James Guest

James Guest
Newcastle University | NCL · School of Natural and Environmental Sciences

PhD

About

101
Publications
42,125
Reads
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3,209
Citations
Citations since 2017
37 Research Items
2030 Citations
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Introduction
My research interests are broad within coral reef science and I have published work on a diverse range of topics including diseases, reproductive and larval ecology, recruitment dynamics, long term community change, bleaching and restoration ecology. I have a marine biology degree from Newcastle University and a PhD on the reproductive ecology of reef corals from the National University of Singapore. I have held postdoctoral research positions in the UK, Singapore and Australia.
Additional affiliations
February 2012 - December 2013
UNSW Sydney
Position
  • Research Associate
January 2009 - January 2012
National University of Singapore
Position
  • Lee Kuan Yew Postdoctoral Research Fellow
Description
  • Independent 3 year research fellowship to study coral reefs in Southeast Asia. Research focused on reproductive biology of corals, rehabilitation of reefs using sexually propagated corals and differential coral bleaching susceptibility.
October 2005 - December 2008
Newcastle University
Position
  • PostDoc Position
Description
  • Postdoctoral research associate working on 3 year EU funded project to examine the effectiveness of various reef rehabilitation techniques in Bolinao, North-western Philippines.
Education
June 1999 - June 2004
National University of Singapore
Field of study
  • Coral reef ecology
September 1995 - May 1998
Newcastle University
Field of study
  • Marine Biology

