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.
The Problem
Over the past decade, we have primarily focused on fine-grained terrestrial sediment dynamics on reefs, due to its role as the greatest stressor to high-island fringing reefs throughout the U.S. and U.S.-Affiliated Pacific Islands, such as Hawaii, Guam, American Samoa, and large Office of Insular Affairs islands. However, recently we have expanded our focus to include carbonate sediment, as approximately 80-90% of coral reefs are constructed of lithified carbonate sediment (carbonate sand and rubble adhered together by calcareous algae, not intact coral growth). Because this carbonate sediment is a critical component of beach sediment supply, it represents an important resource for recreation and coastal storm protection. Although a key factor in the vertical growth of reefs and their ability to keep up with rising sea levels, carbonate reef sediment dynamics are poorly understood and this knowledge gap was recently determined to be a critical area of research for investigating climate-change impacts to coral reef-lined coasts.
Our Approach
The overall objective of this research is to better understand how hydrodynamics and sediment processes influence the development of coral reefs and their adjacent shorelines. Specifically, we are:
- Evaluating the role of coral-reef morphology on waves and wave-driven water levels over coral reefs and their resulting influence on coastal flooding.
- Elucidating the patterns of flow over coral reefs that result from different forcing mechanisms such as waves, currents, surface tides, internal tides, and subtidal motions.
- Determining the sources, pathways, and retention times of sediment, nutrients, and contaminants over complex coral reef morphologies.
- Identifying the circulation pathways that link separate reefs through larval or pollutant transport, and determine the spatial and temporal scales at which these pathways occur.
- Evaluating how these processes and linkages will be affected by projected changes in climate such as sea-level rise and changes in the frequency and intensity of storms.
The overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Caption for large photo at top of page: Photograph of large (6-meter-/20-foot-high) waves resuspending terrestrial flood sediment on the coral reefs off Puʻukoholā Heiau National Historic Site and Kawaihae Harbor, Hawaiʻi.
Learn more about our related studies.
Below are data or web applications associated with this project.
Model parameter input files to compare the influence of channels in fringing coral reefs on alongshore variations in wave-driven runup along the shoreline
Model parameter input files to compare locations of coral reef restoration on different reef profiles to reduce coastal flooding
Cross-reef wave and water level data from coral reef environments
Jurabi, Exmouth, Western Australia, 2016 Coral Reef Circulation and Sediment Dynamics Experiment
Model parameter input files to compare wave-averaged versus wave-resolving XBeach coastal flooding models for coral reef-lined coasts
Below are publications associated with this project.
A numerical study of geomorphic and oceanographic controls on wave-driven runup on fringing reefs with shore-normal channels
Land-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018
Wave-driven flood-forecasting on reef-lined coasts early warning system (WaveFoRCE)
A numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system
The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system.
Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014
Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
Pulse sediment event does not impact the metabolism of a mixed coral reef community
Integrating structure from motion, numerical modelling and field measurements to understand carbonate sediment transport in coral reef canopies
The influence of sea level on incident and infragravity wave-driven sediment dynamics across a fringing coral reef
Controls on sediment transport over coral reefs off southwest Puerto Rico: Seasonal patterns and Hurricane Maria
Guánica Bay in southwest Puerto Rico is highly turbid and has some of the highest PCB concentrations in the USA. To investigate how and to what extent the bay waters influence coral reef ecosystem health along the coastline, 6 months of hydrodynamic data were collected at 8 sites on the insular shelf. Bed shear stresses were primarily driven by waves and were weakest at the site closest to La Parg
- Overview
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.
