Oceanography Flashcards
A species’ success dpeends on the ability to
Find food
avoid predation
Reproduce
cope with physical barriers to movement
Marine Organisms can be classified according to where they live and how they move
Plankton, Nekton, Benthos
Plankton (floaters)
- Algae,animals and bacteria
- majority of oceans biomass
Nekton (swimmers)
capable of propulsion independently of ocean currents
Benthos (bottom dwellers)
Live on the surface of sea floor
attached to rock or moving along the bottom
Two types of plankton
Phytoplankton
zooplankton
Phytoplankton
autotrophic
produce their own food (photosynthesis)
Zooplankton
Heterotrophic
food produced by other organisms
Macroscopic floating Zooplankton
Krill +Cnidarians
Krill
resemble mini shrimp or large copepods
abundant near Antarctica
Critical in Antarctic food chains
Cnidarians
Hydrozoan (gas-filled float)
scyphozoan (jellyfish- soft, low-density bodies)
Krill
resemble mini shrimp or large copepods
abundant near Antarctica
Critical in Antarctic food chains
What kind of swimmers are Nekton
Independent swimmers
- temp, salinity, viscosity and nutrients limit their lateral range
-water pressure limits the vertical range
What do Nekton comprise of
Most adult fish and squid, marine mammals, marine reptiles
Types of fins
pelvic and pectoral fins, dorsal fins, caudal fins
Pelvic and pectoral fins
turn,brake and balance
Dorsal fins
Stabilizers
Caudal fin
propulsion
FIn Designs
Rounded fin, trucated and forked fins, lunate fins, heterocercal fin
Rounded fin
accelerating and maneuvering at slow speeds
Truncated and forked fins
fins flexible for faster propulsion and maneuvering
Lunate fin
Asymmetrical, produces significant lift (sharks)
Heterocercal Fin
fast cruising fish (tuna). very rigid, useless for maneuverability
cruisers
swim constantly in search of prey and capture it with short period of high speed swimming
Lungers
Fish that wait patiently and exert themselves only in short bursts (grouper)
3 types of Benthos
Epifauna, Infauna, nektobenthos
Epifauna
live on the surface of the sea floor.
attached to rocks or moving
Infauna
lived buried in sediments
Nektobenthos
Swim or crawl through water above the seafloor (octopus, crabs)
Stenothermal
Organsims withstand small variation in temp
typically live in open ocean
Eurythermal
organisms withstand large variation in temp
typically live in coastal
Stenohaline
Organisms withstand small variation in salinity
typically live in open ocean
Euryhaline
Organisms withstand large variations in salinity
typically live in coastal waters
what animal has a collapsible rib cage
Sperm whale
countershading (avoiding predation)
dark on top, light on bottom
Disruptive coloration (avoiding predation)
Large bold patterns, contrasting colors make animal blend into background
Schooling (avoiding predation)
safety in numbers, school may appear as single larger unit, Schooling maneuvers confuse predator
what adaptations to fish have to find food
good sensory devices (antennae + sensitive lateral lines)
bioluminescence
pelagic environment divided into two biozones
neritic province and oceanic province
the ocean can be divided into two main environments
Pelagic (open sea)
Benthic (sea floor)
Bioluminesce advantages
searching for food in the dark
attracting prey
communication
staking out territory
neritic Province
from shore seawrd, all water < 200 m
Oceanic Province
Depth decreases beyond 200 m
Oceanic province further divided into four biozones
epipelagic, mesopelagic, bathypelagic, abyssopelagic
epipelagic
only zone to support photosynthesis
dissolved oxygen decreases around 200 m
mesopelagic
orgasnims capable of bioluminescence common
bathypelagic
deepest parts of the ocean > 4000m
represents 75% of living space
completely blind bizzare fish
euphotic
surface to where enough light exists to support photosynthesis
disphotic
sample but measurable quantities of light
aphotic
no light
Benthic environments
supralittoral, subneritic, suboceanic
major marine mammal groups
order carnivora, order sirenia, order cetacea
Order carnivora
prominent canine teeth, sea otters polar bears
pinnipeds -walrus , seals, sea lions
order sirenia
herbivores, manatees (coastal areas of tropical atlantic ocean)
dugongs (coastal areas of indian and western pacific oceans
Order Cetacea
elongated skull, blowholes, few hairs, fluke (horizontal tail fin for vertical propulsion)
whales, dolphins, porpoises
safe levels of mercury determined by
rate of fish consumption by people, mercury concentration in fish consumed, minimum ingestion rate of mercury to cause damages
bioaccumulation
orgasnims concentrate pollutant from seawater
biomagnification
organisms gain more pollutant by eating other contaminated organisms
