As part of USGS Coral Reef Project studies, the USGS has been heavily involved in efforts to improve the health and resilience of Maui's coral reef system, bringing expertise in mapping, circulation and sediment studies, and seismic surveys.
Overview
Maui is located 15 km (9 mi) east of Molokaʻi and 15 km northwest of Lānaʻi. Known as the Valley Isle, it encompasses 1883 sq km (727 sq mi), making it the second largest of the main eight Hawaiian Islands. A fringing reef surrounds much of the island. However much of the live coral growth can only be found on the leeward west coast where the reef is protected from waves by the surrounding islands. Reef growth is limited on the windward northeast coast due to wave impacts.
Motivation
Over the past two decades, there has been a notable change in seafloor-bottom type along west-central Maui, Hawaiʻi. Once dominated by abundant coral coverage, the area is now characterized by an increased abundance of turf algae and macroalgae. In an effort to improve the health and resilience of the coral reef system, the State of Hawaiʻi established the Kahekili Herbivore Fisheries Management Area. In addition, the U.S. Coral Reef Task Force (USCRTF) Watershed Partnership Initiative selected the Kaʻanapali region of west-central Maui as the site of the second national priority study area on which to focus its research and restoration efforts. The USGS has been involved heavily in these studies, bringing expertise in mapping, circulation and sediment studies, and seismic surveys. Other collaborators include the Environmental Protection Agency (EPA), NOAA, University of Hawaiʻi, University of Washington, University of California, Santa Cruz, and The Nature Conservancy.
The Hawaiian island of Maui is just one of the USGS Coral Reef Project's study locations.
Reef Hydrodynamics and Sediment Processes
Role of Reefs in Coastal Protection
Reef Resource Assessments - Planning for the Future
Hydrogeology and Reef Health
Climate Change and Land-use Histories
Maui data sets produced by the Coral Reef Project
Aerial imagery and structure-from-motion-derived shallow water bathymetry from a UAS survey of the coral reef off Waiakane, Molokai, Hawaii, June 2018
Coral geochemistry time series from Kahekili, west Maui
Cross-reef wave and water level data from coral reef environments
Dynamically downscaled future wave projections from SWAN model results for the main Hawaiian Islands
Waiakane, Molokai, HI, 2018 Coral Reef Circulation and Sediment Dynamics Experiment
Projected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the States of Hawaii and Florida, the Territories of Guam, American Samoa, Puerto Rico, and the U.S. Virgin Islands,
Coral growth parameters and seawater chemistry from Kahekili, west Maui, Hawaii
Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA
Publications on Maui, produced by the Coral Reef Project
The value of US coral reefs for flood risk reduction
The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats
Rigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction
Coral skeleton δ15N as a tracer of historic nutrient loading to a coral reef in Maui, Hawaii
Carbonate system parameters of an algal-dominated reef along west Maui
Modeling fine-scale coral larval dispersal and interisland connectivity to help designate mutually-supporting coral reef marine protected areas: Insights from Maui Nui, Hawaii
Vulnerability of coral reefs to bioerosion from land-based sources of pollution
The use of passive membrane samplers to assess organic contaminant inputs at five coastal sites in west Maui, Hawaii
Rigorously valuing the role of coral reefs in coastal protection: An example from Maui, Hawaii, U.S.A.
Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii
A Geochemical and Geophysical Assessment of Coastal Groundwater Discharge at Select Sites in Maui and O’ahu, Hawai’i
The effectiveness of coral reefs for coastal hazard risk reduction and adaptation
Below are news stories about our work in Maui
Below are partners associated with this project.
- Overview
As part of USGS Coral Reef Project studies, the USGS has been heavily involved in efforts to improve the health and resilience of Maui's coral reef system, bringing expertise in mapping, circulation and sediment studies, and seismic surveys.
Overview
Landsat image of Maui. Maui is located 15 km (9 mi) east of Molokaʻi and 15 km northwest of Lānaʻi. Known as the Valley Isle, it encompasses 1883 sq km (727 sq mi), making it the second largest of the main eight Hawaiian Islands. A fringing reef surrounds much of the island. However much of the live coral growth can only be found on the leeward west coast where the reef is protected from waves by the surrounding islands. Reef growth is limited on the windward northeast coast due to wave impacts.
