Polar Regions

Question 1

What are the main Antarctic marine primary producers

Answer 1

Planktonic algae - mainly diatoms; bethic algae, ice algae, some macroalgae.

Question 2

What are main antarctic consumers

Answer 2

Zooplankton, (Krill), soft corals, annelids, molluscs, crustaceans, fish, birds, marine mammals

Question 3

What are the methods of primary production in Antarctic

Answer 3

1. Benthic algal biofilms - on sediments and ice. 2. Ice algae. 3. Macroalgae

Question 4

How are organisms incorporated into Antartic ice

Answer 4

In brine channels - some lay dormant in solid ice

Question 5

What is the keystone Antarctic organism

Answer 5

Krill

Question 6

What threatens krill and therefore the Antarctic food web

Answer 6

Fished commercially for human foodstuffs

Question 7

What are characteristics of krill swarms

Answer 7

Dynamic, by day 20-100m depth, by night at surface to feed. Swarms do not mix - have different sex ratios and krill sizes

Question 8

What do krill feed on

Answer 8

Other zooplankton and phytoplankton

Question 9

How do Krill reproduce and develop

Answer 9

Mature after 3 years and then mate by spawning. Fertilised eggs released and sink into sediment 2000-3000m deep! Hatch into larvae called Nauplii. The Nauplii slowly ascend the water column, develping on the way over 3 years.

Question 10

Give an example of an antarctic echinoderm

Answer 10

Pencil urchin, (Ctenocidaris perrieri) or Sea star (Odontaster meridionalis

Question 11

Give higher vertebrate organism adaptations to the Antarctic environment

Answer 11

1. Short and fat body form to heat loss and also young grow rapidly. 2. Thick skinned with thick fur or feathers. 3. Blubber in marine mammals. 4. Antifreeze production such as some fish and insects

Question 12

Give adaptations of Antarctic fish such as Nototheniidae, (cod icefishes)

Answer 12

No swim bladder but are neutrally buoyant. They do not have haemoglobin because of slower metabolism. Have large gills and scaleless skin. Have high cardiac output and high blood volume

Question 13

What is the advantage of Chaenocephalus aceratis, (White crocodile fish), not having haemoglobin

Answer 13

The fish can live without hemoglobin because of their low metabolic rates and the high solubility of oxygen in water at the low temperatures of their environment.

Question 14

How do macromolecular antifreeze glycopeptides work (AFGPs)

Answer 14

They lower the freezing point of body fluids below that of seawater. It is synthesised in the liver and secreted into the blood. It inhibits the growth of ice crystals - ice present in external tissues but in internal tissues

Question 15

What is the CCAMCR

Answer 15

Convention for the Conservation of Antarctic Marine Life Resources, (think of Chilean Seabass - Antarctic Toothfish).

Question 16

What secondary detrimental effect does long line fishing have

Answer 16

Bi-catch such as unintended fish and even seabirds

Question 17

What is the main food prey of Antarctic bird South-polar skua

Answer 17

Adele penguin chicks and eggs and fish

Question 18

What is the largest flying antarctic bird

Answer 18

Giant Antarctic Petrel

Question 19

What is the smallest antarctic bird and what does it feed on

Answer 19

Wilsons storm petrel - 10cm long - feeds on krill and organic waste

Question 20

What is the main food prey of the Adele penguin

Answer 20

Krill - 99%

Question 21

What are the main predators of the Adele Penguin

Answer 21

Skuas and petrels; killer whales and leopard seals

Question 22

How do Emperor penguins reproduce

Answer 22

Once and year mating; eggs laid in may, male incubates over winter in a large colony. Egg hatch in july and females return - both parents feed young

Question 23

What is the largest proportion of Antarctic shelf bethos fauna made of

Answer 23

Sessile suspension feeders such as sponges, cnidarians, bryozoans, ascidians and echinoderms

Question 24

How is gigantism possible in polar waters

Answer 24

Gigantism brought about by a combination of factors - Low water temperatures slow metabolic rates to increase longevity. But more primarily it is the increase in dissolved oxygen content of the colder water. The physiological limit of an organism is the amount of oxygen it get into its blood. In colder waters the oxygen demands of tissue is less