OC201
Organisms that ingest sediment to obtain food are referred to as what type of feeder.
Deposit feeders
Which stress most affects the supralittoral zone?
Desiccation
Which of the following is an example of a biogenic sediment?
Diatom ooze
Hydrothermal vents are typically found at what type of plate boundary? Hint - What type of plate boundary has high heat flow because new ocean crust is forming?
Divergent plate boundaries
The Mid-Atlantic Ridge and East Pacific Rise are found at what type of plate boundary?
Divergent plate boundaries
Ocean crust is created at what type of plate boundary?
Divergent plate boundary
Aggregates of organic matter (living and dead) as well as inorganic particles are called what?
Marine snow
Explain why coastal upwelling occurs off Oregon (Hint - stick out your right arm) and how it impacts marine productivity.
Upwelling occurs off the Oregon coast due to North winds as well as the Coriolis effect. This bring nutrient-rich waters to the coastal areas of Oregon providing organisms there a bountiful feast such as phytoplankton ---> Zooplankton ---> food chain. Those northerly winds (i.e., winds that blow from north to south) off and on in spring through fall drive Ekman transport of surface water offshore (i.e.,west) because Ekman transport is 90° to the right of the wind direction in the Northern Hemisphere. This water is replaced by nutrient-rich deeper water that upwells. You have the productivity part correct.
Describe a trophic cascade using the kelp forest as an example. What organism is the keystone species in this example?
Within the kelp forests, the otter is a keystone species. A tropic cascade is when you have a predator such as the otter in a food web chain that can have impact on the behavior of the prey in the lower level of the cascade such as the sea urchin. Otters keep the abundance of urchin at bay so that the sea urchin can not be destructive within a kelp forest. Causing them to diminish and in turn ending the ecosystem for other organisms within that kelp forest habitat.
The Wilson Cycle describes how plate tectonics creates and then destroys ocean basins. Which statement best describes the Mature Stage of the Wilson Cycle?
A large ocean basin that is still getting bigger.
To deal with the dark many deep sea organisms exhibit the characteristic of [blank1].
Bioluminescence
What is the name of the eastern boundary current that runs from north to south off the west coast of the United States?
California Current
What two (2) forces work together to generate tides? and .
centrifugal, gravitational
The two most abundant chemical elements in seawater, including hydrogen and oxygen,
chlorine and sodium
In reducing habitats primary production occurs via what process?
Chemosynthesis
Place the following sediment types in order of coarse-grained (1st) to fine-grained (3rd).
Sand, silt, clay
Which statement best describes the Trade winds?
They are located between the Equator and 30 degrees north and south.
Which of the following facts are TRUE about nekton.
They are strong swimmers., They live at least 50% of their life in the ocean.
The flattest region of the seafloor is referred to as the ____ .
abyssal plain
Is the Coriolis Effect a real or an apparent deflection of a moving object relative to the surface of the Earth.
apparent
What are the first organisms to arrive at a whale fall?
Large scavengers
The deep ocean contains a variety of resources. List three (3) such resources.
Oil, gas, and manganese nodules. Correct Answer Oil and gas fall in the same category (hydrocarbons). You also could have said fish or methane hydrate.
List the three (3) factors that determine the size of storm waves get and explain how they affect the size?
One factor that determines the size of storm waves is wind intensity. If the wind blows harder this typically increases wave size. Another factor is the fetch which is the area that the wind is blowing in relation to the wave. Longer fetch tends to make bigger wave size. Lastly, duration of wind blow will affect the wave size. The more wind duration you have the bigger the wave action will become. Also, fully developed seas are the setting point when waves are at maximum size.
What is the main difference between phytoplankton and zooplankton?
Phytoplankton are autotropic that use photosynthesis for nutrients. Zooplankton are heterotopic and can not synthesize food on their own so they must feed eating organic things.
Where would you expect sunlight availability to limit primary production in the ocean seasonally?
