58 terms

Geosci 040 quiz 2

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Phytoplankton are photosynthetic algae that live in the ocean's photic zone and are an important source of energy
True
Marine phytoplankton are photosynthetic organisms. In the photic zone of the ocean their growth rate can be limited by
Availability of nutrients and light
world fish production has increased steadily for the past 50 years and advances in the large-scale fishing techniques will likely allow fish production to increase for another 50 years
false
phytoplankton, apples, whales
examples of organic matter
the trophic pyramid tells us that to grow 1 kg of a top level predator-consumer such as tuna:
it takes 10,000 kg of phytoplankton
phytoplankton are small animals that live in the aphotic zone and are an important source of inorganic energy for nearly all ocean life
false
Ocean deep water is rich in nutrients that are essential to phytoplankton growth
true
Red Tides
Indicate blooms of potentially toxic dinoflagellates
Baleen Whales migrate large distances to feast in the Bering and Chukchi Seas when conditions are optimum for growth of phytoplankton and krill
true
phytoplankton production is often very high in the open ocean because of rapid upward mixing of deeper waters in the photic zone
false
There are very few commercial fisheries that are in danger of collapse from over fishing
false
Phytoplankton that form the basis of the food chain in the ocean
need sunlight and nutrients to flourish
fish maneuverability and swimming speed depends primarily on size and to a lesser extent body shape and turbulent drag
false
fish
- are vertebrates and typically have a streamlined body shape for easy/fast swimming
- are typically cold-blooded vertebrates with scales, gills and fins
- in some cases do not have scales or fins
Anadromous fish
migrate from saltwater to freshwater to spawn (salmon)
Catadromous fish
migrate from freshwater to saltwater to spawn (eels)
Lateral Line Organ
(head to tail) detect the vibrations in the water; equivalent to human ears
red tides occur when there are massive quantities of ______ in the ocean
dinoflagellates
aquaculture is one potential solution to over fishing, but there are problems that need to be addressed, such as overcrowding and disease
true
the cod fishing industry is doing very well, because cod id plentiful and has never been over fished
False
The following are true about phytoplankton
- productivity in polar areas varies significantly during the year
- productivity in Tropical areas does not vary significantly during the year
- productivity in the north polar regions is highest in the summer and lower in the winter
Fish that have long life spans are not a sustainable fishery resource because of
their slow reproductive rates
for bottom waters of Chesapeake Bay, dissolved oxygen is
lowest in summer, because thermal stratification is greatest in summer
Hypoxia is caused by
- eutrophication
- stable stratification of the water column
- lack of oxygen in bottom waters
- over sedimentation, which kills plants
Eutrophication
an environmental nutrient excess -- leads to excess algal production of organic matter
corals
consume phytoplankton and other simple photosynthetic organisms
In the world ocean, large fish are present in the same numbers today as they were 50 years ago
false
In Chesapeake Bay, ____ prohibits oxygenation of bottom waters
stable stratification of the water column
the following help reduce agricultural runoff of nutrients to streams and rivers
- developing wetland or riparian buffers along streams
- increase forested area at the expense of croplands
- adoption of best practice methods of tilling and fertilizer application
modern coral reefs appear to be limited to regions where the
mean annual temperature is less than 20 degrees Celsius
___ are factors in the development of deep water swells
- Fetch
- Duration of wind
- Wind speed
Fetch
The distance over which wind blows uninterrupted in one direction
the motion of water particles beneath the ocean waves in deep water vanishes at distances below the surface exceeding
1/2 the wave length (L)
Shallow water waves interact with the bottom and therefore particle motions near the base of these waves are elliptical rather than circular
true
the speed of celerity of deep water waves
increases with increasing wave period
ocean waves in deep water have a celerity that
increases with increasing period (T) and wave length (L)
Deep water swells tend to sort themselves out during travel the first waves to arrive will have
the longest wavelength
Wave trains travel
travel at half the speed of individual waves in the group
Key terms for ocean waves
- wave length (L), period (T), and frequency (f)
- water particle motion and wave motion
- speed or celerity
- wave height (H)
If you were floating on a life raft at sea, the passage of deep water waves would move you
up and down
Tsunami are
shallow water waves, caused by vertical motion of the seafloor
Spring tide moons
Full Moon, New Moon
Neap Tide Moons
first quarter moon, third quarter moon
Tides are a product of
gravitational and centrifugal "forces"
Tides do not vary from summer to winter in a given location because Earth is always the same direction from the sun and moon
false
The tidal range toward the center of an amphidromic system is ____ the range at the edges of the system
smaller than
semi-diurnal tides produce
a high tide about twice a day with a period of 12 hours 25 minutes
Amphidromic tidal circulation involves
- a counter-clockwise pattern of flow around the basins of the N. hemisphere
- tidal crests that move as waves
- tidal crests that rotate about the amphidromic point and make one complete cycle every 12 hours and 25 minutes
many coasts have semi-diurnal tides because
there are two high tide bulges on Earth, produced by gravity and centrifugal forces, and Earth spins under both of these bulges during a 24 hour and 50 minute period
Amphidromic points are
the focus for cotidal and corange lines
Tidal amplitude increases progressively away from amphidromic points
true
centrifugal forces
result from inertia and rotation
Earth has two tidal bulges because
Gravity together with centrifugal forces, caused by rotation of the Earth-moon-sun system, produce two bulges
a mesotidal coast with a diurnal tide would have
a low tide every 24 hours 50 minutes with 2 to 4 m amplitude
The moon generates a tidal bulge that is about twice that generated by the sun
true
equations
S = L/T
S = 1.56 T
L = 1.56 T^2
Do longer period waves also have a longer wave length than shorter period waves?
Yes
Which travels faster: shorter period waves or longer period waves?
Longer period waves