As part of the USGS Coral Reef Project, recent USGS work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
Overview
The Friendly Isle of Molokaʻi encompasses 673 sq km (260 sq mi), making it the fifth largest of the main eight Hawaiian Islands. The north and west coasts of the island have little coral growth due to impact from northwest swell. However, protected from the southern swell waves by the islands of Lānaʻi and Kahoʻolowe, the south shore of Molokaʻi boasts the longest continuous fringing reef of the U.S. and its holdings. Studies by scientists at the University of Hawaiʻi's Coral Reef Assessment and Monitoring Program have shown that Molokaʻi has sites with the best coral coverage in the main eight Hawaiian Islands. Yet impacts from sediment run-off into the nearshore ecosystem have also caused areas of degradation of the south Molokaʻi reef.
Motivation
The USGS has used the south Molokaʻi reef as its test ground for developing benthic habitat mapping methods including remote sensing and underwater videography. Investigations into sedimentation along the south coast involve deployment of instrument packages to measure oceanographic conditions such as turbidity, currents, waves, temperature, and salinity. Recent work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
The USGS has many cooperators on Molokaʻi including the U.S. Coral Reef Task Force (USCRTF) Hawaiian Local Action Strategy (HI-LAS) for Land-Based Pollution (LBP), University of Hawaiʻi, University of Washington, University of California, Santa Cruz, Australian National University, and The Nature Conservancy.
The Hawaiian island of Molokaʻi 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
Below are data releases associated with this 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
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
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,
Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA
Below are publications associated with this 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
Modeling fine-scale coral larval dispersal and interisland connectivity to help designate mutually-supporting coral reef marine protected areas: Insights from Maui Nui, Hawaii
The effectiveness of coral reefs for coastal hazard risk reduction and adaptation
Response of reef corals on a fringing reef flat to elevated suspended-sediment concentrations: Moloka‘i, Hawai‘i
Seafloor video footage and still-frame grabs from U.S. Geological Survey cruises in Hawaiian nearshore waters
From ridge to reef—linking erosion and changing watersheds to impacts on the coral reef ecosystems of Hawai‘i and the Pacific Ocean
Coastal circulation and water-column properties off Kalaupapa National Historical Park, Molokai, Hawaii, 2008-2010
Numerical modeling of the impact of sea-level rise on fringing coral reef hydrodynamics and sediment transport
Rising sea level may cause decline of fringing coral reefs
The use (and misuse) of sediment traps in coral reef environments: Theory, observations, and suggested protocols
Below are news stories associated with this project.
Below are partners associated with this project.
- Overview
As part of the USGS Coral Reef Project, recent USGS work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
Overview
Multi-spectral LANDSAT 8 and ASTER satellite imagery provided by the US Geological Survey and NASA. The Friendly Isle of Molokaʻi encompasses 673 sq km (260 sq mi), making it the fifth largest of the main eight Hawaiian Islands. The north and west coasts of the island have little coral growth due to impact from northwest swell. However, protected from the southern swell waves by the islands of Lānaʻi and Kahoʻolowe, the south shore of Molokaʻi boasts the longest continuous fringing reef of the U.S. and its holdings. Studies by scientists at the University of Hawaiʻi's Coral Reef Assessment and Monitoring Program have shown that Molokaʻi has sites with the best coral coverage in the main eight Hawaiian Islands. Yet impacts from sediment run-off into the nearshore ecosystem have also caused areas of degradation of the south Molokaʻi reef.
Motivation
The USGS has used the south Molokaʻi reef as its test ground for developing benthic habitat mapping methods including remote sensing and underwater videography. Investigations into sedimentation along the south coast involve deployment of instrument packages to measure oceanographic conditions such as turbidity, currents, waves, temperature, and salinity. Recent work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
The USGS has many cooperators on Molokaʻi including the U.S. Coral Reef Task Force (USCRTF) Hawaiian Local Action Strategy (HI-LAS) for Land-Based Pollution (LBP), University of Hawaiʻi, University of Washington, University of California, Santa Cruz, Australian National University, and The Nature Conservancy.
- Science
The Hawaiian island of Molokaʻi 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
Below are data releases associated with this 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 refracCross-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) windProjected 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 maskPhysics-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
Below are publications associated with this project.
Filter Total Items: 38The 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. BeckModeling 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. EliasThe 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 AiroldiResponse of reef corals on a fringing reef flat to elevated suspended-sediment concentrations: Moloka‘i, Hawai‘i
A long-term (10 month exposure) experiment on effects of suspended sediment on the mortality, growth, and recruitment of the reef corals Montipora capitata and Porites compressa was conducted on the shallow reef flat off south Molokaʻi, Hawaiʻi. Corals were grown on wire platforms with attached coral recruitment tiles along a suspended solid concentration (SSC) gradient that ranged from 37 mg l−1AuthorsPaul L. Jokiel, Ku'ulei S. Rodgers, Curt D. Storlazzi, Michael E. Field, Claire V. Lager, Dan LagerSeafloor video footage and still-frame grabs from U.S. Geological Survey cruises in Hawaiian nearshore waters
Underwater video footage was collected in nearshore waters (AuthorsAnn E. Gibbs, Susan A. Cochran, Peter W. TierneyFrom ridge to reef—linking erosion and changing watersheds to impacts on the coral reef ecosystems of Hawai‘i and the Pacific Ocean
Coral reef ecosystems are threatened by unprecedented watershed changes in the United States and worldwide. These ecosystems sustain fishing and tourism industries essential to the economic survival of many communities. Sediment, nutrients, and pollutants from watersheds are increasingly transported to coastal waters, where these contaminants damage corals. Although pollution from watersheds is onAuthorsJonathan D. Stock, Susan A. Cochran, Michael E. Field, James D. Jacobi, Gordon TribbleCoastal circulation and water-column properties off Kalaupapa National Historical Park, Molokai, Hawaii, 2008-2010
More than 2.2 million measurements of oceanographic forcing and the resulting water-column properties were made off U.S. National Park Service's Kalaupapa National Historical Park on the north shore of Molokai, Hawaii, between 2008 and 2010 to understand the role of oceanographic processes on the health and sustainability of the area's marine resources. The tides off the Kalaupapa Peninsula are miAuthorsCurt D. Storlazzi, Katherine Presto, Eric K. BrownNumerical modeling of the impact of sea-level rise on fringing coral reef hydrodynamics and sediment transport
Most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100; it is not clear, however, how fluid flow and sediment dynamics on exposed fringing reefs might change in response to this rapid sea-level rise. Coupled hydrodynamic and sediment-transport numerical modeling is consistent with recent published results that suggest that an increase in water depth on the orderAuthorsC. D. Storlazzi, E. Elias, M.E. Field, M.K. PrestoRising sea level may cause decline of fringing coral reefs
Coral reefs are major marine ecosystems and critical resources for marine diversity and fisheries. These ecosystems are widely recognized to be at risk from a number of stressors, and added to those in the past several decades is climate change due to anthropogenically driven increases in atmospheric concentrations of greenhouse gases. Most threatening to most coral reefs are elevated sea surfaceAuthorsMichael E. Field, Andrea S. Ogston, Curt D. StorlazziThe use (and misuse) of sediment traps in coral reef environments: Theory, observations, and suggested protocols
Sediment traps are commonly used as standard tools for monitoring “sedimentation” in coral reef environments. In much of the literature where sediment traps were used to measure the effects of “sedimentation” on corals, it is clear from deployment descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted or misapplied. DeAuthorsC. D. Storlazzi, M.E. Field, Michael H. Bothner - News
Below are news stories associated with this project.
- Partners
Below are partners associated with this project.