Polar regions
Transform plate boundary
Shallow earthquakes
Why will ocean acidification affect polar regions the most?
Surface water is colder.
If I group benthic organisms into megafauna, macrofauna, meiofauna, and microfauna what am I classifying them based on?
Their size
The ocean has the ability to moderate the climate in coastal areas because it has a [blank1] heat capacity.
high
The oceans cover ___ % of the Earth's surface.
70
At the Equator the trade winds cause waters to diverge (i.e., waters flow north and south away from the Equator). Therefore, this is a region of open ocean upwelling .
upwelling
Does upwelling strength or weaken off Oregon and California during the positive (aka warm) phase of the PDO?
weaken
Approximately how much organic matter formed in the surface ocean reaches the seafloor?
1 %
Redfield Ratio describes the abundance (in moles) of C:N:P in organic matter. Which of these is the Redfield Ratio?
106:16:1
The deep ocean is considered everything below what water depth?
200 m
The oldest ocean crust is approximately how old?
280 million years old
The average depth of the ocean is approximately ______ .
4000 m
Ekman transport is at what angle to the wind direction?
90° (i.e., right angle to the wind direction)
Siliceous ooze High productivity regions Ice-rafted debris Polar regions Course-grained sand Continental shelf Red clay Abyssal plain
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Which phrase best describes a fishery that has collapsed?
A fishery that is no longer economically viable.
The Arctic Ocean and Southern Ocean (near Antarctic) are both polar oceans but they differ in some important ways. Which characteristic listed below applies to which ocean.
A location for of bottom water formation Antarctic Large freshwater input via rivers Arctic Wide, shallow continental shelves Arctic Many benthic species that are endemic Antarctic
Define the term "water mass". List one location where deep water forms. What is this deep water called?
A water mass is a body of water that shows difference from other bodies of water by the temperature and salinity content of it. Deep water forms in the North Atlantic and Weddell Sea. Antarctic Bottom Water (AABW) is the densest water found being produced in the Weddell Sea.
Gases such as carbon dioxide and methane are greenhouse gases because they do what?
Absorb outgoing long-wave radiation.
The flattest region of the seafloor is referred to as the ___.
Abyssal plain
Are submarine trenches found at passive or active margins?
Active
An oceanic trench is found at what type of continental margin?
Active margin
The water column is referred to as the pelagic environment, while the seafloor is referred to as the benthic environment.
Answer 1:pelagic Answer 2:benthic
Define the term Bathymetry.
Bathymetry is the study of mapping and learning the topography of our oceans seafloors with use of water depth.
Which method of fishing would be used to catch a bottom dwelling fish such as halibut?
Benthic trawl
Silica (aka Si) is removed from surface waters by diatoms. What type of an element is it?
Biogenic
A diatom ooze is an example of what type of sediment?
Biogenous
Since 2002, periods of coastal hypoxia have occurred off the coast of Oregon most summers. What is coastal hypoxia? (2 pts) Why does hypoxia occur? (2 pts) How does it impact marine organisms? (2 pts)
Coastal hypoxia is the lack of oxygen in the water on the coast. This occurs when there is an O2 deficiency in the water called OMZ oxygen minimum zone. The OMZ is much deeper and more stable (i.e., the oxygen content does not fluctuate seasonally). Here is the answer: Coastal hypoxia refers to very low oxygen concentrations (< 1.4 ml/l oxygen) in seawater. The input of abundant nutrients due to upwelling (e.g., off Oregon) or fertilizers being carried into the marine environment (e.g., Gulf of Mexico) cause large phytoplankton blooms. As the bloom ends, the decay of organic matter formed by the phytoplankton (i.e., remineralization) uses up oxygen. The lack of oxygen lead to mass die-offs of marine organisms that cannot escape.
Which of the following organisms are meroplankton when young (i.e., when they are juveniles)?
Fish, Crabs
Which water mass has a higher density?
Cold and high salinity.
