Demographic resilience may sustain significant coral populations in a 2°C‐warmer world

Mason, Robert A. B.; Bozec, Yves‐Marie; Mumby, Peter J.

doi:10.1111/gcb.16741

Cited by 6 publications

(4 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…CoTS outbreak dynamics were fully emergent after the hindcast period (i.e., after 2020). Future regimes of cyclones were derived from a random selection of synthetic cyclone tracks for the GBR (Mason et al, 2023; Wolff et al, 2018). Future heat stress consisted of maximum annual Degree Heating Weeks (DHW) calculated for each GBR reef from daily temperature predictions of the RCP2.6 scenario of climate model MIROC5 (Mason et al, 2023) and converted into bleaching mortality based on GBR historical bleaching (Bozec et al, 2022).…”

Section: Methodsmentioning

confidence: 99%

“…Future regimes of cyclones were derived from a random selection of synthetic cyclone tracks for the GBR (Mason et al, 2023; Wolff et al, 2018). Future heat stress consisted of maximum annual Degree Heating Weeks (DHW) calculated for each GBR reef from daily temperature predictions of the RCP2.6 scenario of climate model MIROC5 (Mason et al, 2023) and converted into bleaching mortality based on GBR historical bleaching (Bozec et al, 2022). While MIROC5 produces middle‐of‐the‐road RCP2.6 projections of coral bleaching for the GBR compared with other climate models (Mason et al, 2023), a single projection of temperature data was available so that mass bleaching events (>3°C‐weeks) occur at fixed years.…”

Section: Methodsmentioning

confidence: 99%

“…Future heat stress consisted of maximum annual Degree Heating Weeks (DHW) calculated for each GBR reef from daily temperature predictions of the RCP2.6 scenario of climate model MIROC5 (Mason et al, 2023) and converted into bleaching mortality based on GBR historical bleaching (Bozec et al, 2022). While MIROC5 produces middle-of-the-road RCP2.6 projections of coral bleaching for the GBR compared with other climate models (Mason et al, 2023), a single projection of temperature data was available so that mass bleaching events (>3 C-weeks) occur at fixed years. However, bleaching mortality was implemented as a normally distributed stochastic process to randomize bleaching responses at the reef level (Bozec et al, 2022).…”

Section: Reef Community Models: Reefmod-gbrmentioning

confidence: 99%

See 2 more Smart Citations

Control efforts of crown‐of‐thorns starfish outbreaks to limit future coral decline across the Great Barrier Reef

et al. 2023

Self Cite

View full text Add to dashboard Cite

Crown‐of‐thorns starfish (CoTS) naturally occur on coral reefs throughout the Indo‐Pacific region. On Australia's Great Barrier Reef (GBR), outbreaks of CoTS populations are responsible for ecologically significant losses of corals, and while they have been documented for decades, they now undermine coral recovery from multiple stressors, especially anthropogenic warming. Culling interventions are currently the best approach to control CoTS outbreaks on the GBR, but assessing control effectiveness under multiple stressors is complicated. Using an ensemble of two reef community models simulating the temporal and spatial dynamics of CoTS and corals under future climate scenarios, we evaluate the present‐day and future effectiveness of the current implementation of the GBR CoTS Control Program. Specifically, we determine the culling effort needed (i.e., number of vessels) to achieve the maximum ecological benefits as predicted by the models under possible warming futures. Benefits were measured by comparing projections of coral cover and CoTS densities under scenarios of increasing control effort and baseline scenarios where no control was simulated. Projections of present‐day control efforts (five vessels) show that the number of individual reefs subject to CoTS outbreaks is reduced by 50%–65% annually, yielding a benefit of 5%–7% of healthy GBR coral area per decade, equivalent to gaining 104–150 km2 of live corals by 2035. A threefold increase in current control efforts is sufficient to reach more than 80% of the maximum coral benefits predicted by each model, but the future amount of effort required to control CoTS effectively depends on the intensity of warming and the early detection of CoTS outbreaks. While culling CoTS across the entire GBR is unfeasible, we provide a framework for maximizing ecosystem‐wide benefits of CoTS control and guide management decisions on the required culling effort needed to reduce CoTS outbreaks to levels that may ensure coral persistence in the face of future climate change impacts.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Reef Community Models: Reefmod-gbrmentioning

confidence: 99%

See 1 more Smart Citation

Control efforts of crown‐of‐thorns starfish outbreaks to limit future coral decline across the Great Barrier Reef

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Many of these reports urge for societal and governmental changes to occur to limit global temperature increases to less than 1 °C warmer than the global temperature was during the second half of the 19 th century, as 70-90% of coral reefs will be lost at 1.5 °C of warming, and nearly 100% eradication will occur with a 2 °C increase (O. Hoegh-Guldberg et al, 2019;Mason et al, 2023). The most recent report from the World Meteorological Organization suggests that global temperatures have a high likelihood (66%) of reaching 1.5 °C of warming between 2023 and 2027, and for this five-year window to be warmer than the last is 98% likely (World Meteorological Organization 2023).…”

Section: The Impacts Of Climate Change On Coral Healthmentioning

confidence: 99%

Partner Switching and Metabolic Carbon Flux under Thermal Stress in the Cnidarian-Dinoflagellate Symbiosis

