OCE2701

Resultant tidal forces are produced by __________.
>density forces balanced by the force of buoyancy
>the difference between centripetal and gravitational forces
>the Coriolis effect (not a true force) combined with Ekman transport
>the force produced by Earth's rotation matched with the spin of the Moon

The reason that a lunar day is _________ a solar day is that __________________.

>longer than; the Sun rises later every morning
>longer than; the Moon is also moving in its orbit around Earth
>shorter than; the Sun rises earlier every morning
>shorter than; the Moon experiences retrograde motion
>the same as; the Moon and the Sun remain in fixed positions relative to Earth

A high tide is at 3:00 p.m. on a particular day. On the very next day, a high tide would most likely be expected at __________.
>2:10 p.m.
>3:30 p.m.
>3:50 p.m.
>4:20 p.m.
>9:00 p.m.
>The time cannot be accurately predicted with the above information

Of the following phases of the Moon, which one is associated with the smallest tidal range?

>crescent moon
>gibbous moon
>full moon
>new moon
>quarter moon

Which of the following statements about the positions of the Earth–Moon–Sun system during a solar eclipse is FALSE?

>Neap tide conditions are experienced.
>The Moon would be in new moon phase.
>The Earth–Moon–Sun system is in alignment (a straight line).
>The Moon is in syzygy.
>From Earth, the Sun is at least partially blocked out by the Moon.

Destructive interference between the solar and lunar tidal bulges occurs during __________.

>apogee
>every day at about noon
>neap tide
>spring tide
>every night at about midnightperigee

Syzygy occurs during __________.

>neap tides
>spring tides
>apogee
>every night at about
>midnight perigee
>every day at about noon

The gravitational force between two bodies is dependent on mass and distance, with distance being the greater influence of the two.

True / False

In a simple model of the tides as tidal bulges, the strongest gravitational influence = maximum seawater bulge = highest tide.

True / False

The best time to go collecting at a tide pool (when there would be the lowest low tides) is during neap tide conditions.

True / False

The greatest tidal range on Earth occurs during the times when the Moon is at ___________ and the Sun is at ___________.

>perigee; perihelion
>perigee; aphelion
>apogee; perihelion
>apogee; aphelion

A tidal pattern with two nearly equal high tides and two nearly equal low tides per lunar day is called a __________ tidal pattern.

>Diurnal
>Quasidiurnal
>Pseudodiurnal
>Semidiurnal
>Mixed

A tidal pattern with one high tide and one low tide per lunar day is called a __________ tidal pattern.

>Diurnal
>Quasidiurnal
>Pseudodiurnal
>Semidiurnal
>Mixed

What tidal pattern occurs along the West Coast of the United States?

>Diurnal
>Quasidiurnal
>Pseudodiurnal
>Semidiurnal
>Mixed

Under ideal conditions for the West Coast of the United States, the time interval between a high tide and the very next high tide would be __________.

>12 hours
>12 hours, 25 minutes
>24 hours
>24 hours, 50 minutes
>about one week (7 and 3/8 days)

What would tides be like on Earth if the Moon did not exist?

>Tides would occur, but the tidal range would be greater.
>There would be no tides on Earth.
>Tides would occur, but the tidal range would be reduced.
>There would be hardly any difference compared to the tides as we know them.

In the open ocean, tidal currents follow which of the following patterns?

>Rotary
>Reversing
>Cresting
>Upwelling
>Boring

Water that is flowing out of a bay as a result of a change in the tides is called __________.

>a neap tide
>a spring tide
>a flood current
>an ebb current
>still water level (datum)
>a grunion run

What is a tidal bore?

>a true tidal wave caused by an incoming high tide that moves up certain rivers
>a type of tidal pattern that occurs only in certain areas of Scandinavia
>the term used to describe tidal phenomena in the open ocean far from effects of shorelines
>a really long, uninteresting tide
>the same thing as an ebb tidal current that occurs in some bays

Which of the following statements about tidal power plants is FALSE?

>Tidal power plants use the flow into and out of coastal bodies of water or from tidal currents that pass through narrow channels. >Power generated from a tidal power plant may need to be transported far from where the power is generated.
>Tidal power electrical generating turbines need to be designed to run in two directions by both advancing and retreating water.
>There are no existing tidal power plants anywhere in the world.
>Tidal power can only be generated during part of the day and thus may not match peak electrical demands.

In general, the sand on most beaches comes from _________.

