Chris Baker
Quantitative ecology

Mark Eakin
Remote sensing, Climate science

Jeffrey Shields
Disease ecolgy

Jerker Tamelander
Coral reef ecology, Marine conservation

Feature Article

 
Coral mass spawning predicted by rapid seasonal rise in ocean temperature

 

Sally A. Keith, Jeffrey A. Maynard, Alasdair J. Edwards, James R. Guest, Andrew G. Bauman, Ruben van Hooidonk, Scott F. Heron, Michael L. Berumen, Jessica Bouwmeester, Srisakul Piromvaragorn, Carsten Rahbek and Andrew H. Baird

 

Proceedings of the Royal Society B (2016)

Photo © AIMS

Abstract

 

Coral spawning times have been linked to multiple environmental factors; however, to what extent these factors act as generalized cues across multiple species and large spatial scales is unknown. We used a unique dataset of coral spawning from 34 reefs in the Indian and Pacific Oceans to test if month of spawning and peak spawning month in assemblages of Acropora spp. can be predicted by sea surface temperature (SST), photosynthetically available radiation, wind speed, current speed, rainfall or sunset time. Contrary to the classic view that high mean SST initiates coral spawning, we found rapid increases in SST to be the best predictor in both cases (month of spawning: R^2 . 0.73, peak: R^2 . 0.62). Our findings suggest that a rapid increase in SST provides the dominant proximate cue for coral mass spawning over large geographical scales. We hypothesize that coral spawning is ultimately timed to ensure optimal fertilization success.

Feature Article

 
A robust operational model for predicting where tropical cyclone waves damage coral reefs

 

Marji Puotinen, Jeffrey A. Maynard, Roger Beeden,
Ben Radford and Gareth J. Williams

 

Scientific Reports (2016)

Photo © R. Beeden

Abstract

Tropical cyclone (TC) waves can severely damage coral reefs. Models that predict where to find such damage (the ‘damage zone’) enable reef managers to: 1) target management responses after major TCs in near-real time to promote recovery at severely damaged sites; and 2) identify spatial patterns in historic TC exposure to explain habitat condition trajectories. For damage models to meet these needs, they must be valid for TCs of varying intensity, circulation size and duration. Here, we map damage zones for 46 TCs that crossed Australia’s Great Barrier Reef from 1985–2015 using three models – including one we develop which extends the capability of the others. We ground truth model performance with field data of wave damage from seven TCs of varying characteristics. The model we develop (4MW) out-performed the other models at capturing all incidences of known damage. The next best performing model (AHF) both under-predicted and over-predicted damage for TCs of various types. 4MW and AHF produce strikingly different spatial and temporal patterns of damage potential when used to reconstruct past TCs from 1985–2015. The 4MW model greatly enhances both of the main capabilities TC damage models provide to managers, and is useful wherever TCs and coral reefs co-occur.

Feature Article

 
Assessing relative resilience potential of coral reefs to inform management

 

Jeffrey A. Maynard, Steven McKagan, Laurie Raymundo, Steven Johnson, Gabby N. Ahmadia, Lyza Johnston,

Peter Houk, Gareth J. Williams, Matt Kendall, Scott F. Heron, Rubn van Hooidonk, Elizabeth Mcleod, Dieter Tracey, Serge Planes

Biological Conservation 192, 109-119, December 2015

Abstract

Ecological resilience assessments are an important part of resilience-based management (RBM) and can help prioritize and target management actions. Use of such assessments has been limited due to a lack of clear guidance on the assessment process. This study builds on the latest scientific advances in RBM to provide that guidance from a resilience assessment undertaken in the Commonwealth of the Northern Mariana Islands (CNMI). We assessed spatial variation in ecological resilience potential at 78 forereef sites near the populated islands of the CNMI: Saipan, Tinian/Aguijan, and Rota. The assessments are based on measuring indicators of resilience processes and are combined with information on anthropogenic stress and larval connectivity. We find great spatial variation in relative resilience potential with many high resilience sites near Saipan (5 of 7) and low resilience sites near Rota (7 of 9). Criteria were developed to identify priority sites for six types of management actions (e.g., conservation, land-based sources of pollution reduction, and fishery management and enforcement) and 51 of the 78 sites met at least one of the sets of criteria. The connectivity simulations developed indicate Tinian/Aguijan are each roughly 10x the larvae source that Rota is and twice as frequent a destination. These results may explain the lower relative resilience potential of Rota reefs and indicates actions in Saipan and Tinian/Aguijan will be important to maintaining supply of larvae. The process we describe for undertaking resilience assessments can be tailored for use in coral reef areas globally and applied to other ecosystems.

