Which of the following statements best defines Net Primary Production?

A. The total amount of CO2 consumed during the photsynthetic reaction

B. The total amount of organic carbon recycled back to CO2

C. The primary production of just large phytoplankton cells that can be caught in fine-mesh plankton nets (ie phytoplankton cells larger than 100-microns in diameter) and studied in the lab

D. The difference between the amount of CO2 gained through photosynthesis and the amount of CO2 lost through respiration

D. The difference between the amount of CO2 gained through photosynthesis and the amount of CO2 lost through respiration

What characteristic distinguished diatoms from the other two common groups of phytoplankton?

A. Diatoms are mobile and can avoid sinking in calm water

B. Diatoms require silica for growth

C. Diatoms are very small and therefore have a high surface to volume ratio relative to other groups. This allows them to grow better than the other two groups in extremely low nutrient conditions

B. Diatoms require silica for growth

The compensation light level refers to the light level where:

A. Respiration exceeds photosynthesis

B. Photosynthesis and respiration are equal

C. Photosynthesis exceeds respiration

B. Photosynthesis and respiration are equal

When phytoplankton are in the light saturated range of light intensity they grow at less than their maximal rate because this light level is so intense that it destroys the light harvesting photosynthetic pigments

A. True

B. False

B. False

Small phytoplankton cells:

A. Have a growth advantage at high nutrient concentrations

B. Have a growth advantage at low nutrient concentrations

C. Never have the growth advantage over larger cells

B. Have a growth advantage at low nutrient concentrations

Why are nitrogen, phosphorus, silica, and iron the principle phytoplankton nutrients studied by oceanographers?

A. They are the only elements, besides carbon, that are needed by phytoplankton cells to build all of the complex molecules making up the cell

B. The concentration of al the elements in the ocean arefound to have a fixed ratio relative to each other and measuring just these four elements allows oceanographers to infer the concentration of all the other elements without directly measuring them.

C. The are elements that, from time to time, can limit the growth of phytoplankton

D. They are found to be in the highest absolute abundance in the ocean

E. They are found to be in the lowest absolute abundance in the ocean

C. The are elements that, from time to time, can limit the growth of phytoplankton

The main source of iron input to the surface ocean layer is from:

A. Dust blowing off of continents

B. Upwelling of deep ocean water

C. Horizontal Ekman transport of coastal water

D. Iron-rich comets impacting the earth

A. Dust blowing off of continents

Subtropical Gyres have low levels of primary production per square meter because:

A. Dust from continents cannot reach out over the central subtropical gyre reigon

B. There is a persistent lens of warm low-nutrient surface water that depresses the thermocline and associated nutricline

C. Persistent trade winds mix phytoplankton below the compensation depth

D. Persistent trade winds mix phytoplankton below the critical depth

B. There is a persistent lens of warm low-nutrient surface water that depresses the thermocline and associated nutricline

Primary production along the equator in the eastern Pacific and Atlantic oceans (extending well out from the coast of Peru and Africa, respectively) is high because:

A. The trade winds force an Ekman layer convergence that creates downwelling conditions

B. The trade winds force and Ekman layer divergence that creates upwelling conditions

C. The trade winds force an Ekman layer divergence in combination with the relatively deep thermocline in the east (off Peru/West Africa)

D. The trade winds force an Ekman layer divergence in combination with the relatively shallow thermocline in the east (off Peru/West Africa)

E. Off shore horizontal Ekman transport of nutrient-rich coastal waters takes coastal water as far as the central equatorial Pacific

D. The trade winds force an Ekman layer divergence in combination with the relatively shallow thermocline in the east (off Peru/West Africa)

What accounts for high levels of primary production in coastal reigons?

A. Enhanced tidal mixing over shallow continental shelf reigons

B. Winds that blow straight offshore cause coastal upwelling of deep water

C. Winds that blow straight onshore drive surface layer phytoplankton close to the shore where they become highly concentrated

A. Enhanced tidal mixing over shallow continental shelf reigons

Is strong coastal upwelling typically seasonal or is it a year-round process?