A plate boundary where crustal plates are colliding is called a _________ .
Convergent plate boundary
What is coral bleaching and why does it happen? Is it fatal to corals and why or why not?
Coral bleaching happens when the coral takes on some kind of stress more often temperature stressors of being to cold or too hot. This expels the symbiote Zooxanthellae from the coral and this causes the coral to bleach or look white in color. This can be fatal to coral because it causes the coral to be more vulnerable to disease and reproductive issues. However, the zooxanthellae can recolonize on this coral but this process is very slow and will take much time for the coral to be itself again. Most importantly, those algal symbionts provide nutrients to the coral. So, if the zooxanthellae don't return quickly enough (or at all) the polyps will basically starve.
There are three major groups of fish (Agnatha, Chondrichthyes, and Bony/Osteichthyes). Match the group to the characteristic that best describes it.
Correct!Agnatha They have a "sucking" mouth rather than jaws. Correct!Chondrichthyes They have a skeleton made of cartilage rather than bone. Correct!Bony They are the largest group of nekton.
Which of the following organisms are considered a type of phytoplankton. Select all that apply.
Cyanobacteria (all types) Diatoms Coccolithophorids
As the amount of oxygen in a sediment decreases the diversity of infaunal organisms does what?
Decreases
Is the California Current is an example of an eastern or western boundary current?
Eastern
If the eastern Pacific Ocean off Peru is anomalously warm it is what phase of ENSO?
El Nino
True or False. All Zooplankton are complex life forms (i.e., are multicellular).
False
True or False. ENSO only affects the climate of the equatorial Pacific Ocean.
False
True or False. The deepest parts of the ocean are lifeless.
False
True or False. Waves are only found at the surface of the ocean.
False
True or False. Zooplankton that undergo Diel Vertical Migration (DVM) only move a few meters up and down in the water column.
False
What type of fish would make a better fishery (i.e., have a higher MSY)?
Fast growing fish or other marine species that produces lots of young each year (e.g., Market squid, Bluefin tuna).
What controls primary production in HNLC regions?
Fe availability
Which statement best describes a "fish stock"?
Fish of the same species that live together in the same area.
Which two (2) types of zooplankton that have "shells" of calcium carbonate?
Foraminifera, Pteropods
Which of the following are examples of biotic stresses (aka controls) on community structure in the intertidal zone? Select all that apply.
Grazing and predation, Competition for space
A large-scale, circular movement of the surface ocean created by a combination of Coriolis and pressure gradient forces is referred to as a what?
Gyre
The zone (i.e., water layer) characterized by a rapid increase in salinity with increasing water depth is called the _____ .
Halocline
Divergent plate boundary
High Heat Flow
Marine mammals have various adaptations to help them live in the marine environment. Match the adaptation (or adaptations) to the environmental condition it helps with.
High metabolism, blubber and/or fur Cold water Muscles that tolerate low oxygen Need to dive to catch food
Deep-sea organisms have to contend which of the following environmental conditions?
High pressure Little or episotic food supply No light Cold Correct! All of the above
What benthic organism would you expect to see living in the deepest part of the ocean (i.e., below 8000 m)?
Holothurians (aka Sea cucumbers)
The oxidation of what chemical compound drives primary production at hydrothermal vents.
Hydrogen sulfide
Why does ice float?
Ice is less dense than liquid water.
What seafloor feature is only observed in polar regions?
Iceberg scours
The North Atlantic Oscillation (NAO) is related to the pressure difference between the Icelandic low pressure system and Azores high pressure system .
Icelandic low pressure system, Azores high pressure system
Most warm water corals contain an algal symbiont called zooxanthellae. Therefore, these corals are only found where?
In the euphotic zone
If there was no biological pump what would happen to the carbon dioxide concentration in the atmosphere?
Increase
When salt is added to water the density ____ and the electrical conductivity ____ .
Increases; increases
Organisms that live within the sediment are called what?
