Projects : Ocean Tipping Points: Hawaiʻi Case Study

Discovering when, where, and how ocean tipping points occur in diverse ecosystems
OverviewCase StudyFindingsValueDataPartnersData Sources

Overview

What Are Tipping Points and Why Do They Matter?

Tipping points occur when shifts in human pressures (e.g., fishing and development) or environmental conditions (e.g., sea surface temperature and productivity) cause large, sometimes abrupt changes in an ecosystem that may be difficult or impossible to reverse. A growing number of examples of tipping points in ecosystems around the world are raising concern among scientists and policymakers. In the oceans, diverse ecosystems ranging from reefs to estuaries to pelagic systems have undergone these sudden, dramatic shifts.

Reef fish

Photo Credit: James Watt.

Goals and Approach of the Ocean Tipping Points Project

A focus on tipping points can be a critical aspect of effective ecosystem-based management of our coasts and oceans. The theory and science of ecosystem tipping points is fast evolving and often unfamiliar to managers looking for best available science. The Ocean Tipping Points collaborative research project seeks to improve knowledge and understanding of ocean tipping points, their potential impacts, and how to manage them effectively. We are synthesizing the latest science and applying new tools that incorporate our growing body of knowledge on ecosystem thresholds in case studies focused on specific management opportunities. In the Main Hawaiian Islands and Haida Gwai, British Columbia we are working closely with local scientists, managers, and stakeholders to make tipping point science and tools applicable and accessible to current management issues. This information will help managers avoid undesirable tipping points, monitor using early warning indicators, prioritize management actions, and evaluate progress toward ecosystem objectives.

 
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“By identifying tipping points, we get a much better sense for just how much of a change we need to make, and then what are the best options to achieve that level of change. The tipping points approach could be very useful for helping us develop the optimal strategies, the most effective strategies to improve resources in an area.”

— Eric Conklin, Marine Science Director, The Nature Conservancy Hawaiʻi Program

“By identifying tipping points, we get a much better sense for just how much of a change we need to make, and then what are the best options to achieve that level of change. The tipping points approach could be very useful for helping us develop the optimal strategies, the most effective strategies to improve resources in an area.”

— Eric Conklin, Marine Science Director, The Nature Conservancy Hawaiʻi Program

 

Learn about the novel science coming out of the Ocean Tipping Points Project that is helping marine managers better understand and protect ocean ecosystems.

More About the Ocean Tipping Points Project

More information about the Ocean Tipping Points Project can be found at http://oceantippingpoints.org .

Ocean Tipping Points Story Map

Click above for Ocean Tipping Points Story Map .

Case Study: Hawaiʻi

Reef ecosystems in many parts of the world have “tipped” into alternate ecosystem states, often with negative consequences for biodiversity and coastal communities. For this reason, the Ocean Tipping Points team selected the coral reefs surrounding the Main Hawaiian Islands as one of their focal case studies to examine reef tipping points. Because of their unique geologic history and oceanographic setting, Hawaiian reefs vary widely in their structure, appearance, and sensitivities—from wave-swept boulder fields to delicate coral-lined lagoons. This diversity means that resilient reefs do not all look the same, and the levels of stressors that trigger big changes will differ among reef types. The archipelago’s well-sampled reefs span strong gradients in environmental conditions and human uses, allowing us to investigate how these factors combine and interact to affect the appearance of various reefs across the island chain as well as their resilience to disturbance.

Coral Infographic
Photo Credit: Keoki Stender, www.marinelifephotography.com.

The people of Hawaiʻi depend upon a healthy nearshore ecosystem for food, clean water, protection from storms, commerce, recreation, and culture—tipping points can dramatically alter these benefits. Once a tipping point has been crossed, restoration can be very costly and may not be feasible over reasonable time scales. For example, in Kāneʻohe Bay and Maunalua Bay on the island of Oʻahu there are huge, ongoing efforts to keep the reefs free of invasive algae. Knowing how much use and stress may push a reef past such a tipping point can help identify the most important actions to take to maintain healthy, resilient reefs, and avoid costly restoration.

Understanding Tipping Points in Hawaiʻi

Leveraging decades of intense reef monitoring data, our collaborative team is working to create a novel view of Hawaiian reef types and asking how environmental factors and human uses interact to shape nearshore Hawaiian reefs. We are identifying key thresholds of human activity that result in big changes on reefs and quantifying the total ecological impact of human stresses to reefs. These analyses will help determine compatible levels of multiple use and develop practical strategies to avoid or reverse these tipping points.

Reef Surveys
Photo Credit: OTP.

