Standard Taxonomic Effort

B-IBI calculations and results are influenced by the level of taxonomic effort specified for benthic macroinvertebrate taxonomic identification. For example, are chironomids identified to the family, subfamily, tribe, or genus-species level for a certain site visit or project year? Comparing data across projects and over time requires some level of taxonomic standardization to ensure that a difference in B-IBI scores and metrics is due to biological condition and not modifications to taxonomic handling.

Three Levels of Taxonomic Effort

We have developed three levels of standard taxonomic effort (STE), fine, medium, and coarse taxonomic resolution, that are used as a guide to labs during taxonomic analysis of samples, as well as during scoring.

Samples analyzed to the fine resolution STE can be rolled up to the medium or coarse STE for scoring. Scoring of certain B-IBI metrics (taxonomic richness, clinger richness, and % dominant) are adjusted based on this selection.

More details about the 3 levels are found in the table and narrative below. Section 2.2 of the B-IBI recalibration report discusses the impact of taxonomic effort on B-IBI and explains how metric scoring was adjusted to ensure B-IBI comparability regardless of STE level.

The effort of various taxa groups for the three levels of standard taxonomic effort.
Taxa Group	Fine STE	Medium STE	Coarse STE
Oligochaeta (segmented worms)	Subfamily/genus	Family	Subclass (“Oligochaeta”)
Acari (mites)	Genus	Subclass (“Acari”)	Subclass (“Acari”)
Gastropoda (snails)	Genus	Genus	Family
Dytiscidae (predaceous diving beetles)	Genus (adults and larvae)	Genus (adults) Family (larvae)	Family (adults and larvae)
Simuliidae (blackflies)	Genus (larvae and pupae)	Genus (larvae) Family (pupae)	Family (larvae and pupae)
Chironomidae (midges; larvae and pupae)	Genus/species/species group	Subfamily/tribe	Family
Trichoptera (caddisflies)	Genus/species/species group	Genus (larvae) Family (pupae)	Genus (larvae) Order (pupae)
All other taxonomic groups	Lowest practical level: typically genus or species	Lowest practical level: typically genus or species	Lowest practical level: typically genus or species

2012 STE: Fine

This is the taxonomic effort level used by the Washington State Department of Ecology. Oligochaetes at lowest possible level, Acari at genus, Snails at genus, Dytiscidae larvae and adults to genus, Simuliidae larvae and pupae to genus, Chironomids at genus/species/species groups, Trichoptera larvae to genus/species/species group and pupae to family.

View scores: Table

2012 STE: Medium

This level is between the coarse and fine levels. Oligochaetes at family, Acari at "Acari", Snails at genus, Dytiscidae adults to genus larvae to family, Simuliidae larvae to genus and pupae to family, Chironomids at subfamily/tribe, Trichoptera larvae to genus/species/species group and pupae to family.

View scores: Table

2012 STE: Coarse

This is the closest to historical, pre-2012 King County sampling efforts. Oligochaetes at "Oligochaeta", Acari at "Acari", snails at family, Dytiscidae to family for adults and larvae, Simuliidae larvae and pupae at family, chironomids at family, Trichoptera larvae to genus/species/species group and pupae to "trichoptera."

View scores: Table

2024 Standard Taxonomic Effort: Fine (provisional)

STE table created 2025_01_16 by Beka Stiling and Kate Macneale to reflect updated and corrected rules for calculating BIBI scores based on rules determined in 2014 recalibration, but had been incorrectly entered at the time. This new table corrects how Trichoptera pupae are counted, for example. This table also includes taxa we need to exclude but that were incorrectly rolled up and included in previous scores. Beth Sosik created this new table and BK and KM are simply adding it to PSSB.

View scores: Table

Select Data Set:
Resolve a Taxon (optional):	Match only common taxa If the organism you need is missing, first make sure the above is not checked. If you still cannot find it, contact Doug Henderson (Douglas.Henderson@KingCounty.gov) with its name, its parent taxon, e.g., a species's genus, and, if available, its TSN.