Infaunal
Which statements about macroalgae are true.
Macroalgae only live in the euphotic zone.acroalgae contain various pigments (e.g., chlorophyll) used in photosynthesis.Macroalgae provide important habitats for other marine organisms.
What is another name for the intertidal zone?
Littoral zone
Will the wave frequency be lower or higher the further you get from the storm generating the waves?
Lower
Which organism would you typically find in the lower littoral zone?
Macroalgae
List two reason why we are concerned about plastic in the ocean.
Microplastic can be consumed by marine life and eventually kill them which is then passed down the food chain. Macoplastics and micoplastic can cause transport of species within different areas of the ocean which can lead to issues with invasive species in some areas. I think you mean passed up the food chain.
What are the two (2) most abundant gases in Earth's atmosphere?
Nitrogen, Oxygen
Can plankton swim against a current?
No
Do deep water corals have zooxanthellae?
No
Define what maximum sustainable yield (MSY) is.
Number of fish that can be taken/caught/harvested without depleting the stock size .... which is a bit different than overexploiting the stock.
Define the term OCEANOGRAPHY
Oceanography is the study of oceans with the use of science. It is interdisciplinary and/or list the key sciences (i.e., geology, physics, chemistry, and biology).
Define the term primary production.
Primary production is the whole amount of accounted biomass (organic material) that has been produced by photosynthetic organisms.
What is the SOFAR channel ? (2 pts) How it is formed? (2 pts) What effects does the SOFAR channel have on sound? (2pts)
SOFAR stands for SOund Fixing And Ranging. The SOFAR channel is a zone of low sound velocity that occurs at intermediate water depths, typically just below the thermocline (roughly 1000 m) where low temperature and relatively low pressure coincide and result in a low sound velocity (... the speed of sound decreases as both temperature and pressure decrease). While the velocity is slow, sound is focused within this zone and therefore can be carried long distances within the SOFAR channel.
Which of the following are methods to determine bathymetry?
Satellite altimetry, Echo sounding
What organism is considered a keystone species in the Intertidal zone?
Sea stars
The continental margin is divided into three zones. Put these zones in order of shallowest to deepest.
Shelf, Slope, Rise
Is the biological pump more effective if a food web is short or long?
Short
Diatoms make their "shells" (aka frustules) out of___while coccolithophores make their "shells" out of
Silica and carbonate
If less sea ice forms in the far North Atlantic would thermohaline circulation slow or speed up?
Slow
Which of the following organisms are considered nekton?
Squid Seagulls Sharks Manatees Correct! All of the above
What is stable stratification? Give an example of and make sure to say where this would occur.
Stratification is a way of explaining the water column in the ocean with different masses of water that are identified by the salinity and temperature of each. A stable stratification means you have less dense water on top of more dense water. Warm, less dense mass of water on top of cold, more dense water. The Atlantic ocean has a stable water column with deep water from the Artic bottom water and lighter water masses topped on top of each other to the lighter surface water masses such as the Antarctic intermediate water. The water column in polar areas where brine is forming, due to sea ice formation, is not stable but it is trying to seek stable stratification. However, the melting of sea ice can create a stable water column because freshwater is less dense than the underlying salty water. Tropical areas where there is intense solar heating are also areas of stable stratification because warm water is less dense than cold water.
Which of the following factors control primary production? Select all that apply.
Sunlight Nutrient supply Mixing of the upper ocean Grazing (i.e., something feeding on something else) Correct! All of the above
More carbonate sediment is found in the Atlantic Ocean compared to the Pacific Ocean. Why?
The CCD is deeper in the Atlantic Ocean.
The Earth is layered (i.e., it has a crust, mantle, and inner and outer core). How do we know this?
The Earth has a magnetic field, Different behaviors of P and S seismic waves.
Define the Wilson Cycle. What stage is the Pacific Ocean at in the Wilson Cycle and how you know this?