The Problem
Tripod deployed on the reef flat off Jurabi, Ningaloo World Heritage Site, Western Australia, with instrumentation designed to measure tides, waves, currents, and sediment being transported across the reef. Over the past decade, we have primarily focused on fine-grained terrestrial sediment dynamics on reefs, due to its role as the greatest stressor to high-island fringing reefs throughout the U.S. and U.S.-Affiliated Pacific Islands, such as Hawaii, Guam, American Samoa, and large Office of Insular Affairs islands. However, recently we have expanded our focus to include carbonate sediment, as approximately 80-90% of coral reefs are constructed of lithified carbonate sediment (carbonate sand and rubble adhered together by calcareous algae, not intact coral growth). Because this carbonate sediment is a critical component of beach sediment supply, it represents an important resource for recreation and coastal storm protection. Although a key factor in the vertical growth of reefs and their ability to keep up with rising sea levels, carbonate reef sediment dynamics are poorly understood and this knowledge gap was recently determined to be a critical area of research for investigating climate-change impacts to coral reef-lined coasts.
Our Approach
Numerically simulated Lagrangian coral larval dispersal patterns from the Olowalu reef on west Maui, Hawaiʻi, for four different coral larval spawning events. Such modeling demonstrates the potential for a given reef to seed different islands and their respective reefs over relatively short timescales. The overall objective of this research is to better understand how hydrodynamics and sediment processes influence the development of coral reefs and their adjacent shorelines. Specifically, we are:
- Evaluating the role of coral-reef morphology on waves and wave-driven water levels over coral reefs and their resulting influence on coastal flooding.
- Elucidating the patterns of flow over coral reefs that result from different forcing mechanisms such as waves, currents, surface tides, internal tides, and subtidal motions.
- Determining the sources, pathways, and retention times of sediment, nutrients, and contaminants over complex coral reef morphologies.
- Identifying the circulation pathways that link separate reefs through larval or pollutant transport, and determine the spatial and temporal scales at which these pathways occur.
- Evaluating how these processes and linkages will be affected by projected changes in climate such as sea-level rise and changes in the frequency and intensity of storms.
The overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Caption for large photo at top of page: Photograph of large (6-meter-/20-foot-high) waves resuspending terrestrial flood sediment on the coral reefs off Puʻukoholā Heiau National Historic Site and Kawaihae Harbor, Hawaiʻi.
- Science
Learn more about our related studies.
- Data
Below are data or web applications associated with this project.
Model parameter input files to compare the influence of channels in fringing coral reefs on alongshore variations in wave-driven runup along the shoreline
An extensive set of physics-based XBeach Non-hydrostatic hydrodynamic model simulations (with input files here included) were used to evaluate the influence of shore-normal reef channels on flooding along fringing reef-lined coasts, specifically during extreme wave conditions when the risk for coastal flooding and the resulting impact to coastal communities is greatest. These input files accompanyModel parameter input files to compare locations of coral reef restoration on different reef profiles to reduce coastal flooding
This dataset consists of physics-based XBeach Non-hydrostatic hydrodynamic models input files used to study how coral reef restoration affects waves and wave-driven water levels over coral reefs, and the resulting wave-driven runup on the adjacent shoreline. Coral reefs are effective natural coastal flood barriers that protect adjacent communities. Coral degradation compromises the coastal protectCross-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 evenJurabi, Exmouth, Western Australia, 2016 Coral Reef Circulation and Sediment Dynamics Experiment
Carbonate reefs are a major source of sediment for coastlines in much of the tropical regions of the world, contributing to significant shoreline accretion and beach nourishment. A collaborative experiment between the U.S. Geological Survey and the University of Western Australia was conducted on Ningaloo Reef, northwest Australia, to investigate this problem and determine the primary oceanographiModel parameter input files to compare wave-averaged versus wave-resolving XBeach coastal flooding models for coral reef-lined coasts
This data release includes the XBeach input data files used to evaluate the importance of explicitly modeling sea-swell waves for runup. This was examined using a 2D XBeach short wave-averaged (surfbeat, XB-SB) and a wave-resolving (non-hydrostatic, XB-NH) model of Roi-Namur Island on Kwajalein Atoll in the Republic of Marshall Islands. Results show that explicitly modelling the sea-swell componen - Publications
Below are publications associated with this project.
