GeoSci 040 Quiz 2
Terms in this set (85)
migrate from freshwater to saltwater to spawn, ex. Eels
migrate from saltwater to freshwater to spawn ex. salmon
Lateral line organ
are used by fish to detect predators and other fish
represents a sustainable and growing part of world fish production, assigning fishing rates can help control overfishing
pros and cons with aquaculture
pros: can make lots of fish and avoid fishing for wild fish
cons: overcrowding and disease
how do coral live?
mean annual temperature is >20C so warm places, low nutrient places, clear, warm, shallow waters and sunlight
do the shells of coral eat?
no, the shells don't eat but the polyps do eat
what are coral polyps and what do they eat?
they are the coral animal that lives within the coral skeleton, they eat photosynthetic and other simple organisms
what are the key factors in the energy flow of coral reefs?
Tertiary consumers: eels
Secondary consumers: sea urchins
Primary consumers: corals
Primary producers : photoplankton
The trophic pyramid for coral reef ecosystems
Diverse, mostly small organisms
Phytoplankton play a minor role!
Where do coral polyps fit into the trophic pyramid for coral reef ecosystems?
Make sure that you've looked at the lecture notes link on the course web site. Looking means clicking on a few links and skimming/browsing the info. there. Make sure that you've read the required reading from the course web site
Why are coral and coral reefs in decline worldwide?
Viral and bacterial infections, nutrient surplus leading to algal growth, overfishing, and carbon dioxide in the atmosphere
Why does global warming have a negative impact on coral?
Ocean warming is the major cause of dying coral reefs, too much carbon dioxide in the water, makes water more acidic so corals can't calcify their skeletons
Why do coral need to live in the photic zone? How can excess nutrients in water harm coral?
Corals need to live in the photic zone because they are tied to photosynthetic organisms and those organisms need sunlight to live
Excess nutrients in the water can easily lead the corals to be outcompeted by algaes and other things that will grow and smother them
Make sure that you understand the concepts we covered about Chesapeake Bay in lectures 18 and 19.
What is hypoxia
development of low concentrations of dissolved oxygen. Primarily occurs near bottom and is deleterious to organisms (different organisms have different tolerances)
What is eutrophication
an environmental nutrient excess. Occurs when algal production of organic matter exceeds that which can be respired without reducing available dissolved oxygen below dangerous levels
EASIER DEF: nutrient excess that leads to excess algal production of organic matter, fertilizer makes things grow like crazy in the pond but kills all the fish but makes algae grow, oxygen levels in pond don't allow fish to live
What is the cycle of eutrophication?
o Excess nutrients supplied in rivers to the Bay support luxurious blooms of phytoplankton (microscopic plants)
o sinking organic matter (that is, the phytoplankton, but sewage and sludge have the same net effect) is oxidized by bacteria, thereby consuming oxygen
o oxygen deficits occur in bottom waters--these are harmful to benthic organisms, many of which have economic value
o the nutrients released during respiration in deeper waters are cycled back to the surface and produce more blooms and further organic matter loading
o a lack of mixing (stratification) resulting from seasonally strong salinity and temperature gradients (surface to bottom) prohibits oxygenation of bottom waters.
What nutrients cause eutrophication?
Nitrogen and phosphorus
Why does "runoff" contribute to eutrophication and related environmental problems?
When we use fertilizer or other nutrient or chemical or pollutant things on the environment when it rains these things can runoff into streams and eventually end up in streams and waterways causing excess nutrients which can lead to eutrophication
What role do wetlands play in alleviating the problems that lead to hypoxia?
Increasing forested regions or wetlands can act as buffers along streams to reduce the nutrient runoff
Why are oxygen concentrations in Chesapeake Bay lower in the summer?