In two focal regions (West Maui and West Hawaiʻi) we are analyzing the social, environmental, and economic costs and benefits of alternate management actions to identify potential win-win solutions that can result in measurable improvements in reef health through coordinated management. Our team is working directly with marine resource managers to develop practical tools to help anticipate and manage for these tipping points.

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“When you’re looking at resilience indicators I haven’t seen something that provides the level of information and insight that this project (OTP) has been able to capture. I think increasingly we are going to be needing that and using it to look at where we prioritize management for things like climate change.”

— Erin Zanre, Community Based Subsistence Fishing Area Planner, Division of Aquatic Resources

“When you’re looking at resilience indicators I haven’t seen something that provides the level of information and insight that this project (OTP) has been able to capture. I think increasingly we are going to be needing that and using it to look at where we prioritize management for things like climate change.”

— Erin Zanre, Community Based Subsistence Fishing Area Planner, Division of Aquatic Resources

 

Our ultimate goal is to develop tools, maps, and guiding principles to help practitioners effectively anticipate, avoid, and respond to coral reef change in Hawaiʻi and beyond. The insights gained in this case study will have potential application for reefs globally.

The Ocean Tipping Points team has synthesized a great deal of data and developed several resulting products to date. The project has expanded datasets of fish and other reef species diversity, identified and mapped different reef types across Hawaiʻi, linked these “regimes” to different environmental and human-based factors, created maps of current coral states, and identified cost-effective management solutions in West Maui. We are bringing these data together with human-use and environmental data to understand what drives changes in reef state as well as determining at what threshold stressors result in disproportionate changes in reef condition. The human-use and environmental data we have synthesized can all be found here in the PacIOOS data repository.

 
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“As we begin to think about adaptive management strategies with a rapidly changing climate, this information is key for providing—really for the first time—a comprehensive understanding of the natural environment, human activities, and the natural resources around the state.”

— Jamie Gove, Research Oceanographer, NOAA Pacific Islands Fisheries Science Center

“As we begin to think about adaptive management strategies with a rapidly changing climate, this information is key for providing – really for the first time – a comprehensive understanding of the natural environment, human activities, and the natural resources around the state.”

— Jamie Gove, Research Oceanographer, NOAA Pacific Islands Fisheries Science Center

Findings

Mapping Drivers of Coral Reef States in Hawaiʻi

We created statewide maps showing the influence of environmental factors and human-based activities on coral reef ecosystems across Hawaiʻi. The environmental driver data was gathered from recent satellite-based sea surface temperature, chlorophyll-a, irradiance, and modeled wave energy data. Human drivers of coral reef ecosystem health included data on commercial and non-commercial fish catch, invasive species, effluent, habitat modification, and sedimentation on reefs.

The maps show differences across the Hawaiian Islands, as well as variation among reefs on each island. Not surprisingly, levels of many human impacts were highest on Oʻahu, including habitat modification, invasive species, and boat-based fishing. Sedimentation and nutrient runoff are the dominant influences of reef condition in specific locations on Maui, Hawaiʻi Island, and the North Shore of Oʻahu.

These maps represent the first-ever integrated picture of how both human and environmental drivers of coral reef health vary in space across the Hawaiian Archipelago and are publically available on this site under the Data tab.

 
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“The most exciting thing for me about this project was all of the data that’s been collected and putting it in one place where I can access it, the communities can access it, the state can access it, and see what’s been done. Getting it all in one place at one level where you can look at it as one dataset instead of all these little pieces of information collected over time, and using that as a place to start moving forward.”

— Katie Nalasere, Community Based Subsistence Fishing Area Planner, Division of Aquatic Resources – Kauaʻi

“The most exciting thing for me about this project was all of the data that’s been collected and putting it in one place where I can access it, the communities can access it, the state can access it, and see what’s been done. Getting it all in one place at one level where you can look at it as one dataset instead of all these little pieces of information collected over time, and using that as a place to start moving forward.”

— Katie Nalasere, Community Based Subsistence Fishing Area Planner, Division of Aquatic Resources – Kauaʻi

Value

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“What I want to see as we move forward in the future is securing the longevity of our reefs and nearshore resources for generations to come. It’s going to be a very different future, and having the information from the Ocean Tipping Points project is going to help us better understand what that future looks like and be able to implement management actions that will hopefully preserve more of it.”

— Darla White, Coral Reef Biologist, Hawaiʻi Division of Aquatic Resources – Maui

“What I want to see as we move forward in the future is securing the longevity of our reefs and nearshore resources for generations to come. It’s going to be a very different future, and having the information from the Ocean Tipping Points project is going to help us better understand what that future looks like and be able to implement management actions that will hopefully preserve more of it.”

