APES 8.5-6

process of eutrophication?

1) Algae bloom covers surface of water, blocking sunlight & killing plants below surface 2) Algae eventually die-off; bacteria that break down dead algae use up O2 in the water (b/c decomp. = aerobic process) 3) Lower O2 levels (dissolved oxygen) in water kills aquatic animals, especially fish 4) Bacteria use up even more O2 to decompose dead aq. animals 5) Creates pos. feedback loop: less O2 → more dead org. → more bacterial decomposition → less O2 Algae bloom due to increase of N/P → decreased sunlight → plants below surface die → bacteria use up O2 for decomp. → hypoxia (low O2) & dead zones

aquatic life interactions with dissolved oxygen

1) All aq. life requires DO (dissolved oxygen) in water for respiration 2) As DO decreases, fewer species can be supported 3) Most fish require at least 3.0 ppm to survive, 6.0 ppm to reproduce

Major N/P sources:

1) Discharge from sewage treatment plants (N/P in human waste & phosphates in soaps/detergents) 2) Animal waste from CAFOS 3) Synthetic fertilizer from ag. fields & lawns

effects of thermal pollution

1) Heat increases the respiration rate of aquatic organisms (thermal shock) 2) Hot water also has less O2 --> This can lead to suffocation without enough O2 to support respiration

Sources of Thermal Pollution

1) Power plants use cool water from surface/ground water sources nearby to cool steam used to turn a turbine back into water to reuse 2)Steel mills, paper mills, and other manufacturing plants also use cool water to cool down machinery & return warmed water to local surface waters 3) Urban stormwater runoff can also cause thermal pollution due to heat from blacktop/asphalt ***4) Nuclear power plants require especially large amounts of cool water to cool steam back into water & to cool the reactor core

how do Aquatic ecosystems naturally undergo succession

1) Sediment buildup on bottom (benthic zone) leads to higher nutrient levels 2) Overtime, ponds naturally shift from oligotrophic, to mesotrophic, to eutrophic

Sources of Thermal Pollution

41) Power plants use cool water from surface/ground water sources nearby to cool steam used to turn a turbine back into water to reuse 2) Steel mills, paper mills, and other manufacturing plants also use cool water to cool down machinery & return warmed water to local surface waters 3) Urban stormwater runoff can also cause thermal pollution due to heat from blacktop/asphalt **4) Nuclear power plants require especially large amounts of cool water to cool steam back into water & to cool the reactor core

solutions to thermal pollution

Cooling towers/ponds are used to cool steam back into water & to hold warmed water before returning to local surface water - Already standard in nuclear power plants, but can be optimized to cool water better or hold it longer before returning to nearby surface waters

what causes dead zones

Decrease in dissolved oxygen (hypoxia)

Explain the environmental effects of excessive use of fertilizers and detergents on aquatic ecosystems.

Eutrophication occurs when a body of water is enriched in nutrients.

what is the relationship between water temp & oxygen solubility

Inverse relationship between water temp & oxygen solubility As water temp. ⬆️ DO (dissolved oxygen) ⬇️

Eutrophication

The increase in nutrients in eutrophic aquatic environments causes an algal bloom. When the algal bloom dies, microbes digest the algae, along with the oxygen in the water, leading to a decrease in the dissolved oxygen levels in the water. The lack of dissolved oxygen can result in large die-offs of fish and A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.

why does thermal pollution accure in aquatic ecosystems.

Thermal pollution occurs when heat released into the water produces negative effects to the organisms in that ecosystem.

effects of thermal pollution on aquatic ecosystems.

Variations in water temperature affect the concentration of dissolved oxygen because warm water does not contain as much oxygen as cold water.

Oligotrophic Waterways

Waterways with low nutrient (N/P) levels, stable algae pop, and high dissolved oxygen

what are Anthropogenic causes of eutrophication

agricultural runoff and wastewater release.

what are Hypoxic waterways

bodies of water that are low in dissolved oxygen.

Oligotrophic Waterways are caused by

lack of nutrient pollution, or age of the body of water

Compared to eutrophic waterways to oligotrophic waterways

oligotrophic waterways have very low amounts of nutrients, stable algae populations, and high dissolved oxygen.

3 different types of waterways amounts of nutrients

oligotrophic, to mesotrophic, to eutrophic

what is Solubility

the ability of a solid/liquid/gas to dissolve into a liquid (oxygen dissolving into water in this case)

Thermal pollution:

when heat released into water has negative effects on organisms living in the water