A. Seasonally varying

B. Constant all year

A. Seasonally varying

In the Westerly Wind Belt Reigon (30-60 degrees latitude), there is strong seasonal variation in sea-surface temperature in both the Pacific and the Atlantic, but the depth of winter mixing is greater in the Atlantic because:

A. Wind speeds are higher in the Atlantic than in the Pacific

B. Coriolis force is greater in the Atlantic than in the Pacific

C. The surface salinity in the Atlantic is greater than in the Pacific

D. Solar energy inputs are lower in the Atlantic than in the Pacific

C. The surface salinity in the Atlantic is greater than in the Pacific

Which is true about the Critical Depth?

A. It is the depth at which light intensity is just bright enough for photosynthesis to balance respiration

B. It is the depth at which pressure reaches a critical level and beyond which phytoplankton cannot survive

C. It is the depth to which phytoplankton can mix whereby the time they spend below the compensation depth losing carbon just balances the time they spend above the compensation depth gaining carbon

D. It is the depth which phytoplankton can mix whereby net primary production over the course of the day is 0

E. Both "c and "d"

E. Both "c and "d"

What causes the spring phytoplankton blooms in the North Atlantic?

A. Springtime stratification

B. Deep winter mixing

C. Both "a" and "b"

C. Both "a" and "b"

What percentage of the oxygen you breathe can you thsank for the ocean? (What fraction of global primary production takes place in the ocean)?

A. 10%

B. 25%

C. 50%

D. 90%

C. 50%

Net primary production summed over the entire open-ocean reigon exceeds net primary production summer over the coastal reigon:

A. True

B. False

B. False

Which nutrient limits net primary production in the Southern Ocean?

A. Nitrogen

B. Phosphorus

C. Magnesium

D. Iron

E. Molybdenum

D. Iron

Which of the following is the best definition for Plagic Environment?

A. The solid bottom of the ocean (seafloor or rocky shore or coral reef)

B. The fluid water column environment

C. Continental shelf environment

D. Low nutrient environment

E. High nutrient environment

B. The fluid water column environment

In order to make sense out of the confusing mix of all the organisms that make up pelagic communities, oceanographers classify organisms into broad groups based on:

A. Autotrophic

B. Heterotrophic

C. Body Size

D. All of the above

D. All of the above

Why is prey body size about 1/10 the size of the predator's body size?

A. Swimming speed is proportional to the body size and predators require about a 10-fold advantage in swimming speed over their prey to effectively find and capture their prey

B. A preadator's mouth is about 1/10 of its full body size

C. Visual perception sets the lower limit and the ability to hold onto prey sets an upper limit and together it turns out that 1:10 is the optimal range where prey can be seen and still caught and held onto

B. A preadator's mouth is about 1/10 of its full body size

Exploitation Efficiency is the efficiency with which the members of one trophic level are able to:

A. Turn ingested food mass into their own biomass

B. Rise up through all the trophic level ranks to become members of the very top trophic level

C. Find, capture, and ingest all the members of a lower trophic level

D. Turn lower trophic level members into low wage (or often times unpaid) workers

C. Find, capture, and ingest all the members of a lower trophic level

Gross Production Efficiency is less than 100% because of:

A. Respiration

B. Defecation

C. Excretion

D. All of the above

D. All of the above

The Exploitation Efficiency of copepod community that has just come out of winter diapaus (hibernation) at the start of the spring phytoplankton bloom in the North Atlantic is expected to be:

A. Low

B. Medium

C. High

A. Low

If there are three trophic steps between primary producers (phytoplankton) and commercially harvestable fish and you start with 1000 units of phytoplankton, how many units of harvestable fish should you expect?