— Darla White, Coral Reef Biologist, Hawaiʻi Division of Aquatic Resources – Maui

The people of Hawaiʻi depend on a healthy nearshore ecosystem for food, clean water, commerce, and culture, but dramatic shifts in reef health that result from crossing tipping points can be costly or impossible to reverse and are often accompanied by big losses in these ecosystem benefits, including the loss or degradation of:

  • fishing opportunities and seafood supply (e.g., some of the bays that were the most productive around Oʻahu are now the least productive: Waikīkī, Maunalua, Kāneʻohe);
  • wildlife viewing, snorkeling, and diving opportunities;
  • water quality;
  • swimmable waters (some of West Maui’s waters can be subject to closure due to poor water quality from pollution runoff, e.g., Kīhei);
  • aesthetic value of clean, clear water and vibrant reef communities;
  • cultural benefits (e.g., decreased access to or restriction on harvest of culturally important species that are now rare, such as algal harvest that used to happen in Pūpūkea).
Ocean Collage

Photo Credit: Lois Elling, Steve Dunleavy, Brocken Inaglory.

The loss of these benefits from the reef can negatively impact people’s way of life and their wallets through loss of revenue and jobs, diminished food security, and impacts on cultural practices (e.g., diminished opportunities to practice species-specific traditions or traditional harvest methods).

Without integrating the state of Hawaiʻi’s reefs and the potential for reef tipping points into management, we are more likely to face more costly, surprising, and potentially irreversible changes. Using this science as a basis for management could help avoid spending a substantial amount of money and time tackling difficult problems that might have been prevented with a more proactive, ecosystem-based approach.

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“Most often, you do the science first and then bring it to the stakeholders. In this case, stakeholders and managers were actually around the table from Day 1, with targeted objectives that we had to collaborate on to provide a scientific basis for whatever their future decision would be.”

— JB Jouffray, PhD Student, Stockholm Resilience Centre

“Most often, you do the science first and then bring it to the stakeholders. In this case, stakeholders and managers were actually around the table from Day 1, with targeted objectives that we had to collaborate on to provide a scientific basis for whatever their future decision would be.”

— JB Jouffray, PhD Student, Stockholm Resilience Centre

Data

As part of this project, the Ocean Tipping Points team mapped environmental and anthropogenic drivers of coral reef ecosystem states. These data layers provide a novel picture of how factors that influence coral reef state vary in space across the Main Hawaiian Islands. These datasets will allow new understanding of what drives variation in Hawaiʻi’s reefs and support management designed to promote reef resilience and protect reef ecosystem services.

All data can be found in the map viewer, and are also available for download in various formats from the categories listed further below.

 

NOTE: This interactive mapping application is ill-suited for small screen sizes. Below is a screenshot only. Please visit again from a laptop or desktop computer to enable the application.

Anthropogenic Drivers

Sedimentation

Sedimentation

Photo Credit: Bill Rathfon.

Sediment from coastal erosion and various land-based activities can affect reef health by covering corals, blocking light, and inhibiting new coral settlement. This can lead to degradation of reef ecosystems. To quantify sedimentation, we modeled how much sediment was being transported into the nearshore marine environment around the Main Hawaiian Islands.

The annual amount of sediment (tons/yr) reaching the coast was calculated using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Sediment Delivery Ratio model for each of the eight main Hawaiian Islands. Sediment load is a function of land use and vegetation type, geology, soil characteristics, rainfall, slope, and hydrology. Only land areas that drain to a stream which reaches the coast and have a sediment supply were considered. The resulting sediment load at each point where a stream meets the coast was dispersed offshore using the Kernel Density tool in ArcGIS, resulting in a map of annual average sediment conditions offshore.

Sediment Export to Nearshore Waters – Hawaii

id: hi_otp_all_nearshore_sediment

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Effluent

Effluent

Photo Credit: USDA.

There are over 95,000 onsite sewage disposal systems (OSDS) (i.e., cesspools and septic tanks) used in Hawaiʻi, many close to coastlines and streams. These systems have varying levels of treatment capacity for nutrients, bacteria, and other pollutants found in wastewater and may leech into groundwater that flows to the ocean. Excess nutrients can promote rapid algal growth, outcompeting corals and disrupting the natural balance of the ecosystem.

Using findings from the Hawaiʻi Department of Health, this data consisted of estimated nitrogen flux and phosphorous flux from points representing Tax Map Key (TMK) parcels with OSDS in units of kg/day and effluent in gal/day (Whittier and El-Kadi 2009; 2014). We converted the points to raster by summing nutrient flux values within 500-m pixels and then calculated the total flux within a 1.5-km radius of each cell.