Publications

Publications (101)
Article
Full-text available
Coral reefs are facing unprecedented mass bleaching and mortality events due to marine heatwaves and climate change. To avoid extirpation, corals must adapt. Individual variation in heat tolerance and its heritability underpin the potential for coral adaptation. However, the magnitude of heat tolerance variability within coral populations is largel...
Preprint
Full-text available
As marine species adapt to climate change, their heat tolerance will likely be under strong selection. Yet trade-offs between heat tolerance and other life history traits could compromise natural adaptation or restorative assisted evolution. This is particularly important for ecosystem engineers, such as reef-building corals, which support biodiver...
Conference Paper
Full-text available
The paper discusses the implications of placing artificial structures within ocean ecologies and the culture of human interventions that aid ecological networks. The role of the architect is examined in relationship to the design and development of non-human habitats and the potential for utilizing architectural skills within interdisciplinary coll...
Article
Identifying relatively intact areas within ecosystems, and determining the conditions favoring their existence, is necessary for effective management in the context of widespread environmental degradation. In this study, we used 3,766 surveys of randomly selected sites in the United States and U.S. Territories to identify the correlates of sites ca...
Article
Full-text available
1. Size is a biological characteristic that drives ecological processes from micro- scopic to geographic spatial scales, influencing cellular energetics, species fit- ness, population dynamics, and ecological interactions. Methods to measure size from images (e.g., proxies of body size, leaf area, and cell area) occur along a gradient from manual a...
Article
The Great Barrier Reef has become one of the latest casualties of the climate crisis, suffering mass coral mortalities following three marine heat waves since 2016. Two new papers untangle the cumulative effects of these disturbances on the reef’s resilience.
Article
Full-text available
Sesoko Station, Okinawa, has been the site of many significant advances in coral reproductive research and it continues to be a preferred destination for both Japanese and international researchers. Consequently, there are decades of spawning observations, which we present and explore here with the aim of making it easier to predict when species sp...
Article
Full-text available
Early research into coral reproductive biology suggested that spawning synchrony was driven by variations in the amplitude of environmental variables that are correlated with latitude, with synchrony predicted to break down at lower latitudes. More recent research has revealed that synchronous spawning, both within and among species, is a feature o...
Article
Full-text available
The brooding reef-building octocoral Heliopora is widespread on Indo-West Pacific reefs and appears to be relatively resistant to thermal stress, which may enable it to persist locally while scleractinians diminish under Anthropocene conditions. However, basic physiological measurements of “blue corals” are lacking and prevent their inclusion in tr...
Article
Full-text available
Reef-building corals are found across > 30° of latitude from tropical to temperate regions, where they occupy habitats greatly differing in seawater temperature and light regimes. It remains largely unknown, however, how the demography of corals differs across this gradient of environmental conditions. Variation in coral growth is especially import...
Article
Ecosystem restoration has been practiced for over a century and is increasingly supported by the emergent applied science of restoration ecology. A prerequisite for successful ecosystem restoration is determining meaningful and measurable goals. This requires tools to monitor success in a standardized way. Photogrammetry uses images to reconstruct...
Article
Full-text available
Increasingly intense marine heatwaves threaten the persistence of many marine ecosystems. Heat stress-mediated episodes of mass coral bleaching have led to catastrophic coral mortality globally. Remotely monitoring and forecasting such biotic responses to heat stress is key for effective marine ecosystem management. The Degree Heating Week (DHW) me...
Article
Despite decades of research, many aspects of coral reproductive biology, such as colony size and age at the onset of sexual maturity remain poorly studied. In this study, wild colonies of different size classes and colonies of a known age of the massive scleractinian Favites abdita were examined for the presence or absence of mature oocytes to dete...
Article
Full-text available
Coral cover on tropical reefs has declined during the last three decades due to the combined effects of climate change, destructive fishing, pollution, and land use change. Drastic reductions in greenhouse gas emissions combined with effective coastal management and conservation strategies are essential to slow this decline. Innovative approaches,...
Preprint
Full-text available
Increasingly severe marine heatwaves under climate change threaten the persistence of many marine ecosystems. Mass coral bleaching events, caused by periods of anomalously warm sea surface temperatures (SST), have led to catastrophic levels of coral mortality globally. Remotely monitoring and forecasting such biotic responses to heat stress is key...
Article
Full-text available
The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary efort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawn...
Preprint
Full-text available
Coral cover on tropical reefs has declined during the last three decades due to the combined effects of climate change, destructive fishing, pollution, and land use change. Drastic reductions in greenhouse gas emissions combined with effective coastal management and conservation strategies are essential to slow this decline. Innovative approaches,...
Article
Full-text available
The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spaw...
Preprint
Full-text available
Scleractinian corals are modular colonial organisms and are the main framework builders of coral reefs. Most corals reproduce by broadcast spawning with external fertilization and these processes are essential to replenish reef coral populations. Despite decades of research, many aspects of coral reproductive biology remain poorly studied. For exam...
Article
Full-text available
Studies of broadcast spawning in corals are fundamental to our understanding of early life history characteristics, reproductive biology, restoration etc. Spawning of corals for research is routinely conducted, but this is mostly restricted to sites adjacent to reefs and from broodstock collected from the wild just prior to gamete release. Only rec...
Article
Full-text available
Anthropogenic environmental change has increased coral reef disturbance regimes in recent decades, altering the structure and function of many coral reefs globally. In this study, we used coral community survey data collected from 1996 to 2015 to evaluate reef‐scale coral calcification capacity (CCC) dynamics with respect to recorded pulse disturba...
Article
Full-text available
Reef restoration efforts, utilising sexual coral propagation need up-scaling to have ecologically meaningful impact. Post-settlement survival bottlenecks, in part due to competitive benthic algae interactions should be addressed, to improve productivity for these initiatives. Sea urchins are keystone grazers in reef ecosystems, yet feeding behaviou...
Article
Full-text available
Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we...
Article
Full-text available
Scleractinian corals are vulnerable to a range of environmental disturbances, but generally suffer the highest rates of mortality during early life-history stages, i.e., from larval settlement until a few months post-settlement. Variations in survival rates of corals during this period play a key role in structuring adult coral populations. Many co...
