"Higher Level Taxa Exclusions" occur when fish are unable to be identified down to species level. This most often occurs with species that are difficult to distinguish in the field, such as the sculpin species. In these cases, they are often recorded as "Sculpin spp.", shorthand for "Undetermined Sculpin Species".

For FIBI calculations, these higher level taxa groups are not included as a separate, unique species in the species count metrics if there are one or more species identified down to species level within this taxa group. For example, a fish sample containing both Sculpin spp. and Mottled Sculpin would only count as one unique species, not two.