Effects of Municipal Wastewater and Run-off on Aquatic Systems

Question 1

Environmental Stress

Answer 1

-rarely exposed to just 1 stressor, cumulative stressors

Question 2

Freshwater pollution

Answer 2

• chemical cocktail
• temperature
• fishing

Question 3

Municipal wastewater effluent

Answer 3

• Pharmaceuticals
• Hormones
• Personal care products
• Microplastics
• Bisphenol A
• Illicit drugs
• Caffeine

Question 4

Pharmaceuticals

Answer 4

• Non-steroidal anti-inflammatory drugs (ibuprofen-alters gene expression)
• Birth control pills (endocrine disruption)

Question 5

Hormones

Answer 5

• estradiol, estrone, estriol
• testosterone
• natural hormones and compounds with structural similarities to estrogens can make wastewater have estrogenic effects

Question 6

Personal care

Answer 6

• antibacterial products

- lead to selection of resistant bacteria

Question 7

Bisphenol A

Answer 7

• BPA, BPS

- potent estrogenic compounds, replacement still bad, consequences are unknown

Question 8

Pollutants impacts on aquatic ecosystems

Answer 8

• all effluent moves into sewage treatment plant at the same time
• treatment plants only filter out phosphorous
• affects areas downstream

Question 9

Endocrine disrupting compounds

Answer 9

• interfere with normal hormone function
• estrogen mimics
• compounds in sewage effluent act like estrogen in organisms living downstream
• feminization of male fish (intersex)

Question 10

intersex

Answer 10

-development on eggs in the testes

Question 11

Endocrine disrupting compounds example-birth control

Answer 11

• multiyear whole lake manipulation (experimental lakes area)
• ecotox BACI (before-after-control-impacted) design
• ethynylestradiol was added
• same response in both female and male fish
• population collapsed
• exposure levels were really high, very potent but not always detected in Canadian rivers

Question 12

Endocrine disrupting compounds example-sampling fish

Answer 12

• sample fish to determine what is going on
• longnose dace from rivers in Alberta (electrofishing)-even though water too potent for other fish species, their population will grow and thrive
• collection of fish from a variety of areas near Lethbridge and Red Deer
• cattle feed lots along Oldman river-hormones from cows move into river way
• sex of fish turned towards females, males less abundant
• vitellogenin-measure the gene expression levels
• small testosterone amounts and more estrogenic compounds
• gonad size and vitellogenin (estrogen compounds) have negative correlation