The Wilson Cycle is the name for describing the life cycle of an ocean basin. We know that the ocean basin is getting smaller not larger like the Atlantic ocean, being that the cycle describes ocean basins that are getting smaller are in the declining stage of the Wilson Cycle and that is where the Pacific ocean is at in its maturity. We also know that it has the oldest water on Earth so it makes sense that it is now declining and getting smaller because it is very mature. There are four stages in the Wilson Cycle and these are : Embryonic stage, juvenile, mature, declining, terminal, and suturing stage. The next steps for the Pacific ocean would be the end of the basin and the continental land colliding with another continent and creating uplift and mountains. The Pacific Ocean is at the declining stage (i.e., large but getting smaller due to subduction of ocean crust at convergent plate boundaries).
What is the biological pump?
The biological pump is a biological process that removes carbon from the atmosphere to the ocean surface by various biological occurrences on its way down into the deep sea and eventually into the deep ocean floor sediment where it can remain for thousands of years.
Which of the following statements best describes the carbonate compensation depth (CCD).
The depth in the ocean where carbonate input from above equals dissolution.
Where is one (1) location in the ocean where we observe permanent upwelling?
The eastern equatorial Pacific Ocean.
Define the term "Greenhouse Effect". Your answer should list at least one greenhouse gas.
The greenhouse effect is a natural occurrence when the sun radiation is trapped in the Earth's atmosphere, causing warming of the planet. Main greenhouse gases are water vapor, methane, and nitrous oxide. This is good for the planet but not in high volumes. Greenhouse gases do not affect the incoming short wavelength radiation from the sun. However, they do trap the outgoing long wavelength radiation (i.e., heat) leaving the Earth.
Why are mangroves important? Select all that apply.
They are a habitat for juvenile fish.They reduce coastal erosion.
What is the euphotic zone?
The region of the ocean with enough light for photosynthesis.
Why do more tsunamis occur in the Pacific Ocean basin?
There are many subduction zones.
Why is it common to find methane hydrates near the continental margin? Select all that apply.
There is a high flux of organic carbon to the seafloor. The water depth isn't too deep or too shallow (...it's just right).
A Region of the ocean where temperature rapidly increases with increasing water depth is called at what?
Thermocline
What happens to the Trade winds during an El Nino?
They get weaker
True or False. In the northern hemisphere the Coriolis force is to the right.
True
True or False. More carbonate sediment is found in the Atlantic Ocean because the CCD is deeper.
True
True or False. Siphonophores and pyrosomes are colonial (i.e., live in physically connected and interdependent groups).
True
True or False. The shape of the coastline can affect the tidal range.
True
True or False. Western boundary currents are faster and deeper than eastern boundary currents.
True
Deep water forms in what two (2) regions of the ocean?
Weddell Sea, North Atlantic Ocean
Explain when and why seasonal upwelling occurs along the Oregon coast. (3 pts) How and why it affects marine production? (2 pts) Name one other location where coastal upwelling occurs. (1 pt)
Upwelling occurs off the Oregon coast due to North winds as well as the Coriolis effect. This bring nutrient-rich waters to the coastal areas of Oregon providing organisms there a bountiful feast such as phytoplankton ---> Zooplankton ---> food chain. Your answer is missing some important details (e.g., Ekman transport) and you did not answer the third question. Here is the full answer: In late spring through fall winds blow from the north along the coast (i.e., parallel to the shoreline). This results in Ekman transport of surface water offshore (i.e., 90° to the right of the wind direction in the Northern Hemisphere) and this water is replaced by nutrient-rich water from below (i.e., upwelled water). The nutrients in this water stimulate phytoplankton to bloom (i.e., higher productivity) and could result in hypoxia. Coastal upwelling also occurs off Peru and NW Africa.
Convergent plate boundary
Volcanoes
What are the two main factors that affect the shape (i.e., morphology) of reef forming corals?
Water depth which affects the amount of sunlight., Wave energy
Why do you NOT find warm water corals off the coast of California?