>outer space
>coastal sand dunes
>offshore deposits
>Rivers
>coastal cliff erosion

Of the following zones, which one is defined as the portion of the shore that extends from the low-tide shoreline to the low-tide breaker line?

>Foreshore
>Backshore
>Longshore
>Nearshore
>Offshore

In a typical coastal region, the berm is _________.

>usually underwater
>the wet, steep part of a beach
>another term for longshore transport
>a wave-cut bench
>a dry, nearly level or gently sloping platform

Normally, beaches would have the greatest amount of sand on the berm near the end of _________.

>spring tides
>neap tides
>Summer
>Winter
>none of the above, because beaches always have about the same amount of sand on the berm.

During periods of very heavy wave activity, _________.

>the berm grows, and the longshore bar shrinks
>the berm shrinks, and the longshore bar grows
>both berm and longshore bar grow
>both berm and longshore bar shrink
>both berm and longshore bar stay the same size.

Which of the following features are associated with erosional shores?

>spits and bay barriers
>sea cliffs and sea stacks
>estuaries and bays
>barrier islands and lagoons

All of the following features are associated with emerging shorelines EXCEPT _________.

>drowned beaches
>wave-cut cliffs above sea level
>stranded beach deposits
>uplifted marine terraces

Submerging shorelines commonly exhibit _________.

>uplifted marine terraces
>groins and jetties
>drowned river valleys
>wave-cut cliffs above sea level

The movement of sand parallel to the shoreline _________.

>is called longshore drift or longshore transport
>can be interrupted by groins
>is caused by the angled approach of waves to shore
>can create spits and bay-mouth bars
>is all the above (all the responses are true)

Along the U.S. West Coast, longshore transport generally moves ________, and along the U.S. East Coast, longshore transport generally moves ________.

>north, south
>south, south
>south, north
>north, north
>in various directions depending on local conditions

Imagine that you are caught in a rip current in the ocean. What is the best thing to do to avoid drowning?

>Do not move; wait it out, because it won't last that long.
>Swim sideways to the current before attempting to come ashore.
>Dive below the surface, and hold your breath.
>Swim strongly into it to prevent being carried out to sea.
>Wish that you had studied oceanography more.

All of the following are alternatives to hard stabilization EXCEPT _________.

>placing sand on the beach through beach replenishment
>increasing the rate of glacial ice cap melting so that there is a rise in eustatic sea level
>restricting coastal construction to prevent building in areas prone to coastal erosion >relocating threatened structures to safer areas

Beach nourishment is the establishment of coastal structures that prevent the movement of sand downcoast.

False / True

Where does most of the sand involved in longshore transport in beach compartments eventually end up?

>on the mid-ocean ridges
>down submarine canyons
>in a deep ocean trench
>on the beaches near river mouths
>as tourist souvenirs

With rising sea level, barrier islands tend to _________.

>become stabilized along their length
>wash out toward the sea
>grow higher by deposition of sediment >develop wave-cut terraces
>migrate landward

All of the following events can produce a global (eustatic) rise in sea level EXCEPT _________.

>melting of polar ice caps
>isostatic rebound of the land following glacial melting
>thermal expansion of warmer water
>faster sea floor spreading rate

Which U.S. coast would most likely experience the LEAST amount of shoreline retreat related to a 1-meter rise in sea level?

>West Coast
>East Coast
>Gulf Coast

Which of the following human-made structures or natural features does NOT interfere with the natural flow of sand on the beach?

>Jetties
>Spits
>Breakwaters
>Groins

Which longshore drift management technique was implemented at Santa Monica, California, before the breakwater was destroyed?

>Groins were built downcoast from the breakwater.
>A wave machine was installed at the breakwater.
>Sand was dredged from behind (inshore of) the breakwater.
>The breakwater was redesigned to be more solid.
>The breakwater was moved out further away from shore and raised up on wooden pilings.

The type of hard stabilization that protects a harbor or bay entrance and is almost always found in pairs is called a _________.

>coastal fortification
>Jetty sea wall
>Groin Breakwater
>beach stabilizer

The Law of the Sea Treaty provides for all of the following EXCEPT ___________.

>the private exploitation of deep-ocean mineral resources
>the arbitration of disputes
>the right of any nation to dump plastic trash at sea
>the right of free passage for ships on the high seas and in straits
>the establishment of a uniform exclusive economic zone for coastal nation jurisdiction

Runoff flowing into coastal waters can produce all of the following EXCEPT ___________.

