Transcript Chapter 16: Marine and Costal Systems

Chapter 16: Marine and Coastal
Systems
Resources,
Impacts and
Conservation
www.irreplaceablewild.com
Oceans
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salinity
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is due to runoffs and evaporation
can vary → different areas evaporate at different
rates
vertically structured
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temperature
density
salinity
Currents: Horizontal Variation
www.aw-bc.com/Withgott
Upwelling
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diverging of currents
cold displaces warm waters
rich in nutrients from bottom
high primary productivity
Seafloor Topography
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complex
www.aw-bc.com/Withgott
Marine Ecosystem
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Open Ocean
pelagic primary producers→phytoplankton
primary consumers→ zooplankton
secondary consumers→ free swimming
animals (fishes, whales, jellyfish)
tertiary consumers (predators)→birds, fishes,
turtles, sharks
www.aw-bc.com/Withgott
Kelp Forest
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brown algae
temperate coasts
shelter and food
protect shores from erosion by waves
industry uses alginates as thickener
www.aw-bc.com/Withgott
westworld.com
Coral Reefs
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member of the hydra, jellyfish and
anemonies phylum
CaCO3 exoskeletons
colonies
symbiotic algae
barrier reefs and atolls
protect shorelines
biodiversity
www.aw-bc.com/Withgott
Coral Bleaching
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zooxanthellae leave the coral
deprives nutrition to coral
lose color and die
increase in temperature?
influx of pollutants?
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sandstorms from Africa
runoffs
invasive algae
www.aw-bc.com/Withgott
Other Factors Affecting Corals
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cyanide used for fishing
capture for food use
capture for pet trade
acidification of the sea resulting of climate
change → production of H2CO3 from reaction
between air CO2 and sea water
trawling
Intertidal Zone
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ocean meets land
affected by tides
exposed to the air and submerged in water causes:
changes in temperature
changes in salinity
exposure to waves
exposed to sun
marine and land predators
www.wallawalla.edu
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Salt Marshes
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gently sloping sand or silt
creating the marshes flats
herbaceous plants
high primary productivity
habitat for shorebirds, waterfowl, commercial
fishes and shellfish
filter pollution
destruction due to coastal development
www.aw-bc.com/Withgott
Estuaries
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deltas of rivers
fluctuation of salinity
shorebirds, commercial fishes
transition for anadromous fishes (salmon)
urban and coastal development
pickledbeets.net
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water pollution
habitat alteration
overfishing
Human Use and Impact
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transportation
mining
pollution
Transportation
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ballast water
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invasive species
www.join.co.kr
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oil transportation
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oil spills when
discharging
www.piersystem.com
Corpus Christy, 6/2006
Mining
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crude oil
natural gas
methane hydrate
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crystals of methane
Arctic seafloor
should it be used as energy?
minerals from the seafloor
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uneconomical so far
Pollution
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sink for waste and pollution
oil
plastic
industrial waste
sewage
excess nutrients (fertilizers)
Pteropods' demise
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tiny mollusk, salmon feeds on
it in the ocean.
been affected by ocean pH
cannot build its shell
www.ipyeaso.aari.ru
www.geog.ucsb.edu
Nets and Plastic
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not biodegradable
drifts for decades
wash up in beaches
animals get tangled
animals mistake them for
food
Marine Debris research, Prevention, and
Reduction Act, 2006
Oil
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spills
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www.greenexpander.com
more stringent standards for tankers
tugboats escorts
have decreased due to prevention
accumulation of smaller sources
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leakage of smaller boats
runoffs
seeps from natural seafloor deposits
Toxic Pollutants
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mercury
bioaccumulates in tissue
biomagnifies up in the food chain
found in seafood
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www.cityofportsmouth.com
not recommended for pregnant women
swordfish, albacore tuna, shark
Toxic Pollutants
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algal blooms are due to excess fertilizer use
red tides
illness and death to
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plankton
birds
fishes
marine mammals
people
www.whoi.edu
Emptying the Oceans
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half marine population is fully exploited
25% of the marine population are
overexploited→ driven to extinction
prediction of collapsation by 2048
overfishing
www.aw-bc.com/Withgott
Industrialization
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factory fishing
huge nets
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drifnetting→ pelagic schools of fishes
long lining→ baited hooks to capture predators
bottom-trawling→ bottom dwelling fishes
Effect on Nontarget Animals and
Ecosystems
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known as by-catch
drifnetting
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longlining
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dolphins and turtles
turtles, sharks and albatrosses
bottom-trawling
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destruction of ecosystems like coral reefs
Depletion of Marine Life
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fishing seems to be stable but:
fleets now travel longer distances
fishing is now done in deeper waters
fleets spend more time at sea
boats are setting out more nets
sonar mapping equipment to detect schools
aerial spotters (planes) to detect schools of
fishes
Fishing Down the Food Chain
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size and age of caught fish is declining
smaller and less desirable species are
targeted now because of the lack of the
commonly fished in the past
to prevent this, consumers can chose which
product to buy according to fishing practices
Loss of Marine Biodiversity
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due to
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overfishing
pollution
habitat change
related to reduction in detoxification of water leading
to
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algal blooms
dead zones
fish kills
beach closures
Marine Conservation
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fisheries management
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surveys
study population biology
monitor catches
determines when and how much to catch
Marine Conservation
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protected areas
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doesn't necessarily protect, fishing is allowed
need to be changed to reserves or national park
status
fish population will increase if it is protected in
some areas
great opposition from industrial and recreational
fishing
Benefits of Marine Reserves
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studies done in 2001
rapid and long term increases in abundance,
biodiversity and productivity
decrease mortality
decrease in chances of species disappearance
individuals from protected areas spilled t
unprotected ones
"seeding the seas"
ecotourism increased
THE END