When Deciding Which Endangered Species to Prioritize, What Role Do Biodiversity and Ecosystem-Level Assessments Play?

This post is the second of a pair focused on the challenges facing the Endangered Species Act and the U.S. Fish and Wildlife Service in the 21st century. You can read the first post here. 

In drafting the 1973 Endangered Species Act (ESA), Congress gave explicit attention and priority, and therefore funding, to individual species. Rather than approaching species conservation through a more holistic consideration of a species' importance within its ecological community, giving broader attention to biodiversity, or looking to the ability of a species to provide ecosystem services, this decision has had the effect of a creating a gap between politics and ecology. Critics of the ESA who argue the law does not go far enough have long advocated for these more comprehensive approaches. 

To date, scientists have bolstered recommendations for species conservation based in part on biodiversity and ecosystem effects. However, these have had a scientific basis rather than a legal one. Could the species triage framework advanced by Australia's Hugh Possingham and Arizona State University Professor Leah Gerber (see my previous ESA post for more on that) help to fill this gap and provide an impetus for FWS to update its thinking and shift toward a more ecologically coordinated and consistent framework? 

Transitioning FWS guidance toward a triage approach may help to formalize the ad hoc prioritization process that already takes place, but in a concrete way with a distinct legal foundation. In addition, placing recovery potential's importance ahead of extinction risk also opens the door to grapple with some aspects of the ESA that critics have long identified. 

For example, species triage may help to force FWS' hand to place other factors – such as climate adaptation issues – into their prioritization calculus. Not only would this help to more accurately determine recovery potential, but it could also have serious implications for future listing issues. Although the triage approach focuses on saving species with a high recovery potential, it has yet to be determined whether or not climate will be taken into account for recovery projections and rankings. However, considering the measurable changes to water and land environments already underway due to climate change, including increased temperatures and shifting habitat zones, systematically determining how viable a species' ability to recover is in light of changing environments will be essential in conversations about funding priorities. 

The other question, beyond climate, is whether or not recovery potential could also be expanded to encompass other applications of the "how worthwhile is it?" mantra of species triage. This includes asking what role, if any, should biodiversity, ecosystem importance, and ecosystem services play in evaluating the application of this approach. Considering the constraints of the individual species-focused statute, the likelihood of these questions overriding attention to single species is low, even under a species triage methodology. Despite this, touting species triage as an approach that can redirect already allocated ESA funding in ways that save more species more consistently may be a successful way forward. 

Questions and potential problems remain. If a keystone species experiences a high risk of extinction, but its recovery potential is deemed exceptionally low due to a fully diminished environment, including reduced food sources and degraded habitat, how will its resource allocation be determined? Since losing that species may collapse an entire ecosystem, would the essential nature of that species be able to override the "futility" measure? And more generally, how will futility be defined? Defining some of these problems and working out how flexible FWS could be will be crucial in assessing whether the species triage approach means simply an updated ad hoc protocol or a new era of successful conservation.