There is considerable doubt as to whether this is a valid taxon, and some authors argue that it is just a form of Coregonus artedi.

The number of salmonid taxa within some genera (e.g. Salmo, Salvelinus, and Coregonus) listed in various taxonomic databases (e.g. Fishbase or Eschmeyer's Catalog of Fishes) has increased very rapidly over the past 15-20 years. Many of these taxa are not widely accepted across the international community and are associated with very sparse data, leading to significant difficulty in accurately carrying out Red List assessments. The SSG strongly recommends a rigorous evaluation of the validity of these species designations, which can have real implications where legal protection is reflected by the use of these binomial taxonomic names.

This species is listed as Data Deficient in view of taxonomic uncertainties. There is no agreement on whether the species is distinct from the more common and widespread Coregonus artedii. See 2007 COSEWIC report for a more complete description of the taxonomic uncertainty.

The historical range is obscured by taxonomic uncertainties but apparently included the North American Great Lakes (perhaps only lakes Huron and Michigan); the last known specimens from Lake Huron are from 1923 and from Lake Michigan are from 1969. Populations of what may be this species are extant in Lake Nipigon and possibly in other localities in central Canada (Turgeon et al. 1999, T. N. Todd pers. comm. 1999, cited by Nelson et al. 2004). Lake Nipigon has a surface area of 4,848 km². There continues to be a nigripinnis ecomorph captured regularly in Lake Nipigon. It has declined in abundance by about 50% over the past decade, however. See the COSEWIC (2007) for additional details on geographic range.

This species is represented possibly by one or more extant populations (Nelson et al. 2004).

The total adult population size is unknown but probably small.

Formerly this was one of the most commercially valuable of coregonids in the Great Lakes. See 2007 COSEWIC report for information on status in Canada

Trend over the past three generations (about 22 years) is unknown, but adult population size suspected to be declining.

This species has been found mostly in deep water of large lakes, at depths of 90-160 m in lakes Michigan and Huron, 2-100 m in Lake Nipigon (Page and Burr 2011).

Decline and extirpation from the Great Lakes was due to overfishing, sea lamprey predation, and introgressive hybridization (Miller et al. 1989). Current threats to the Lake Nipigon population include commercial fishing, predation by rainbow smelt, and interbreeding with cisco (Coregonus artedi) (Royal Ontario Museum and Ontario Ministry of Natural Resources, COSEWIC 2007).

This species at least formerly was taken in commercial fisheries.

The identity of the population in Lake Nipigon needs to be confirmed. Current range and abundance need to be determined. Turgeon and Bernatchez (2003) document phenotypic diversity in coregonid fishes and recommend establishing Evolutionarily Significant Units (ESUs) for lakes with distinct ecomorphotypes.