Heit

View full text Add to dashboard Cite

Reef corals depend heavily on their symbiotic relationship with dinoflagellates of the family Symbiodiniaceae, which are their primary source of metabolic energy and hence allow them to survive in oligotrophic tropical seas. The symbiotic relationship between these two partners is exceptionally sensitive to environmental change, however, and global warming is known to induce dysbiosis (i.e., breakdown of the symbiosis) in a process referred to as ‘coral bleaching’. The adaptive bleaching hypothesis posits that the host may acquire a new dominant Symbiodiniaceae species after a bleaching event, either from a shift in the relative abundance of the resident symbionts (‘shuffling’) or the uptake of new symbionts from the environment (‘switching’), better equipping the holobiont (i.e., the whole symbiosis) for the new environmental regime. However, different symbiont types may have different nutritional implications for the coral, potentially limiting the potential for partner shuffling or switching. Energy-rich carbon compounds are primarily provided by the symbiont to their coral host as glucose, glycerol, and lipids. Yet, it is poorly understood how climate change impacts this carbon translocation and how symbiont identity influences the response. This thesis, therefore, addressed this topic, using the sea anemone Exaiptasia diaphana (‘Aiptasia’), a globally adopted model system for the study of the cnidarian-dinoflagellate symbiosis.First, I aimed to quantify and compare pools of carbon-based metabolites under thermal stress in the host and symbiont, focusing on glucose, glycerol, and total carbohydrates (Chapter 2). It was hypothesized that thermal stress (33 °C) would cause a decline in the pools of these various metabolites, likely due to decreased photosynthetic function of the symbiont and carbon translocation to the host, combined with elevated catabolism in the host under thermal stress. Metabolites were measured using a range of commercially available metabolite-specific assay kits. As predicted, total carbohydrates in the symbionts decreased in abundance at high temperature, however, host and symbiont glucose and glycerol pools either remained constant or even increased under thermal stress relative to controls. This latter observation is consistent with gluconeogenesis (i.e., the synthesis of glucose from the likes of glycerol) in response to increased metabolic demands at high temperatures. The increased pools of glycerol, on the other hand, are consistent with the use of this metabolite as an osmolyte or moderator of cellular stress. While the test-kit approach used here was associated with a considerable amount of inter-sample variability, it nevertheless confirmed and added to previous observations gained using much more expensive, technically complex metabolomics methods.I then compared the synthesis and translocation of photosynthates in Aiptasia under low, control, and high temperature (15, 25, 33 oC), when colonized by either Breviolum minutum, which is the only known symbiont of Aiptasia through the Indo-Pacific region (the source of the Aiptasia used here), Durusdinium trenchii or Breviolum psygmophilum (Chapter 3). D. trenchii is a thermally tolerant but opportunistic species not typically associated with Aiptasia, while Breviolum psygmophilum is often associated with temperate and sub-tropical species, including Aiptasia in the western Atlantic Ocean. I hypothesized that B. minutum would translocate more photosynthate to its host at the control temperature but that D. trenchii and B. psygmophilum would out-perform B. minutum at high and low temperatures, respectively. To test this, a radiotracer (NaH14CO3) was used to measure photosynthetic fixation and translocation. Contrary to expectations, anemones hosting D. trenchii bleached completely at both low and high temperatures. However, the population density of B. psygmophilum increased at low temperature relative to B. minutum and controls, and anemones containing B. psygmophilum did not bleach as extensively as those containing B. minutum at high temperature, confirming the reputation of the former as a ‘thermal generalist.’ With respect to carbon metabolism, B. psygmophilum performed similarly or slightly out-performed B. minutum across all temperatures, though both species provided the most nutritional benefit at the low temperature. However, at the high temperature, symbiont density had a major influence on total carbon flux to the host, lessening the impact of bleaching. Specifically, a low symbiont population density facilitated proportionally higher rates of symbiont-cell specific photosynthesis and translocation, presumably due to reduced competition for CO2, such that heat-stressed anemones continued to receive similar amounts of photosynthate to controls.In summary, this thesis demonstrates that both thermal stress and symbiont type impact carbon flux and metabolism in the cnidarian-dinoflagellate symbiosis. Most interestingly, my findings highlight the potential importance for more research on the cellular processes that underlie the physiology of thermal generalists such as B. psygmophilum and the potential for such generalists to aid the adaptation of reef corals to climate change, either through natural processes or the development of tools for coral reef conservation.

show abstract

A remote sensing model for coral recruitment habitat

Radford,

Puotinen,

Sahin

et al. 2024

Remote Sensing of Environment

View full text Add to dashboard Cite

Demographic resilience may sustain significant coral populations in a 2°C‐warmer world

Cited by 6 publications

References 71 publications

Control efforts of crown‐of‐thorns starfish outbreaks to limit future coral decline across the Great Barrier Reef

Control efforts of crown‐of‐thorns starfish outbreaks to limit future coral decline across the Great Barrier Reef

Partner Switching and Metabolic Carbon Flux under Thermal Stress in the Cnidarian-Dinoflagellate Symbiosis

A remote sensing model for coral recruitment habitat

Contact Info

Product

Resources

About