Polar Benthos

Question 1

Features of polar seas (5)

Answer 1

Cold all year long 
Dramatic seasonal cycles in light availability 
Ice cover -- ice packs or icebergs 
High levels of disturbance (ice scour)
Important benthic habitats

Question 2

Features of the arctic ocean (4)

Answer 2

Enclosed ocean
Lots of lands, rivers give freshwater input
Restricted ocean circulation
Multi-year and seasonal pack ice, icebergs

Question 3

Features of the antarctic ocean (3)

Answer 3

Less land
Surrounded by the Southern Ocean
Mostly seasonal pack ice

Question 4

Characteristics of polar benthos (3)

Answer 4

Strong benthic-pelagic coupling
High levels of disturbance and extreme seasonality
Gigantism

Question 5

Strong benthic-pelagic coupling

Answer 5

Primary and microbial production generate subsidies to the benthic zone

Sessile suspension feeders are relatively abundant

Size-selective, different suspension feeders have different filtering size ranges to take advantage of available particles

Growth and reproduction seasonal pulses

Question 6

High levels of disturbance and extreme seasonality

Answer 6

Due to iceberg scouring

This leads to lots of opportunistic and seasonal organisms

Question 7

Gigantism

Answer 7

This occurs in many taxa in the polar benthos but not all

Likely many different hypotheses interact causing this gigantism

Question 8

Reason for Southern Ocean Diversity

Answer 8

One reason is the Antarctic circumpolar current keeps species contained within it causing high levels of endemism

Question 9

What controls spatial variability in sampling (3)

Answer 9

Opportunistic sampling
Presence of long-term stations
Sampling conditions

Question 10

Threats (4)

Answer 10

Fishing and exploitation
Tourism
Climate change – temperature and ice cover and acidification
Invasive species – not observed yet but this is a future threat