Wildlife in Northwestern Hawaiian Islands at Risk from Sea Level Rise
New research predicts that up to 65% of some Northwestern Hawaiian Islands (NWHI), may be submerged by 2100 if sea level
rises by 48 cm (a median estimate of the likely change). The islands are biologically rich, important breeding areas for
the critically endangered Hawaiian monk seal, endemic birds and sea turtles. The waters surrounding the NWHI are slated
to become the largest National Marine Sanctuary in the USA.
The findings will be reported later today in the international conservation journal Endangered Species Research and can
be freely downloaded at the journal’s website http://www.int-res.com/journals/esr/contents/. The study was carried out by Jason Baker of the U.S. National Marine Fisheries Service Pacific Islands Fisheries
Science Center and the University of Aberdeen Lighthouse Field Station and collaborators.
Sea level rose 15 cm during the 20th century and is anticipated to increase further due to thermal expansion of the
warming oceans and melting of glaciers and ice caps. The NWHI are the most remote archipelago in the world and while
stretching across some 1800 km, they are primarily comprised of low-lying islands with a total land area of just 800 ha.
Nonetheless, this habitat supports a spectacular assemblage of endangered and threatened species, many of which are
endemic and unique to the islands.
Baker and colleagues developed 3-dimensional maps of several NWHI and predicted the effects of potential sea level rise
and their possible impact on selected species. Most at risk from habitat loss are the Hawaiian monk seal, the endemic
Laysan finch, and the Hawaiian green sea turtle, 90% of which nest at one NWHI atoll. As Baker notes, “These little
islands are important nurseries for monk seals, sea turtles and millions of seabirds; yet much of this lively activity
occurs just a few meters above sea level.” As the elevations of several NWHI remain undocumented, Baker believes
continuing this work will be critical to conservation planning for several NWHI species in the long term, and he has
ideas for mitigating losses using methods, such as beach nourishment, that have proven successful elsewhere. “If large
portions of these islands slip into the sea, much of our previous conservation efforts will be compromised.”
ENDS