Water is too cold due to upwelling.
List four (4) special properties of water. (4 pts) Explain how two (2) of these properties influence the real world. (2 pts)
You can find the answer in Lecture 5 (slide 8). Technically this question was asking about water, not salt water. However ... Since it is more dense you could have said it influences Thermohaline circulation (...not exactly what I was looking for but I would have given you the mark). And yes salty water has a higher electrical conductivity and we use this to measure salinity.
Why is seawater salty when the water coming into the ocean (i.e., rivers, rain, glacier melt water) is not salty? (6 pts) Hint - Think about what elements are most abundant in seawater and why.
Your Answer: Sodium (Na) and chlorine (Cl) are the two most abundant elements in seawater because very few processes remove them from seawater (e.g., not taken up by biology and not scavenged). These are conservative-type elements and they build up over time (i.e., they have a long residence time). This is why seawater is salty
Oceanic crust is composed of [ Select ] ["basaltic", "granitic"] rock, which is [ Select ] ["less", "more"] dense than continental crust crust.
basaltic, more
When saltwater freezes the salt is excluded from the crystal structure of the ice. This is referred to as [blank1].
brine rejection
Select the organism will be affected by ocean acidification more. Diatoms vs coccolithophorids Coral polyps versus coralline algae
coccolithophorids Coral polyps
Neritic sediments are found on the___ while pelagic sediments are found on the ___
continental shelf, abyssal plain
Photosynthesis creates organic matter. The process that destroys organic matter is call____ . This process causes the amount of oxygen dissolved in seawater to____ .
decomposition, decrease
If the concentration of carbon dioxide in surface seawater increases the pH [ Select ] ["increases", "does not change", "decreases"] . This process is referred to as [ Select ] ["ocean carbonation", "ocean deoxygenation", "ocean acidification"] . This process is having the greatest effect in the [ Select ] ["polar regions", "everywhere", "tropical regions"] because the solubility of carbon dioxide gas [ Select ] as temperature
decreases, ocean acidification, polar regions, increases
When carbon dioxide dissolves in seawater the pH of that seawater _____ and the water becomes ____ acidic.
decreases; more
Waves that do not interact with the seafloor are referred to as ____ waves.
deep-water
The shallowest zone of the pelagic environment is referred to as the___ zone while the deepest part is referred to as the ___zone.
epipelagic, hadal-pelagic
The two (2) main drivers of salinity variations in the surface ocean are and . In other words, changes in what 2 things cause salinity to increase or decrease?
evaporation and precipitation
A large-scale, circular movement of the surface ocean that is created by a combination of Coriolis and pressure gradient forces is referred to as a ___.
gyre
Think about your answer to the previous question. Would you expect heat flow to be high or low at this type of plate boundary?
high
The two factors that most influence the primary productivity in the polar oceans are
ice, sunlight
If the carbon dioxide concentration of the atmosphere increases will ocean acidification increase or decrease?
increases
When salty is added to fresh water what happens to the following characteristics? Surface tension [ Select ] ["increases", "decreases"] Density [ Select ] ["decreases", "increases"] Freezing point decreases
increases, increases, decreases
The salinity of surface water will _____ if evaporation increases and/or precipitation _____ .
increases; decreases
If the sun and moon are aligned will the tidal range be larger or smaller.
larger
Do you expect greater species richness (i.e., more species) in a high-energy environment or a low-energy environment?
low-energy environment
Which has the greater influence on the tides, the sun or the moon?
moon
Does cold water hold more or less gas (e.g., oxygen, carbon dioxide) than warm water?
more
If there are 2 high tides and 2 low tides each day and both are the same size (i.e., same tidal range) it is referred to as a ___ tide.
semi-diurnal
Constructive interference results in what type of wave?
sneaker
Would a nutrient-type element (e.g., Si) have a lower concentration in the surface ocean or the deep ocean?
surface ocean
