Climate Change Induced Coral Bleaching and Algal Phase Shift in Reefs of the Gulf of Mannar, India

2013 ◽  
pp. 87-94
Author(s):  
J. Joyson Joe Jeevamani ◽  
B. Kamalakannan ◽  
N. Arun Nagendran ◽  
S. Chandrasekaran
Keyword(s):  
Climate Change ◽  
Phase Shift ◽  
Coral Bleaching ◽  
Gulf Of Mannar

scholarly journals Coral reefs in the Gilbert Islands of Kiribati: Resistance, resilience, and recovery after more than a decade of multiple stressors

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255304
Author(s):  
Sara E. Cannon ◽  
Erietera Aram ◽  
Toaea Beiateuea ◽  
Aranteiti Kiareti ◽  
Max Peter ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Phase Shift ◽  
Coral Reefs ◽  
Coral Bleaching ◽  
Coral Cover ◽  
Hard Coral ◽  
Turf Algae ◽  
The World ◽  
Coral Communities

Coral reefs are increasingly affected by a combination of acute and chronic disturbances from climate change and local stressors. The coral reefs of the Republic of Kiribati’s Gilbert Islands are exposed to frequent heat stress caused by central-Pacific type El Niño events, and may provide a glimpse into the future of coral reefs in other parts of the world, where the frequency of heat stress events will likely increase due to climate change. Reefs in the Gilbert Islands experienced a series of acute disturbances over the past fifteen years, including mass coral bleaching in 2004–2005 and 2009–2010, and an outbreak of the corallivorous sea star Acanthaster cf solaris, or Crown-of-Thorns (CoTs), in 2014. The local chronic pressures including nutrient loading, sedimentation and fishing vary within the island chain, with highest pressures on the reefs in urbanized South Tarawa Atoll. In this study, we examine how recovery from acute disturbances differs across a gradient of human influence in neighboring Tarawa and Abaiang Atolls from 2012 through 2018. Benthic cover and size frequency data suggests that local coral communities have adjusted to the heat stress via shifts in the community composition to more temperature-tolerant taxa and individuals. In densely populated South Tarawa, we document a phase shift to the weedy and less bleaching-sensitive coral Porites rus, which accounted for 81% of all coral cover by 2018. By contrast, in less populated Abaiang, coral communities remained comparatively more diverse (with higher percentages of Pocillopora and the octocoral Heliopora) after the disturbances, but reefs had lower overall hard coral cover (18%) and were dominated by turf algae (41%). The CoTs outbreak caused a decline in the cover and mean size of massive Porites, the only taxa that was a ‘winner’ of the coral bleaching events in Abaiang. Although there are signs of recovery, the long-term trajectory of the benthic communities in Abaiang is not yet clear. We suggest three scenarios: they may remain in their current state (dominated by turf algae), undergo a phase shift to dominance by the macroalgae Halimeda, or recover to dominance by thermally tolerant hard coral genera. These findings provide a rare glimpse at the future of coral reefs around the world and the ways they may be affected by climate change, which may allow scientists to better predict how other reefs will respond to increasing heat stress events across gradients of local human disturbance.

Impact of Climate Change Induced Coral Bleaching in the Northern Part of Gulf of Mannar and Palk Bay, Southeast Coast of India

2014 ◽  
Vol 14 (4) ◽  
pp. 276-283 ◽  
Author(s):  
S. Manikandan ◽  
S. Ganesapand ◽  
Manoj Singh ◽  
M. Anand ◽  
A.K. Kumaraguru
Keyword(s):  
Climate Change ◽  
Coral Bleaching ◽  
Gulf Of Mannar ◽  
Southeast Coast Of India ◽  
Impact Of Climate Change ◽  
Southeast Coast ◽  
Palk Bay

The impacts of climate change and post bleaching effects on the octocoral communities of Gulf of Mannar, India

2021 ◽  
Vol 130 (4) ◽  
Author(s):  
Mahalakshmi Boopathi ◽  
P Dinesh Kumar ◽  
J K Patterson Edward
Keyword(s):  
Climate Change ◽  
Gulf Of Mannar ◽  
Impacts Of Climate Change

A Sea Country Learning Partnership in Times of Anthropocenic Risk: Offshore Coral Reef Education and Our Story of Practice

2017 ◽  
Vol 33 (3) ◽  
pp. 160-170 ◽  
Author(s):  
Hilary Whitehouse ◽  
Marie Taylor ◽  
Neus (Snowy) Evans ◽  
Tanya Doyle ◽  
Juanita Sellwood ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Environmental Change ◽  
Great Barrier Reef ◽  
Coral Bleaching ◽  
Educational Experiences ◽  
Barrier Reef ◽  
Local Schools ◽  
Rapid Environmental Change ◽  
Civic Environmentalism

