Studies and Research in the Priority Watersheds & Related Links
Maui-area coral reefs described in detail, including threats
Release Date: JULY 1, 2019
A new USGS Open-File Report describes the coral reefs of Maui, Moloka‘i, Lānaʻi, and Kahoʻolawe in detail, including location, extent, coral cover, and connectivity.
The nine major coral reefs surrounding Maui and three nearby Hawaiian Islands (collectively Maui Nui) are critical to the local ecology, culture, and economy. Reef health has slowly declined over decades, and recent events such as the 2015 thermal bleaching have accelerated reef loss significantly, in some areas by an order of magnitude. A new USGS Open-File Report describes these coral reefs in detail, including location, extent, coral cover, and connectivity. The publication also describes threats to reef health, including overfishing, land-based pollution, and climate change. The report provides information that could inform Federal and State governments in their effort to establish a network of large-scale, connected Marine Protected Areas for effective management and protection of coral reefs in Hawai’i.
Credit: Curt Storlazzi,Research Geologist, USGS Pacific Coastal and Marine Science Center
Assessing the Resilience of Leeward Maui Reefs to Help Design a Resilient Managed Area Network - 2019 Report
The project team assessed the relative resilience of reef sites at two depths along areas of West and South-West Maui ("leeward Maui") in March of 2018. The surveys were conducted as a collaborative effort with DAR, The Nature Conservancy, and community organizations. This report presents findings from meeting these project objectives: 1) assess benthic cover comparisons among sites and depths, 2) complete resilience assessment including relative resilience and rankings for two depths, 3) conduct analyses that determine the primary drivers of differences in resilience between sites, and 4) develop a framework for using the resilience analysis outputs to identify and prioritize potential management actions to support the resilience of coral reefs in Maui.
Citation: Maynard J, Conklin E, Minton D, Williams GJ, Tracey D, Amimoto R, Carr R, Fielding E, Lynch H, Rose J, Sparks R, Sylva R, White D. (2019). Assessing the Resilience of Leeward Maui Reefs to Help Design a Resilient Managed Area Network. NOAA Coral Reef Conservation Program. NOAA Technical Memorandum CRCP 33, 40 pp.
Detailed maps of West Maui Reefs from the Pacific Islands Benthic Habitat Mapping Center
Rigorously Valuing the Role of U.S. Coral Reefs in Coastal Hazard Risk Reduction
Open-File Report 2019-1027
Prepared in cooperation with the University of California Santa Cruz and The Nature Conservancy
By: Curt D. Storlazzi, Borja G. Reguero, Aaron D. Cole, Erik Lowe, James B. Shope, Ann E. Gibbs, Barry A. Nickel, Robert T. McCall, Ap R. van Dongeren, and Michael W. Beck
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, social, and economic tools to provide a rigorous valuation of the coastal protection benefits of all U.S. coral reefs in the States of Hawaiʻi and Florida, the territories of Guam, American Samoa, Puerto Rico, and Virgin Islands, and the Commonwealth of the Northern Mariana Islands. We follow risk-based valuation approaches to map flood zones at 10-square-meter resolution along all 3,100+ kilometers of U.S. reef-lined shorelines for different storm probabilities to account for the effect of coral reefs in reducing coastal flooding. We quantify the coastal flood risk reduction benefits provided by coral reefs across storm return intervals using the latest information from the U.S. Census Bureau, Federal Emergency Management Agency, and Bureau of Economic Analysis to identify their annual expected benefits, a measure of the annual protection provided by coral reefs.
Learn the Basics
Mahalo to our research partners for sharing your slides.
The County of Maui works in many ways to protect storm water and receiving waters from pollutants that could negatively impact receiving water quality. The County’s goal is to work with community individuals, businesses, large landowners, and State and Federal agencies to foster joint responsibility and positive action to protect our precious surface water resources. https://www.mauicounty.gov/2129/Storm-Water-Management-Program
Sunscreens & Reef Health
Link between fire and ocean health- by HWMO
Created in 1997 through the community based West Maui Watershed Management Advisory Committee is the West Maui Watershed Owners Manual. Despite the changes to our land use patterns and environmental challenges since its release, this guide written for the community still contains highly relevant advice about actions anyone living, working or playing in West Maui can take to make a positive difference. This was funded by the DOH, USEPA and NOAA.