Because thermal stratification is greatest in summer
Why are they lower in the bottom waters than in shallow water
in part because of thermal stratification of the bay water, the water column is stably stratified and oxygen just cant get to the bottom
What is the role of bacteria in eutrophication?
sinking organic matter (that is, the phytoplankton, but sewage and sludge have the same net effect) is oxidized by bacteria, thereby consuming oxygen, bacteria consume oxygen lowering the levels even further
How are deep water waves different than shallow water waves?
Deep water waves: symmetrical, depth is greater than wavelength
Shallow water waves: steep on one side relative to the other, depth is less than wavelength
How does wave speed depend on period and wavelength?
Wave speed increases as wavelength increases and as wave period increases
Which travels faster: shorter period waves or longer period waves?
Longer period waves? The longest wavelength will arrive first
Do longer period waves also have longer wavelength than shorter period waves
What is the depth of wave disturbance for deep water waves?
½ the wave length L
If you were scuba diving and a wave of wavelength 100 meters passed by, how deep would you need to be to not feel it?
You would need to be deeper than 50 meters
Why do waves "break" in shallow water
the bottom of the wave hits the ocean floor and the bottom part of wave moves slower than top causing wave to break
Why are Tsunami considered shallow water waves?
Tsunami caused by vertical motion of the seafloor
Make sure that you can work with these equations. For example, you should be able to calculate wave speed or wavelength from period, and vice versa.
Deep water waves obey the following equations.
1) S = L / T, 2) S = 1.56 T, 3) L =1.56 T2, where S is velocity in m/s, T is period in sec, and L is wavelength in m. Also, Waveheight H generally obeys: H ≤ L / 7
Fish maneuverability and swimming speed depends primarily on size and to a lesser extent on body shape and turbulent drag.
Red tides occur when there are massive quantities of ______ in the ocean
are typically cold-blooded vertebrates with scales, gills and fins, in some cases do not have scales or fins, are vertebrates and typically have a streamlined body shape for easy/fast swimming
There are very few commercial fisheries that are in danger of collapse from over fishing
Aquaculture is one potential solution to over fishing, but there are problems that need to be addressed, such as overcrowding and disease.
phytoplankton need ___ and ____ to flourish
sunlight and nutrients
For bottom waters of Chesapeake Bay, dissolved oxygen is
lowest in the summer, because thermal stratification is greatest in summer
In Chesapeake Bay, which of the following prohibit(s) oxygenation of bottom waters?
stable stratification of the water column
what would 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
Hypoxia is caused by
eutrophication, stable stratification of the water column, lack of oxygen in bottom waters, over sedimentation, which kills plants
Fish with long life spans are not a sustainable fishery resource because of
their slow reproductive rates
If you were floating on a life raft at sea, the passage of deep water waves would move you
up and down
Ocean waves in deep water have a celerity that
increases with increasing L and T, where L is wave length and T is period
Shallow water waves interact with the bottom and therefore particle motions near the base of these waves are elliptical rather than circular
wave trains travel
at half the speed of individual waves in the group
Deep-water swells tend to sort themselves out during travel. The first waves to arrive will have:
the longest wavelength
Key terms for ocean waves include:
wavelength L, period T, and frequency f
water particle motion and wave motion
speed or celerity
all of the above
Which of the following is a factor in the development of deep-water swells?
fetch, wind speed, duration of wind
shallow water waves
Marine (saltwater) fishes
drink lots of seawater, excrete salt through gills, secrete small amount urine through kidneys, osmoregulation
don't drink. They absorb salt through gills, excrete large amounts of urine
what happens when corals die?
they turn white
Coral spawn at night by
releasing eggs and sperm into the water column to what advantage
To synchronize spawning over a reef to guarantee survival of many eggs
To provide a larger gene pool for fertilizing to guarentee health for population
To avoid predation of eggs and larvae by fish feeding mainly in daylight
Anemone provides a tentacle guarded home for
clownfish and the clownfish drive off predators that would chew its protector
which of the following are true?
