Transcript Unit 3 “Human Footprint”

Unit 3
“Oceans, Coasts, and Fisheries”
Oceans on the Earth
• 71% of Earth’s surface is covered by oceans
• Composition of ocean water is as follows:
– 96% water
– 3.5% salt (mostly NaCl – sodium chloride)
– .5% consists of trace amounts of Sulfate, Mg, Ca,
K, and Bicarbonate
Oceans on the Earth
• As depth increases, pressure _________.
Why?
• As depth increases, temperature __________.
Why?
• As depth increases, salinity _________. Why?
• As depth increases, light penetration
decreases
Movement of Ocean Water
• Currents – large volume of ocean water that
flows due to changes in density, temperature,
gravity, and wind
– Horizontal currents: usually due to wind
– Vertical currents: due to density, temperature, and
gravity
Movement of Ocean Water
• Upwelling - vertical flow of cold, dense water to the
surface; occurs in areas where horizontal currents
diverge
• Downwelling – vertical flow of warm, less dense
water toward the ocean bottom; occurs in areas
where horizontal currents converge
Movement of Ocean Water
• It is important to understand the
interconnectedness of air currents (wind) and
ocean currents
– Air currents affect horizontal ocean currents and
horizontal ocean currents affect vertical ocean
currents
– Therefore, a change in meteorological conditions
can affect/change ocean conditions
Ocean’s Vertical Zones
Ocean’s Zones Continued
Ocean Currents Summary
• http://www.youtube.com/watch?v=Hu_Ga0JY
FNg&feature=related
• http://www.youtube.com/watch?v=L9zjmC8In
KA&feature=related
• http://www.youtube.com/watch?v=FuOX23yX
hZ8&feature=channel
Marine Habitats
• The ocean contains a great variety of species
that include invertebrates and vertebrates
• There are two categories of marine habitats:
– Benthic: the ocean bottom in either shallow or
deep water
– Pelagic: the open ocean
Marine Habitats
• The majority of marine ecosystems are
Benthic, but there are also a few found in the
Pelagic habitat
– Coral Reef
– Tide Pool
– Salt Marsh
– Mangrove Forest
– Deep Ocean
– Kelp Forest
Human Impact on the Ocean
• The ocean is used in much the same way as is
the lithosphere
• Transportation, Resource Extraction (both
biotic and abiotic), Tourism etc. are all ways in
which people use oceans
• As a result of the above-mentioned ocean
usage, pollution and overexploitation occurs
Pollution and Overexploitation
• Pollution – any unwanted substance that is
released into the ocean as a result of resource
extraction, transportation, or tourism
• Overexploitation – is the taking of too many
individuals of a marine species thereby making it
impossible for those remaining to replenish the
numbers lost through fishing
• Bycatch – non target marine species are killed as
a result of becoming entangled in nets meant to
catch another marine species
Examples of Pollution &
Overexploitation
• http://www.upi.com/Top_News/International
/2010/02/14/Canada-to-close-ports-due-toover-fishing/UPI-74111266192280/
• http://marineconservation.suite101.com/article.cfm/what_i
s_bycatch
• http://www.buzzle.com/articles/oceanpollution-causes.html
MPA’s & MR’s
• Marine Protected Area (MPA): Geographic area with
discrete boundaries that has been designated to
enhance the conservation of marine resources. This
includes MPA-wide restrictions on some activities such
as oil and gas mining and the use of zones such as
fishery and ecological reserves to provide higher levels
of protection.
• Marine Reserve: A zone in which some or all of the
biological resources are protected from removal or
disturbance; encompasses both fishery and ecological
reserves.