Water Pollution

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• Water Pollution Components
• Other Chemicals and Minerals
• Acids and acidifying compounds
• Many originate in the atmosphere (sulfuric acid,
  nitric acid) or from runoff passing through mine
  tailings
• Aquatic organisms generally intolerant of low pH
• Effects
• Irritates gills of fishes and crustaceans and
  interferes with gas exchange
• Irritates slime layer of fishes (reduces
  resistance to pathogens)
• Erodes shells of aquatic mollusks and arthropods
• Impedes ability of crustaceans to recalcify after
  molting
• Facilitates release of toxins bound to particles
  in sediments

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• Water Pollution Components
• Other Chemicals and Minerals
• Acids and acidifying compounds
• Many originate in the atmosphere (sulfuric acid,
  nitric acid) or from runoff passing through mine
  tailings
• Aquatic organisms generally intolerant of low pH
• Effects
• Irritates gills of fishes and crustaceans and
  interferes with gas exchange
• Irritates slime layer of fishes (reduces
  resistance to pathogens)
• Erodes shells of aquatic mollusks and arthropods
• Impedes ability of crustaceans to recalcify after
  molting
• Facilitates release of toxins bound to particles
  in sediments

4

• Water Pollution Components
• Other Chemicals and Minerals
• Nutrients
• Nitrates, nitrites, phosphates
• Common sources
• Crop and lawn fertilizers
• Manure
• Sewage
• Detergents containing phosphates and nitrates
• Excessive nutrient loading ? eutrophication
• Effects
• Plant growth can clog waterways (ecology,
  navigation)
• Plants can interfere with recreation (swimming,
  boating)
• Algal growth can impede submerged plant growth
• Nighttime oxygen depletion
• Nitrate ? methemoglobinemia (blue baby syndrome)
• Nutrients can be difficult to control once in a
  system
• Recycling and regeneration

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Kiely 1997 Environmental Engineering
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• Water Pollution Components
• Other Chemicals and Minerals
• Metals
• Normal constituents of fresh waters at low
  concentrations
• Human activities sometimes lead to elevated
  levels
• May not be toxic at low concentrations or low
  trophic levels
• Toxic at higher concentrations
• May bioaccumulate and biomagnify
• Effects
• Health Ex Aluminum interferes with salt
  regulation in fishes and causes gills to produce
  large quantities of mucus
• Chelators Bind nutrients, trace elements, and
  other necessary chemicals

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• Water Pollution Components
• Sediments (Siltation)
• Suspended particles, usually from erosion in
  watershed
• Especially problematic in areas with
• Plowed fields
• Construction sites
• Logging sites
• Strip-mined areas
• Effects
• Clog respiratory/feeding structures
• Abrade skin and shells
• Smother eggs and larvae on bottom
• Impair photosynthesis by blocking light
• Transport bound chemicals
• Decrease aesthetic, recreational, commercial
  value (beneficial uses)
• Fill in crevices and, eventually, water bodies

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• Water Pollution Components
• Heat (Thermal pollution)
• Sources
• Condenser cooling water from electricity
  generating facilities (industrialized nations)
• Especially problematic in areas with low flow
  rates
• Heat discharged per kW generated has dropped by
  50-70 since 1950
• Generation capacity has increased substantially
• Total heat discharge today 50-100 greater than
  in 1950
• Effects
• Reduces solubility of O2
• Increases rate of degradation (exacerbates O2
  depletion)
• Disrupts life cycles of organisms that use
  temperature changes as cues
• Enhances development of some eggs/larvae/juveniles
  and inhibits/kills others
• Alters composition of algal community
• - Diatoms dominate cool, oligotrophic
  waters
• - Chlorophytes dominate warm,
  oligotrophic waters
• - Cyanobacteria dominate still warmer
  waters

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• Biodiversity Definitions and Assessment
• Major issue Potential loss as a result of human
  activities
• Definitions
• Discussion requires clear consensus about what
  biodiversity is and how its defined
• Fundamental unit species
• What is a species??
• Species
• Group of genetically similar organisms that
  interbreed naturally and freely to produce
  viable, fertile offspring, but do not share this
  behavior and outcome with individuals of other
  species
• Problem Some people consider this definition to
  be inadequate. Why??

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• Biodiversity Definitions and Assessment
• Definitions
• Species
• Geographic Isolation
• Populations could interbreed if geographic
  barrier could be surmounted
• Separate species? Subspecies? Populations?
• Natural Hybrids
• Ex Horse Donkey ? Mule
• Ex Queen Blue ? Townsends Angelfish
• Separate species? If a natural hybrid
  disappears, is it really gone so long as parent
  species remain?
• Polymorphism
• Ex - Hamlets
• How different must two species be to constitute
  separate species? Humans and chimpanzees are
  estimated to be 98 identical at the DNA level.

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• Biodiversity Definitions and Assessment
• Definitions
• Species
• Geographic Isolation
• Populations could interbreed if geographic
  barrier could be surmounted
• Separate species? Subspecies? Populations?
• Natural Hybrids
• Ex Horse Donkey ? Mule
• Ex Queen Blue ? Townsends Angelfish
• Separate species? If a natural hybrid
  disappears, is it really gone so long as parent
  species remain?
• Polymorphism
• Ex - Hamlets
• How different must two species be to constitute
  separate species? Humans and chimpanzees are
  estimated to be 98 identical at the DNA level.

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Blue
Queen
Townsends
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• Biodiversity Definitions and Assessment
• Definitions
• Species
• Geographic Isolation
• Populations could interbreed if geographic
  barrier could be surmounted
• Separate species? Subspecies? Populations?
• Natural Hybrids
• Ex Horse Donkey ? Mule
• Ex Queen Blue ? Townsends Angelfish
• Separate species? If a natural hybrid
  disappears, is it really gone so long as parent
  species remain?
• Quagga
• Polymorphism and Genetic Variability
• Ex - Hamlets
• How different must two species be to constitute
  separate species?

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Barred
Black
Golden
Blue
Indigo
Yellowtail
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• Biodiversity Definitions and Assessment
• Definitions
• Species
• How do we identify a species?
• How do we quantify the number of species in an
  area when there is disagreement about what
  constitutes a species?
• Recently Focus on preservation of processes that
  lead to speciation
• Suggests emphasis on conservation of intact
  habitat vs. single species (HCP vs. ESA)