RESEARCH PROJECT

Restoring Hawai‘i’s wetlands and investigating potential impacts from climate change

ʻAlae ʻula tends to its offspring in a nest on the water.
ʻAlae ʻula nest at James Campbell National Wildlife Refuge.

James Campbell National Wildlife Refuge (Refuge) provides core wetland habitat for four species of endangered waterbirds: ae‘o (Hawaiian stilt, Himantopus mexicanus knudseni), ‘alae ke‘oke‘o (Hawaiian coot, Fulica alai), ‘alae ‘ula (Hawaiian gallinule, Gallinula galeata sandvicensis), and koloa maoli (Hawaiian duck, Anas wyvilliana). However, suitable habitat and successful fledging of chicks are threatened by invasive species and potential impacts from climate change. In particular, California bulrush (Schoenoplectus californicus) is an aggressive plant that provides poor habitat, and American bullfrogs (Lithobates catesbeianus) depredate young chicks of Hawaiian waterbirds. The Refuge can increase the salinity of this wetland to eradicate these species as California bulrush can only tolerate slight salinity of 0-5 ppt, and American bullfrogs’ eggs and tadpoles up to 10 days old experience a 100% mortality when salinity is 6 ppt or higher. The goal of this project is to examine the effectiveness of salinity to control invasive species (bulrush and bullfrogs).

PROJECT DETAILS

FUNDED:

FY2024

PI:

Kelly Goodale
Biologist, USFWS, Oʻahu National Wildlife Refuge Complex