ENV330H5 Lecture 1: env330- 1
Document Summary
Environmental studies of freshwater systems bioassessment and the reference. Sampling designs and their limitations in freshwater systems. Contamination = presence of a foreign substance (concentrations above background) Pollution = contamination that causes harm (adverse biological effects; harm to infrastructure) Reliance on water/sediment guidelines (wqg/sqgs) can produce false positives. Reference sites may have low levels of contamination. to determine polluted areas that are truly of concern, investigators should not be distracted by relatively minor levels of contamination that are unlikely to be causing major ecosystem alterations. (chapman 2007) Measuring levels of chemical substances in the environment measures contamination, not pollution. We cannot measure all possible contaminants, run all possible tests, or determine the health of all organisms. Determine possible ecological impacts from chemical or other stressors based on multiple lines of evidence (loe) Include both chemical and biological measurements; laboratory and field components. Observations: (e. g. , of the status of resident communities; physical/chemical/wq data)
