Polar Seas Flashcards
Seasonality in polar environments
Lots of change in seasonal ice cover with extreme of photoperiods with summer having 24hr sunlight and winter 4hours of sunlight
Animals response and behaviour productivity due to growing seasons
The Arctic
Arctic is an ocean covered in ice, shallowest ocean therefore temp and salinity varies across the year
Salinity very low due to melting of ice in summer influx of freshwater however more so that it’s surrounded by land and therefore riverine inputs
Low nutrient levels
B-road shallow continental shelf
The Antarctic
98% of continental covered by thick ice 90% of the worlds ice and 70% of worlds freshwater
Colder than Arctic
Circumpolar polar current reduced connectivity with other basins isolating it hydrographically making it colder.
Warming influence of the sea makes the coast warmer
Large change in ice seasonally
Marrow deep continental shelf due to isostatic pressure
High levels of nutrients
Ice sheets and ice bergs
Ice sheets grow by accumulation and waves break up ice sheets to ice bergs
Sea/pack ice
Formed from freezing seawater in autumn
Inoculated with organisms as ice isn’t fully solid and is a network of pores and Chanel’s where the organisms live
What is sympagic
Communities within ice
Summaries sympagic system
Sea ice biota become caught up in the semi solid matrix
Adapted to low light low temp and high salinity
What is cryopelagic
Communities under ice
Summarise cryopelagic systems
Prescient of larval krill and adult krill is distributed in the open ocean. The krill takes advantage of the sympagic algae
In summer there are lots of blooms, ice melts releasing lots of algae in the water
Upwelling occurs in summer bringing up more nutrients as less dense coldwater sinks
Productivity in Arctic and Antarctic
Arctic is strongly stratified
Antarctic high nutrients and low chlorophyll, not stratified
