Analysis. Synthesis. Communication.
Selected Publications
You can view a complete list of publications by the Director via Google Scholar.
Feature Article
Coral reefs benefit from reduced land–sea impacts under ocean warming
Jamison Gove and Gareth Williams with
Joey Lecky, Eric Brown, Eric Conklin, Chelsie Counsell, Gerald Davis, Mary K. Donovan, Kim Falinski, Lindsey Kramer, Kelly Kozar, Ning Li, Jeffrey A. Maynard, Amanda McCutcheon, Sheila A. McKenna, Brian J. Neilson, Aryan Safaie, Christopher Teague, Robert Whittier and Gregory P. Asner
Nature, August 2023
Abstract
Coral reef ecosystems are being fundamentally restructured by local human impacts and climate-driven marine heatwaves that trigger mass coral bleaching and mortality1. Reducing local impacts can increase reef resistance to and recovery from bleaching2. However, resource managers lack clear advice on targeted actions that best support coral reefs under climate change3 and sector-based governance means most land- and sea-based management efforts remain siloed4. Here we combine surveys of reef change with a unique 20-year time series of land–sea human impacts that encompassed an unprecedented marine heatwave in Hawai‘i. Reefs with increased herbivorous fish populations and reduced land-based impacts, such as wastewater pollution and urban runoff, had positive coral cover trajectories predisturbance. These reefs also experienced a modest reduction in coral mortality following severe heat stress compared to reefs with reduced fish populations and enhanced land-based impacts. Scenario modelling indicated that simultaneously reducing land–sea human impacts results in a three- to sixfold greater probability of a reef having high reef-builder cover four years postdisturbance than if either occurred in isolation. International efforts to protect 30% of Earth’s land and ocean ecosystems by 2030 are underway5. Our results reveal that integrated land–sea management could help achieve coastal ocean conservation goals and provide coral reefs with the best opportunity to persist in our changing climate.
Feature Article
2022 Ecosystem Status Report for Hawaiʻi
Jamison Gove and Jeffrey Maynard with
Joey Lecky, Dieter P. Tracey, Mary E. Allen, Gregory P. Asner, Eric Conklin, Courtney Couch, Kimberly Hum, Rebecca J. Ingram, Tye L. Kindinger, Kirsten Leong, Kirsten L.L. Oleson, Erica K. Towle, Ruben van Hooidonk, Gareth J. Williams, and Justin Hospital
NOAA, 2022
Excerpt from the Executive Summary
Strong connections between people and the ocean environment are a hallmark of communities across all the Hawaiian Islands and this is the key theme throughout this report. These connections are often circular and reciprocal in nature, within which human communities affect, depend on, and care for ecosystem health. Our actions and activities influence ecosystem status and trends; they are also the conduits through which we experience values, feel meaning, or benefit from ecosystem goods and services. This report begins with a section on Human Connections to further highlight and explain human-land-sea connections. The report concludes with a description of some of the applied research most likely to inform management and conservation. Summaries and result highlights of each of the six report sections are within the Executive Summary section of the Full Report (see download link to the right). The six report sections are: Human Connections, Small Boat Commercial Fishers, Coral Reefs and Reef Fish, Climate and Ocean, Human Impacts, and Vulnerability of Coral Reefs to Climate Change.
Feature Article
US Coral Reef Monitoring Data Summary 2018
Jeffrey Maynard, Dieter Tracey, and Justine Kimball
Jeremiah Blondeau, Rusty Brainard, Courtney Couch, Mark Eakin, Kimberly Edwards, Peter Edwards, Ian Enochs, Erick Geiger, Matt Gorstein, Laura Jay Grove, Sarah Groves, Matthew W. Johnson, Arielle Levine, Gang Liu, Jarrod Loerzel, Derek Manzello, Tom Oliver, Dione Swanson, Bernardo Vargas-Angel, Shay Viehman, and Ivor Williams
NOAA, December 2018
Abstract
The data summary report consists of a report for each of the priority geographic areas. The report for each area has three sections: Human Connections, Coral Reefs and Reef Fish, and Ocean Chemistry and Temperature.
Human Connections: This section presents data from social surveys and secondary sources on demographics, values, resource use, and information sources; perceptions of resource condition, threats, and severity; and perceptions of reef management policies.
Coral Reefs and Reef Fish: This section presents data on benthic cover, adult and juvenile coral density, coral disease, coral mortality, the biomass and size-class distribution of reef fish, and the presence or absence of corals listed as Threatened under the Endangered Species Act (ESA-listed corals).
Ocean Chemistry and Temperature: This section presents data on aragonite saturation state, calcium carbonate accretion, pH, sub-surface temperature, and remotely sensed observations of temperature anomalies and heat stress.
