Coasts Flashcards
Where are coastal zones?
Barrier Islands (13% of coastlines)
Beaches
Rocky coasts
Seagrass beds
estuaries
mangroves
coral
Who owns coastal zones?
Each country has 12 nautical miles of jurisdiction from low tide (contiguous zone). Foreign vessels are allowed innocent passage. 200 miles from coast of “exclusive economic zone”
Why are coastal zones important?
One of the most biologically productive areas on Earth. 90% of world’s marine fish catch reproduces in coastal waters (primary protein for 1 billion people)
40% of earth’s population lives within 100km of coast
60% of world GNP comes from coastal areas (85% of global tourism on coasts)
coasts offer shoreline protection, store and cycle nutrients, provide food, shelter, and nursery for many fish and crustacean species, commercial, sport, and subsistence fisheries, purify water and remove waste products, settle suspended sediment
How are coasts used?
fishing, aquaculture, forestry, developments, mining, shipbuilding, oil extraction, transport, electric power, tourism, recreation
What threatens coasts?
Overcollection of resources. Fishing top trophic level fish, taking out coral, big fishing fleets, boats, trawling or longline fishing (30% bycatch)
Tourism threatens coasts, scuba diving, anchor damage
coastal development, like roads
ports create air and water pollution, introduce invasive species
housing development
removing sand from beaches for concrete, landfill, other beaches
dredging harbors
What is non-conservative pollution?
Will degrade, dissipate, assimilate into organisms
Degradable waste: sewage, food processing wastes, brewing, pulp and paper
Dissipating wastes: heat from power stations, acids, alkalines, cyanide.
What is eutrophication?
Caused by excessive nutrients, causes algal blooms, which, when dead, have bacteria that use up all the oxygen which creates dead zones where nothing or little lives.
What is conservative pollution?
Non-biodregradable pollutants - particulates (mining waste, plastics). Persistent wastes: heavy metals, mercury, lead, copper. Hydrocarbons: DDT, pesticides.
What do petroleum hydrocarbons do to fish?
Cause cardiac arrest in vertebrates, hypersalty water.
What are the causes of the biggest oil spills?
war, tanker accidents, well ruptures.
What cause little oil spills that make up more gallons than big spills?
Natural seeps, like seafloor cracks 64%. Land and sea vehicles leaking small, constant leaks 34%. Oil transport 4%. Exploration and extraction 2%
What coastal systems are affected by development, recreation, aquaculture, and overexploitation?
Coral reefs, mangroves, seagrasses, marshes
What happened at Waikiki beach?
The mangrove forest was removed to clear the beach, now they have to ship in sand because nothing holds it to the shore or they bring back the sand that washed away.
Why are coral reefs mined?
Lime for cement, bricks, calcium supplements, jewelry, for aquariums.
Where are coral reefs found?
Between 30 degrees north and 30 degrees south.