Motivation
Examining the coral reef along Molokini Crater, Maui. Over the past two decades, there has been a notable change in seafloor-bottom type along west-central Maui, Hawaiʻi. Once dominated by abundant coral coverage, the area is now characterized by an increased abundance of turf algae and macroalgae. In an effort to improve the health and resilience of the coral reef system, the State of Hawaiʻi established the Kahekili Herbivore Fisheries Management Area. In addition, the U.S. Coral Reef Task Force (USCRTF) Watershed Partnership Initiative selected the Kaʻanapali region of west-central Maui as the site of the second national priority study area on which to focus its research and restoration efforts. The USGS has been involved heavily in these studies, bringing expertise in mapping, circulation and sediment studies, and seismic surveys. Other collaborators include the Environmental Protection Agency (EPA), NOAA, University of Hawaiʻi, University of Washington, University of California, Santa Cruz, and The Nature Conservancy.
- Science
The Hawaiian island of Maui is just one of the USGS Coral Reef Project's study locations.
Reef Hydrodynamics and Sediment Processes
As part of the USGS Coral Reef Project, the overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.Role of Reefs in Coastal Protection
We are combining ocean, engineering, ecologic, social, and economic modeling to provide a high-resolution, rigorous, spatially-explicit valuation of the coastal flood protection benefits provided by coral reefs and the cost effectiveness of reef restoration for enhancing those benefits.Reef Resource Assessments - Planning for the Future
We are mapping and assessing all of the important geologic and oceanographic factors to identify those coral reefs most at risk and those reefs that are potentially the most resilient and the most likely to recover from natural and human-driven impacts.Hydrogeology and Reef Health
As part of the USGS Coral Reef Project, we are conducting geophysical and geochemical research to address questions about coastal groundwater-to-reef flow and coral reef health, with the goal of informing management decisions related to planning and implementing activities in priority watershed-coral reef systems.Climate Change and Land-use Histories
As part of the USGS Coral Reef Project, we are developing new and unique oceanographic and environmental archives from coral skeleton records to better understand the compounding effects of land-use and environmental change on coral reef health. - Data
Maui data sets produced by the Coral Reef Project
Aerial imagery and structure-from-motion-derived shallow water bathymetry from a UAS survey of the coral reef off Waiakane, Molokai, Hawaii, June 2018
An unoccupied aerial system (UAS) was used to acquire high-resolution imagery of the shallow fringing coral reef at Waiakane, Molokai, Hawaii, on 24 June 2018. Imagery was acquired over an area between the shoreline and approximately 900 meters offshore, covering approximately 16 hectares. The imagery was processed using structure-from-motion (SfM) photogrammetric techniques with additional refracCoral geochemistry time series from Kahekili, west Maui
Geochemical analysis (including stable boron, boron:calcium ratio, and carbon and oxygen isotopes) were measured from coral cores collected in July 2013 from the shallow reef at Kahekili in Kaanapali, west Maui, Hawaii from scleractinian Porites lobata.Cross-reef wave and water level data from coral reef environments
Coral reefs provide important protection for tropical coastlines against the impact of large waves and storm damage by energy dissipation through wave breaking and bottom friction. However, climate change and sea level rise have led to growing concern for how the hydrodynamics across these reefs will evolve and whether these changes will leave tropical coastlines more vulnerable to large wave evenDynamically downscaled future wave projections from SWAN model results for the main Hawaiian Islands
Projected wave climate trends from WAVEWATCH3 model output were used as input for nearshore wave models (for example, SWAN) for the main Hawaiian Islands to derive data and statistical measures (mean and top 5 percent values) of wave height, wave period, and wave direction for the recent past (1996-2005) and future projections (2026-2045 and 2085-2100). Three-hourly global climate model (GCM) windWaiakane, Molokai, HI, 2018 Coral Reef Circulation and Sediment Dynamics Experiment
