Corals spread across the dark sea floor.

Predicting and mapping Hawaiian mesophotic coral ecosystems for sustainable coastal development

PI: Robert Toonen
This study sought to address our fundamental lack of knowledge regarding vulnerable low-light, mesophotic coral ecosystems (at depths of 30-180 m) in order to better manage impacts from invasive species, coastal development, and exploration. By using statistical modeling, combined with machine learning, researchers created predictive maps to illustrate the distribution of mesophotic reefs and invasive algae across the main Hawaiian Islands. They found that all islands had some stretches of coastline identified as highly susceptible to invasion of the green alga Avrainvillea amadelpha, in both shallow and mesophotic depths.
Photo of Heeai Fishpond wall.

Integration of next-generation sequencing into traditional Hawaiian practices to improve management and restoration of fishponds

PI: Robert Toonen
With Hawaiian fishponds as models of sustainable aquatic resource management, this study uses two important crab species, Portunus sanguinolentus hawaiiensis and Scylla serrata, to explore whether fishponds are self-seeding, importing, or exporting species, and whether traditional harvest practices continue to be viable. Early results show a broad diversity of crab sizes, with a possibility of tagging and tracking crabs outside the fishpond, as well as within.
Aerial view of wastewater treatment plant.

Assessing the vulnerability of coastal wastewater infrastructure to climate change

PI: Daniele Spirandelli
This research aimed, with community and agency stakeholders, to identify and map critical factors contributing to wastewater infrastructure vulnerability to a changing climate, particularly sea-level rise and extreme precipitation, and to develop a process that builds adaptive capacity into the system. Results showed groundwater inundation as a significant threat to sewer pipes, and a policy gap analysis identified discontinuities in key components of Hawaiʻi’s current onsite management program between land-use planning efforts and state siting regulations.
Students examine tidal pools

Longitudinal assessment: Our Project in Hawaiʻi’s Intertidal (OPIHI)

PI: Kanesa Seraphin
This project revisited the Hawaiian intertidal zone, last studied over a decade ago, to document, monitor, and assess changes in species compositions due to factors like climate change, coastal development, and the spread of invasive species. The project trained and mentored undergraduate students as interns, for college credit, gaining important, required hands-on research experience. By engaging these students as well as community members in this place-based research, 48 comprehensive surveys were completed across the state, with preliminary results suggesting the spread of invasive algae and changes to water quality.
A tiny juvenile tilapia perches on the lip of its mother.

The use of a euryhaline Tilapia to assess the endocrine disrupting effects of anthropogenic chemicals on growth and osmoregulation of a tropical teleost species inhabiting coastal waters and wetlands in Hawaiʻi and the tropics

PI: Andre Seale
This work sought to understand the integrated physiological and developmental effects of endocrine-disrupting agricultural chemicals on the tropical euryhaline tilapia, Oreochromis mossambicus. Mozambique tilapia are widely used for aquaculture production so this research may better inform those interested in the effects of these waterborne chemicals on the growth and health of these fish. It will also provide critical information towards proper management of pesticide use and water resources to mitigate the effects of these agricultural chemicals on aquatic wildlife in general.
Graphic showing average temperature and water consumption on O'ahu.

Predicting Hawaiʻi water demand under climate change

PI: Michael Roberts
This project studied how climate change may affect future water demand on Oʻahu, focusing on variations in temperature, precipitation, and prevailing climatic conditions. Results imply that microclimates play an important role in demand, with the hot and dry area households using typically 100 gallons more per day than those in cooler, wetter aras. Using water billing data cross-referenced with fine-scale weather data, a model was developed that estimates the growth of Oʻahu aquifer yields needed to satisfy possible shifts in demand (up to 50% increase) under different climate scenarios, or alternatively, the price increases necessary to limit consumption levels.
Green plume of dye drifts upward from red sponge in fishtanks

The role of sponges in nitrogen cycling in Kāneʻohe Bay, Oʻahu

PI: Brian Popp
This study focused on quantifying respiration, pumping rates, and chemical reactions of an invasive sponge, Mycale grandis, to understand the species’ impacts on nitrogen cycling in the coastal environment of Kāne‘ohe Bay, whether adding or subtracting usable nitrogen from the system. Researchers found that the M. grandis sponge can pump 83 times its own volume of water per day, giving its associated microbial communities abundant opportunity to perform nitrification, converting ammonia to forms of nitrogen oxides unusable to algae. The rapid nitrogen transformations with the high pumping rates of these sponges means this invasive species may play a significant role in nitrogen concentrations in the bay.
Contamination warning sign on Kailua Beach

Source tracking coastal groundwater and runoff contamination with microbial genomics and dissolved organic fluorometry

PI: Craig Nelson
This project focused on using new techniques of microbial genomics and fluorescent characterization of organic matter to track sources of groundwater contamination in several important Hawaiian watersheds, in order to provide tools to protect streams, groundwater, and coastal ecosystems. The high density of cesspools in Hawaiʻi is a potentially significant source of contamination to streams and coral reefs, but it is currently prohibitive to identify contamination sources. For this project, hundreds of water samples from Oʻahu, Maui, and Hawaiʻi have been collected and are being characterized to develop microbial source tracking and better testing techniques.
Arlan Brucal working on computers with models

Do seawalls lower property values?

PI: John Lynham
This work examined the economic consequences of a strategy commonly used in years past of building sea walls to protect property threatened by increased coastal erosion. Based on a technique previously used successfully by the authors in San Diego, CA, the researchers examined property sales on Oʻahu for the last 30 years and combined this with locations of seawalls built over those years. They found that while properties with coastal armoring maintain their value, there is evidence that neighboring properties show a decrease in value with time.
Student collecting water sample from beach shallows.

Rapid Response: Application of a qPCR-based test for Enterococci as a rapid beach management tool in Hawaiʻi

PI: Marek Kirs
The goal of this project was to design a rapid, simple, molecular-based water quality test that authorities can easily apply on Hawaiian beaches to increase hazard resilience of coastal communities. Standard coastal water quality testing techniques require 24-48 hours of culturing Enterococci bacteria, which often gives falsely high readings in Hawaiʻi from environmental sources. This newly developed method uses a specifically human-sewage-borne pathogen, Bacteroides, detected by rapid molecular tests, and is proving to give efficient and accurate detection of contamination to provide more timely notice and better protect public health.