Nitrogen Flux from Onsite Sewage Disposal Systems (OSDS) – Hawaii

id: hi_otp_all_osds_nitrogen

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Phosphorus Flux from Onsite Sewage Disposal Systems (OSDS) – Hawaii

id: hi_otp_all_osds_phosphorus

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Total Effluent from Onsite Sewage Disposal Systems (OSDS) – Hawaii

id: hi_otp_all_osds_effluent

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Development

Development

Photo Credit: Edmund Garman.

New construction sites that strip land of vegetation, leaving bare and tilled soil that is vulnerable to erosion, are an additional source of sediment that can affect reef health. Often these sites also have large piles of soil on site for grading and landscaping that contribute to sedimentation before the property is landscaped. To capture this issue, we identified areas that had been newly developed over a recent 5-year period.

Using high resolution data from NOAA’s Coastal Change Analysis Program (C-CAP), we identified all map pixels that changed from undeveloped land to a hard, man-made surface from 2005 to 2010, and calculated the area of this new development by watershed. We then used a function that decays with distance from shore to disperse this watershed-scale proxy for sediment from new construction into the nearshore environment. Values were re-scaled from 0 to 1 in order to represent the relative level of new development.

Nearshore New Development Impact, 2005-2010/2011 – Hawaii

id: hi_otp_all_nearshore_dev

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Habitat Modification

Habitat Modification

Photo Credit: Bishop Museum.

Coastal habitats are utilized and altered for a suite of human uses. Here we define habitat modification as the alteration or removal of landscape features as a result of human use. This includes several habitat-modifying features like seawalls, piers, breakwaters, dredged areas, artificial land (i.e., filled wetlands), and offshore structures.

We mapped the presence of habitat-modifying features by combining several existing datasets derived primarily from satellite and aerial imagery from the State of Hawaiʻi GIS Program, NOAA Environmental Sensitivity Index (ESI) data, NOAA Biogeography Branch, and MarineCadastre.gov. The layer represents the presence or absence of habitat modification, with a cell size of 500 m.

Coastal Habitat Modification – Hawaii

id: hi_otp_all_coastal_mod

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Invasive Species

Invasive Species

Photo Credit: Keoki Stender, www.marinelifephotography.com; Jim and Becca Wicks.

Due to the geographic isolation of the Hawaiian Islands, close to 25% of Hawaiʻi’s reef fishes and red algae species are found only in Hawaiʻi. This leaves Hawaiian coral reefs particularly vulnerable to invasions from non-native species.

Algae

Invasive Algae

Photo Credit: Keoki Stender, www.marinelifephotography.com.

Invasive algae can pose a serious threat to coral reefs by spreading and growing rapidly, smothering or outcompeting corals and other organisms. This can significantly alter the structure and function of the reef ecosystem. Four species of alien red algae have become invasive in Hawaiʻi: prickly seaweed (Acanthophora spicifera), hookweed (Hypnea musciformis), smothering seaweed (Kappaphycus spp.), and gorilla ogo (Gracilaria salicornia).

Invasive algae data were from monitoring surveys in the Hawaiʻi Fish and Benthic Biological Synthesis Database (200-2013) as well as invasive algae surveys conducted across the state in 2002 by Dr. Jennifer Smith. Data consist of point locations of invasive algae presence that were subsequently converted to raster. To account for uncertainty in geographic position, and the fragmentation and spread of algae, we estimated presence within a 1-km radius of observed invasive algae presence. As the data are presence-only, the status in un-surveyed areas is unknown and there is the potential that a survey failed to observe an invasive species where it is actually present.

Observed Presence of Alien and Invasive Algae, 2000-2013 – Hawaii

id: hi_otp_all_invasive_algae

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Fish

Invasive Fish

Photo Credit: Keoki Stender, www.marinelifephotography.com.

Invasive fish species can have a large impact on biodiversity and fisheries on reef ecosystems. By predating upon or outcompeting native species, non-native fish can alter the balance of coral reefs. Several fish species have become invasive in Hawaiʻi following intentional introductions for food fish in the 1950s, including roi or bluespotted grouper (Cephalopholis argus), taʻape or bluestripe snapper (Lutjanus kasmira), and toʻau or blacktail snapper (Lutjanus fulvus).

Data were synthesized from underwater visual surveys from multiple monitoring programs on fish and benthic assemblages over the years 2000-2013 in the Hawaiʻi Fish and Benthic Biological Synthesis Database. Transects were categorized with presence of invasive fish species, and the point data representing these transects were then converted to raster. To account for uncertainty in geographic position and movement of the fish species, we estimated presence within a 2-km radius of observed invasive fish presence. As these data are presence-only, the status in un-surveyed areas is unknown and there is the potential that a survey failed to observe an invasive species where it is actually present.

Observed Presence of Alien and Invasive Reef Fish, 2000-2013 – Hawaii

id: hi_otp_all_invasive_fish

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Fisheries Catch

Fisheries Catch

Photo Credit: Justine De La Ornellas.

