Exam 2 Flashcards
How have marine organisms adapted to cope with the constant water movement in the ocean?
• Float along with currents
• “Fight” currents by swimming against them
• “Fight” currents by attaching to/digging into sea floor
• no swimbladder, other air spaces
• limit diving depth
• collapsible rib cages
• tolerate effects of pressure
• water not compressible
• most deep sea organisms are mostly water
• have no air pockets (lungs, swim bladders, sinuses)
What is salinity?
amount of salt dissolved in a body of water
What are the two major salt ions in seawater?
Sodium (Na) & Chloride (C1) make up ~86% of salts
What is the typical salinity of seawater?
~35 g of salts/ ppt
What processes cause salinity to vary (increase or decrease)
Red: net evaporation leads to higher salinity
Blue: net precipitation leads to lower salinity
What is osmosis?
movement of a solvent (water) through a semipermeable membrane into a solution of higher solute (salt) concentration that tends to equalize the concentrations of solute (salt) on the two sides of the membrane
How do organisms cope with osmosis?
Drinks large volume of salt water > secretion of salts > loss of water by osmosis > small volume of concentrated urine
How does temperature affect marine organisms
Activity level, growth rate, reproduction, and metabolism fluctuate with temperature (slower when cold)
How have these organisms adapted to the temperature environment
• (Cold-Blooded) organisms don’t regulate body temperature
• Some generate their own heat or regulate body temperature
Latitude zones?
Polar: High Latitude, 66N
Temperate: Middle Latitude, 23.5 N
Tropic: Low Latitude, 0
Temperate: 23.5 S - 66 S
How sea surface temperature & salinity vary with latitude?
Solar radiation at the equator is double of what our polar regions receive.
Sea surfaces are warmer along the equator than the poles.
Currents near the equator move this heat to the poles; currents that flow from the poles are cold.
Profile graph for temp, salinity, & density. How variable changes with depth
Salinity profile: surface mixed layer at the top, halocline the dip in the graph (depth of rapid salinity change), rest of dip: deep ocean
Temperature profile: surface mixed layer at the top, thermocline the dip in the graph (depth of rapid temperature change), rest of dip: deep ocean
Density profile: surface mixed layer at the top, pycnocline the dip in the graph (depth of rapid density change), rest of dip: deep ocean
How do temperature & salinity affect density of seawater
• Temperature + Salinity = Density
• Higher temperature = lower density
• Higher salinity = higher density
• Warm, less saline water: less dense
• Cold, saline water: denser
Where is the coastal ocean located?
Waves, tides, ecosystems, humans interactions
Where is open ocean located?
Ocean interior, currents, primary production, food webs, ecosystems, climate
How has sea level changed over the last 140 thousand years?
Has varied over a range of more than 120 meters
How sea level changed shorelines?
Higher water levels erode beaches, dunes, cliffs, low lying areas, inundate wetlands, increased salinity of estuarine systems
Where does most of the worlds population live relative to the coast?
Asia & some of Europe
Where in the ocean are autotrophs most abundant?
shallow coastal ocean: artic ocean
where in the ocean are benthic organism most abundant?
shallow coastal ocean: around the continents
where in the ocean are marine pelagic organisms most abundant
near the surface or in the open water column away from the bottom of the ocean
What processes cause shoreline erosion
Waves, tides (low & high), and tsunamis
the different types of waves & forces that generate them
Wind generated waves: wind
Tides: moon & sun
Tsunami: earthquakes, volcanoes, landslides, & storms
How do wind generated waves form
wind waves form locally where wind blows across the sea surface
where do wind generated waves form
“sea” area where waves are actively being generated
what determines wind generated waves size
wind speed, wind duration, fetch (distance over which wind blows), fully developed seas
what is fetch
distance over which wind blows
what is a fully developed sea & when it occurs & what it depends on
when the waves are at their maximum size for the existing wind speed, duration, and fetch
difference between wind waves and swell
wind waves form locally where wind blows across the sea surface
swell are waves that have left the area where they were formed
why are waves large in the southern ocean
more high winds over the southern ocean driving bigger waves
how is sand moved perpendicular to the beach (on & off the beach)
Not always straight up and down the beach, often waves approach the beach at an angle
what is swash & backwash
uprush (onshore flow):
• higher velocity & shorter duration than backwash
backwash (offshore flow):
• offshore velocities increase towards end of backwash
how the beach change with seasons
summer (calm weather)
• sand stored on beach
swash stronger than backwash, sand moved onto beach
winter (rough weather)
• stand stored offshore
backwash stronger than swash, sand moved off beach
what is a longshore current
current that flows parallel to the shore within the zone of breaking waves
how a longshore current is formed
when a train of waves reach the coastline & release bursts of energy
how longshore current influences sediment movement (longshore drift)
net movement of sand grains (clay, silt, pebbles, sand, & shingle) along a coast parallel to the shoreline
methods used to prevent shoreline erosion along NJ coast
beach replenishment/nourishment, jetties & groins, seawall/bulkhead
how longshore current & sediment transport cause sand accumulation & erosion around jetties & groins
groins & jetties interfere with longshore drift
which side does deposition occur & which side does erosion occur
deposition: land / upstream end
erosion: downstream end
what causes waves
• boats
• whales
• people
• wind
• moon + sun
• interactions between currents
• tectonic activity/landslides
