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WorksheetsLife on the Continental Shelf
Total questions: 20
Worksheet time: 10mins
The continental shelf (subtidal zone) extends from:
the high tide mark to the low tide mark
the shelf break to the abyssal plain
the low tide mark to the shelf break
Benthos are organisms that
swim against currents
drift with the currents
live in the subtidal zone
live on the bottom
These organisms drift on the ocean's currents
plankton
nekton
benthos
infauna
These organisms are capable of swimming against the currents
plankton
nekton
benthos
infauna
What percentage of commercial fish is caught in waters above the continental shelf?
25%
50%
75%
90%
Why are nutrients suspended in water above the continental shelf?
water turbulence
water stratification
the bottom is deep
tectonic activity
The source of the suspended nutrients in the subtidal zone
estuaries
salt marshes
mangroves
all answers are correct
These benthic organisms dig or burrow in the sediment:
epifauna
infauna
phytoplankton
primary producers
These organisms live on the surface of subtidal substrates
epifauna
infauna
meiofauna
interstitial organisms
Infauna organisms are capable of burrowing deeper in sandy bottoms because
more porous
better water circulation
more oxygen
all answers are correct
Soft-bottom subtidal zones are rich in organic matter which means
there's more detritus
there's less oxygen
there's more deposit feeders
all answers are correct
Soft-bottom organisms are distributed in patches because
they drift on currents randomly
they "taste" the sediment for specific nutrients
they smell the water where they were born
they sense the magnetism in the bottom
These are the primary producers for shallow soft-bottom communities
diatoms
microscopic algae
photosynthetic bacteria
all answers are correct
Since there isn't much primary production in soft-bottom subtidal zones this is a very important food source
seaweed
invertebrates
detritus
phytoplankton
Deposit feeders prefer this type of sediment because it's rich in organic matter
lithogenous
muddy
sandy
rocky
Seagrasses are found in these geographic locations
temperate
subtropical
tropical
all answers are correct
This seaweed growth pattern allows seaweeds to cope with wave action
filamentous
branched
encrusting
all answers are correct
How do seaweeds defend themselves against grazing herbivores?
having calcium carbonate in their cell walls
producing chemical toxins
having multiple stipes
having huge pneumatocysts
Grazers and carnivores are important to hard-bottom subtidal zones because
they increase primary production for seagrasses
they can open up patches for larvae and spore colonization
they produce detritus for deposit feeders
they fix nitrogen for algal growth
Some seaweeds are able to live in deeper water with low levels of light because
they can tolerate cold water
they have higher levels of chlorophyll
they can absorb nutrients from the water
they can chemosynthesize water from thermal vents