Nearshore fisheries in the Main Hawaiian Islands encompass a diverse set of fisheries in which multiple gear types are used to harvest reef finfishes and invertebrates, estuarine species, and schooling coastal pelagic fishes. Communities in Hawaiʻi often rely on these fisheries for economic, social, and cultural services. Stress from over-fishing can cause ecosystem degradation and long-term economic loss.

We created a series of fisheries catch data layers for catch of reef finfishes, grouped into three categories of fishing platforms (non-commercial shore, non-commercial boat, and commercial) and three subcategories of fishing gear (line, net, and spear). For all fishing layers we accounted for marine protected areas (MPAs) where fishing is prohibited and de facto MPAs (e.g., military danger areas) where access is restricted. All fisheries catch layers represent average annual catch in units of kg ha-1 yr-1.

Non-commercial Shore-based Fisheries Catch

We used estimates of average annual catch by platform and gear type at the island scale, from 2004-2013, derived from Marine Recreational Information Program (MRIP) survey data. These island-scale estimates were combined with measures of shoreline accessibility (terrain steepness and presence of roads) to spatially distribute catch offshore around each island.

  • Line: Catch was extended 200 m offshore.
  • Net: Catch was extended offshore to the 20-ft (6.1-m) depth contour or a maximum distance of 1 km from shore.
  • Spear: Catch was extended offshore based on a decay function where catch decreases with depth to 40 m or a maximum distance of 2 km offshore, and assumes the vast majority of catch occurs shallower than 20 m.

Non-commercial Shore-based Line Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_shore_line

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Shore-based Net Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_shore_net

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Shore-based Spear Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_shore_spear

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Shore-based Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_shore

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Boat-based Fisheries Catch

We used estimates of average annual catch by platform and gear type at the island scale, from 2004‑2013, derived from Marine Recreational Information Program (MRIP) survey data. In order to spatially distribute catch offshore around each island, we used a function that decays with distance to boat harbors and launch ramps, and weighted the amount of catch out of each ramp/harbor based on the human population within the surrounding 30 km.

Non-commercial Boat-based Line Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_boat_line

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Boat-based Net Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_boat_net

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Boat-based Spear Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_boat_spear

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Boat-based Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec_boat

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Non-commercial Fisheries Catch Combined

This data layer represents the sum of all of the non-commercial boat-based and shore-based fisheries catch layers.

Non-commercial Fishing Estimated Average Annual Catch of Reef Fish, 2004-2013 – Hawaii

id: hi_otp_all_fishing_rec

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Commercial Fisheries Catch

We used average annual catch of reef fish by gear type over the years 2003-2013 as reported in commercial catch data collected by the State of Hawaiʻi Department of Aquatic Resources (DAR). Commercial catch is reported to DAR in large irregular reporting blocks, by gear and by species. Since it is not possible to distinguish between boat- and shore-based fishing activity with DAR’s gear categories, we assumed that catch is evenly distributed across each reporting block.

Commercial Line Fishing Estimated Average Annual Catch of Reef Fish, 2003-2013 – Hawaii

id: hi_otp_all_fishing_com_line

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Commercial Net Fishing Estimated Average Annual Catch of Reef Fish, 2003-2013 – Hawaii

id: hi_otp_all_fishing_com_net

access methods: WMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Commercial Spear Fishing Estimated Average Annual Catch of Reef Fish, 2003-2013 – Hawaii

id: hi_otp_all_fishing_com_spear

access methods: WMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Commercial Fishing Estimated Average Annual Catch of Reef Fish, 2003-2013 – Hawaii

id: hi_otp_all_fishing_com

access methods: WMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

All Fisheries Catch Combined

This data layer represents the sum of all of the non-commercial and commercial fisheries catch layers.

Total Estimated Average Annual Catch of Reef Fish, 2003-2013 – Hawaii

id: hi_otp_all_fishing

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Environmental Drivers

Wave Power

Wave Power

Photo Credit: Brocken Inaglory.

Wave power is a major environmental forcing mechanism in Hawaiʻi that influences a number of marine ecosystem processes including coral reef community development, structure, and persistence. By driving mixing of the upper water column, wave forcing can also play a role in nutrient availability and ocean temperature reduction during warming events. Wave forcing in Hawaiʻi is highly seasonal, with winter months typically experiencing far greater wave power than that experienced during the summer months.

Wave power data (kW/m) was obtained from the University of Hawaiʻi at Mānoa (UH) School of Ocean and Earth Science and Technology (SOEST) SWAN model (Simulating WAves Nearshore) from 1979-2013. Raw hourly data were converted to maximum daily and then averaged over each month, creating a monthly time series from which monthly climatologies were made. Time series of anomalies were calculated for the time period of 2000-2013 by quantifying the number and magnitude of events from the maximum daily data set that exceeded the maximum climatological monthly mean. Nearshore map pixels with no data were filled with values from the nearest neighboring offshore pixel.

