Three-foot high wooden walls enclose a small plot of soil and plants.

When the Unmentionable becomes Unavoidable

Wastewater is a fact of life we tend to shy away from. But with sea-level rise compromising many coastal cesspools, attention (and legislation) has focused on the larger cesspool issue in Hawaiʻi. Read more about our 2020 Grau Fellow’s experience working on this unmentionable problem.
flying drone

Wai, from mauka to makai

New technology can to help detect hidden waters that carry unwanted contaminants into Kāneʻohe Bay, according to Michael Mathioudakis. Come read about his efforts to help trace submarine groundwater discharge as one part of managing Hawaiʻi’s critical coastal resources.
Graphic saying "The Plans"

Hawaiʻi Coastal Resilience at PRiMO 2020

Hawaiʻi Sea Grant helped to organize an interactive session for the 2020 PRiMO Conference on coastal resilience planning across the islands. Come inside to read about the event from the perspective of one of our Grau Fellows!
Small plants are growing in numerous pots in a laboratory setting

Vulnerability of Coastal Ecosystems to Increased Salinity from Climate Change

PI: Kasey Barton
Critical Hawaiian coastal habitats are at risk from climate change impacts, particularly sea-level rise, which threaten protective coastal plant species. This work examines the salinity tolerance of native, and invasive, coastal plants to identify those in need of greater management and conservation action.
A water hazard sign sits near a beach

Tracking groundwater nutrients using novel tracers to inform coastal watershed management in South Kohala, Hawaiʻi

PI: Henrietta Dulai
Using a combination of nitrogen isotopes and microcontaminants as source tracers, this project aims to identify pathways of groundwater flow to the coastline along South Kohala, Hawaiʻi, tracing sources of groundwater contaminants and excess nutrients. Managers can use results to improve wastewater management and improve coral reef resilience.
A split image with the left showing a researcher adding dye to the top of a cesspool, and the right showing a natural rock-enclosed pool dyed green.

Identifying hot spots of sewage pollution in Hilo, Hawaiʻi

PI: Tracy Wiegner
Hawaiʻi banned new cesspools in 2015, but groundwater contamination from the remaining 8700 cesspools in the Hilo area is a continuing concern. This work will use dye tracer studies to track cesspool outflows and use sewage indicators to establish contaminant sources to coastal groundwaters to inform future management decisions.
Map view image showing 2/3 of pond-ringing mangrove removed between 2007 and 2017 and project sampling sites

Microbial biogeochemical cycling across a chronosequence of mangrove introductions across Hawaiʻi

PI: Rosanna Alegado
Invasive mangroves harm Hawaiian coastal ecosystems, choking native plants, providing footholds for invasives, and generating leaf litter mounds inedible to Hawaiian species. This study investigates whether microbial communities can evolve to tackle the detritus and examines the resilience of our coastal ecosystems to mangrove invasion.