Coral reefs generate significant volumes of carbonate sediment that becomes the primary source of beach material along many low-latitude shorelines that protect hundreds of millions of people globally. Despite this fact, there is little understanding of the specific processes that transport the carbonate sediment produced on the outer portions of coral reefs to the shoreline, let alone how those pProjected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the States of Hawaii and Florida, the Territories of Guam, American Samoa, Puerto Rico, and the U.S. Virgin Islands,
This data release provides flooding extent polygons (flood masks) and depth values (flood points) based on wave-driven total water levels for 22 locations within the States of Hawaii and Florida, the Territories of Guam, American Samoa, Puerto Rico, and the U.S. Virgin Islands, and the Commonwealth of the Northern Mariana Islands. For each of the 22 locations there are eight associated flood maskCoral growth parameters and seawater chemistry from Kahekili, west Maui, Hawaii
This data release contains time-series of seawater carbonate chemistry variables, including salinity, dissolved inorganic nutrients, pH, total alkalinity, and dissolved inorganic carbon, from sites along Kahekili Beach Park, Kaanapali, west Maui. It also contains data from coral cores collected from the shallow reef at Kahekili in July 2013 and analyzed for coral growth parameters (tissue thicknesPhysics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA
Here we present surface current results from a physics-based, 3-dimensional coupled ocean-atmosphere numerical model that was generated to understand coral larval dispersal patterns in Maui Nui, Hawaii, USA. The model was used to simulate coral larval dispersal patterns from a number of existing State-managed reefs and large tracks of reefs with high coral coverage that might be good candidates fo - Publications
Publications on Maui, produced by the Coral Reef Project
Filter Total Items: 30The value of US coral reefs for flood risk reduction
Habitats, such as coral reefs, can mitigate increasing flood damages through coastal protection services. We provide a fine-scale, national valuation of the flood risk reduction benefits of coral habitats to people, property, economies and infrastructure. Across 3,100 km of US coastline, the top-most 1 m of coral reefs prevents the 100-yr flood from growing by 23% (113 km2), avoiding flooding to 5AuthorsBorja G. Reguero, Curt Storlazzi, Ann E. Gibbs, James B. Shope, Aaron Cole, Kristen A. Cumming, Mike BeckThe major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats
Coral reefs are widely recognized as critical to Hawaiʻi’s economy, food resources, and protection from damaging storm waves. Yet overfishing, land-based pollution, and climate change are threatening the health and sustainability of those reefs, and accordingly, both the Federal and State governments have called for protection and effective management. In 2000, the U.S. Coral Reef Task Force stateAuthorsMichael E. Field, Curt D. Storlazzi, Ann E. Gibbs, Nicole L. D'Antonio, Susan A. CochranRigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision making. Here we combine engineering, ecologic, geospatialAuthorsCurt D. Storlazzi, Borja G. Reguero, Aaron Cole, Erik Lowe, James B. Shope, Ann E. Gibbs, Barry A. Nickel, Robert T. McCall, Ap R. van Dongeren, Michael W. BeckCoral skeleton δ15N as a tracer of historic nutrient loading to a coral reef in Maui, Hawaii
Excess nutrient loading to nearshore environments has been linked to declining water quality and ecosystem health. Macro-algal blooms, eutrophication, and reduction in coral cover have been observed in West Maui, Hawaii, and linked to nutrient inputs from coastal submarine groundwater seeps. Here, we present a forty-year record of nitrogen isotopes (δ15N) of intra-crystalline coral skeletal organiAuthorsJoseph Murray, Nancy G. Prouty, Sara E. Peek, Adina PaytanCarbonate system parameters of an algal-dominated reef along west Maui
Constraining coral reef metabolism and carbon chemistry dynamics are fundamental for understanding and predicting reef vulnerability to rising coastal CO2 concentrations and decreasing seawater pH. However, few studies exist along reefs occupying densely inhabited shorelines with known input from land-based sources of pollution. The shallow coral reefs off Kahekili, West Maui, are exposed to nutriAuthorsNancy G. Prouty, Kimberly K. Yates, Nathan A. Smiley, Christopher Gallagher, Olivia Cheriton, Curt D. StorlazziModeling fine-scale coral larval dispersal and interisland connectivity to help designate mutually-supporting coral reef marine protected areas: Insights from Maui Nui, Hawaii
