Biodiversity 2- Aquatic Ecosystems Flashcards
Explain Wetlands
- In between fully aquatic and fully terrestrial ecosystems
- Standing water for at least part of the year
- Vegetation adapted to growing with submerged roots
Explain wetland vegetation type
1.Swamps – woody plants and shrubs
- Marshes – reeds, rushes, other grasses
- Bogs – sphagnum moss
- Fens – sedges, rushes
- Mangroves
Explain wetland function
- Perform services useful to humans
- Purify water by trapping sediments and breaking down toxic wastes and chemicals that run off agricultural land
- Serve as reservoirs that reduce the risk of flooding
What are the 3 types of aquatic ecosystems / wetlands
- Freshwater
- Marine
- Brackish water
Explain freshwater aquatic ecosystems
- Lakes, ponds, rivers, streams
- Only 1% of water is freshwater
- Only 0.3% of freshwater is available on the Earth’s surface, the rest is locked in glaciers, polar ice and underground aquifers
Explain marine aquatic ecosystems
Coral reefs, seashores, oceanic pelagic and benthic
zones
Explain the 2 types of freshwater ecosystems
- Standing water (ponds and lakes)
- Flowing water (streams and rivers)
Explain marine brackish water ecosystems
- Mixture of salt and fresh water
- Estuaries
What are the 3 nutrient statuses of lakes
- Oligotrophic
- Eutrophic
- Mesotrophic
Explain Mesotrophic lakes
In between Oligotrophic and Eutrophic
Explain Oligotrophic
lakes
Nutrient poor, deep, very clear water
Explain Eutrophic
Nutrient rich, shallower, water murky with phytoplankton
Explain streams and rivers heaed waters and lowest points
Headwaters :
- Water is clear
- Little sediment
- Few nutrients
- Channel is narrow
- Rocky substrate
- Water flows swiftly
At the lowest point of river :
- Water moves slowly
- More sediment
- Murkier
- Sandy substrate
- High nutrient content
- Chanel is wider
Explain estuaries
- Partially enclosed body of water where freshwater and seawater mix
- River meets the ocean
- Salinity varies greatly
- Highly productive due to nutrien
What are the 4 types of estuaries
- Salt wedge
- Partially mixed
- Well mixed
- Fjord type estuary with a sill
Explain estuary biodiversity
- Salt marsh grasses, algae, and phytoplankton are the major producers
- Many species of annelids, oysters, crabs and fish
- Many marine invertebrates and fish breed in estuaries
- Large number of waterfowl and other semi- aquatic vertebrates use estuaries as feeding areas
Explain streams and rivers fully
- Streams highest point is in the mountain
- Streams = smaller rivers
- Bodies of water that move continuously in one direction
- May originate from springs, runoffs from melting snow or ice, or outlets of lakes
- Structure changes from their point of origin (headwaters) to where they empty into a larger body of water (mouth)
Explain lake stratification
- The way it gets / is exposed to sunlight
- Layers do not usually mix; less dense water floats on top of more dense water
- In autumn, the epilimnion cools to a temperature below that of the hypolimnion
- Causes surface water to sink to the bottom and vice versa
- In winter, ice forms on the surface, maintaining a uniform temperature
- Overturn is repeated again in spring as the ice melts
What are the three layers of lakes
- Epilimnion
- Thermocline
- Hypolimnion
Explain each lake layer
- Epilimnion – Surface layer, warm from solar radiation, least dense
- Thermocline – Thin middle layer
- Hypolimnion – Lower layer, cold,
most dense
Explain what life zones can be stratified according to
1.Amount of sunlight penetration
2. Nutrient levels
3. Temperature
4. Amount of dissolved oxygen
What are the different life zones
- Littoral zone
- Limnetic zone
- Profundal zone
- Benthic zone
Explain the littorial zone
- Shallow inshore region
- Rooted vegetation
- Shallow part where you can still walk
Explain the limnetic zone
- After littorial zone
- Becomes deeper but lots of sunlight
- Upper level of open water
- Light levels are high
Explain profundal zone
Below the level of light penetration
Explain benthic zone
Bottom substrate and soil-water interface