Wave Power Maximum Monthly Climatological Mean, 1979-2013 – Hawaii

id: hi_otp_all_wave_clim_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Wave Power Average Annual Maximum Anomaly, 2000-2013 – Hawaii

id: hi_otp_all_wave_anom_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Wave Power Average Annual Frequency of Anomalies, 2000-2013 – Hawaii

id: hi_otp_all_wave_anom_freq

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Wave Power Long-term Mean, 2000-2013 – Hawaii

id: hi_otp_all_wave_avg

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Wave Power Standard Deviation of Long-term Mean, 2000-2013 – Hawaii

id: hi_otp_all_wave_std

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Sea Surface Temperature

Sea Surface Temperature

Photo Credit: Hawaiʻi Department of Aquatic Resources.

Sea surface temperature (SST) plays an important role in a number of ecological processes and can vary over a wide range of time scales, from daily to decadal changes. SST influences primary production, species migration patterns, and coral health. If temperatures are anomalously warm for extended periods of time, drastic changes in the surrounding ecosystem can result, including harmful effects such as coral bleaching.

SST data (℃) were obtained from the 4-km AVHRR Pathfinder v5.2 dataset, available at weekly time-steps from 1985‑2013. NOAA Coral Reef Watch (CRW) methodology was used to calculate SST climatology and Degree Heating Weeks (DHW). Nearshore map pixels with no data were filled with values from the nearest neighboring offshore pixel.

Sea Surface Temperature (SST) Maximum Monthly Climatological Mean, 1985-2013 – Hawaii

id: hi_otp_all_sst_clim_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Sea Surface Temperature (SST) Average Annual Maximum Anomaly, 2000-2013 – Hawaii

id: hi_otp_all_sst_anom_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Sea Surface Temperature (SST) Average Annual Frequency of Anomalies, 2000-2013 – Hawaii

id: hi_otp_all_sst_anom_freq

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Sea Surface Temperature (SST) Long-term Mean, 2000-2013 – Hawaii

id: hi_otp_all_sst_avg

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Sea Surface Temperature (SST) Standard Deviation of Long-term Mean, 2000-2013 – Hawaii

id: hi_otp_all_sst_std

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Sea Surface Temperature (SST) Maximum Degree Heating Week, 2000-2013 – Hawaii

id: hi_otp_all_sst_dhw_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Chlorophyll-a

chlorophyll a

Photo Credit: NASA.

Chlorophyll-a is a widely used proxy for phytoplankton biomass and an indicator for changes in phytoplankton production. As an essential source of energy in the marine environment, the extent and availability of phytoplankton biomass can be highly influential for fisheries production and dictate trophic-structure in marine ecosystems. Changes in phytoplankton biomass are predominantly effected by changes in nutrient availability, through either natural (e.g., turbulent ocean mixing) or anthropogenic (e.g., agriculture runoff) processes.

Data for chlorophyll-a (mg/m3) for the time period 2002-2013 were obtained from the MODIS (Moderate-resolution Imaging Spectroradiometer) Aqua satellite instrument from the NASA OceanColor website. Time series of anomalies were calculated by quantifying the number and magnitude of events (from the 8-day time series) that exceed the maximum climatological monthly mean. Data were excluded if any part of the cell was < 30-m water depth, due to bias that occurs in shallow waters where the ocean bottom is visible. Nearshore map pixels with no data were then filled with values from the nearest neighboring offshore pixel.

Chlorophyll-a Maximum Monthly Climatological Mean, 2002-2013 – Hawaii

id: hi_otp_all_chlor_clim_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Chlorophyll-a Average Annual Maximum Anomaly, 2002-2013 – Hawaii

id: hi_otp_all_chlor_anom_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Chlorophyll-a Average Annual Frequency of Anomalies, 2002-2013 – Hawaii

id: hi_otp_all_chlor_anom_freq

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Chlorophyll-a Long-term Mean, 2002-2013 – Hawaii

id: hi_otp_all_chlor_avg

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Chlorophyll-a Standard Deviation of Long-Term Mean, 2002-2013 – Hawaii

id: hi_otp_all_chlor_std

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Irradiance

irradiance

Solar irradiance is one of the most important factors influencing coral reefs. As a majority of their nutrients are obtained from symbiotic photosynthesizing organisms, reef-building corals need sunlight as a fundamental source of energy. Seasonally low irradiance at high latitudes may be linked to reduced growth rates in corals and may limit reef calcification to shallower depths than that observed at lower latitudes. However, high levels of irradiance can lead to light-induced damage, production of free radicals, and in combination with increased temperatures, can exacerbate coral bleaching. Irradiance is here represented by PAR (photosynthetically available radiation), which is the spectrum of light that is important for photosynthesis.

