Coastal and Climate Science

08 Mar: The role of surface and groundwater inputs in driving water quality in Kāneʻohe Bay, Oʻahu

PI: Henrietta Dulai
The goal of this project was to identify submarine groundwater discharge locations and quantify groundwater and its derived nutrient flow into Kāneʻohe Bay, particularly as it varies with wet and dry seasonal cycles. The researchers found that most freshwater in nearby coral reefs derives from streams during the wet season, but during the dry season, input from groundwater increases 150%. These results have led to maps with quantification of groundwater discharge, and measurements of nutrient fluxes have identified several watershed hotspots of wastewater contamination.

08 Mar: Coastal Ocean Hawaiʻi Acidification Monitoring Network (COHAMN) and carbonate mineral dissolution study

PI: Eric DeCarlo
This project is part of a long-term, ongoing effort to record carbon dioxide concentrations in multiple coral reef settings, producing the longest continuous CO2 record in the world from a coral reef environment, and has illustrated that time series data are critical to understanding and quantifying reef contributions to global carbon cycling. Results so far show that, currently, Hawaiian coastal waters largely release CO2 to the atmosphere, but with elevated carbon dioxide that is absorbed, models show that tropical reefs will be net dissolving by the mid-21st century.

08 Mar: Fish Flow: Filling the gap between spawning and settlement

PI: Brian Bowen
This project aimed to track reef fish, using their genetic data, from where they spawned as larvae to where they settle on the reef, as a direct measure of population connectivity. Engaging student volunteers, the research team collected over 1500 samples of three target species across the Hawaiian islands. Using advanced genetic technology and computer-aided population connectivity texts, the team generated maps that illustrate that most adult reef fish in Kāneʻohe Bay originate from neighboring East Oʻahu reefs rather than from inside the bay, useful information for appropriate managers.