Aquatic Biomes Broad aquatic ecological associations can be characterized by their physical...
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Transcript of Aquatic Biomes Broad aquatic ecological associations can be characterized by their physical...
• Aquatic BiomesBroad aquatic ecological associations can be characterized by their physical environment, chemical environment, geological features, photosynthetic organisms, and heterotrophs
97% oceans2% glaciers1% lakes, rivers, streams
Precipitationover land
Transportover land
Solar energy
Net movement ofwater vapor by wind
Evaporationfrom ocean
Percolationthroughsoil
Evapotranspirationfrom land
Runoff andgroundwater
Precipitationover ocean
LakesCoral reefsRiversOceanicpelagic andbenthic zonesEstuariesIntertidal zones
Tropic ofCancer
EquatorTropic ofCapricorn
30ºN
30ºS
fresh water or salt water (marine)Oceans cover about 75% of Earth’s surface and have an enormous impact on the biosphere
Inland aquatics
“Areas of marsh, fen, peatland, or water, whether natural or artificial, permanent or temporary, static or flowing, fresh, brackish, or salt, including areas of marine water, the depth of which at low tide does
not exceed 6 meters”
International Union for the Conservation of Nature
ENSC 2400 will cover the intertidal in Marine Biomes lecture
Running water flows down• Standing water – LENTIC systems
• Flowing water – LOTIC systems
Lakes
Oligotrophic lakes Eutrophic Lakes
Fig. 52-18d
A headwater stream in the GreatSmoky Mountains
Streams and Rivers
The Mississippi River far fromits headwaters
CurrentLifeEffect of damming
Fig. 52-18c
Okefenokee National Wetland Reserve in Georgia
Wetlands
Fig. 52-18f
An estuary in a low coastal plain of Georgia
Estuaries
Fig. 52-16a
Littoralzone Limnetic
zone
Photiczone
PelagiczoneBenthic
zoneAphoticzone
Rooted and floating aquatic plants live in the shallow and well-lighted littoral zoneLimnetic zone is too deep
Stratification - Dimictic example, effects oxygen and nutrient levels in water
Winter
4º4º4º
4ºC
4º 4º
Spring Summer Autumn
Thermocline
4º4º4º
4ºC
4º 4º4º4º
4º4ºC
2º 0º
4ºC5º6º
8º18º20º22º
Hydrology and wetland diversity• Climate (rainfall, temperature, seasonality)• Geomorphology (soils, geology, relief)
Impact defined by the water budget where the volume of water depends on
PrecipitationInterceptionSurface flow
Groundwater in and outflowTidal flow
Water budgets• General
• Marsh – Borders open water (rivers, estuaries), high energy, may be tidal, no OM buildup, plenty of dissolved O2
• Swamp – Occur in depressions, low energy, OM buildup – peat formation, low O2
• Bog- On level groundhigh rain, low evaporation,low energy, organic sediment,high water table
PrecipitationInterceptionSurface flow
Groundwater in and outflowTidal flow
Permanence and periodicityHydroperiod:Frequency of inundation
tidal marsh groundwater fed (constant)vernal poolseasonal rapid flooding from rain or
meltwater
Hydrology factors and results
High energy • Streams, rivers, tidal
marshes• High dissolved O2• High flushing• Open cycling• Erosion dominant• Not much organic matter• High primary productivity• Benthic invertebrates
Low Energy• Swamps and bogs and lakes
• Low dissolved O2• Low flushing• Closed nutrient cycling• Sedimentation dominant• Organic matter accumulates• Variable Primary Productivity• Benthic/planktonic inverts.
Human impacts• Water removal for human use– Wetlands drained, rivers
dammed, groundwater depleted
– Sustainable water usage requires considering the needs of the environment
– Global warming effects on montaine snow
Environmental factors
• Light, Temperature, Dissolved O2, pH, Salinity, Nutrients, Stratification
Light
• Light penetration depth determines how deep photosynthesis can occur
• Penetration of light into the water depends on color of the water and turbidity– Color – caused by dissolved substances from
decaying organic matter – Turbidity – from suspended materials (clay, algae)• Depends on flow, erosion, rainfall rate
Human Impacts - Light
• Clearing vegetation – increased sediment, less shading, quicker photodegradation of organic matter
• Runoff from impermeable surfaces (roads)• Nutrients in sediments cause algal blooms,
clog gills, increase turbidity for other aquatic vegetation
Temperature and Dissolved O2
Temperature• Temperature more variable
due to shallower depth• Changes seasonally or daily• Affects stratification,
metabolism • Affects dissolved O2• Human impacts include:
– Tree clearing reduces shading– Warm/cold water pollution
release from power plants or dams
Dissolved O2 (DO)• Depends on energy of
system, temp, photosynthesis, and stratification
• Used during respiration and decomposition
• Fish kills occur when DO is low – Secondary human impacts
due to effects on other things like temperature
pH (acidity), Salinity
pH• Decreases due to decomposition• Reduces wetland metabolism at
extremes (peat or limestone bogs)
• Human impacts include acid rain (Nox, SO2) from power generation , acid sulfate soils in depleted waters.
• Lowered pH increases availability of heavy metals which then kills fish
• Heavy metal waters can pollute groundwater
Salinity• Salts
– Fresh water, brackish, sea water, salt marsh, hypersaline
• Changes in salt concentration affect osmoregulation of animals
pH (acidity), Salinity
pH• Decreases due to decomposition• Reduces wetland metabolism at
extremes (peat or limestone bogs)
• Human impacts include acid rain (Nox, SO2) from power generation , acid sulfate soils in depleted waters.
• Lowered pH increases availability of heavy metals which then kills fish
• Heavy metal waters can pollute groundwater
Salinity• Salts
– Fresh water, brackish, sea water, salt marsh, hypersaline
• Changes in salt concentration affect osmoregulation of animals
• Human impacts: secondary salinity (removal of deeper rooted perennials with shallow rooted annuals, or through irrigation ) causes salts from the soil to rise and stay in surface soil. Then runoff adds salinity to waterways.
Fig. 55-14c
Decomposers
N2 in atmosphere
Nitrification
Nitrifyingbacteria
Nitrifyingbacteria
Denitrifyingbacteria
Assimilation
NH3 NH4 NO2
NO3
+ –
–
Ammonification
Nitrogen-fixingsoil bacteria
Nitrogen-fixingbacteria
Fig. 55-14d
Leaching
Consumption
Precipitation
Plantuptakeof PO4
3–
Soil
Sedimentation
Uptake
Plankton
Decomposition
Dissolved PO43–
Runoff
Geologicuplift
Weatheringof rocks
Lakes
Oligotrophic lakes Eutrophic Lakes
• When excess nitrogen and phosphorus is discharged from the watershed, massive algal blooms develop which result in the depletion of dissolved oxygen.
Eutrophication
A Dead Zone 6,000-7,000 sq miles develops
Pollution