>coastal geostrophic currents
>a strong halocline
>dry offshore winds
>decreased seawater salinity

Which of the following is an example of a coastal plain estuary?

>the Mediterranean Sea
>Puget Sound
>San Francisco Bay
>Chesapeake Bay
>the Columbia River
>Prince William Sound

A fjord is a type of estuary that was created by ___________.

>growth of a barrier island
>submergence of a glacially carved valley.
>uplifting of the sides along faults
>natural movement of a barrier island away from shore.
>folding of rocks

Of the following types of estuaries, which one has the best developed "estuarine circulation pattern"?

>a salt wedge estuary
>a slightly stratified estuary
>a vertically mixed estuary
>a highly stratified estuary

Which of the following statements about Mediterranean Intermediate Water is FALSE?

>It is composed of low-salinity water.
>It sinks below the surface in the Atlantic Ocean.
>It occurs as a subsurface flow over the Gibraltar sill to the Atlantic Ocean.
>It is denser than surface water in the Atlantic Ocean.
>Its formation causes the classic Mediterranean circulation pattern, which is opposite that of most estuaries.

Which of the following statements about coastal wetlands is FALSE?

>Coastal wetlands have very low productivities.
>Coastal wetlands naturally cleanse runoff from land.
>Salt marshes are a type of coastal wetland.
>Coastal wetlands are often deemed useless land, and so they are filled in for development.
>Many species of fish use coastal wetlands as nurseries for their young.
>Mangrove swamps are a type of coastal wetland.

Mangroves grow in latitudes as high as 65 degrees north or south of the equator.

False / True

By law, storm drains now divert flow into treatment facilities, not to the ocean as they once did.

False / True

Toxins often accumulate and concentrate from organism to organism up marine food chains.

False / True

Although the effects of DDT on the environment were devastating, they have long since disappeared.

False / True

It is still legal to dump raw sewage into the ocean in the United States.

False / True

It is still legal to dump raw sewage into the ocean in the United States.

False / True

Based on the World Heath Organization's definition of marine pollution, all of the following would be considered pollution (provided that the item results in harmful effects) EXCEPT ___________.

>raw sewage
>warm water discharged into the ocean from a power plant
>an oil spill a plastic six-pack ring
>"natural pollution," such as piles of dead seaweed at the beach.

The standard laboratory bioassay is used to determine ___________.

>whether there is any non-point source pollution in the water
>the amount of plankton in the water
>the concentration of a pollutant in the water
>the rate of decline of fish populations
>the amount of marine biomass

Minamata disease is caused by eating fish contaminated with ___________.

>raw
>sewage Mercury
>radioactive waste
>DDT
>PCBs

Years after the oil spill from the Exxon Valdez, ecologic recovery has largely taken place because ___________.

>the water temperature is cold there, causing the oil to freeze
>most substances that comprise oil are naturally biodegradable
>the spill did not come ashore
>ocean water is a good solvent
>oceans have good mixing mechanisms

Bioremediation ___________.

counteracts bioaccumulation >
is a method of oil cleanup that uses microbes to break down oil
>is a treatment that cures sick pelicans that are infected with DDT poisoning
>prevents non-point source pollutionis used to cure Minamata disease

Other than the oil spilled intentionally by the Iraqi army during their invasion of Kuwait in 1991, the world's largest oil spill was from ___________.

>the freighter M/V New Carissa in Coos Bay, Oregon (1999)
>the cargo freighter Cosco Busan that hit the San Francisco Bay Bridge (2007)
>the blowout of the Ixtoc #1 oil well in the Bay of Campeche, Mexico (1979)
>the oil tanker Exxon Valdez in Prince William Sound, Alaska (1989)
>the oil tanker Amoco Cadiz near the coast of France (1978)

What is the source of the majority of human-caused marine oil pollution?

>oil tankers that spill oil during transportation
>consumers who use oil
>oil refineries gasoline stations that store and dispense oil
>activities that are associated with extracting oil from underground reservoirs

Based on a working definition of life, which of the following is NOT a characteristic of living organisms?

>Living organisms can adapt to their environment.
>Living organisms can capture, store, and transmit energy.
>Living organisms are capable of reproduction.
>Living organisms must be large enough to be seen with the naked eye.
>Living organisms change through time.

Which of the following kingdoms of organisms lack nuclei?

