reading #3 coasts, estuaries, and environmental issues

Reading #3

Coasts, Estuaries, and Environmental Issues

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Question of the Day

How would you describe the word “coast”?

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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

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Question of the Day

What are estuaries?

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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)

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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