The area reports can be seen as modules within the larger data summary report. Readers can navigate to each part of the report using the hyperlinks in the Table of Contents and can navigate from the area reports back to the Table of Contents.
Feature Article
A Guide to Assessing Coral Reef Resilience
for Decision Support
Jeffrey Maynard, Paul Marshall, Britt Parker, Elizabeth Mcleod, Gabby Ahmadia, Ruben van Hooidonk, Serge Planes, Gareth J. Williams, Laurie Raymundo, Roger Beeden and Jerker Tamelander
UN Environment, ISBN 978-92-807-3650-2
Abstract
Maintaining and restoring resilience is now a major focus of most coral reef managers around the world. A focus on resilience gives us options - and hope - in the face of new and often daunting challenges. Underpinning this is the fact that local actions can positively influence the future of coral reefs, despite powerful external forces like climate change. As examples, coral recovery from disturbances in Bermuda and the Bahamas has been greater in recent decades than in other parts of the Caribbean. Differences in recovery rates in the Caribbean have been partially attributed to establishing and enforcing fishing regulations, especially on key herbivores such as parrotfish (Jackson et al. 2014). Overall though, the application of resilience theory to management planning and the day-to-day business of coral reef management has been challenging. One of the key stumbling blocks has been the lack of a robust and easily implementable method for assessing coral reef resilience in a way that can inform marine spatial planning and help to prioritize the implementation of management strategies. Our ability to assess relative resilience of coral reefs has advanced dramatically in recent years, and we are now at a point where a feasible and useful process can be recommended for use in environmental planning and management. This Guide presents a 10-step process for completing a resilience assessment, putting into managers' hands the means to assess, map and monitor coral reef resilience, and the means to identify and prioritize actions that support resilience in the face of climate change. The guidance presented here represents the culmination of over a decade of experience and builds on ideas first presented by West and Salm (2003), Obura and Grimsditch (2009), and McClanahan and coauthors (2012). This guide is first and foremost intended for the individuals in charge of commissioning, planning, leading or coordinating a resilience assessment. The Guide also provides a resource for 'reef managers' of all kinds, including decision-makers, environmental planners and managers in coral reef areas, with influence over pressures affecting coral reefs. Outreach coordinators and educators working in coral reef areas may also benefit from the Guide, and they can participate in parts of the resilience assessment process, but the Guide focuses on the needs of decision-makers and the scientists who support them.
Feature Article
Coral Reefs Vulnerability to climate change in West Hawai‘i
Jeffrey Maynard, Jamison Gove, Dieter Tracey, Johanna Johnson, Joey Lecky, Eric Conklin, Ruben van Hooidonk, Mary Donovan, Justin Hospital, Danika Kleiber, Rusty Brainard, Ivor Williams, Dione Swanson, Tom Oliver, William Walsh, Chad Wiggins, Lindsey Kramer
NOAA 2019
Abstract
The West Hawai‘i Integrated Ecosystem Assessment (WH-IEA) is a program that builds relationships with State and Federal agencies and community organizations to deliver science that meets management needs. Assessing the vulnerability of key ecosystems and species to climate change is a goal of the IEA.
Our team has generated information on climate change, resilience, and human impacts, and then combined these inputs to assess coral reef ecosystem vulnerability. The results indicate that vulnerability to climate change varies greatly among the coral reefs of West Hawai‘i. Coral reef vulnerability is relatively low near Kīholo, Kealakekua Bay, Hōnaunau, and Miloli‘i, and relatively high near Puakō, Keāhole Point, and Kailua-Kona. Reef fish productivity is likely to be lower where coral reef vulnerability is high and productivity is likely to be higher where coral reef vulnerability is low.
Feature Article
Assessing the Resilience of Leeward Maui Reefs to Help Design a Resilient Managed Area Network
Jeffrey Maynard *, Eric Conklin *, Dwayne Minton, Gareth J. Williams, Dieter Tracey, Russell Amimoto, Harry Lynch, Ryan Carr, Julia Rose, Russell Sparks, Emily Fielding, Roxie Sylva, Darla White (*Project co-leaders)
NOAA 2019
Abstract
Our 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) benthic cover comparisons among sites and depths, 2) resilience assessment including relative resilience and rankings for two depths, 3) analyses that determine the primary drivers of differences in resilience between sites, and 4) a framework for using the resilience analysis outputs to identify and prioritize potential management actions to support the resilience of coral reefs in Maui.
