Final Report: Connecting ecosystems from mountain to the sea upon changing climate
Dates
Acquisition
2023-10-14
Summary
Freshwater is a critical driver for island ecosystems. In Hawai‘i, though rainfall intensity has increased, total rainfall has been on the decline for the last two decades and, as a result, reduced streamflow. Climate change has fundamentally altered the water cycle in these tropical islands. The changes in dynamic patterns of streamflow could result in temporal and spatial differences in the fluvial, estuarine, and coastal habitats. These habitats support the nine native aquatic species in Hawaii at different stages of their amphidromous life cycle. To examine how changes in streamflow regime has impacted habitat quality for native migratory aquatic species, an ongoing project has examined statewide long-term stream records and found [...]
Summary
Freshwater is a critical driver for island ecosystems. In Hawai‘i, though rainfall intensity has increased, total rainfall has been on the decline for the last two decades and, as a result, reduced streamflow. Climate change has fundamentally altered the water cycle in these tropical islands. The changes in dynamic patterns of streamflow could result in temporal and spatial differences in the fluvial, estuarine, and coastal habitats. These habitats support the nine native aquatic species in Hawaii at different stages of their amphidromous life cycle. To examine how changes in streamflow regime has impacted habitat quality for native migratory aquatic species, an ongoing project has examined statewide long-term stream records and found a general drying across islands with a significant decline in baseflows in recent decades (1987-2016), and particularly a substantial decrease in the dry season (May – October). We are in the process of building hydrological models and connecting the stream dynamics with biological data to address the climate impact on stream habitats, and the connection to downstream estuaries and coastal ecosystems. We developed and improved tools and framework to prioritize conservation effort for Hawaii aquatic ecosystems from ridge to reef (mauka to makai). With similar concept, we connected with like-minded researchers in Alaska to explore and develop a comparative study to address the changing aquatic ecosystems from mountain to the sea. This research project has arisen explicitly from discussions with local stakeholder groups (e.g., Commission on Water Resource Management, Hawaii Fish Habitat Partnership, National Fish Habitat Partnership, Pacific Island Fisheries and Wildlife Services) about science needs for aquatic ecosystems to better manage in current conditions and prepare for projected changes.
