Lecture 15 - Extreme enviroments (Antarctica)

Question 1

what seasonal changes does changes does the Antarctic go through?

Answer 1

Over summer ice sheets retreat making the land smaller, in winter they grow

Question 2

Explain biodiversity in the antarctic

Answer 2

due to extreme habitat diversity is reduced, but still wide range of oraganisms

Question 3

What are primary producers found here

Answer 3

Planktonic algea - mainly diatoms, benthic algea, icea algea although some macroaglea

Question 4

What are the consumers found here (8)

Answer 4

Zooplankton, soft corals, annelids, molluscs, crustaceans, fish, birds, mammals

Question 5

List a simple food web for this

Answer 5

Diatoms -> zooplankton > fish, squid > sea birds, mammals > apex predators killer whale, leopard seal

Question 6

What four organisms make up the “ice food web”

Answer 6

Worms, Bacteria, uniceullar algea and diatom chains, curstaceans

Question 7

what is the keystone species of consumers in the antarctic

Answer 7

Krill, form dense swamps of up to 10,000 per square meter. Swams do not mix and have different sex rations, size and stage of moult. Also commerically fished

Question 8

Explain the ecology of krill

Answer 8

Grow to up 6cm long, feed on other zooplankton and phytoplankton, have swimming legs, filter deeding appendages, will feed on sea ice algea like a “lawnmower”

Question 9

Explain the cycle of life for a krill

Answer 9

Fast swimmers, mature after 3 years when mate by spawning, fertilised eggs released which sink to sediment (2000-3000)m deep, then hatch into larvae called naupliii, slowly ascend developing on the way over three years. Immature krill will hide in ice carvens to avoid >predation

Question 10

Explain the four adaptations of higher organisms (vertebrates) to antarctic environment

Answer 10

> Body form - short and fat to reduce sa/v ration, young grow rapidly
Thick skinned with thick fur or feathers (birds have very thick downy under feathers)
Blubber
Antifreeze - have it in their blood to stop it solidifying

Question 11

Give details on the antartic fish ecology

Answer 11

> have no swim bladder, neutrally buoyant
Dint have haemoglobin
have slow metabolism
Large gills and scale less skin
high cardiac output and high blood volume

Question 12

Explain the antifreeze found in fish blood

Answer 12

Sythesized in the liver and secrete into the blood, prevent freezing by adsorbing and inhibiting growth of ice crystals, may have ice externally but inside is ice free. Possible removal of ice in the spleen

Question 13

What is CCAMCR

Answer 13

Convention for conservation of Antarctic marine life resources

Question 14

Give an example of two fish that are over exploited

Answer 14

Dissotichus spp. (2 types) are fished and sold in japan for £1000 per fish

Question 15

Explain the birds that live / migrate here

Answer 15

All migrate away in the winter apart from penguins (only some species)

Question 16

Explain the life of the South-polar Skua

Answer 16

It is the bird of prey here, arrives in September and leaves in march. Main food - Penguin chicks and eggs including fish. Parenting - lays on single egg

Question 17

Explain the life of the Giant antartic petrel

Answer 17

Largest flying bird found here 2.2m wingspan and weigghts 5kg. Feeds on fish, offal and carrion. Arives august, leaves april

Question 18

Explain the life of the Wilsons Storm petrel

Answer 18

Smallest bird at 10cm long, migrates 40000km per year! July feeds in Arctic, December breeds in Antarctica. Feeds on krill and organic waste

Question 19

Explain the life cycle of the adelie penguin

Answer 19

Common, arrives in october and leaves in feb. 99% of food is krill, nests in rookeries and has the main apex predators to contend with

Question 20

Explain the life cycle of the Emperor Penguin

Answer 20

Found on antarctic ice zones. Mating last 10 seconds and occurs one a year. Eggs laid in may male incubates the egg in large colony. During winter they are “packed in” with about 10 per square meter. Egg hatches in July

Question 21

Two examples of marine mammals that are present here

Answer 21

Weddell seal, Leopard Seal