Feature Article
Fire coral clones demonstrate phenotypic plasticity among reef habitats
Caroline Dube, Emilie Boissin, Jeffrey A. Maynard and Serge Planes
Molecular Ecology 26(15), 3860-3869, August 2017
Abstract
Clonal populations are often characterized by reduced levels of genotypic diversity, which can translate into lower numbers of functional phenotypes, both of which impede adaptation. Study of partially clonal animals enables examination of the environmental settings under which clonal reproduction is favoured. Here, we gathered genotypic and phenotypic information from 3,651 georeferenced colonies of the fire coral Millepora platyphylla in five habitats with different hydrodynamic regimes in Moorea, French Polynesia. In the upper slope where waves break, most colonies grew as vertical sheets (“sheet tree”) making them more vulnerable to fragmentation. Nearly all fire corals in the other habitats are encrusting or massive. The M. platyphylla population is highly clonal (80% of the colonies are clones), while characterized by the highest genotype diversity ever documented for terrestrial or marine populations (1,064 genotypes). The proportion of clones varies greatly among habitats (≥58%–97%) and clones (328 clonal lineages) are distributed perpendicularly from the reef crest, perfectly aligned with wave energy. There are six clonal lineages with clones dispersed in at least two adjacent habitats that strongly demonstrate phenotypic plasticity. Eighty per cent of the colonies in these lineages are “sheet tree” on the upper slope, while 80%–100% are encrusting or massive on the mid slope and back reef. This is a unique example of phenotypic plasticity among reef-building coral clones as corals typically have wave-tolerant growth forms in high-energy reef areas.
Feature Article
Local-scale projections of coral reef futures and implications of the Paris Agreement
Ruben van Hooidonk, Jeffrey Maynard, Jerker Tamelander, Jamison Gove, Gabby Ahmadia, Laurie Raymundo, Gareth Williams, Scott F. Heron and Serge Planes
Scientific Reports 6, 39666, December 2016
Abstract
Increasingly frequent severe coral bleaching is among the greatest threats to coral reefs posed by climate change. Global climate models (GCMs) project great spatial variation in the timing of annual severe bleaching (ASB) conditions; a point at which reefs are certain to change and recovery will be limited. However, previous model-resolution projections (~1 × 1°) are too coarse to inform conservation planning. To meet the need for higher-resolution projections, we generated statistically downscaled projections (4-km resolution) for all coral reefs; these projections reveal high local-scale variation in ASB. Timing of ASB varies >10 years in 71 of the 87 countries and territories with >500 km² of reef area. Emissions scenario RCP4.5 represents lower emissions mid-century than will eventuate if pledges made following the 2015 Paris Climate Change Conference (COP21) become reality. These pledges do little to provide reefs with more time to adapt and acclimate prior to severe bleaching conditions occurring annually. RCP4.5 adds 11 years to the global average ASB timing when compared to RCP8.5; however, >75% of reefs still experience ASB before 2070 under RCP4.5. Coral reef futures clearly vary greatly among and within countries, indicating the projections warrant consideration in most reef areas during conservation and management planning.
Feature Article
and Cover Image
Extreme Inverted Trophic Pyramid of Reef Sharks Supported by Spawning Groupers
Johann Mourier, Jeffrey Maynard, Valeriano Parravicini, Laurent Ballesta, Eric Clua, Michael L. Domeier and Serge Planes
Current Biology 26(15), 2011-2016, August 2016
Abstract
The extent of the global human footprint limits our understanding of what is natural in the marine environment. Remote, near-pristine areas provide some baseline expectations for biomass and suggest that predators dominate, producing an inverted biomass pyramid. The southern pass of Fakarava atoll—a biosphere reserve in French Polynesia—hosts an average of 600 reef sharks, two to three times the biomass per hectare documented for any other reef shark aggregations. This huge biomass of predators makes the trophic pyramid inverted. Bioenergetics models indicate that the sharks require ∼90 tons of fish per year, whereas the total fish production in the pass is ∼17 tons per year. Energetic theory shows that such trophic structure is maintained through subsidies, and empirical evidence suggests that sharks must engage in wide-ranging foraging excursions to meet energy needs. We used underwater surveys and acoustic telemetry to assess shark residency in the pass and feeding behavior and used bioenergetics models to understand energy flow. Contrary to previous findings, our results highlight that sharks may overcome low local energy availability by feeding on fish spawning aggregations, which concentrate energy from other local trophic pyramids. Fish spawning aggregations are known to be targeted by sharks, but they were previously believed to play a minor role representing occasional opportunistic supplements. This research demonstrates that fish spawning aggregations can play a significant role in the maintenance of local inverted pyramids in pristine marine areas. Conservation of fish spawning aggregations can help conserve shark populations, especially if combined with shark fishing bans.
