Aquatic Biomes Flashcards
What are the Two Types of Aquatic Biomes?
- Marine (ocean - salty)
- Aquatic (freshwater)
What are the 4 zones of the Ocean (from top to bottom)
- intertidal (littoral) zone
- neritic zone
- pelagic zone
- benthic zone
Characteristics of the Intertidal Zone
- shallow shoreline
- influenced by tides and substrate stability
- exposed to wide variation in light intensity and temperature
Examples of the Intertidal Zone
- estuaries, salt marsh, mangrove, rocky intertidal, sandy shores
What is an Estuary?
- freshwater from rivers/steams meets with the oceans forming brackish water
- terrestrial sediments, nutrients, high productivity
What are the 4 types of Estuaries?
- Coastal plain (ex. chesapeake bay)
- Tectonic (ex. san francisco bay)
- bar-built (ex. outer banks of the eastern USA)
- Fjord (ex. glacier bay, Alaska)
Salt marshes and Mangroves
- transition land and sea
- highly variable and dynamic due to rising and lowering tides
- typically low species diversity, but very productive
Characteristics of Salt Marshes
- high salinity (approx. 16ppt)
- concentrated along sandy shores of temperate-high latitudes
Characteristics of Mangroves
- associated with tropical latitudes
- salt tolerant evergreen trees and shrubs replace grasses
- differing tree species are generally distrusted according to height within intertidal zone
Characteristics of the Pelagic Zones
- light and temperature dependent upon depth
- most photosynthesis species inhabit the photic zone
- Coral Reefs and Kelp Forests
Characteristics of Coral Reefs
- mutualism between coral and algae
- hard corals build skeleton of calcium carbonate
- highly threatened
What is Bleaching?
- occurs in tropical coral reefs
- high temperatures causes bleaching
-ocean acidification (increase CO2) inhibits skeleton formation, as calcium carbonate is chemically basic
Characteristics of the Deep Sea
- light does not reach beyond 200 m from the ocean’s surface
- organic matter floats down from the surface, resulting in it ‘snowing’
Characteristics of Deep Sea Coral Reefs
- can be found at depths up to 600m
- do not need sunlight - fed on passing tiny organisms
-some of the oldest organisms alive on earth - deep sea coral gardens act like tropical ones
Threat to the Deep Sea Corals
Industrial Trawling
- fishing with a weighted net is smoothing out the sea floor and changing the entire ecosystem and actively destroying deep sea corals
3 types of Aquatic Freshwater Biomes
- lakes (lentic)
- rivers and streams (lotic)
- wetlands
Lotic Ecosystems
- rivers and streams
- natural channels of moving water varying in size
- canals are human-made channels of flowing water
What is the River Continuum Concept?
a model for how flow regime and food sources change with respect to river size
Lentic Ecosystems
-standing water
-lakes and ponds
- formed by natural depression, damn, glacial processes, meandering rivers, volcanic craters
- lake depth and area influence composition
- deep lakes, nutrient poor, cold, higher O2
- shallow lakes, nutrient rich, warm, lower O2
Stratification and Lake Turn Over
- occurs when lakes form three distinct thermal layers
- liquids of differing densities fo not mix well
-cold water is denser - lakes turn over in the fall when the water throughout the lake reaches a uniform temperature
Why is lake turn over necessary?
- water and wind mix evenly throughout the body of water, replenishing O2 concentrations
- lake turnover is necessary to maintain O2 balance for lake organisms
Two forms of Wetlands?
- those that form peat
- those that do not form peat
Two forms of Peatland?
- bog - found in depressions of the landscape
- fens - receive water from groundwater or surface water and are usually flat