MARPOL
proposed treaty banning disposal of plastics, regulating another trash dumping at sea, 122 nations ratified by 2005
pollution enters ocean from multiple sources
trash, pesticides and feritlizers, road oil, plastics
how long is great barrier reef
2000km long
about coral reefs
provide shelter, food, breeding grounds, home to 25% of all marine species
what is coral reef composed of
calcium carbonate which is secreted by tiny animals called polyps
most coral contain a symbiotic algae called zooxanthellae
what do coral reefs need in order to live
warm (but not hot) seawater, sunlight (for symbiotic algae), strong waves or currents, clear seawater, normal salinity, hard substrate for attachment
although there are many other types of reef, the distinction is made between
fringing reefs, barrier reefs, atolls
fringing reefs
extend out from coast
barrier reefs
separated from the coast by a deep lagoong
atolls
fairly continuous reef islands surrounding a central lagoon
threats to coral reefs
humans (greatest threat), hurricanes, global warming, floods, tsunami
cyanide fishing
kills the coral and the algae on which fish feed, big increase of co2 and ocean absorbs 25% of that
coral bleaching
describes the loss of colors in corals that causes them to turn white. associated with elevated water temp that cuased zooxanthellae algae to be expelled
indirect evidence using natural recorders of climate variability
tree rings, seafloor sediments, glacial ice rings, coral deposits, pollen, historical documents
tree rings
growth of trees depends on rainfall and temp
rings are wider when conditions favour growth, narrower when condition inhibit growth
dendroclimatology
Climate data provided by tree rings
seafloor sediments
recovered by coring lakes and ocean basins
samples are analyzed to provide data on climate change
glacial ice rings
obtained by drilling into the ice
contain small bubbles of air deposited at the time of snow (very reliable)
Corals
their skeletons have alternating light and dark layers that result from seasonal changes in growth rates
similar to tree rings
pollen
accumulated with sediment in a variety of environments
the types of pollen found reflect climate
historical documents
measurements of temp and precipitation date to the late 17th century
solar energy changes
variable energy from the sun over time, luminosty, sun spots, faculae
Milankovitch Theories
Eccentricity of earths orbit
obliquity angle off earths axis
precession wobble of axis
volcanic forcing
ash from eruption becomes suspended in atmosphere, reflect sunlight having a cooling effect
ex: Mount Tambora 1815 cooling in North America and Europe
IPCC Intergovernmental Panel on Climate Change
a global group of scientists
peer-reviewed literature
published assessments since 1990
Ocean conveyor belt
Circulation of ocean water
can cause fast changes in climate
cold dense water sink - which also brings down 02
Our possible future:
anaerobic bacteria takes over
releases hydrogen sulphide- purple oceans and green sky
poisons all land animals
bacteria are the last living things on earth
Changes in climate patterns:
Increases storms
main contributors to rising sea levels
melting of antarctic and greenland ice sheets
thermal expansion of ocean surface water
melting of land glaciers and ice caps
thermal expansion of deep ocean waters
Montreal Protocol
1987 agreement to limit depletion of the ozone layer by CFCs
CFCs have declined since protocol implemented
Kyoto Protocol
1997 agreement from United Nations Framework convention on climate change
reduce greenhouse gas emissions by 2012
Summit in the Hague
2000 conference that focused on alternative methods to reduce emission
conferenc ended without an agreement
Paris Climate Agreement
2017
the agreement sets out a global action plan to pit the world on a track to avoid dangerous climate change by limiting global warming to well below 2 degrees
Carbon sequestration
process that refers to the capture and storing of carbon dioxide before it enters the atmosphere
Biological sequestration
planting more trees
Ocean Sequestration
injection carbon dioxide deep in the oceans
Geologic sequestration
Power plants and industrial facilities designed to capture co2
iron hypothesis
fertilize the ocean to increase productivity
increase phytoplankton, increase carbon dioxide removal from the atmosphere
earths temp depends on three things
amount of sunlight received
amount of sunlight reflected
degree to which atmosphere retains heat
weather
conditions of atmosphere at a particular time and place
Climate
long term average of weather
earths climate includes interactions of
atmosphere, hydrosphere, geosphere, biosphere, cryosphere
