2. Diversity Indices and Standards
Ecology – study of the interrelationships between plants and animals and their abiotic environment.
Species – individuals that interbreed freely to produce fertile offspring.
Population – all the individuals of the same species in a defined area. All the Micropeterus salmoides in Lake Ray Roberts.
Community – all the populations in a defined area, or all the fish in Lake Ray Roberts.
Ecosystem – Lake Ray Roberts, the surrounding watershed and all the organisms there in.
Watershed – the area of land that catches precipitation that then if transported along the surface drains to a common point.

3. Historically pollution and organic enrichment problems were synonymous
Historically pollution and organic enrichment problems were synonymous. Engineers and chemists used physical and chemical surveys to tell them about the “health” of a system.
Measured parameters like: pH, dissolved oxygen, and BOD5
Why can’t you use physical/chemical measurements alone to tell you about the “health” of an ecosystem?
When biologists became significantly involved they tended to provide lists of species they found in a survey.
Species Lists…. Head of chironomid… dichotomous key
Indicator organisms
Diversity indices
Eventually developed a belief that organisms living in a system are probably the best indicator of their health.

5. In the discussion that follows the letters used in the listing of organisms represent species A = a species, B = a species, etc.
The indices that are used in the following series of slides are examples of the kinds of indices that have been developed. There are many variations of these indices and each has its own inherent strengths and weaknesses.
If you are using diversity indices you would never
represent your data by a single index!

30. CCC criteria continuous concentration
CMC criteria maximum concentration

35. The State criterion in Texas for a given river might look like the formula below where the accounts for the acid soluble function and the 1.60 for the water effects ratio assigned to a particular receiving system.
(0.960)(1.60)e(0.9422([ln hardness])
For the chronic value for 100 mg/L hardness as CaCO3
Answer is:
29.5 ug/L copper; without the and the 1.60 the standard would be 19.2 ug/L