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Aquatic Biomes Broad aquatic ecological associations can be characterized by their physical environment, chemical environment, geological features, photosynthetic organisms, and heterotrophs. 97% oceans 2% glaciers 1% lakes, rivers, streams. Transport over land. Solar energy.
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Aquatic BiomesBroad aquatic ecological associations can be characterized by their physical environment, chemical environment, geological features, photosynthetic organisms, and heterotrophs
97% oceans 2% glaciers 1% lakes, rivers, streams Transport over land Solar energy Net movement of water vapor by wind Precipitation over land Precipitation over ocean Evaporation from ocean Evapotranspiration from land Percolation through soil Runoff and groundwater
Lakes Coral reefs Rivers Oceanic pelagic and benthic zones Estuaries 30ºN Intertidal zones Tropic of Cancer Equator Tropic of Capricorn 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 Streams and Rivers Current Life Effect of damming A headwater stream in the Great Smoky Mountains The Mississippi River far from its headwaters
Fig. 52-18c Wetlands Okefenokee National Wetland Reserve in Georgia
Fig. 52-18f Estuaries An estuary in a low coastal plain of Georgia
Fig. 52-16a Littoral zone Limnetic zone Photic zone Pelagic zone Benthic zone Aphotic zone Rooted and floating aquatic plants live in the shallow and well-lighted littoral zone Limnetic zone is too deep
Stratification - Dimictic example, effects oxygen and nutrient levels in water Summer Spring Autumn Winter 22º 4º 0º 4º 20º 4º 2º 4º 18º 4º 4º 4º 8º 4º 4º 4º 6º 4º 4º 4º 5º 4ºC 4ºC 4ºC 4ºC Thermocline
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 Precipitation Interception Surface flow Groundwater in and outflow Tidal 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 ground high rain, low evaporation, low energy, organic sediment, high water table Precipitation Interception Surface flow Groundwater in and outflow Tidal flow
Permanence and periodicity Hydroperiod: Frequency of inundation tidal marsh groundwater fed (constant) vernal pool seasonal rapid flooding from rain or meltwater
Hydrology factors and results High energy 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. • Streams, rivers, tidal marshes • High dissolved O2 • High flushing • Open cycling • Erosion dominant • Not much organic matter • High primary productivity • Benthic invertebrates
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 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 • 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
pH (acidity), Salinity pH Salinity Salts Fresh water, brackish, sea water, salt marsh, hypersaline Changes in salt concentration affect osmoregulation of animals • 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
pH (acidity), Salinity pH 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. • 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
Fig. 55-14c N2 in atmosphere Assimilation Denitrifying bacteria NO3 – Nitrogen-fixing bacteria Decomposers Nitrifying bacteria Ammonification Nitrification NH3 NH4 NO2 – + Nitrogen-fixing soil bacteria Nitrifying bacteria
Fig. 55-14d Precipitation Geologic uplift Weathering of rocks Runoff Consumption Decomposition Plant uptake of PO43– Plankton Dissolved PO43– Soil Uptake Leaching Sedimentation
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