>Fungi
>Monera
>Plantae
>Protoctista
>Animalia

Of the following groupings, which one is the most inclusive (contains the greatest number of species)?

>Family
>Class
>Order
>Phylum
>Genus

What is the total number of marine species that have been catalogued?

>25,000
>250,000
>860,000
>1,800,000
>18,000,000

Only 14% of Earth's species live in the ocean. Which is the most logical explanation of why there are so few marine species?

>In general, the water is just too cold to support much marine life.
>The relatively uniform conditions of the open ocean create an easier life for marine organisms than terrestrial organisms.
>The large volume of the deep ocean is less friendly for life.
>The high pressures at depth in the ocean are not conducive to living organisms.
>The depth of the ocean inhibits the easy transmission of sunlight.

What percentage of marine species live in or on the ocean floor?

>2%
>19%
>54%
>71%
>98%

Which type of marine organism comprises the greatest percentage of marine biomass?

>Detritus
>Nektobenthos
>Nekton
>Benthos
>Plankton

All of the following adult-stage organisms are considered nektonic organisms EXCEPT ___________.

>Squid
>Dolphin
>a surfer paddling out to the waves
>Tuna
>Jellyfish

All of the following adult-stage organisms are considered benthos EXCEPT ___________.

sea stars
>sand dollars
>marine worms that burrow into the sea floor
>Jellyfish
>sea urchins
>Coral

Organisms that are plankton in their juvenile stage but become nekton or benthos in their adult stage are called ___________.

>Ultraplankton
>Macroplankton
>Microplankton
>Picoplankton
>Meroplankton
>Holoplankton

Osmosis is a process that describes the movement of water molecules from the less concentrated solution into the more concentrated solution.

True / False

Diffusion is a process that involves passing particles or molecules from areas of low particle concentration to areas of high particle concentration.

True / False

Countershading is a term used to describe an organism that is dark colored on bottom and light colored on top, thus able to avoid being seen by predators.

True / False

The deep scattering layer (DSL) is found close to the surface at noon every day.

True / False

The increasing pressure with depth in the oceans has a significant impact on most marine organisms.

True / False

Organisms that can tolerate only a narrow range of salinity conditions are said to be ___________.

>Isohaline
>Euryhaline
>Thermohaline
>Stenohaline
>Hypertonic
>Hypotonic

The oxygen minimum layer (OML) ___________.

>occurs only in deep-ocean trenches
>is a zone of low dissolved oxygen concentration
>is located between the surface and a depth of 100 meters
>occurs at the bottom of the euphotic zone is the same as the abyssopelagic zone

Because of seawater's high salinity, most marine fish have the following adaptations EXCEPT that ___________.

>they are less salty than the surrounding seawater.
>they drink large quantities of water
>they have a small volume of highly concentrated urinethey secrete excess salt through special cells
>they are considered hypertonic

Dead and decaying organic matter, including waste products, is called ___________.

>detritus
>fodder
>cyanobacteria
>osmosis
>bioluminescence

Which of the following shows the correct order of benthic environments, going from shallow water to deep ocean depths?

>sublittoral, littoral, abyssal, hadal, bathyal
>littoral, sublittoral, abyssal, bathyal, hadal
>abyssal, hadal, bathyal, littoral, sublittoral
>littoral, sublittoral, bathyal, abyssal, hadal
>bathyal, sublittoral, littoral, abyssal, hadal
>abyssal, bathyal, hadal, littoral, sublittoral

Of the following statements about photosynthesis, which one is true?

>All animals photosynthesize.
>Water and carbon dioxide are converted to sugar and oxygen gas.
>Nitrogen and sulfuric acid are converted to water and sulfur dioxide.
>Photosynthesis is another term for respiration.
>Photosynthesis can occur in the absence of sunlight.

It might seem a bit unusual that the richest concentration of marine life is (1) in the very margins of the oceans, where conditions are the least stable; and (2) in colder water, which seems less conducive to a good life. What factor(s) provide an explanation of these observations?

>Cold water holds more dissolved carbon dioxide than warm water.
>Nutrient availability is greater in the margins of the oceans.
>Shallow water depths create seasonal variations in salinity.
>Cold water holds more dissolved carbon dioxide than warm water, and nutrient availability is greater in the margins of the oceans.
>Nutrient availability is greater in the margins of the oceans, and shallow water depths create seasonal variations in salinity.
>Cold water holds more dissolved carbon dioxide than warm water, and shallow water depths create seasonal variations in salinity.

