Polar Regions Flashcards
What are the main Antarctic marine primary producers
Planktonic algae - mainly diatoms; bethic algae, ice algae, some macroalgae.
What are main antarctic consumers
Zooplankton, (Krill), soft corals, annelids, molluscs, crustaceans, fish, birds, marine mammals
What are the methods of primary production in Antarctic
- Benthic algal biofilms - on sediments and ice. 2. Ice algae. 3. Macroalgae
How are organisms incorporated into Antartic ice
In brine channels - some lay dormant in solid ice
What is the keystone Antarctic organism
Krill
What threatens krill and therefore the Antarctic food web
Fished commercially for human foodstuffs
What are characteristics of krill swarms
Dynamic, by day 20-100m depth, by night at surface to feed. Swarms do not mix - have different sex ratios and krill sizes
What do krill feed on
Other zooplankton and phytoplankton
How do Krill reproduce and develop
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.
Give an example of an antarctic echinoderm
Pencil urchin, (Ctenocidaris perrieri) or Sea star (Odontaster meridionalis
Give higher vertebrate organism adaptations to the Antarctic environment
- 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
Give adaptations of Antarctic fish such as Nototheniidae, (cod icefishes)
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
What is the advantage of Chaenocephalus aceratis, (White crocodile fish), not having haemoglobin
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.
How do macromolecular antifreeze glycopeptides work (AFGPs)
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
What is the CCAMCR
Convention for the Conservation of Antarctic Marine Life Resources, (think of Chilean Seabass - Antarctic Toothfish).
What secondary detrimental effect does long line fishing have
Bi-catch such as unintended fish and even seabirds
What is the main food prey of Antarctic bird South-polar skua
Adele penguin chicks and eggs and fish
What is the largest flying antarctic bird
Giant Antarctic Petrel
What is the smallest antarctic bird and what does it feed on
Wilsons storm petrel - 10cm long - feeds on krill and organic waste
What is the main food prey of the Adele penguin
Krill - 99%
What are the main predators of the Adele Penguin
Skuas and petrels; killer whales and leopard seals
How do Emperor penguins reproduce
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
What is the largest proportion of Antarctic shelf bethos fauna made of
Sessile suspension feeders such as sponges, cnidarians, bryozoans, ascidians and echinoderms
How is gigantism possible in polar waters
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
