Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Marine Biology > Lecture 6 - Benthic Ecosystems > Flashcards

Lecture 6 - Benthic Ecosystems Flashcards

1
Q

What is a continental shelf?

A

A shallow, horizontal seafloor extension from the shoreline to the upper continental slope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the average gradient for a continental shelf?

What is the exception to this?

A

1 degree.

Unless when glacially structured.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the average depth of continental shelf ecosystems?

A

150m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which zone is the continental shelf ecosystem in?

A

The euphoric zone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give some physical factors that the continental shelf is strongly influenced by.

A
  • Waves
  • Tides and currents
  • Input of materials/nutrients from adjacent land masses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does seasonal stratification occur in the ocean?

A

Between 20 and 100m.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What has shaped the benthos?

A

Past glacial events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are hard-bottomed habitats formed?

A

From strong currents removing sediments.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What kind of benthos is found in

a) Sheltered, deeper areas?
b) High energy/shallower areas?

A

a) Sheltered, deeper areas = muddy, silty.

b) High energy, shallower areas = bare rock, pebbles or sand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Finish this sentence:

The more sheltered…

A

The finer the sand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Other than fineness of substrate, what do waves and currents affect in the benthos?

A

The rate of food supply from pelagic to benthos; in strong currents, food at the surface is moved away before it reaches the bottom.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give a description of an organism living in high current.

A
  • Encrusting
  • Very flexible (in order to avoid breaking)
  • Burrowing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the body structure of an organism living in low current.

A
  • Delicate
  • Elaborate
  • Leafy/branched
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What two factors affect light levels in water?

A
  • Depth

- Turbidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is water very turbid?

A
  • At estuaries

- Near rivers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the zonation of algae.

A

In deeper waters:

From green, to brown, to red.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are macrofauna?

A

Fauna larger than 0.5mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are meiofauna?

A

Would pass through a sieve with a mesh diameter of 0.5mm, but retained on one of 0.063mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are microbiota?

A

Organisms smaller than 0.063mm (includes dinoflagellates, diatoms and bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are infaunal organisms?

A

Organisms that bury within the mud.

21
Q

What is the difference in habitat requirements of juvenile and adult mobile animals?

A

Juvenile mobile animals have specific habitat requirements for predator avoidance, but adults show more flexibility.

22
Q

What is an ecological function?

A

The job that animals do in their environment.

23
Q

Give 5 key feeding modes.

A
  • Surface suspension feeder
  • Sediment processors
  • Suspension feeders
  • Surface deposit feeder
  • Carnivore/scavengers
24
Q

What is a scavenger?

A

An animal that can feed on a dead carcass.

25
Q

True or false:

Herbivores such as sea urchins, and suspension feeders such as brittlestars, are known to feed on carrion.

A

TRUE.

26
Q

What is the largest amphipod family/

A

Lysianassoids

27
Q

What is the ecological function of amphipods?

A

Scavengers; important for removing carcasses from seabed.

28
Q

What are sea mice?

A

Epifaunal polychaetes, covered in bristles.
Scavengers that predate on small crabs and worms.
Spines act like optical fibres due to reflective properties.

29
Q

Give an example of a carnivorous grazer.

A

Nudibranchs feast on bryozoans by scraping.

30
Q

Give three examples of particle feeders.

A
  • Mussels
  • Clams
  • Oysters
31
Q

What are bulk sediment processors?

Give two examples.

A

Organisms that process sediment and remove microbes from the sediment.

  • Heart sea urchin
  • Sea cucumbers
32
Q

What are biogenic reefs?

A

Where whole groups of organisms come together to form their own structure, e.g. mussel bed, coral reefs.

33
Q

What percentage of shallow continental shelf is composed of

a) Muds?
b) Sands?
c) Rocky substrata?
d) Reef-structures?

A

a) Muds = 37%
b) Sands = 47%
c) Rocky substrata = 6%
d) Reef structures = 10%

34
Q

How are hard bottom communities kept clean of sediment?

A

By flow or scouring by sand.

35
Q

How do macroalgae compete for space in hard bottom communities?

A

Have pneumatocysts; large gas bubbles to help them float.

36
Q

Give and describe two encrusting species.

A
  • Sea squirts; filter feeders.

- Sponges, e.g. Cliona celata.

37
Q

Describe pink sea fans.

A
  • Protected species - Found in turbulent water; good at capturing particles in fast-flowing water.
  • Can orientate itself perpendicular to the current.
38
Q

Describe brittlestar beds.

A
  • Live at high densities, living on bedrock

- Can find other invertebrates living within them as a microhabitat

39
Q

Up to what depth can organisms live in burrows?

A

2m

40
Q

How does particle/grain size determine what can live there?

A
  • Larger particles hold more water
  • Larger grains easier to burrow into.
  • Microbes in fine sand use up oxygen quickly, gets anoxic more quickly.
41
Q

What is bioturbation?

A

Moving mud around.

42
Q

Why is bioturbation important?

A

Helps to keep water and oxygen circulating within the sediment.

43
Q

What is the name of the biogenic reef formed by polychaetes?

A

Calcium carbonate rubes

44
Q

What are ecosystem engineers?

A

Organisms that cause a biologically-mediated habitat modification.

45
Q

What are cryptic fauna?

A

Organisms that live inside nooks and crannies

46
Q

Name some cryptic fauna you might find in mussel beds.

A
  • Perinereis cultifera
  • Barnacles
  • Periwinkle
  • Hydroids
47
Q

What are mearl beds?

A

Collective term for several species of red seaweed with hard, chalky skeletons.
Have calcium carbonate in the fronds of the seaweed, forming hard habitat structures when they grow in big aggregations.
Not attached to bottom.
Slow growing.

48
Q

Name some method for sampling benthic ecosystems.

A
  • Manta tow / scuba tow; dragged off the back of a boat, record everything you see.
  • Sonars
  • Grab sampling
  • Trawling (nets dragged over the bottom)

Marine Biology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions