Sources/Usage: Public Domain. View Media Details

The U.S.-Affiliated Pacific Islands (USAPI) consists of two U.S. territories (American Samoa and Guam), the Commonwealth of the Northern Mariana Islands, and three independent countries (the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau). The geology of the USAPI varies greatly – from volcanic high islands, to low coral atolls. As a result, the native ecosystems, agricultural systems, hydrology, and interactions with the ocean are remarkably diverse across this vast region. The USAPI faces many threats from climate change, such as ocean acidification, sea level rise, and increasing storm intensity. Communities in the USAPI rely on rainfall for freshwater, making the freshwater supply particularly vulnerable to dry conditions. One of the most important stressors that human communities, ecosystems, and agriculture face is drought. Enhanced drought promises huge implications for freshwater availability in this region. Understanding the impacts of drought in the USAPI, summarizing the current state of the science, and providing information on areas of resilience is important to successful adaptation and management.

In August 2018, the National CASC, with support from the University of Maryland Center for Environmental Science Integration and Application Network, U.S. Forest Service, and the Pacific Islands CASC, held a two-day workshop to synthesize the impacts of drought on various sectors in the USAPI to address this need. Twenty-seven participants from government agencies and universities in the USAPI participated in the meeting. The main goal of the workshop was to summarize information for managers and decision-makers to develop solutions to drought-induced impacts. Participants developed three, two-page summaries highlighting drought impacts on USAPI ecosystems, freshwater supply, and agriculture. The workshop participants also produced a two-page summary on data monitoring needs and limitations. The PI CASC released a comprehensive four-page newsletter, summarizing the workshop and what was learned about drought and its effects in the USAPI.

The workshop results and materials were highlighted at the March 2019 Pacific Islands Forestry Council Meeting in Honolulu, HI, where they sparked important discussions and future ideas to better manage for the unique impacts of drought in the USAPI.  

Fact Sheet Highlights

• Agriculture can be affected because crops respond to drought through reduced growth, increased mortality, and reduction in overall production. Rain-fed crops are more vulnerable to drought compared to irrigated crops.
• Water resources will also be affected because contamination of water resources commonly occurs during drought and can threaten human health. Multi-year droughts can significantly impact groundwater storage and salinity while the intrusion of saltwater into groundwater systems impacts the production of subsistence crops.
• The impact of drought on ecosystems has not been extensively studied and one of the main goals of the PI CASC Ecological Drought Workshop was to bring this issue to light. The workshop concluded that the main impact of drought on ecosystems is the increased intensity of wildfires. Ecosystems in the USAPI are not naturally adapted to wildfires and a wet year with excessive fuel buildups (i.e. increased vegetation) followed by a dry year creates opportune conditions for wildfires to flourish. Although the initial ignitions of wildfires in the USAPI are almost always human-induced, drought conditions affect the intensity and duration of the wildfire events.
• Lastly, the workshop also focused on drought monitoring and identifying data needs in the USAPI. It concluded that the use of citizen science and increased outreach to users and partners is needed to increase available information on rainfall, soil moisture, groundwater, and streamflow and to engage the public and increase observations and reporting of drought impacts in the USAPI.