The Modoc sucker (Catostomus microps), a small fish with a range limited to northeast California and south-central Oregon, was listed as endangered (pdf) in 1985.  A recovery plan for the species was adopted by the Service in 1992, and in February 2014, the Fish and Wildlife Service proposed the delisting of the species (pdf).  In the proposed rule, the Service made the following determinations:

As a result of the discovery of five populations not known at the time of listing and the documentation of the genetic integrity of populations considered in the 1985 listing rule to have been lost due to hybridization, the known range of the Modoc sucker has increased and it currently occupies its entire known historical range.  Additionally, the distribution of occupied stream habitat for populations known at the time of listing has remained stable or expanded slightly since the time of listing, even though the region has experienced several droughts during this time period.  Additionally, the relevant recovery objectives outlined in the Recovery Plan for the Modoc sucker have been met, indicating sustainable populations exist throughout the species’ range.  Finally, an assessment of factors that may be impacting the species did not reveal any significant threats to the species, now or in the future.

79 Fed. Reg. at 8665.  Corbin Hiar recently reported in Greenwire that the final determination to delist hit a roadblock (“How ESA advertising requirement snagged fish delisting,” March 2, 2015 [subscription required]).  Specifically, the Service failed to fulfill the requirement under section 4(b)(5)(D) of the Endangered Species Act (ESA) to “publish a summary of the proposed regulation in a newspaper of general circulation in each area of the United States in which the species is believed to occur.”  As a consequence, Hiar reports, the species will remain on the list of threatened and endangered species and subject to the ESA’s protections for another year.  This outdated requirement is embodied in the statute, and it will remain there along with other provisions in need of reform until Congress has the wherewithal to update the Act.