Article
Full-text available
Human activities have led to widespread ecological decline; however, the severity of degradation is spatially heterogeneous due to some locations resisting, escaping, or rebounding from disturbances. We developed a framework for identifying oases within coral reef regions using long‐term monitoring data. We calculated standardised estimates of cora...
Article
The majority of research focusing on coral reproductive biology (e.g. spawning timing and synchrony) is carried out in facilities adjacent to reefs that the corals originated from. This is in part because transporting corals over long distances by air leads to sub-lethal stress that may confound the results of any experimental study. However, these...
Article
Full-text available
The use of sexually propagated corals is gaining popularity as an approach for reef restoration. However, manually attaching substrates with recently settled corals to the reef using binding materials is both time-consuming and expensive, limiting the use of this technique to small spatial scales. We present a novel approach whereby young corals ar...
Article
Full-text available
For many corals, the timing of broadcast spawning correlates strongly with a number of environmental signals (seasonal temperature, lunar, and diel cycles). Robust experimental studies examining the role of these putative cues in triggering spawning have been lacking until recently because it has not been possible to predictably induce spawning in...
Article
Full-text available
Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on...
Article
Full-text available
Most studies of coral reproductive biology to date have focused on oocyte numbers and sizes. Only one ( ex situ ) study has enumerated sperm numbers, even though these data have multiple potential applications. We quantified total coral sperm and eggs per gamete bundle collected from six species in situ during a synchronous spawning event in Singap...
Data
Raw data of sperm and egg counts for six coral species.
Article
Full-text available
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 assembla...
Article
Full-text available
Herbivores play a critical role in structuring benthic communities on tropical coral dominated reefs by removing macroalgae. Reducing herbivory has been implicated in promoting phase shifts from coral dominance to other ecosystem states following disturbances. Turbidity and sedimentation are key physical processes that also structure coral reef com...
Article
Full-text available
Herbivores play a critical role in structuring benthic communities on tropical coral dominated reefs by removing macroalgae. Reducing herbivory has been implicated in promoting phase shifts from coral dominance to other ecosystem states following disturbances. Turbidity and sedimentation are key physical processes that also structure coral reef com...
Preprint
Full-text available
Background .Herbivores play a critical role in structuring benthic communities on tropical coral dominated reefs because they remove macro and microalgae, which might otherwise overgrow adult corals or prevent successful recruitment of juveniles. Reducing herbivory has been implicated in promoting phase shifts from coral dominance to other ecosyste...
Article
Little is known about the reproductive biology of corals from the Philippines, despite this archipelago being at the center of coral reef biodiversity. Here, we report on the reproductive biology of a branching poritid species provisionally identified as Porites cf. cylindrica in the Bolinao-Anda reef complex (BARC), northwestern Philippines. Histo...
Article
Full-text available
While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of ma...
Article
Full-text available
Processes occurring early in the life stages of corals can greatly influence the demography of coral populations, and successful settlement of coral larvae that leads to recruitment is a critical life history stage for coral reef ecosystems. Although corals in Singapore persist in one the world's most anthropogenically impacted reef systems, our un...
Article
Full-text available
Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems. Data on the timing of spawning and extent of synchrony, however, are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we presen...
Article
Full-text available
Projected increases in the magnitude and frequency of sea surface temperature anomalies present a significant threat to the persistence of tropical coral reefs, however, detailed studies of community level responses to thermal stress are needed if its effect on reef resilience are to be understood. While many studies report on broad, regional scale...
Preprint
Full-text available
Projected increases in the magnitude and frequency of sea surface temperature anomalies present a significant threat to the persistence of tropical coral reefs, however, detailed studies of community level responses to thermal stress are needed if its effect on reef resilience are to be understood. While many studies report on broad, regional scale...
Article
Full-text available
Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems, however, data on spawning timing and extent of synchrony are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we present the fi...
Preprint
Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems, however,data on spawning timing and extent of synchrony are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we present the fir...
Article
Full-text available
Early work on coral reproduction in the far northern Red Sea suggested that the spawning times of ecologically abundant species did not overlap, unlike on the Great Barrier Reef where many species spawn with high synchrony. In contrast, recent work in the northern and central Red Sea indicates a high degree of synchrony in the reproductive conditio...
Article
Full-text available
The early post-settlement stage is the most sensitive during the life history of reef building corals. However, few studies have examined the factors that influence coral mortality during this period. Here, the impact of fouling on the survival of newly settled coral spat of Acropora millepora was investigated by manipulating the extent of fouling...
Article
Full-text available
Sexual propagation of corals specifically for reef rehabilitation remains largely experimental. In this study, we refined low technology culture and transplanta-tion approaches and assessed the role of colony size and age, at time of transfer from nursery to reef, on subsequent survival. Larvae from Acropora millepora were reared from gametes and s...
Article
Scleractinian coral mariculture plays an increasingly important role in reef rehabilitation and the aquarium trade, but its efficiency can be impeded by fouling macroalgal blooms, thus compromising coral health and increasing maintenance costs. In this study, the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus were introduced in...
Article
Full-text available
Low cost, simple approaches leading to enhanced numbers of viable, mature corals on reefs are prerequisite to active reef rehabilitation at even modest spatial scales. Mass culture of coral larvae to settlement, utilising improved knowledge of major coral spawning events, promises to be relatively straightforward, but very significant mortality in...
Article
Full-text available
We present the first experimental evidence of a coral (Oulastrea crispata) ingesting and assimilating seagrass material. Tropical seagrass meadows export a substantial portion of their productivity and can provide an important source of nutrients to neighbouring systems such as coral reefs; however, little is known about the mechanisms of this link...
Article
The dietary habits of the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus in ex situ mariculture were examined. Fouling algal assemblages on terracotta tiles were exposed to the grazers and compared. Except for Day 0, the assemblages on Days 2, 13 and 27 differed significantly across treatments. S. sphaeroides rapidly consumed m...