Feature Article

 

First geneaology for a wild marine fish population reveals multigenerational philopatry

 

Océane C. Salles, Benoit Pujol, Jeffrey A. Maynard, Glenn R. Almany, Michael L. Berumen, Geoffrey P. Jones, Pablo Saenz-Agudelo, Maya Srinivasan, Simon R Thorrold and Serge Planes

 

PNAS 113(46), November 2016

Abstract

Natal philopatry, the return of individuals to their natal area for reproduction, has advantages and disadvantages for animal populations. Natal philopatry may generate local genetic adaptation, but it may also increase the probability of inbreeding that can compromise persistence. Although natal philopatry is well documented in anadromous fishes, marine fish may also return to their birth site to spawn. How philopatry shapes wild fish populations is, however, unclear because it requires constructing multigenerational pedigrees that are currently lacking for marine fishes. Here we present the first multigenerational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) during a 10-y period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. Progeny tended to settle close to their parents, with related individuals often sharing the same colony. However, successful inbreeding was rare, and genetic diversity remained high, suggesting occasional inbreeding does not impair local population persistence. Local reproductive success was dependent on the habitat larvae settled into, rather than the habitat they came from. Our study suggests that longitudinal philopatry can influence both population replenishment and local adaptation of marine fishes. Resolving multigenerational pedigrees during a relatively short period, as we present here, provides a framework for assessing the ability of marine populations to persist and adapt to accelerating climate change.

 

Warming trends and bleaching stress of the world's coral reefs 1985-2012

 

Scott F. Heron, Jeffrey A. Maynard, Ruben van Hooidonk and C. Mark Eakin

 

Scientific Reports 6, 38402, December 2016

Abstract

Coral reefs across the world’s oceans are in the midst of the longest bleaching event on record (from 2014 to at least 2016). As many of the world’s reefs are remote, there is limited information on how past thermal conditions have influenced reef composition and current stress responses. Using satellite temperature data for 1985-2012, the analysis we present is the first to quantify, for global reef locations, spatial variations in warming trends, thermal stress events and temperature variability at reef-scale (~4 km). Among over 60,000 reef pixels globally, 97% show positive SST trends during the study period with 60% warming significantly. Annual trends exceeded summertime trends at most locations. This indicates that the period of summer-like temperatures has become longer through the record, with a corresponding shortening of the ‘winter’ reprieve from warm temperatures. The frequency of bleaching-level thermal stress increased three-fold between 1985-91 and 2006-12 – a trend climate model projections suggest will continue. The thermal history data products developed enable needed studies relating thermal history to bleaching resistance and community composition. Such analyses can help identify reefs more resilient to thermal stress.

Feature Article

 
A Reef Manager's Guide to Fostering Community Stewardship

 

Paul Marshall, Anna Lyons, Carolyn Luder,
Jeffrey Maynard and Roger Beeden

 

eBook (2015)

Why reef stewardship, and why a guide? 

This guide has been written to inspire and empower reef managers and community leaders to develop reef stewardship programs. Stewardship is a way of empowering local communities to take a more active role in sustaining the natural resources on which they depend. Stewardship programs create a framework for greater participation and more organised allocation of resources, resulting in stronger alignment between community activities and government (or NGO) initiatives and, ultimately, better outcomes for coral reefs and communities. We hope that by enabling more formal stewardship programs this guide can inspire a community of practice that will accelerate learning and contribute to the global movement toward people-powered conservation of coral reefs. 

Feature Publication