Ecology - Southern Ocean Flashcards
Ecological Connectivity
The degree of connection between the naturual envrionments within a landscape
Processes determining ecological connectivity…
Advection (dissolved nutriet transportation, ocean currents etc)
Biological
Antarctic Bottom Water
A southern ocean water mass surrounding Antarctic with temperatures from -0.8 to 2)
Antarctic Circmpolar Current
Connects the three major basins flowing around the southern ocean
Antarctic Polar Fron
The point of convergence of water masses with major eddy activity.
Stokes Drift
Refers to the net drift that a particle moving in a fluid experiences in the direction of propogation of the fluids wave field.
Importance of souther ocean…
Global circulation, biogeochemical cycles nutrient distribution and climate reuglation
High Nutrient Low Chlorophyll
Ocean regions where phyotplankton abundance is low and fairly constant despite availabilty of macronutrients.
Iron limitation in ocean…
Diatom community generates differentaly of silicon/p conc
Why are southern ocena species often endemic?
Cold weathers and high O2 concentrations highly adapted.
Passive Dispersal
Requirement of assiistance to move from one place to another
Active Dispersal
Is movement by their own ability.
Importance of passive dispersal…
Regulates competition and accumulation allowing more favourable regions to be colonized
Example of passive dispersal…
Whales target colder areas with high prey densities in summer and in winter occupy warmer waters for calving
Phytoplankton spatial control…
By passive dispersal of eddy curents and surface currents.
What does Antarctic Poalr Front represent?
A sharp transition from warm and cold waters thus limiting potential of migration
Feature of APF…
north and south have fish populatiosn largely distinct.
Dominant fish in Antarctica….
Notothenioid…
Active dispersal in birds…
Conglomerate to ice-free alnds on islands northward and regions aroudn the ocntinent.
Why do animals breeding south of APF migrate northward during autumn/winter?
Avoid lower productiivty, harsher weather and shorter photoperiods.
Bird species migration distance…
SA, australasia, NH.
Cetacean migration….
In spring for Antarctic Krill.
