chapter 16 Flashcards
Cod fishery issue
people eat too many cod, they can’t recover
Ocean-how much earth it covers and its content, how many people live near it
71% of earth’s surface, 97% earth’s surface water
Ocean water is 96.5% water
Vertical Structure, Temperatures, thermocline
Temperature declines with depth
Heavier (colder saltier) water sinks
light (warmer and less salty) water remains near surface
temperatures are more stable than land temperatures
water’s high heat capacity
Oceans regulate earth’s climate
absorb and release heat
ocean’s surface circulation
Surface zone
warmed by sunlight and stirred by wind
consistent water density
Pycnocline
below surface zone
density increases rapidly with depth
Deep Zone
below pycnocline
dense, sluggish water
unaffected by winds, storms, sunlight and temperature
Currents
ocean is composed of vast riverlake flows
driven by density differences, heating and cooling, gravity, and wind
transport heat, nutrients, pollution,a nd larvae of many marine species
Upwelling
vertical flow of cold, deep water towards the sruface
high primary productivity and lucrative fisheries
Downwellings
oxygen-rich water sinks where surface currents come together
Bathymetry
measurement of ocean depths
Topography
physical geography or shape and arrangement of landforms
Continental shelves
gently sloping areas that underlie the shallow waters bordering continents
Shelf-slope break
sudden drop off of the continental shelf
Continental slope
connects the continental shelf to the ocean floor
Photic
well lighted top layer that supports high primary productivity
Pelagic
habitats and ecosystems occurring between ocean’s surface and floor
Benthic
habitats and ecosystems occurring on the ocean floor
kelp
large, dense, brown algae growing from the floor of continental shelves
coral
tiny colonial marine organisms
related to sea anemones and jellyfish
coral reefs
a mass of calcium carbonate composed of skeletons of corals
Coral bleaching
occurs when zooxanthellae leave the coral
coral lose their color and die, leaving white patches
from climate change, pollution , or unknown natural causes
nutrient pollution causes algal growth, which covers coral
Intertidal ecosystems
where ocean meets the land
between the uppermost reach of the high tide and lowest limit of the low tide
Tides
periodic rising and falling of ocean’s height due to gravitational pull of sun and moon
salt marshes
occur along coasts at temperate latitude
tides wash over gently sloping, sandy, silty substrates
high primary productivity
critical habitat for birds and commercial fish
filter pollution
mangrove forests
trees with unique roots
curve upwards for oxygen
curved downwards for support
have been destroyed
estuaries
water bodies where rivers flow into ocean
critical habitat for shorebirds and shellfish
transitional zone for anadromous fishes
Methane hydrate
a potential energy source
Minerals
Human pollution of oceans
Us oil pollution Act
creates a one billion prevention and cleanup fund
requires all ships have double hulls
BP Oill Spill
Deep Horizon Oil Spill
Factory fishing
highly industrialized, huge vessels use powerful technologies to capture fish in huge volumes
driftnets
for herring, sardines, mackerel, sharks
Longline
tuna and swordfish
Trawling
pelagic fish and groundfish
By-catch
accidental capture of animal
Marine Protected areas (MPA)
established along the coastlines of developed countries
Marine reserves
areas where fishing is prohibited
leave ecosystems intact, without human interference
improve fisheries, because young fish will disperse into surrounding areas
