What is an example of a biotic index?

Ecological Indices For example, the Trent biotic index of water quality is derived from a mix of the presence or absence of certain indicator species and the number or diversity of taxa (or groups) or organisms present.

What is the EPT index?

The EPT Index is the total number of distinct taxa within the groups, Trichoptera, Ephemeroptera, and Plecoptera. For example, if five species of Ephemeroptera (mayflies), five Plecoptera (stoneflies), and two Trichoptera (caddisflies) are found at a site, the total number of EPT taxa and Index would equal 12.

What does high biotic index mean?

The Hilsenhoff Biotic Index (HBI) estimates the overall tolerance of the community in a sampled area, weighted by the relative abundance of each taxonomic group (family, genus, etc.).

What is biotic analysis?

Biotic element analysis is an alternative to the areas-of-endemism approach for recognizing the presence or absence of vicariance events in a given region. If an ancestral biota was fragmented by vicariance events, biotic elements or clusters of distribution areas should emerge.

How is BOD measured ESS?

BOD is essentially the amount of dissolved oxygen required to break down organic materials in a given volume of water through aerobic activity. Essentially it is a measure of oxygen uptake in water. Determined by the number of aerobic organisms and their rate of respiration.

What is family biotic index?

Hilsenhoff Family Biotic Index (FBI) The FBI is calculated by multiplying the number in each family by the tolerance value for that family (Table 1), summing the products, and dividing by the total arthropods in the sample (Hilsenhoff 1988).

How do I calculate my EPT index?

EPT Index is the total number of Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) divided by the total number of individuals across all taxa.

How is BOD calculated?

Dissolved oxygen (D.O.) is measured by probe before and after incubation. BOD is computed based on the difference between initial and final D.O. The test uses dilution water and a known amount of sample in a 250-300 ml incubation bottle.

How is BOD 5 measured?

Measuring biochemical oxygen demand requires taking two measurements. One is measured immediately for dissolved oxygen (initial), and the second is incubated in the lab for 5 days and then tested for the amount of dissolved oxygen remaining (final).