IUCN Red List Assessment
Red List Category Year Assessed
Near Threatened Red List Criteria Version
Reeves, R.R., Jefferson, T.A., Karczmarski, L., Laidre, K., O’Corry-Crowe, G., Rojas-Bracho, L., Secchi, E.R., Slooten, E., Smith, B.D., Wang, J.Y. & Zhou, K. Reviewer/s
Brownell Jr., R.L. & Cooke, J. (Cetacean Red List Authority) Contributor/s Justification
This species was described as separate from O. brevirostris only as recently as 2005. The available evidence supports the reasoning that there are fewer than 10,000 mature individuals and therefore the species meets the C criterion for Vulnerable in terms of population size. However, data are lacking to substantiate a continuing decline (C2). Similarly, no studies of population structure have been carried out so it is uncertain if either of the C2a subcriteria is met (i.e., whether no subpopulation is larger than 1000 mature, or all mature individuals are in a single subpopulation). Although the species could be listed as Data Deficient, Near Threatened is more appropriate given its limited range, low densities in surveyed areas, and its continuing vulnerability to bycatch. Rigorous, more extensive surveys are needed to support a reassessment of the species; it may then be found to qualify for listing as Vulnerable or possibly even Endangered.