Puget Sound Stream Benthos

Excluded Taxa

B-IBI scores can be influenced by taxonomic handling including which organisms are sorted, identified, counted, and used to calculate the ten individual B-IBI metric calculations. Stream biological monitoring programs throughout Puget Sound are conducted to assess the biological condition of freshwater ecosystems. Samples are collected in the aquatic benthos, therefore most organisms in the final sample are likely freshwater benthic critters. However, taxa that are predominantly terrestrial, surface water or marine may find their way into samples. For example, terrestrial taxa such as spiders may be picked up in the collection net as field crews navigate riparian forests. Some macroinvertebrate project stewards request that taxonomic labs count all organisms in a sample while others specify that certain taxa be excluded.

Macroinvertebrate bioassessment data are increasingly being combined from individual projects to assess regional conditions. To standardize regional B-IBI calculations and ensure that differences in B-IBI scores are related to biological condition rather than taxonomic handling, certain terrestrial, surface water, microscopic, and marine taxa are excluded from B-IBI metric score calculations within the Puget Sound Stream Benthos data management system. Benthic taxa, water column taxa, and taxa not specified are included in B-IBI calculations. Rhithron Associates, Inc. helped develop the list of taxa to be excluded. If the classification of any taxa were questionable, inclusion trumped exclusion to avoid erroneously excluding freshwater aquatic critters.

The table below lists the excluded taxa by reason and notes exceptions to exclusion rules. Alternatively, click the ‘view’ button below to see a list of organisms excluded in B-IBI calculations with exceptions marked as ‘no’ in the “Excluded” column (please note this is not a complete list of all potential taxa). For example, the Class Archnida is excluded, but one of its “children”, the subclass Acari (aquatic mites) is included because Acari are frequently found in freshwater benthic samples.

Exclusion Reason Taxa Excluded
(exceptions marked with * and explained in next column)
Exceptions to Include
Microscopic Cladocera, Copepoda
Marine Gnorimosphaeroma
Water Surface Gerridae, Veliidae, Hebridae, Hydrometridae, Macroveliidae, Mesoveliidae, Saldidae
Terrestrial Lumbricidae, Eiseniella tetraedra, Araneae, Opiliones, Pseudoscorpiones, Isopoda*, Ligia, Ligidium, Armadillidium, Cylisticus, Porcellio, Porcellionides, Trachelipus, Oniscidae, Oniscus, Philoscia, Trichoniscus, Collembola, Entomobryomorpha, Entomobryidae, Isotomidae, Poduromorpha, Hypogastruridae, Poduridae, Sminthuridae, Carabidae, Bostrichidae, Dermestidae, Cerambycidae, Chrysomelidae, Cleridae, Melyridae, Coccinellidae, Corylophidae, Cryptophagidae, Latridiidae, Nitidulidae, Phalacridae, Brentidae, Curculionidae, Anthicidae, Melandryidae, Meloidae, Mordellidae, Oedemeridae, Salpingidae, Scraptiidae, Tenebrionidae, Buprestidae, Byrrhidae, Heteroceridae, Cantharidae, Elateridae, Eucnemidae, Lampyridae, Scirtidae, Scarabaeidae, Ptiliidae, Staphylinidae, Muscomorpha*, Agromyzidae, Anthomyiidae, Asilidae, Bombyliidae, Calliphoridae, Carnidae, Chloropidae, Conopidae, Drosophilidae, Fanniidae, Heleomyzidae, Hippoboscidae, Hybotidae, Lauxaniidae, Lonchaeidae, Lonchopteridae, Milichiidae, Nemestrinidae, Piophilidae, Pipunculidae, Scathophagidae, Sepsidae, Sphaeroceridae, Tachinidae, Tephritidae, Therevidae, Rhagionidae, Xylophagidae, Bibionidae, Cecidomyiidae, Mycetophilidae, Sciaridae, Scatopsidae, Cercopidae, Cicadellidae, Cicadoidea, Membracidae, Achilidae, Cixiidae, Delphacidae, Anthocoridae, Nabidae, Miridae, Reduviidae, Tingidae, Coreidae, Rhopalidae, Berytidae, Geocoridae, Lygaeidae, Piesmatidae, Pentatomidae, Scutelleridae, Thyreocoridae, Aphididae, Coccoidea, Pseudococcidae, Psyllidae, Hymenoptera, Apoidea, Andrenidae, Apidae, Colletidae, Crabronidae, Halictidae, Sphecidae, Bethylidae, Chrysididae, Formicidae, Pompilidae, Tiphiidae, Vespidae, Megaspilidae, Chalcidoidea, Chalcididae, Mymaridae, Perilampidae, Cynipidae, Figitidae, Braconidae, Ichneumonidae, Mymarommatidae, Proctotrupoidea, Diapriidae, Proctotrupidae, Symphyta, Cephidae, Pamphiliidae, Cimbicidae, Tenthredinidae, Bombycidae, Coleophoridae, Geometridae, Noctuidae, Nymphalidae, Papilionidae, Pieridae, Crambidae*, Pyralidae, Tortricidae, Orthoptera, Acrididae, Tetrigidae, Tettigoniidae, Neuroptera, Chrysopidae, Hemerobiidae, Carychium occidentale, Arionidae, Cionella, Columella, Arachnida* Isopoda*:
  • Anthuridea,
  • Asellota,
  • Calabozoida,
  • Epicaridea,
  • Flabellifera,
  • Gnathiidea,
  • Microcerberidea,
  • Oniscidea,
  • Phreatoicidea,
  • Valvifera
  • Dolichopodidae,
  • Empididae,
  • Ephydridae,
  • Muscidae,
  • Phoridae,
  • Sciomyzidae,
  • Syrphidae
  • Petrophila,
  • Parapoynx
  • Acari