reading #3 coasts, estuaries, and environmental issues
TRANSCRIPT
Reading #3
Coasts, Estuaries, and Environmental Issues
2
Question of the Day
How would you describe the word “coast”?
2
Coasts
Affected by Marine ProcessesWhat are some marine processes?Continuously Changing
Includes bays and estuaries alsoCategories
Emergent vs. SubmergentPrimary vs. Seconday
What do you find at the beach?
Accumulation of sedimentHow is the beach constantly changing?
Beach ProfileBeach AnatomyWinter vs Summer BeachTypes of based upon
shape and structurecomposition of sedimentssize of sediment materialcolor
Beach Process
Constant balance between supply and removal of material
Onshore currentsLongshore currentsCoastal Circulation Cells
Rip Currents
10
Question of the Day
What are estuaries?
10
Estuaries Why are wetlands important?Tides, river flow, inlet geometry affect
CirculationWater exchange with oceanCurrent patterns
4 basic types of estuaries based on circulation and salinity distributionSalt WedgeWell MixedPartially MixedFjord (Poorly Mixed)
14
Marsh Anatomy & Common Plant Species
What do you think Flushing time is?
Why do you think Flushing time is important to an estuary?
What would the benefit be of a rapid (fast) flushing time?
What would the risk be of a slow flushing time?
Facts related to issues affecting the oceans
80% of population w/in 50 miles of coast1960-EPA formed
Marine Laws developed between1940-90Clean Air/Water ActMarine Protection & Restoration Sanctuaries ActMarine Plastic Pollution Restriction and Control Act
Issues at Beaches
43% of shoreline is losing more sediments than it is receiving.
Man-made alternations decreases sediment accumulationDamning riversBreakwaters, jetties, seawallsRestoration of beaches
Issues in Wetlands
Between 1950-1980, 200,000 acres/year50% of mangroves lost in the tropicsOver 50% have been destroyed and the
remaining are under threat
Issues with Water Quality
“Dilution is the Solution” Dilution is NOT the solution
Fertilizers, Pesticides, Nuclear/Toxic waste, surface runoff, urban runoff
Hg, Pb, PAH Biomagnification
“Dead Zones” are areas where there is extremely low oxygen levels and life can’t survive (Gulf of Mexico)
Issues with Plastics
Approx. 135,000 tons/yearCommercial Fisheries
149,000 tons fishing gear26,000 tons packaging materialEntanglement, Choking, Starvation, by-catchApprox. 450 years for 1 6-pack ring to break
down
Issues with Oil Spills
Increased demands since 1960sSupertankers can carry up to 250,000 metric
tons of oilAbout 15% of spilled oil is recovered on
average