Topic 32 Flashcards
Total amount of water on Earth can be constant for
millennia
Aquatic biomes connected through the ..
hydrologic cycle
Aquatic biomes could equally be defined by their..
flora and fauna
Aquatic biomes mainly based on physical characters
- velocity
- temp
- clarity
- chemistry
Rivers and streams
freshwater, lotic, plants and animals must be adapted to withstand current (firmly rooted, hide in less turbulent zones by debris on river bottom) drain landscapes into oceans,
Lotic
water flows through the system
Flow rate is an important determinant of..
communities this biome can support
Streams organized into orders..
two first order streams connect to make a second order stream, the nile is a 6th order lactic system (leads to differences ins species composition)
Riparian zone
transition between rivers edge and surround land
River collects..
run off, sediment and detritus from surrounding land. also accumulate pollutants and toxins leached from surround lands
Lakes and ponds
typically freshwater. lentic. collections of water is natural depressions in the landscape. depending on depth can be thermally stratified (lake baikal) some are highly saline (great salt lake 10x ocean)
Lentic
water is stationary (non flowing)
Photic zone
depth to which light can penetrate and support plant life.
Littoral zone
shallow waters at shore
Limnetic zone
deep waters where light still penetrates
Profundal zone
deep waters where light doesn’t penetrate
Benthic zone
lake floor
Primary production of lakes and ponds can be determined by
color of lake. green is high, blue is low.
Eutrophication
addition of nutrients supports massive algal blooms, severely reducing dissolved oxygen concentrations and drastically altering lake communities
Wetlands
lotic systems formed from shallower depressions. transient moisture levels (high rate of succession) low levels of decomposition due to low oxygen.
Function of wetlands
liver of the ecosystem (filter toxins and pollutants from surrounding land) natural flood plains.
Wetlands were historically drained to..
produce agriculture land, this practice was responsible for the extirpation of malaria, vectoring mosquitoes form North America
Marshes
dominated by herbaceous plants, important breeding grounds for water fowl.
Swamps
dominated by woody plants, on every continent besides antarctica
Bogs
Secluded to northern regions, floating mats of sphagnum moss, “peatlands”
Estuaries
vertical gradients of salinity where ocean water sinks below incoming freshwater flowing from rivers. gradual slope of landscape buffers incoming tides. ultimate aquatic edge habitat (high diversity). often destroyed for coastal development
Rocky intertidal zones
on sloping rock shores between average low and high tide levels. dominated by algal and invertebrates species that can adhere to substrate and survive periods of desiccation
Kelp forests
found along temperate coasts, form an underwater “forest like” ecosystem.
Coral reefs
tropical coasts (where water is roughly 18 C) similar to underwater rainforest ecosystem but supports even higher levels of diversity
3 types of coral reefs
- fringing
- barrier
- atolls
Fringing
on rocky substrate near coastline
Barrier
separated from coast by lagoon
Atolls
independent islands
Variations in temp of coral reefs can lead to..
expulsion of symbiotic zooxanthellae and “bleaching”
Marine environment is characterized by…
salinity, waves, tides, depth and vastness
70% of the earths surface is covered by ..
the oceans and at its deepest point the ocean is 10 km
Similar to lakes and pond oceans undergo thermal stratification w presence of a thermocline..
- photic zone
- middle zones
- bottom benthic zone
The rain of organic material of the photic zone supports..
lower strata
Open ocean thought of as a ..
desert like wasteland (only 1% of harvest fish stocks come form open ocean)
Open ocean
all primary production comes form phytoplankton (algae, dinoflagellates, diatoms). some floating islands of Sargassum seaweed from discreet communities in the open ocean
Pelagic
living in the water column
Open ocean divided by depth
- epipelagic zone (200m)
- mesopelagic zone (200-1000m)
- bathypelagic (1000-4000m)
- abyssal (4000-6000m)
- hadal (below 6000m)
Garbage island
great pacific garbage patch, predicted in 1988 by NOAA. discovered in 1997. forms from gathering of debris in ocean gyre funnelling it into the centre.
Garbage island consists of
plastics, chemical sludge, and debris. estimated range from 700,000 to 15, 000, 000 km 2
Hydrothermal vent communities
largest unexplored area on earth, recently discovered on ocean floor. adapt to extreme temp (heat from vents but otherwise temp is 0) and primary production from chemosynthesis, utilizing sulphur in place of oxygen and thermal energy from vents
In reality to the ocean supports far more ..
phyla of animals than then terrestrial environment
Deep sea species adapt to..
life under significant pressure.