Data for PAR (mol m-2 day-1) for the time period 2002‑2013 were obtained from the MODIS (Moderate-resolution Imaging Spectroradiometer) Aqua satellite instrument from the NASA OceanColor website. Time series of anomalies were calculated by quantifying the number and magnitude of events (from the 8-day time series) that exceed the maximum climatological monthly mean. Data were excluded if any part of the cell was < 30-m water depth, due to bias that occurs in shallow waters where the ocean bottom is visible). Nearshore map pixels with no data were then filled with values from the nearest neighboring offshore pixel.

Photosynthetically Active Radiation (PAR) Maximum Monthly Climatological Mean, 2002-2013 – Hawaii

id: hi_otp_all_par_clim_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Photosynthetically Active Radiation (PAR) Average Annual Maximum Anomaly, 2002-2013 – Hawaii

id: hi_otp_all_par_anom_max

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Photosynthetically Active Radiation (PAR) Average Annual Frequency of Anomalies, 2002-2013 – Hawaii

id: hi_otp_all_par_anom_freq

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Photosynthetically Active Radiation (PAR) Long-term Mean, 2002-2013 – Hawaii

id: hi_otp_all_par_avg

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

Photosynthetically Active Radiation (PAR) Standard Deviation of Long-term Mean, 2002-2013 – Hawaii

id: hi_otp_all_par_std

access methods: WMS-CWMSWCSGeoTIFFKMLGeoServerGeoExplorermetadata

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Cumulative Impacts (coming soon!)

Cumulative Impacts

The nearshore reef environment in Hawaiʻi is impacted by a wide range of human activities. As a result of these anthropogenic stressors, economic and sociocultural benefits to communities in Hawaiʻi have diminished over time. Understanding the spatial distribution, intensity, overlap, and cumulative impact of human activities is essential for effective marine management and protection of ecosystem services generated by coral reefs. Currently, this kind of information is not readily available to resource managers and policy makers in Hawaiʻi.

This research project builds on the set of anthropogenic drivers developed by the Ocean Tipping Points project and uses existing data and novel approaches to produce statewide maps for additional stressors like coastal recreation, aquarium fishing, marine debris, urban runoff, shipping, and additional climate change stressors.

Expert knowledge surveys were conducted to assess the vulnerability of three nearshore habitat types to anthropogenic stressors. The resulting vulnerability weighting factors for stressor-habitat pairs were used to produce continuous maps of cumulative impacts across the Main Hawaiian Islands.

Spatial datasets developed by this study are available for use in future research on patterns of reef state and coral reef degradation. These maps also directly benefit management by identifying what places and habitat types are most impacted, which drivers should be of greatest concern in different areas, and where different management strategies (e.g., regulations, restoration, enforcement, or increased monitoring) should be prioritized.

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Partners

Collaborators

Center for Ocean Solutions logo Stanford Woods Institute for the Environment logo NCEAS logo Cal Poly logo
National Geographic logo EDF logo Bangor University logo University of Hawaii at Manoa logo
Stockholm Resilience Centre logo NOAA logo UCSB logo
Center for Ocean Solutions logo Stanford Woods Institute for the Environment
NCEAS logo Cal Poly logo
National Geographic logo EDF logo
Bangor University logo University of Hawaii, Manoa logo
Stockholm Resilience Centre logo NOAA logo
UCSB logo

Support

Direct

Gordon and Betty Moore Foundation logo NOAA Coral Reef Conservation Program logo USDA NIFA logo
Gordon and Betty Moore Foundation logo NOAA Coral Reef Conservation Program logo
USDA NIFA logo

In kind

University of Hawaii, Manoa logo Hawaiian Islands Humpback Whale National Marine Sanctuary logo EDF logo Scripps Institution of Oceanography UCSD logo
Pristine Seas logo Bangor University logo Stockholm Resilience Centre logo
PacIOOS logo Conservation International logo
University of Hawaii, Manoa logo Hawaiian Islands Humpback Whale National Marine Sanctuary logo
EDF logo Scripps Institution of Oceanography UCSD logo
Pristine Seas logo Bangor University logo
Stockholm Resilience Centre logo PacIOOS logo
Conservation International logo

