An extensive study of the life history and genetics of at-risk fish species may help ensure the U.S. military can continue to operate its multiple installations throughout Hawaii and other Pacific Islands sustainably for decades to come. Training troops and testing weapon systems at these installations is essential to DoD’s mission. At the same time, the Department has an obligation to conduct its activities in ways that do not harm the environment or prevent continued military use. In recent years, DoD has taken a holistic approach, exploring how to improve its land use and natural resource management within ecosystem and watershed contexts that extend beyond the installation boundary.

To that end, a SERDP-funded project led by Dr. Michael Blum of Tulane University tracked the life history and genetic attributes of two at-risk native fish species in the Hawaiian Islands. Over the course of their life cycle, these fish start out in fresh water, move to the near-shore marine environment, then migrate out to sea and eventually return to fresh water. Because these species spend periods of their lives throughout the linked watershed-marine environment, studying these fish can serve as a surrogate for studying the health of the Islands’ complex ecological systems. At all points along the way, the condition of the ecological system must be healthy and connected for the species to survive and thrive.

Using genetic assessment protocols, researchers identified potential watershed impacts from multiple sources, including land use associated with the military, urbanization, and agriculture; however, the presence of non-native fish also had a prominent impact on native fish species’ population viability. The study results reinforce the need for DoD natural resource managers to continue taking steps to monitor and protect resources within a watershed context, through management practices such as avoiding excessive sediment and nutrient loadings to streams, as well as working with other land managers to take a holistic approach to protecting the complex ecological systems of Hawaii and other Pacific Islands.

For this innovative work, Dr. Blum and his project team received the 2013 SERDP Project-of-the-Year Award for Resource Conservation and Climate Change. Project Summary 

• Dr. Peter B. McIntyre, University of Wisconsin-Madison
• Dr. James F. Gilliam, North Carolina State University