A. 1/10

B. 1

C. 100

D. 1000

B. 1

The main reason that coastal upwelling reigons have much higher amounts of harvestable fish prodution each year is because:

A. They are close to fishing port cities and are therefore efficiently harvested by coastal fishing fleets

B. They have the largest number of trophic steps between primary production and harvestable fish

C. Upwelled waters are colder so fish mature more slowly and thus can grow larger before reaching adulthood

D. None of the above

D. None of the above

Epifluorescent microscopy and fluorescent DNA stains came into widespread use by oceanographers between 1975 and 1985 and this new technology dramatically increase oceanographers' estimates of:

A. Copepods

B. Heterotrophic bacteria

C. Fish larvae

D. Diatoms

B. Heterotrophic bacteria

Marine heterotrophic bacteria use what to grow?

A. Dissolved organic matter

B. Sunlight and carbon dioxide

C. Predation on viruses that are 1/10 the size of heterotrophic bacteria

D. None of the above

A. Dissolved organic matter

Prochlorococcus is:

A. A type of heterotrophic bacteria

B. The main contributor to primary production in coastal upwelling environments

C. A marine protozoan that feeds on heterotrophic bacteria

D. The main contributor to primary production in the open-ocean oligotrophic environments

D. The main contributor to primary production in the open-ocean oligotrophic environments

The vast majority of living biomas in oligotrophic open-ocean environments is in the form of large (about 100-micron diameter) phytoplankton cells and large (flea-sized) herbivorous copepods

A. True

B. False

B. False

The Biological Carbon Pump is at its most efficient in:

A. Eutrophic conditions

B. Oligotrophic conditions

C. Mesotrophic conditions

D. Anoxic conditions

A. Eutrophic conditions

What is the main form of carbon sinking into the deep ocean?

A. Fecal material from large (flea sized) copepods

B. Dead bodies of copepods

C. Dead bodies of large fish

D. Fecal material of large fish

E. Dead phytoplankton

A. Fecal material from large (flea sized) copepods

Recycled Primary Production makes up an increasing fraction of Total Primary Production with increasing nutrient concentration:

A. True

B. False

B. False

The nutrient that is usually chosen for study in nutrient cycling experiments is:

A. The nutrient in lowest concentration

B. The nutrient that can be measured at lower concentrations that of any other nutrient

C. The nutrient that limits the growth of phytoplankton

D. None of the above

C. The nutrient that limits the growth of phytoplankton

What is the relative abundance of viruses to bacteria in the ocean?

A. 1 virus for every 1000 bacteria

B. 1 virus for every 10 bacteria

C. 1 virus for every bacterium

D. 10 viruses for every bacterium

E. 1000 viruses for every bacterium

D. 10 viruses for every bacterium

What must occur for virus infection to propagate?

A. Virus abundance must be high

B. Host density must be high

C. Both "a" and "b"

C. Both "a" and "b"

What level of mortality can viruses inflict on marine bacteria?

A. 1-2% of total mortality with grazing by protozoans making up the rest

B. 10-50% of total mortality with grazing by protozoans making up the rest

C. 50-90% of total mortality with grazing by protozoans making up the rest

B. 10-50% of total mortality with grazing by protozoans making up the rest

Is the genetic diversity of the marine virus communities considred to be remarkably high?

A. Yes

B. No

A. Yes

Why is water able to dissolve so much salt?

A. Because it is a highly polar molecule

B. Because it is a highly non-polar molecule

C. Because it can form covalent bonds with salt ions

D. None of the above

A. Because it is a highly polar molecule

The two opposing forces and/or energies that determine the three phases of water (solid/liquid/gas) are:

A. H-Bonds and Hydrostatic energy

B. Covalent bonds and Electrostatic energy

C. Nuclear bonds and Fusion energy

D. Planck bonds and Photochemical energy

E. H-Bonds and Thermal-Kinetic energy

E. H-Bonds and Thermal-Kinetic energy

Imagine adding the same amount of heat to the ocean, atmosphere, and the land. Which one would experience the smallest temperature change?

A. Ocean

B. Atmosphere

C. Land

A. Ocean

When winds blow over the surface ocean to cause evaporative cooling, what happens to the heat that leaves the ocean surface?