Data Sources

Anthropogenic Drivers Units Temporal Range Data Source
Fisheries Catch – Commercial Annual average catch in kg/ha by gear (line, net, and spear) 2003-2013 Reported Commercial Catch 2003-2013 (DAR); Commercial Reporting Blocks (OP)
Fisheries Catch Non-Commercial (Shore-Based) Annual average catch in kg/ha by gear (line, net, and spear) 2004-2013 Island-scale estimates of catch (kg/yr by gear) from MRIP 2004-2013 (McCoy 2015); USGS DEM (slope); TIGER Roads; HMRG Bathymetry
Fisheries Catch Non-Commercial (Boat-Based) Annual average catch in kg/ha by gear (line, net, and spear) 2004-2013 Island-scale estimates of catch (kg/yr by gear) from MRIP 2004–2013 (McCoy 2015); Boating Facility locations (OP); Human population (US Census, 2010)
Sedimentation Average annual amount of sediment (tons/yr) 2002–2013 InVEST Sediment Delivery Ratio Model output (Falinski 2016); National Hydrography Dataset
New Development Relative level of new development 2005–2011 NOAA C-CAP High Resolution 2005-2010/11; NHD Watersheds; Distance from shore
Nutrients from OSDS kg/day and effluent in gallons/day 2000–2013 OSDS Point location and estimated effluent/nutrient flux (Whittier & El Kadi 2009, 2014)
Invasive Species Presence only of invasive fish and algae 2000–2013 FERL / OTP Fish and Benthic Biological Synthesis Database (2000-2013); Invasive marine algae surveys (Smith et al. 2002)
Habitat Modification Presence of habitat-modifying features 2001–2013 NOAA CCMA Habitat Maps (2007); NOAA ESI lines (2001); Maintained channels (2013); Offshore aquaculture point locations
Oceanographic Drivers Units Temporal Range Data Source
Sea Surface Temperature °C 2000-2013 NOAA Pathfinder, NOAA/NESDIS/STAR Blended SST 0.1 and 0.05 degree (weekly composites)
Chlorophyll-a mg/m3 2002–2013 MODIS (8-day composites)
Irradiance (PAR) mol m-2 d-1 2002–2013 MODIS (8-day composites)
Wave Power kW/m 2000–2013 Simulating Waves Nearshore (SWAN) model (hourly) (Li et al. 2016)

Acronyms

  • C-CAP – NOAA Coastal Change Analysis Program
  • CCMA – NOAA Center for Coastal Monitoring and Assessment
  • DAR – State of Hawaiʻi Division of Aquatic Resources
  • DEM – Digital Elevation Model
  • ESI – NOAA Environmental Sensitivity Index
  • FERL – Fisheries Ecology Research Laboratory
  • HMRG – Hawaiʻi Mapping Research Group
  • InVEST – Integrated Valuation of Ecosystem Services and Tradeoffs
  • MODIS – Moderate Resolution Imaging Spectroradiometer
  • MRIP – Marine Recreational Information Program
  • NESDIS STAR – National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research
  • NHD – National Hydrography Dataset
  • NOAA – National Oceanic and Atmospheric Administration
  • OP – State of Hawaiʻi Office of Planning
  • OSDS – Onsite Sewage Disposal Systems
  • OTP – Ocean Tipping Points
  • PAR – Photosynthetically Available Radiation
  • SST – Sea Surface Temperature
  • SWAN – Simulating Waves Nearshore
  • TIGER – Topologically Integrated Geographic Encoding and Referencing
  • USGS – United States Geological Survey

References

Falinski, K.A. 2016. Predicting sediment export into tropical coastal ecosystems to support ridge to reef management. University of Hawaiʻi at Mānoa – Ph.D. Dissertation.

Falinski, K., Oleson, K., Lecky, J., Hamel, P., Yost, R., Sutherland, R. 2017. Development of a subtropical, volcanic geology-specific model for sediment delivery in the Hawaiian Islands. Ecological Modeling and Software. In prep.

Li, N., Cheung, K.F., Stopa, J.E., Hsiao, F., Chen, Y.-L., Vega, L., and Cross, P. 2016. Thirty-four years of Hawaiʻi wave hindcast from downscaling of climate forecast system reanalysis. Ocean Modelling 100: 78-95.

McCoy K. 2015. Estimating nearshore fisheries catch for the main Hawaiian Islands. Thesis. University of Hawaiʻi at Mānoa.

Smith, J.E., Hunter, C.L., and Smith, C.M. 2002. Distribution and reproductive characteristics of nonindigenous and invasive marine algae in the Hawaiian Islands. Pacific Science 56.3: 299-315.

Whittier, R.B. and El-Kadi, A.I., 2009. Human and environmental risk ranking of onsite sewage disposal systems.

Whittier, R.B. and El-kadi, A.I., 2014. Human Health and Environmental Risk Ranking of On-Site Sewage Disposal Systems for the Hawaiian Islands of Kauaʻi, Molokaʻi, Maui, and Hawaiʻi.