BIO3082 Lecture Notes - Lecture 18: Colobanthus Quitensis, Antarctic Krill, Tardigrade
Lecture 18 – Antarctica
Antarctica Hosts an Endemic and Specialised Biodiversity
• Antarctica: vast land mass twice the size of Australia
• Over 98% of its land is covered in thick ice
• Coldest, driest and most isolated of continents – harbours little terrestrial life
• Biodiversity is rich in ice-free regions
o Animal and plant life can be observed in ice-free regions of Antarctica
▪ Comprise of <1% of Antarctica
o Many species occur in single region e.g. tardigrade and rotifer
o Many ice free regions are geographically isolated
▪ Abiotic factors (temperature, wind and water content are
favourable in north Antarctic peninsula than east) → drive
regional endemism
• Lichens and Moss Species
o Antarctica hosts over 200 lichen and 100 moss species
▪ Two flowering plant species present: Antarctic pearlwort
▪ Found in warm and moist Antarctic Peninsula
o Can survive prolonged desertification
• Range of Invertebrates
o Endemic springtails, nematodes, mites, rotifers and tardigrades
o One insect species is present
o Ice free regions are important breeding grounds for seals, penguins,
petrels and albatrosses
Features of Biodiversity in Terrestrial and Marine Antarctica
• Microbes comprise most terrestrial biodiversity
o Very rich microbial life in
▪ >400 microbial species
o Special adaptations to survive the freezing temperatures and low
nutrient conditions
▪ Use organic carbon available instead of photosynthesis
▪ Survive
o Dominant community generate biomass and energy by scavenging
atmospheric hydrogen
• Sea Hosts Vast – Marine
o Over 8000 marine species have been described around Antarctica –
many of them endemic
o Richest diversity are invertebrate species: isopods, cephalopods,
hexacorals, sea spiders and krill
o E.g. Antarctic Krill – form basis of Marine Food Webs
▪ Component of Southern ocean food web
▪ Colossal numbers – filter feeding on sea and ice algae
▪ Support higher trophic levels
• Other species: diverse invertebrates, toothfish, seabirds,
seals and whales
• Depend on kill through primary or secondary trophic
interactions
Anthropogenic Pressures Affecting Antarctic Region
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