A. Last year at this time, an algae bloom off southwest Florida called Florida red tide killed over 174 manatees
B. A red tide is a higher than normal concentration of microscopic algae that appears in the Gulf of Mexico. At high enough concentrations, the algae can turn te water red or brown, hence the name
C. Red tides are generally not caused by pollution, they have been document in the 1700s and along Florida's gulf coast in the 1840s
D. All of the above ANSWER
Ingest coral skeletons and polyps in their quest for algae
Are responsible for considerable reef erosion
Produce much of the carbonate sand found in reef systems and tropical isalnds
Are found in small schools over the reef
Which of the following are true?
a. Fishes and other animals require dissolved pxygren to live in seawater
b. Many species of fishes require dissolved oxygen levels of 4 mg/l or higher
c. Hypoxia and low levels of dissolved oxygen in the bottom waters of Chesapeake bay are exacerbated by thermal stratification of the bay water
d. All of the above TRUE
What is true about eutrophication?
It starts with excess nutrients which causes blooms of algae
It involves bacteria that use (and eventually severely deplete) dissolved oxygen in the process of decomposing organic matter
It can be caused by sewage discharge into streams and lakes
The nutrients released during respiration in deeper waters are cycled back to the surface and produce more blooms and further organic matter loading
Which of the following are true?
a. Rainwater from state college ends up in the Chesapeake bay
b. Excess nutrients in the bay and other bodies of water can cause eutrophication which means that dissolved oxygen becomes very low
c. Hypoxia is primarily caused by strong winds which blow away
d. All of the above
e. A and B TRUE
Oxygen concentrations in the Chesapeake bay:
a. Are generally higher in the surface waters because oxygen mixes into the water frin the air
b. Are generally lower in the bottom waters
c. Generally increase in bottom waters during the summer
d. All of ther above
e. A and B TRUE
Why are oxygen concentrations during times of eutrophication generally lowest in the upper chespeake bay?
This is where nutrients enter from bay from rivers
Why are oxygen concentration during times of eutrophication generally lowest in the upper Chesapeake bay?
This is where nutrients enter the bay from the Susquehanna and other rivers
Constructive interference (waves)
means that waves interact to build crests or troughs higher or deeper than those of the original waves
destructive interference (waves)
waves cancel one another out
Which of these will likely have the largest wave length?
a. waves with period of 1 second
b. waves produced in a storm with weak winds that lasted a short time
c. waves produced in a storm with strong winds that lasted a longtime ANSWER
d. waves produced by a school parrot fish
Why do most places on Earth have two high tides and two low tides each day?
Gravity of the moon and sun together with centrifugal forces, caused by rotation of the earth moon system produces two bulges
What are semi-diurnal tides?
Two high tides and two low tides each day
twice a day (12hrs 25min)
For semi-diurnal tides, why is one of the highs (lows) sometimes higher (lower) than the other
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 50 minute period
The moon generates a tidal bulge that is about twice that generated by the sun:
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 hrs 50 min. with 2 to 4 m amplitude
Centrifugal "forces" result from
inertia and rotation
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 distance from the sun and moon.
Tidal amplitude increases progressively away from amphidromic points
Why does the earth have two tidal bulges?
The earth moon system rotates during the 28 day lunar cycle, this creates centrifugal forces that cause a bulge (tide) in the ocean water on the side of the earth that is opposite of the moon
Gravity pulls the ocean water up creating a bugle (tide) beneath the moon
moon is on same side of earth as the sun or opposite side of earth as the sun, these are big tides
these are smaller tides, the moon is makes a bugle on a different place than the sun, it doesn't line up with the sun
nce a day (24hr 50min)
example: Gulf coast of US
usually twice a day but varying amplitude
example: Pacific coast of US
Microtidal, mesotidal and macrotidal
small, medium, and large tides
Equilibrium theory of tides
we can think of the tidal bulges as stationary during a given day. So points on Earth rotate under them, creating two highs and two lows per day.