Of the following ocean locations, where would the level of nutrients be highest?

>in deep water
>near continents
>in warm water
>in downwelling areas
>on the ocean floor where nutrients settle out

Chlorophyll is ______ in color; a group of marine organisms that contains chlorophyll are called _____________.

>blue; phytoplankton
>blue; zooplankton
>red; phytoplankton
>green; zooplankton
>green; phytoplankton
>red; zooplankton

Kelp belongs to which of the following types of organisms?

>macroscopic algae
>Diatoms
>seed-bearing plants
>Eelgrass
>surf grass

Dinoflagellates are important examples of _____________ that are often associated with ________________.

>phytoplankton; red tides
>zooplankton; tidal bores
>nekton; grunion runs
>benthic life; spring tides
>krill; neap tides

Late one night as you are flipping channels on TV, you come across the Alfred Hitchcock thriller The Birds. You know that this movie showing unusual bird behavior was inspired by an actual event involving birds that pecked people because the birds were affected by ________________.

>denitrifying bacteria
>domoic acid
>paralytic shellfish poisoning (PSP
>western intensification
>Minamata disease

Photosynthesis in tropical waters is limited by which of the following factors?

>availability of nutrients
>amount of solar radiation
>presence of reef predators
>color of the water
>lack of a prominent thermocline (and associated pycnocline) in this region

In middle-latitude waters during the winter, the supply of sunlight is ___________, and the supply of nutrients is _____________.

>maximized; maximized
>maximized; minimized
>minimized; maximized
>minimized; minimized

In middle-latitude waters, productivity of marine algae ___________ during the spring because _______________________.

>decreases; a strong thermocline develops
>increases; the amount of sunlight is increasing
>decreases; the nights are getting longer
>increases; there is an abundance of grazers at that time
>remains constant; the conditions are the same as in the fall

In middle-latitude waters, nutrients __________ during the spring because _____________________.

>increase; the days are getting shorter
>decrease; they are getting used up by phytoplankton
>increase; that is when spring tides occur
>decrease; the water is isothermal
>constant supply; the water is isothermal

Photosynthetic productivity is the result of action by herbivores.

True / False

The clear indigo blue color of tropical waters is due to high biologic productivity.

True / False

The productivity values of algae beds and coral reefs average about the same as those of tropical rainforests on land.

True / False

When a population of organisms at a low trophic (feeding) level becomes depleted, organisms that are at the top of a food chain are more vulnerable to ecological collapse than those that are at the top of a food web.

True / False

Why do the majority of the ocean's organisms live within the ocean's surface waters?

>Phytoplankton need to be in the sunlit zone, and they are the base of the entire food web.
>The water is clear enough for sunlight to penetrate, and thus food items are more easily seen.
>Most organisms cannot withstand the cold ocean temperatures that exist below this depth.
>Surface waters lack predators.
>They would be crushed by high pressures at depth in the ocean.

Except for Trophic Level 1, on average about _____% of the mass that is taken in at one trophic level is passed on to the next.

>3.5
>10
>19
>29
>50
>72

In marine food webs, individual members of a feeding population are generally _________ in size and ______ numerous than their prey.

>larger; less
>smaller; less
>larger; more
>smaller; more

Which ecosystem produces the largest percentage of the world's marine fishery?

>the open ocean
>coastal waters and coral
>upwellings
>non-tropical shelves
>tropical shelves

A fishery's maximum sustainable yield (MSY) is defined as _____________.

>the maximum fishery biomass that can be removed yearly and still be sustained by the fishery ecosystem
>the maximum amount of fish that can be caught during a sustainable season (its yield)
>the maximum yield of fish produced in an ecosystem that sustains it
>the maximum size that fish reach before being removed (yielded) from the ocean by eating (food webs) or harvesting (by humans in fisheries)
>the maximum number of fishing vessels that can be sustained by the yield of a local fishery per year.

Which of the following statements about benthic life is FALSE?

>Benthic life includes deposit feeders that burrow into sea floor sediment.
>Benthic life includes filter feeders that are attached to firm surfaces.
>Benthic life includes active predators that live on the bottom but move freely across the sea floor.
>Benthic life includes organisms that live suspended within the water column.

Life on rocky shores of the supratidal (spray) zone is influenced primarily by _____________.

