed - partially-mixed - salt wedge (highly stratified)

22. Inverse Estuaries • Some estuaries show an increase in salinity over time, these are considered “inverse estuaries” or “negative estuaries.” • There is a net increase in salinity over time mostly due to human impacts (i.e. dams and loss of freshwater flow into the system)

23. (Zedler et al. 2001) Swan River Estuary, W. Australia (Neira et al., 1992)

24. “Human activities have greatly increased the delivery of plant nutrients to estuarine and coastal waters throughout the world. Over abundant nutrients fuel excessive algal growth, which destroys critical habitats for fish and shellfish by depleting oxygen in the water and by blocking light from reaching sea grasses.” - Smithsonian Environmental Research Center

25. Flushing Time? • Considered the amount of time in which all water is totally exchanged in an estuary • Varies according to the estuary due to ocean access, freshwater runoff (called inflow) and depth of the estuary tF = VF / R tF is the flushing time Vf is the freshwater volume R is the river discharge rate

26. Flushing Time* Comparisons

27. Estuaries as Habitats • Estuaries provide multiple habitat types including marshes, marsh pools, tidal creeks, and shoreline deep water habitats • Finfish can inhabit specific habitats with fish being considered seasonal residents (19%), residents (21%) , nursery (38%) or strays (22%) in a study on Great Bay and Little Egg Harbor (Able et al. 1996 in Estuarine Shores).

28. Marsh Zonation • High Marsh – Not flooded regularly with predominant Spartina patens and Phragmites • Series of marsh pools at higher elevations • Low Marsh – Floods regularly with Spartina alterniflora • Creeks and ditches with sometimes tidal effects • Support a higher density of finfish than SAV beds (Sogard and Able 1991).

29. Marsh Zones (Jones and Strange 2006)

30. Submerged Aquatic Vegetation • In some estuaries over 300 species of fish reside all in which SAV is important: • Provide habitat for juveniles • Key source of oxygen production • Important part of nutrient cycling • Binds and stabilizes sediments

32. Data from the CRSS and Barnegat Bay Estuary Program 2001

34. Species and habitats Specialist Specialist Sygnathus fuscus Cyrpinodon variegatus

35. Three-spine sticklebackGasterostreus aculeatus Generalist

36. Striped Bass (Morone saxatilis) Reproductive Specialist www.stripertracker.org

37. Anthropogenic Effects on Coastlines Coastal erosion in Norfolk in 1997

38. Human Impacts and Changes in Estuaries Delaware Bay and human impacts In the past eighteen thousand years, sea level has risen one hundred meters (three hundred feet), converting freshwater rivers into brackish estuaries (Donn, Farrand, and Ewing 1962). The Delaware River is an Alluvial Plain

39. Delaware River Fluxes in Sea Level Rise Hull, C.H.J. and J.G.Titus (eds). 1997. Greenhouse Effect, Sea Level Rise, and Salinity in the Delaware Estuary.. Washington, D.C.: U.S. Environmental Protection Agency and Delaware River Basin Commission.

40. Marsh Systems Hartig et al. 2002

43. Hartig et al. 2002

44. Proposed Bruun Model with changing sea level Shifting of dunes and berms in response to sea level rise Davidson-Arnott, R. 2005. Conceptual model of the effects of sea level rise on sandy coasts. Journal of Coastal Research 21 (6): pp. 1166-1172.

45. Jones & Strange 2006

46. Jones & Strange 2006

47. Jones & Strange 2006

48. Habitat Alteration Models from Jones and Strange 2006 Phrag. model (blue 3 mm/ red 9 mm) SAV model (blue 3 mm/ red 9 mm) Based on the inundation model through 2195

49. Habitat Alteration Models from Jones and Strange 2006 S. alterniflora model (blue 3 mm/ red 9 mm) S. patens model (blue 3 mm/ red 9 mm) Based on the inundation model through 2195