OCNG 251: FINAL EXAM
71 Cards in this Set
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species success depends upon
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-finding food
-avoiding predation
-reproduction
-accommodate physical barriers to movement
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plankton
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floater, cannot swim faster than the current
high surface area to volume ratio
need to be small to float and stay alive
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nekton
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swimmers, above the bottom, faster than the current
most adult fish
marine mammals
marine reptiles
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benthos
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bottom dwellers
can live in buried sediments on seafloor
most abundant in shallow water
many live in perpetual darkness, stillness and coldness
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phytoplankton
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autotrophic
primary producers (photosynthesis)
ex: coccolithophores, diatoms, dinoflagellates (have tails)
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zooplankton
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heterotrophic (consume phytoplankton or other zooplankton)
water is viscous because operating on molecular level
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life cycle of a squid
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benthic egg sacs
zoolpankton larvae
nektonic adults --> mating
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number of marine species
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more land species
ocean has relatively uniform conditions
less adaptation required, less speciation
overwhelmingly benthic (98%), rather than pelagic
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physical support adaptations
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buoyancy to resist sinking (oil)
different support in different temperatures (warm = more appendages) warm water is less dense
high surface area to volume ratio (more appendages)
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viscosity and streamlining
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streamlining is important for larger organisms
less resistance to fluid flow
flattened body
tapering back end
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temperature and marine life
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narrow range of temp in ocean
deep ocean is nearly isothermal
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reasons for ocean stability
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higher heat capacity of water
ocean warming reduced by evaporation
solar radiation penetrates into ocean layers
ocean mixing
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cold v warm water species
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smaller in warm water
more appendages in warmer seawater
tropical organisms grow faster, die sooner, reproduce more
more species in warmer water
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Salinity Adaptations
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extracting minerals from seawater
high concentration to low concentration
cell membrane permeable to nutrients
waste passes from cell to ocean
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osmosis
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water molecules move from high concentrated to less concentrated solutions
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osmotic pressure
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in more concentrated solutions, prevents passage of water molecules
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marine fish
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drink large quantities of water
secrete salt through special cells
small volume of high concentrated urine
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freshwater fish
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do not drink water
cells absorb salt
large volume of diluted urine
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dissolved gases
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animal extract dissolved oxygen from seawater through gills
gills exchange oxygen and carbon dioxide directly with seawater
low marine oxygen can kill fish
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water's transparency
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many marine organisms see well
some are transparent to help elude predators and stalk prey
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countershading
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dark on top light on bottom
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water pressure
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many organisms have no inner air pockets
collapsible rib cages
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primary productivity
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rate at which energy is stored in organic matter
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primary producers
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photosynthesis users solar radiation
chemosynthesis uses chemical radiation
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factors affecting primary productivity
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nutrient availability
solar productivity
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light transmission
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visible light of electromagnetic spectrum
blue wavelengths penetrate deepest
longer wavelengths (red, orange) absorbed first
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nutrient supply
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cooler and deeper seawater is more rich
coastal upwelling = high productivity
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polar ocean productivity
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winter darkness, summer sunlight
phytoplankton blooms
zooplankton productivity follows
productivity decreases from UV light
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tropical ocean productivity
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permanent thermocline is barrier to vertical mixing
low rate of primary productivity due to lack of nutrients
symbiotic algae
recycle nutrients within an ecosystem
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temperate ocean productivity
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productivity limited by sunlight and nutrients
highly seasonal pattern
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temperate ocean productivity winter
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low productivity
many nutrients
little sunlight
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temperate ocean productivity spring
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high productivity
spring bloom
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temperate ocean productivity summer
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low productivity
few nutrients
abundant sunlight
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temperate ocean productivity fall
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high productivity
fall bloom
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producers
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nourish themselves
photosynthesis of chemosynthesis
autotrophic
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consumers
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eat other organisms
heterotrophic
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decomposers
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break down dead organisms or waste
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trophic levels
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chemical energy transferred from producers to consumers
about 10% energy transferred to next trophic level
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food chains
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primary producer -> herbivore -> one or more carnivores
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food web
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branching network of many consumers
consumers more likely to survive with alternative food sources
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biomass pyramid
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number of individuals and total biomass decreases at successive trophic levels
organisms increase in size
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marine fisheries
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commercial fishing
most come from continental shelves
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marine fisheries
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over 20% from areas of upwelling that make up 0.1% of ocean surface area
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bycatch
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non-commercial species are taken incidentally by commercial fisheries
can make up to 8 times more than intended catch
birds, dolphins, turtles, sharks
purse seine nets
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standing stock
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mass present in ecosystem at any given time
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overfishing
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fish stock harvested too rapidly, juveniles not sexually mature to reproduce
reduction in max sustainable yield
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overfishing
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80% of available fish stock fully exploited, overexploited, or depleted/recovering
large predatory fish reduced
increased fish production, decreased stocks
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ozone depletion
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scientific understanding
montreal protocol
global participation, technological solutions, willingness of developed countries to help underdeveloped countries
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global warming
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scientific understanding
Kyoto protocol
lack of global participation
lack of willingness to help
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fisheries management
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regulate fishing, enforcement of regulation is difficult, governments subsidize fishing
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reef
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shallow water communities restricted to tropics
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polyps
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individual corals
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zooxanthallae
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gives color, photosynthetic, grow best in limited nutrient environment
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zooxanthallae
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shrimp farming harms these because nutrients are injected into the environment attracting phytoplankton
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conditions for coral reef development
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warm but not hot seawater
sunlight from symbiotic algae
strong waves/currents
clear seawater
normal salinity
hard substrate
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coral reef zonation (bottom up)
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ancient coral reefs -> insufficient sunlight for growth
active coral reef -> builds up over time as volcano sinks (50m)
20 m 20% of surface light remains
reef flat/crests at surface
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importance of coral reefs
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largest structure created by living organisms
great diversity of species
important tourist locales
fisheries
reefs protect shorelines
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humans and coral reefs
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fishing, tourist collecting and sediment influx due to shore development harm coral reefs
sewage discharge and agricultural fertilizers increase nutrients in reef waters
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coral reef declines
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30% healthy today
1/3 of corals in high risk extinction
humans are greatest threat
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coral bleaching
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loss of zooxanthallae triggered by stress
often followed by morality
affects symbiotic organisms
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deep ocean floor communities
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expensive to explore the deep
limited oxygen
robotic technology for exploration
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deep ocean physical environment
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no primary productivity
only 1-3% of euphotic food present
special adaptations for detecting food
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deep sea hydrothermal vent communities
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discovered by Alvin in 1977
galapagos rift in Pacific Ocean
water temp 8-12 C
chimney vents (black smokers)
chemosynthesis
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hydrothermal vent species
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giant tubeworms, giant clams, giant mussels, crabs,
supported by chemosynthesis
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hydrothermal vent communities
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vents are active for decades or years
animal species similar at widely separated vents
larvae drift from site to site
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what does not limit coral growth
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high concentrations of calcium carbonate
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if an ecosystem has four trophic levels and primary production of 100,000 how much energy will top producer get
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100
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in temperate oceans during summer:
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nutrient concentrations are low, solar input is high and oxygen solubility decreases
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jellyish (B, P or N)
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plankton
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barnacle (B, P or N)
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benthic
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whale (B, P or N)
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nekton
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Study Guide: Exam 4