Guidance for Watershed Managers
The US Coral Reef Task Force Watershed Working Group Metrics Subcommittee has developed metrics guidance documents to assist with what parameters are important for watershed managers to collect to track progress. The priority Ecosystem Indicators include water quality and coral metrics, while the Programmatic Checklist focuses on the non-ecological factors that play into success, such as institutional support, a watershed management plan, local governmental support etc.
Hawaii Regional Sediment Management (RSM): Regional Sediment Budget for the West Maui Region by US Army Corps of Engineers
By: Jessica H. Podoski, Thomas D. Smith, Zeki Demirbilek, Lihwa Lin, and Linda S. Lillycrop
ABSTRACT: (June 2016) This technical report provides a description of the Regional Sediment Management (RSM) investigations performed by the U.S. Army Corps of Engineers (USACE), Honolulu District (POH), along the West Maui coastal region of the Island of Maui, HI. The methodology for determining volume change rates as well as numerical modeling is discussed, including the particle tracking modeling, in support of identifying sediment pathways for the development of the regional sediment budget for the West Maui coast. The West Maui Region incorporates a thin coastal margin backed by steep mountainous terrain that has been vastly altered by agricultural and urbanized development. Shoreline hardening is being proposed along portions of the region’s coastline. Shoreline change for this area was quantified by the U.S. Geological Survey (USGS). All subregions were found to be erosional in the long and short term, based on average rates. The dynamics of the area are complex with a wave climate affected by intricate bathymetry, wind, and island sheltering. Currents vary from nearshore to offshore and within the water column. Coastal morphology includes headlands and reefs with a very limited supply of sediment. Wave and current models indicate that large waves in the summer and winter drive the majority of sediment transport (northward-directed in summer and southward-directed in winter). Because of these seasonal patterns, the net transport of sediment is small. There is evidence of nearshore eddy formation that increases the complexity of sediment transport in the region with sediment pathways changing on short-term (hours) to longerterm (weeks to months) temporal scales. This is a very dynamic and seasonally affected shoreline, and the present RSM study is one tool that will help inform future shoreline management in the region.
Reconnaissance Sediment Budget for Selected Watersheds of West Maui, Hawai‘i
Open-File Report 2015-1190
By:Jonathan D. Stock, Kim A. Falinski, and Tova Callender
ABSTRACT: Episodic runoff brings suspended sediment to the nearshore waters of West Maui, Hawaiʻi. Even small rainfalls create visible plumes over a few hours. We used mapping, field experiments, and analysis of recent (July 19–20, 2014) and historic rainfall to estimate sources of land-based pollution for two watersheds in West Maui: Honolua, and Honokōwai. Former agricultural fields and some unimproved roads are plausible sources for polluted runoff, but have saturated hydraulic conductivities greater than the 10–15 millimeters per hour rainfalls of July 2014. These fields and roads showed minor evidence for storm runoff, and could not have contributed substantially to July 2014 plume generation. Since 1978, rain at intensities capable of causing runoff from former agricultural fields sustained for 1–2 hours is also rare; such intensities have 2–5 year recurrence rates in the north, and greater than 25 year recurrence rates to the south near Lahaina. Streambanks now eroding into historic terraces of sands, silts, and clays are a more plausible source. Although past large storms contributed to sediment loading, annual plume generation is now caused by smaller rainfalls eroding these near-stream legacy deposits. Treatments of former agricultural fields, roads, and reserve forests are consequently not likely to measurably affect sediment pollution from smaller, more frequent storms. Increased runoff from the development of West Maui has the potential to exacerbate sediment plumes from such storms unless there is an effective strategy to reduce bank erosion. Uncertainties in the extent and erosion rate of historic terraces, however, limit our ability to plan mitigation.
Rain Catchment Resources
In 2004, CTAHR developed Guidelines on Rainwater Catchment Systems for Hawai‘i. An estimated 30,000 to 60,000 people in the state of Hawai‘i are dependent on a rainwater catchment system for their water needs. With proper design, maintenance, and water treatment, a rainwater catchment system can provide water that is relatively free of contamination, soft, clear, and odorless; this water can be used for drinking, bathing, washing, flushing,laundry, and gardening. Follow the link to read the 52 page guide and begin catching your own water!