>the ability of an organism to avoid drying out whether symbiosis occurs there
>the amount of wave activity experienced along a particular shoreline
>whether an organism is a suspension or deposit feeder
>the nature of the sediment

Mussel beds are commonly found in the _________ subzone of the intertidal zone.

>Supratidal
>high tide
>middle tide
>low tide
>Spray

Based on how a sea anemone feeds, what should you avoid doing to a sea anemone so that it won't hurt you?

>put your tongue into one
>feed it any human food
>touch it with your finger
>feed it fish food
>accidentally step on it

All of the following are adaptations that organisms in rocky intertidal zones use to avoid predators EXCEPT _____________.

>stinging cells
>the ability to break off body parts and regrow them later
>firm attachment of a hard shell Camouflage
>release of large numbers of eggs/sperm into the water during reproduction cycles

Which of the following statements about meiofauna is FALSE?

>Meiofauna are found only in the supratidal (spray) zone.
>Meiofauna feed primarily on bacteria removed from the surface of sediment particles.
>Meiofauna live in the tiny spaces between sediment particles.
>Meiofauna are found from the intertidal zone to deepest ocean trenches.
>Meiofauna are very small organisms, generally only 0.1 to 2 millimeters (0.004 to 0.08 inch) long.

Generally, kelp that forms kelp forests is attached to _____________.

>mud flats in the low tide zone
>the rocky bottom in the subtidal zone
>the sandy beach in the middle tide zone
>rocky shores in the high tide zone
>either rocky, sandy, or muddy bottoms, but always in the supratidal zone

All of the following statements about kelp forests are true, EXCEPT:

>Kelp is the main source of food for most whales.
>Kelp is one of the fastest growing types of marine algae on Earth.
>Kelp forests provide a home for organisms that live directly on the kelp.
>Kelp forests provide a food source for animals living nearby, such as sea urchins. >Kelp forests provide shelter and protection for a wide variety of life forms.

The term sessile describes organisms that have the ability to swim.

True / False

There is less species diversity in sediment-covered shores than in rocky shores, but the number of individuals may be similar.

True / False

Hypersaline, hydrocarbon, and subduction-zone seep biocommunities all derive their energy from microbial oxidation of hydrogen sulfide or methane.

True / False

Coral reefs need all of the following conditions EXCEPT _____________.

>good wave or current action
>a hard substrate for attachment
>normal-salinity seawater
>warm water (64–86ºF)
>abundance of turbidity

What causes the potentially lethal bleaching of coral reefs?

>Bioaccumulation
>Bioerosion
>expulsion of algae
>the presence of sulfuric acid
>the covering of coral by white beach sand

The environmental factor that is most consistently associated with coral bleaching episodes involves _____________.

>spring tide/neap tide cycles
>more dissolved carbon dioxide than normal in seawater
>high sea surface temperatures
>the occurrence of sunspots
>excess amounts of turbidity

The pressure in deep-ocean trenches is typically ________ times that at the ocean's surface.

>2
>10
>20
>100
>1000

On the deep-ocean floor, studies suggest that organisms the size of humans would have their soft tissue devoured in about _____________.

>1 hour
>2 hours
>12 hours
>24 hours
>3 days
>1 week

During which year were deep-sea hydrothermal vent biocommunities first discovered on the ocean floor?

>Coastal wetlands have very low productivities.
>Coastal wetlands naturally cleanse runoff from land.
>Salt marshes are a type of coastal wetland.
>Coastal wetlands are often deemed useless land, and so they are filled in for development.
>Many species of fish use coastal wetlands as nurseries for their young.
>Mangrove swamps are a type of coastal wetland.

Adaptations of deep-sea hydrothermal vent biocommunities (such as high metabolic rates and rapid reproduction) exist because _____________.

>the amount of productivity is restricted in these deep areas that are below the euphotic zone
>the food supply is so limited active hydrothermal vents are short-lived phenomena
>productivity is highly seasonal, especially in the midlatitudes
>benthic biomass is so low

What is the primary food source for organisms in deep-sea hydrothermal vent biocommunities?

>bacteria-like microbes that chemosynthesize
>deep currents that bring nutrients and oxygen
>zooplankton
>detritus from the euphotic zone above
>organisms, such as whales, that die and sink to the bottom

Hydrothermal vent biocommunities have as much as _______________ biomass as compared to the normal deep-ocean floor.

>10 times more
>100 times more
>1000 times more