You may well not have noticed when the US Fish and Wildlife Service (Service) issued a proposal back in September to list the Kenk’s amphipod (Stygobromus kenki) as an endangered species. 81 Fed. Reg. 67270 (September 30, 2016). Even the Center for Biological Diversity, which pushed for the listing, concedes that this small, eyeless, shrimp-like creature “may be one of the most uncharismatic species considered for protection under the [Endangered Species] Act.” This proposal is worthy of note, however, for at least a couple of reasons.

There is some question whether the Kenk’s amphipod is a valid species in its own right. According to the Service, it was first collected in 1967 by Roman Kenk from a spring in Rock Creek Park in Washington, DC. The Service found that the Kenk’s amphipod is distinguished from other closely related “co-occurring” amphipods, such as the Potomac groundwater amphipod and the Hay’s spring amphipod, as well as the Blue Ridge stygobromid and the Luray Caverns amphipod, based on “various morphological features,” in particular the size and shape of certain appendages. This kind of fine distinction has the effect of drastically limiting the size and range of the population of the creature in question, and significantly enhances the likelihood of a listing under the ESA due to “small population dynamics,” which make such a species vulnerable to both natural and manmade variations in environmental conditions. Even if the Service’s determination that Kenk’s amphipod is a distinct species is supportable as matter of biology, it is less clear that the distinction is sufficiently meaningful considered in the context of the overall ecosystem to justify the regulatory consequences of a listing decision. As a matter of public policy, what are the benefits from preserving the Kenk’s amphipod in particular, as distinct from the apparently still numerous Potomac groundwater amphipod, and do those benefits justify the costs, both for recovery efforts and in terms of regulatory burdens? The Service’s listing notice does not address any such considerations. The CBD says efforts to protect the Kenk’s amphipod also will help people by improving the local groundwater quality. The ESA would seem to be an inefficient means of protecting general water quality, however, and other regulatory programs already exist for that purpose.

The Service acknowledges that “there are no reliable total population numbers for the Kenk’s amphipod.” There are two reasons for this uncertainty. First, the Kenk’s amphipod is a groundwater dwelling species. The Service says that, as a result, “the species is typically found in small numbers and then only when the groundwater levels are high and springs are flowing freely,” conditions that cause the Kenk’s amphipod to be transported to the surface. To say that the species is only “found” under such conditions, however, does not mean that it exists only where it is found. Perhaps it is only rarely transported to the surface but is still abundant underground where it primarily lives. Adding further to the uncertainty is the fact, as the Service explains, that “accurate identification of the Kenk’s amphipod” requires a species expert to preserve a specimen in alcohol and then “remove[] legs and other appendages from the specimen for microscopic identification.” Needless to say, this process results in mortality of the specimen. The Service presumably relies on some kind of statistical analysis to estimate the species’ relative abundance, but there is apparently no way of knowing (short of killing them all) just how many Kenk’s amphipods may be present among the larger group of closely related amphipods inhabiting a given groundwater spring. Nonetheless, in the case of Kenk’s amphipod, the Service considers this uncertain data to represent the “best available scientific evidence” and thus to pass muster under the ESA.

The proposed listing of Kenk’s amphipod does not necessarily reflect the outer limits of where the Service may exercise its authority under the ESA. Expect the CBD and other environmental groups to keep up the pressure. This listing proposal stems from the Service’s agreement in 2011, settling litigation brought by CDB and others, to consider 757 plant and animal species for possible listing under the ESA. There is a lot more to come.