by Alexander Birk
The United States Endangered Species Act (ESA) is responsible for the protection of species and their habitats. The ESA maintains a list of the species at risk; the ultimate goal is to get these species off of the list. In order to get an endangered species removed (delisted) the ESA must regard that species as self-sustaining. The definition of a self-sustaining species becomes difficult as the ESA looks at conservation-reliant species. A conservation-reliant species is defined as a species that has been delisted; however it requires management in order to prevent it from once again being at risk.
There are multiple dimensions that qualify a species as conservation-reliant; the two categories are either one time intervention or continuous intervention. A few examples of one time interventions would be dam removal or habitat restoration. Continuous intervention would be defined by actions like translocation or invasive species control. Most species that have been classified as conservation-reliant species are ones that require some of the following conservation action: controlling other species, controlling pollutants, managing habitats, controlling exploitation by humans, or assistance in population growth. Per ESA mandate these species are still self-sustaining outside of requiring these actions, therefor justifying delisting these species.
This becomes problematic as the focus of restoration shifts away from these species. Many conservation-reliant species are in need of intervention due to human interaction such as pollution, as mentioned previously. Even though this pollution does not put the species in a high risk of immediate danger, the intervention is needed to prevent long term harm. The popular view is to focus on populations of species in greater danger. However even though conservation-reliant species may also be classified as self-sustaining, this should not in turn lead to them needing less assistance. People generally decide against helping a cause that does not seem as though it is an immediate concern. This is a problem that the ESA is faced with as they choose how to label different populations of species.
Carroll, C., Rohlf, D. J., Li, Y.-W., Hartl, B., Phillips, M. K. and Noss, R. F. (2014), Connectivity conservation and endangered species recovery: a study in the challenges of defining conservation-reliant species. Conservation Letters. doi: 10.1111/conl.12102 http://onlinelibrary.wiley.com/doi/10.1111/conl.12102/full#leftBorder