A. It is driven out of the ocean by turbulent mixing in the form of sensible heat to raise atmospheric temperatures

B. It is transformed from the ocean to the atmosphere as latent heat in the form of atmospheric water vapor

C. It is still in the ocean, but it has been mixed out of the surface ocean and into deeper ocean interior

B. It is transformed from the ocean to the atmosphere as latent heat in the form of atmospheric water vapor

If you have a 1000-gram (equivilent 1-kg) sample of seawater that has a salinity of 34%% (34 psu) and you boiled away all of the water, how much salt would remain?

A. 3.4 grams

B. 34 grams

C. 340 grams

D. 3,400 grams

B. 34 grams

The relative proportion of sodium to chloride to magnesium, and other ions making up the salt content of seawater, changes dramatically over the surface ocean.

A. True

B. False

B. False

What determines surface ocean salinity for a given geographic location?

A. Amount of precipitation in the reigon

B. Amount of evaporation in the reigon

C. The difference between evaporation and precipiation in the reigon

Seawater salinity is intially set at the ocean surface and then when the water sinks into the ocean interior:

A. The salinity steadily decreases significantly because of chemical reactions under high-pressure conditions

B. The salinity steadily increases significantly because of continued river input of salt ions

C. The salinity remains unchanged except when mixed with other deep-sea water of different salinity

D. None of the above

C. The salinity remains unchanged except when mixed with other deep-sea water of different salinity

Where is surface ocean salinity typically highest?

A. Equator

B. Subtropical Gyres

C. Subpolar Gyres

D. Polar Seas

B. Subtropical Gyres

Salt ions like sodium and chloride entered the ocean when it was first formed about 4 billion years ago and these very same ancient ions have remained dissolved in the ocean ever since this early time.

A. True

B. False

B. False

An example of a non-conservative constituent in seawater is:

A. Argon gas

B. Salt

C. Oxygen gas

D. Temperature

C. Oxygen gas

The conveyor belt circulation explains, in part, why nitrate and phosphate concentrations in the deep ocean (bottom waters at 4000 meters depth) are:

A. High in the deep North Atlantic and low in the deep North Pacific

B. Low in the deep North Atlantic and high in the deep North Pacific

C. Evenly distributed between both ocean basins

B. Low in the deep North Atlantic and high in the deep North Pacific

Oxygen concentration reaches a minimum level just below the sunlit later (euphotic zone) of the ocean because:

A. Microbial respiration fueled by dead organic material raining down from above consumes oxygen down to low levels

B. Oxygen rapidly diffuses out of this reigon because of the very high mixing rates found just below the euphotic zone

C. Subsurface water with low oxygen from another geographic reigon moves horizontally into the reigon at this mid-depth

D. None of the above

A. Microbial respiration fueled by dead organic material raining down from above consumes oxygen down to low levels

Carbon dioxide is high in the deep ocean because:

A. Photosynthesis produces carbon dioxide in the deep ocean

B. Carbon dioxide out-gasses from mid-ocean ridge volcanoes and then spreads outward through the abyssal ocean as part of the conveyor belt circulation

C. Carbon dioxide diffusses downward into the deep ocean

D. Microbial consumption of organic matter and associated respiration produces carbon dioxide

D. Microbial consumption of organic matter and associated respiration produces carbon dioxide

 When carbon dioxide is added to the ocean it reacts with water to form:

A. A more basic solution

B. A more acidic solution

C. No effect

B. A more acidic solution

Where is the largest mobile reservoir of CO2 on the planet?

A. In the surface ocean

B. In the deep ocean

C. In the atmosphere

B. In the deep ocean

In which direction would carbon dioxide diffuse across the air-sea interface if deep water were brought up to the surfae and into contact with the atmosphere?

A. CO2 would rapidly diffuse into the ocean

B. CO2 would rapidly diffuse out of the ocean

C. No CO2 diffusion would take place

B. CO2 would rapidly diffuse out of the ocean