A delisting recommendation for the Apache Trout

I’ve spent the last 5 years working on various aspects of the Apache Trout Oncorhynchus apache, a species currently listed as ‘threatened’ on the U.S. Fish and Wildlife's List of Threatened and Endangered Species.

Apache Trout. Credit: Z. Beard AZGFD

In 2017, I worked with Arizona Game and Fish Department, U.S. Fish and Wildlife Service, and White Mountain Apache Tribe to finalize a monitoring protocol for Apache Trout populations that was straight forward conceptually – backpack electrofishing at as set of sites sampled systematically across each stream occupied by an Apache Trout population – but also produced a good estimate of adult population size. The general guideline was that 20% of the occupied habitat needed to be sampled to get streamwide estimates of abundance of adult Apache Trout with reasonable precision. It was more ambitious that what most trout population monitoring entails, but the agencies really got after it and implemented the protocol.

Arizona Game and Fish Department crew implementing the Apache Trout monitoring protocol in the South Fork Little Colorado River. Credit: D. Dauwalter

In September 2022, I worked with those same partners, and the Apache-Sitgreaves National Forests, to complete a Species Status Assessment (SSA) for the Apache Trout using the U.S. Fish and Wildlife Service SSA framework. The information yielded by the monitoring protocol fed directly into the status assessment for the Apache Trout – very rewarding to see firsthand.

The SSA is a comprehensive science document that provides the basis for Endangered Species Act (ESA) listing decisions. The SSA for the Apache Trout basically outlined that there are currently 30 genetically pure (and 8 hybridized) Apache Trout populations occupying 280 kilometers of habitat and threatened by, or protected from, non-native trout. Across the board, the populations graded out with an average of a B- (grade point average of 2.53) based on various factors. The future condition of the species under various scenarios that included cooperative management plans, climate change, and other factors was also outlined by species experts.

A) Frequency of grade-point-average, and B) final grades, across 38 Apache Trout populations and unoccupied recovery streams in east-central Arizona (from the Apache Trout SSA).

The U.S. Fish and Wildlife used aspects of the SSA to complete a 5-year Status Review, that was then used to recommend that the species be taken off the List of Threatened and Endangered Species. They are expected to publish a proposed rule to delist the species by the end of 2022. Stay tuned!