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Coral Reef Project: Kahoʻolawe Active

By Pacific Coastal and Marine Science Center April 15, 2021

As part of the USGS Coral Reef Project, the USGS is trying to better understand how nearshore processes impact the deeper, scattered coral reef communities of Kahoʻolawe.

Coral Reef Project

Overview

Aerial view of an island with an extinct volcano.
Sources/Usage: Public Domain.
Satellite view of the Hawaiian island of Kahoʻolawe, southwest of the island of Maui.

The smallest of the main eight Hawaiian Islands is Kahoʻolawe. Located between the islands of Lānaʻi and Maui, it encompasses only 117 sq km (45 sq mi). Known as the Forbidden Isle, this culturally significant island was at different times used as a penal colony, a ranch, and a forest reserve. In 1941, Kahoʻolawe Ranch leased the island to the U.S. Navy and for many years it was used as target practice training grounds. In 2003 the island was transferred back to the State of Hawaiʻi and efforts are currently underway for restoration of native vegetation and protection of cultural artifacts.

NOTE: Due to unexploded ordinance in the surrounding waters, unauthorized entry to the island and to waters within two miles of the island is prohibited (H.A.R. §13-260).

 

Motivation

Camera was positioned halfway in and out of water to show a coastal bluff with vegetation in background, coral reef underwater.
Sources/Usage: Public Domain.
Photograph of the shallow fringing coral reef flat and adjacent land at Kaulana, Kahoʻolawe.

Coral growth on Kahoʻolawe is limited to scattered coral communities at deeper depths. Due to the deforestation of the island, there is a significant problem with erosion and sediment run-off into the nearshore environment. The USGS is assisting the Kahoʻolawe Island Reserve Commission to better understand how sediment processes impact coral reefs.

The Hawaiian island of Kahoʻolawe is just one of the USGS Coral Reef Project's study locations.

Coral Reef Project

Coral head that looks like lettuce sits on sandy bottom in clear blue water and is surrounded by brightly colored fish.
Coral Reef Project

Project Study Locations

A geologic tour of the Hawaiian Islands: Maui...
Study Locations

Coral Reef Facts

Simple illustration of coral anatomy showing tentacles, mouth, polyps, corallium, nenatocysts, zooxanthellae.
Coral Reef Facts
link
Underwater photograph of a shallow, partially sandy reef environment with a 3-legged metal frame holding instruments.

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.
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
link

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.
Learn More
link
Underwater photo of corals taken from a video feed, where the camera displays text on the image like date and location.

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.
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
link

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.
Learn More
link
Underwater photo of a shallow coral environment.

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.
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
link

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.
Learn More
link
Cartoon showing the cross-section of a hill near an ocean and the movement of groundwater underneath.

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.
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center
link

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.
Learn More
link
Computed tomography scan and photograph of a coral core section, side-by-side.

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.
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, 3-D CT Core Imaging Laboratory, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory
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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.
Learn More

Below are data releases associated with this project.

Dynamically 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) wind
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

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,

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 mask
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Physics-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
By
Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Below are publications associated with this project.

The 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 5
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

The 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 state
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Rigorously 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, geospatial
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center

Modeling 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 complex
By
Pacific Coastal and Marine Science Center

The 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 en
By
Pacific Coastal and Marine Science Center

From 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 on
By
Ecosystems Mission Area, Pacific Island Ecosystems Research Center, Pacific Coastal and Marine Science Center

The 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. De
By
Woods Hole Coastal and Marine Science Center, Pacific Coastal and Marine Science Center

Turbidity on the shallow reef off Kaulana and Hakioawa watersheds, north coast of Kaho'olawe, Hawai'i: Measurements of turbidity and ancillary data on winds, waves, precipitation, and stream flow discharge, November 2005 to June 2008

The island of Kaho`olawe has particular cultural and religious significance for native Hawaiians. Once known as Kanaloa, the island was a center for native Hawaiian navigation. In the mid-20th century, the island was used as a bombing range by the U.S. Navy, and that practice, along with the foraging by feral goats, led to a near-complete decimation of vegetation. The loss of ground cover led to g
By
Pacific Coastal and Marine Science Center

Science-Based Strategies for Sustaining Coral Ecosystems

Coral ecosystems and their natural capital are at risk. Greenhouse gas emissions, overfishing, and harmful land-use practices are damaging our coral reefs. Overwhelming scientific evidence indicates that the threats are serious, and if they are left unchecked, the ecological and social consequences will be significant and widespread. Although the primary stressors to coral ecosystems are known, sc
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program

Below are news stories associated with this project.

link

Maui-area coral reefs described in detail, including threats

A new USGS Open-File Report describes the coral reefs of Maui, Moloka‘i, Lānaʻi, and Kahoʻolawe in detail, including location, extent, coral cover...

Read Article

Below are partners associated with this project.

Kahoʻolawe Island Reserve Commission