Rain Garden Resources
Six minute PBS video documenting a movement in Seattle to install 12,000 rain gardens.
This community based non-profit on Oahu developed Hawaii's first rain garden manual (below) and has great rain garden examples and resources available on line.
Download the Hawaii Residential Rain Garden Manual here
Links to Partner Agencies & Organizations
NOAA Coral Reef Program: http://coralreef.noaa.gov/
DLNR Department of Aquatic Resources: http://www.hawaiicoralreefstrategy.com/
U.S. Army Corps of Engineers: http://www.poh.usace.army.mil/
Hawaii State Department of Health: http://health.hawaii.gov/
U.S. Environmental Protection Agency: http://www.epa.gov/
U.S. Geological Survey: http://www.usgs.gov/
U.S. Fish and Wildlife Service: http://www.fws.gov/
National Fish and Wildlife Foundation: http://www.nfwf.org/coralreef/Pages/home.aspx#.U8SnrrHCd8E
Hui O Ka Wai Oka: https://www.huiokawaiola.com/
West Maui Mountains Watershed Partnership: http://www.westmauiwatershed.org/
The Nature Conservancy: http://www.nature.org
The Coral Reef Alliance: http://www.coral.org/
County of Maui: http://www.co.maui.hi.us/
Maui Nui Marine Resource Council: http://www.mnmrc.org/
Additional Resources from the USGS Pacific Coastal & Marine Science Center Team
Cochran, S.A., Gibbs, A.E., and White D.J., 2014, Benthic habitat map of the U.S. Coral Reef Task Force Watershed Partnership Initiative Kāʻanapali priority study area and the State of Hawaiʻi Kahekili Herbivore Fisheries Management Area, west-central Maui, Hawaiʻi: U.S. Geological Survey Open-File Report 2014-1129, 42 p.
Gibbs, A.E., Cochran, S.A., and Tierney, P.W., 2013, Seafloor video footage and still frame-grabs from U.S. Geological Survey cruises in Hawaiian nearshore waters: U.S. Geological Survey Data Series 735, 11 p.
Gibbs, A.E., Grossman, E.E., and Richmond, B.M., 2005, Summary and preliminary interpretations of USGS cruise A-2-02-HW; Underwater video surveys collected off of Oʻahu, Molokai, and Maui, Hawaii, June-July 2002: U.S. Geological Survey Open-File Report 2005–1244, 57 p.
and there are numerous other data associated with positions listed in tables in the following reports:
Storlazzi, C.D. and Presto, M.K., 2005. “Coastal Circulation and Sediment Dynamics along West Maui, Hawaii, PART IV: Measurements of waves, currents, temperature, salinity and turbidity in Honolua Bay, Northwest Maui: 2003-2004” USGS Open-File Report 2005-1068, 34 p. http://pubs.usgs.gov/of/2005/1068/
Storlazzi, C.D., Field, M.E., Ogston, A.S., Logan, J.B., Presto, M.K. and Gonzales, D.G., 2004. “Coastal Circulation and Sediment Dynamics along West Maui, Hawaii, PART III: Flow and particulate dynamics during the 2003 summer coral spawning season” USGS Open-File Report 2004-1287, 36 p. http://pubs.usgs.gov/of/2004/1287/
Hatcher, G.A., Reiss, T.E. and Storlazzi, C.D., 2004. “Application of GPS drifters to track Hawaiian coral spawning” USGS Open-File Report 2004-1309, 14 p. http://pubs.usgs.gov/of/2004/1309/
Storlazzi, C.D., Logan, J.B., McManus, M.A., and McLaughlin, B.E., 2003. “Coastal Circulation and Sediment Dynamics along West Maui, Hawaii, PART II: Hydrographic Survey Cruises A-3-03-HW and A-4-03-HW Report on the spatial structure of currents, temperature, salinity and turbidity along Western Maui” USGS Open-File Report 03-430, 50 p.
Storlazzi, C.D. and Jaffe, B.E., 2003. “Coastal Circulation and Sediment Dynamics along West Maui, Hawaii, PART I: Long-term measurements of currents, temperature, salinity and turbidity off Kahana, West Maui: 2001-2003” USGS Open-File Report 03-482, 28 p. http://pubs.usgs.gov/of/2003/of03-482/