Filter Total Items: 23A numerical study of geomorphic and oceanographic controls on wave-driven runup on fringing reefs with shore-normal channels
Many populated, tropical coastlines fronted by fringing coral reefs are exposed to wave-driven marine flooding that is exacerbated by sea-level rise. Most fringing coral reef are not alongshore uniform, but bisected by shore-normal channels; however, little is known about the influence of such channels on alongshore variations on runup and flooding of the adjacent coastline. We con-ducted a parameLand-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018
The effects of runoff from land on nearshore ecosystems, including coral reef communities, are influenced by both sediment supply and removal by coastal processes. Integrated studies across the land-sea interface describing sources and transport of terrestrial sediment and its nearshore fate allow reef protection initiatives to target key onshore and offshore areas. Geochemical signatures in the fWave-driven flood-forecasting on reef-lined coasts early warning system (WaveFoRCE)
Increasing the resilience of coastal communities while decreasing the risk to them are key to the continued inhabitance and sustainability of these areas. Low-lying coral reef-lined islands are experiencing storm wave-driven flood events that currently strike with little to no warning. These events are occurring more frequently and with increasing severity. There is a need along the world’s coralA numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system
Two-dimensional mean wave-driven flow and setup dynamics were investigated at a reef-lagoon system at Ningaloo Reef, Western Australia, using the numerical wave-flow model, SWASH. Phase-resolved numerical simulations of the wave and flow fields, validated with highly detailed field observations (including >10 sensors through the energetic surf zone), were used to quantify the main mechanisms thatThe contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system.
Coral reefs generate substantial volumes of carbonate sediment, which is redistributed throughout the reef‐lagoon system. However, there is little understanding of the specific processes that transport this sediment produced on the outer portions of coral reefs throughout a reef‐lagoon system. Furthermore, the separate contributions of currents, sea‐swell waves, and infragravity waves to transportNearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014
Coral reefs worldwide are experiencing rapid degradation in response to climate and land-use change, namely effects of warming sea-surface temperatures, contaminant runoff, and overfishing. Extensive coral bleaching caused by the steady rise of sea-surface temperatures is projected to increase, but our understanding and ability to predict where corals may be most resilient to this effect is limiteSpectral wave-driven bedload transport across a coral reef flat/lagoon complex
Coral reefs are an important source of sediment for reef-lined coasts by helping to maintain beaches while also providing protection in the form of wave energy dissipation. Understanding the mechanisms by which sediment is delivered to the coast as well as better constraining the total volumes generated are critical for projecting future coastal change. A month-long hydrodynamics and sediment tranIn situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
The character and energetics of infragravity (IG, 25 s < period < 250 s) and very-low frequency (VLF, period > 250 s) waves over coral reef flats can enhance shoreline erosion or accretion, and also govern extreme shoreline events such as runup, overwash, and flooding on coral reef-lined coasts. Here we use in situ wave measurements collected along cross-reef transects at 7 sites on Pacific islandPulse sediment event does not impact the metabolism of a mixed coral reef community
Sedimentation can bury corals, cause physical abrasion, and alter both spectral intensity and quality; however, few studies have quantified the effects of sedimentation on coral reef metabolism in the context of episodic sedimentation events. Here, we present the first study to measure coral community metabolism - calcification and photosynthesis - in a manipulative mesocosm experiment simulatingIntegrating structure from motion, numerical modelling and field measurements to understand carbonate sediment transport in coral reef canopies
Reef canopies are complex and extremely variable across a range of spatial scales. This variability affects the velocity above as well as within the canopy, and directly impacts the transport of sediment along the bed as well as suspended in the water column. How a canopy affects the transport of sediment is important to understand and predict changes in the position of the adjacent shoreline, parThe influence of sea level on incident and infragravity wave-driven sediment dynamics across a fringing coral reef
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 pControls on sediment transport over coral reefs off southwest Puerto Rico: Seasonal patterns and Hurricane Maria
Guánica Bay in southwest Puerto Rico is highly turbid and has some of the highest PCB concentrations in the USA. To investigate how and to what extent the bay waters influence coral reef ecosystem health along the coastline, 6 months of hydrodynamic data were collected at 8 sites on the insular shelf. Bed shear stresses were primarily driven by waves and were weakest at the site closest to La Parg