Connectivity among individual marine protected areas (MPAs) is one of the most important considerations in the design of integrated MPA networks. To provide such information for managers in Hawaii, USA, a numerical circulation model was developed to determine the role of ocean currents in transporting coral larvae from natal reefs throughout the high volcanic islands of the Maui Nui island complexAuthorsCurt D. Storlazzi, Maarten van Ormondt, Yi-Leng Chen, Edwin P. L. EliasVulnerability of coral reefs to bioerosion from land-based sources of pollution
Ocean acidification (OA), the gradual decline in ocean pH and [ ] caused by rising levels of atmospheric CO2, poses a significant threat to coral reef ecosystems, depressing rates of calcium carbonate (CaCO3) production, and enhancing rates of bioerosion and dissolution. As ocean pH and [ ] decline globally, there is increasing emphasis on managing local stressors that can exacerbate the vulnerabiAuthorsNancy G. Prouty, Anne Cohen, Kimberly K. Yates, Curt D. Storlazzi, Peter W. Swarzenski, Darla WhiteThe use of passive membrane samplers to assess organic contaminant inputs at five coastal sites in west Maui, Hawaii
Five passive membrane samplers were deployed for 28 continuous days at select sites along and near the west Maui coastline to assess organic compounds and contaminant inputs to diverse, shallow coral reef ecosystems. Daily and weekly fluctuations in such inputs were captured on the membranes using integrative sampling. The distribution of organic compounds observed at these five coastal sites showAuthorsPamela L. Campbell, Nancy G. Prouty, Curt D. Storlazzi, Nicole D'antonioRigorously valuing the role of coral reefs in coastal protection: An example from Maui, Hawaii, U.S.A.
The degradation of coastal habitats, particularly coral reefs, raises risks by exposing communities to flooding hazards. The protective services of these natural defenses are not assessed in the same rigorous, economic terms as artificial defenses such as seawalls, and therefore often not considered in decision-making. Here we present a new methodology that combines economic, ecological, and enginAuthorsCurt D. Storlazzi, Borja G. Reguero, Erik Lowe, James B. Shope, Ann E. Gibbs, Mike Beck, Barry A. NickelObservations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii
Study regionThe study region encompasses the nearshore, coastal waters off west Maui, Hawaii. Here abundant groundwater—that carries with it a strong land-based fingerprint—discharges into the coastal waters and over a coral reef.Study focusCoastal groundwater discharge is a ubiquitous hydrologic feature that has been shown to impact nearshore ecosystems and material budgets. A unique combined geoAuthorsPeter W. Swarzenski, H. Dulai, K.D. Kroeger, C.G. Smith, N. Dimova, C. D. Storlazzi, N.G. Prouty, S. B. Gingerich, C. R. GlennA Geochemical and Geophysical Assessment of Coastal Groundwater Discharge at Select Sites in Maui and O’ahu, Hawai’i
This chapter summarizes fieldwork conducted to derive new estimates of coastal groundwater discharge and associated nutrient loadings at select coastal sites in Hawai’i, USA. Locations for this work were typically identified based on pronounced, recent ecosystem degradation that may at least partially be attributable to sustained coastal groundwater discharge. Our suite of tools used to evaluate gAuthorsPeter W. Swarzenski, Curt D. Storlazzi, M.L. Dalier, C.R. Glenn, C.G. SmithThe effectiveness of coral reefs for coastal hazard risk reduction and adaptation
The world’s coastal zones are experiencing rapid development and an increase in storms and flooding. These hazards put coastal communities at heightened risk, which may increase with habitat loss. Here we analyse globally the role and cost effectiveness of coral reefs in risk reduction. Meta-analyses reveal that coral reefs provide substantial protection against natural hazards by reducing wave enAuthorsFilippo Ferrario, Michael W. Beck, Curt D. Storlazzi, Fiorenza Micheli, Christine C. Shepard, Laura Airoldi - News
Below are news stories about our work in Maui
- Partners
Below are partners associated with this project.