AbstractThis is a researched account of an offshore coral reef education partnership formed during a time of rapid environmental change (the coral bleaching events in the years 2015 to 2017). The aim of the partnership is to encourage a learning connection with Sea Country. Framed as civic environmentalism, this article explores the dimensions of practice between a reef tourism provider, local schools, a local university, and local Indigenous rangers that enables primary, secondary and university students, rangers, and educators to travel together on day trips to the outer Great Barrier Reef and islands and have immersive and sharing educational experiences. Offshore environmental education and higher quality marine education is increasingly important in the Anthropocene, when Australian reefs are subject to the pressures of climate change and other impacts other impacts that diminish their resilience.

Coral Bleaching and Climate Change

1999 ◽  
Vol 38 (7) ◽  
pp. 521
Author(s):  
Dan Harries
Keyword(s):  
Climate Change ◽  
Coral Bleaching

scholarly journals Model-based assessment of the role of human-induced climate change in the 2005 Caribbean coral bleaching event

2007 ◽  
Vol 104 (13) ◽  
pp. 5483-5488 ◽  
Author(s):  
S. D. Donner ◽  
T. R. Knutson ◽  
M. Oppenheimer
Keyword(s):  
Climate Change ◽  
Coral Bleaching ◽  
Bleaching Event ◽  
Model Based ◽  
Caribbean Coral

A new conceptual model for the warm-water breakdown of the coral - algae endosymbiosis

2009 ◽  
Vol 60 (6) ◽  
pp. 483 ◽  
Author(s):  
Scott A. Wooldridge
Keyword(s):  
Climate Change ◽  
Coral Bleaching ◽  
Warming Trend ◽  
Warm Water ◽  
Bisphosphate Carboxylase ◽  
Co2 Partial Pressure ◽  
Cellular Processes ◽  
Cellular Events ◽  
Precise Understanding ◽  
Limiting Condition

The symbiosis between reef-building corals and their algae endosymbionts is sensitive to temperature stress, which makes coral reefs vulnerable to climate change. However, a precise understanding of the capacity for the symbiosis to adapt to climate change is currently restricted by the lack of coherent explanation for the set of cellular events leading to its warm-water breakdown (= coral bleaching). Here, a new coral bleaching model is proposed in which the triggering event is a disruption to the ‘dark’ photosynthetic reactions of the algae endosymbionts, primarily due to a limited availability of CO2 substrate around the Rubisco enzyme (ribulose-1,5-bisphosphate carboxylase). Paradoxically, this CO2-limiting condition may be enhanced by the modern increase in atmospheric CO2 partial pressure (pCO2). Importantly, the model delivers a new standpoint from which to explain: (i) upper thermal bleaching thresholds; and (ii) the mechanism underpinning endosymbiont shuffling. Overall, the model leaves little doubt as to the diminished stability and functioning (i.e. resilience) of the coral–algae endosymbiosis due to the rising pCO2 and warming trend in the upper ocean surface layer. It is concluded that whole-colony bleaching is the destructive endpoint to a suite of cellular processes that operate near continuously in modern symbiotic corals.

Trend in coral-algal phase shift in the Mandapam group of islands, Gulf of Mannar Marine Biosphere Reserve, India

2016 ◽  
Vol 15 (6) ◽  
pp. 1080-1086 ◽  
Author(s):  
M. Machendiranathan ◽  
L. Senthilnathan ◽  
R. Ranith ◽  
A. Saravanakumar ◽  
T. Thangaradjou ◽  
...  
Keyword(s):  
Phase Shift ◽  
Biosphere Reserve ◽  
Gulf Of Mannar ◽  
Marine Biosphere

scholarly journals Mangrove habitats provide refuge from climate change for reef-building corals

2014 ◽  
Vol 11 (3) ◽  
pp. 5053-5088 ◽  
Author(s):  
K. K. Yates ◽  
C. S. Rogers ◽  
J. J. Herlan ◽  
G. R. Brooks ◽  
N. A. Smiley ◽  
...  
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Coral Bleaching ◽  
Anthropogenic Impacts ◽  
Management Strategies ◽  
Reef Coral ◽  
Scleractinian Corals ◽  
Seawater Chemistry ◽  
Recent Climate ◽  
Resiliency Factors

Abstract. Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business as usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef, coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove shaded and exposed (unshaded) areas. At least 33 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies was living shaded by mangroves, and no shaded colonies bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies bleached. A combination of substrate and habitat heterogeniety, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.

scholarly journals Nitrogen pollution interacts with heat stress to increase coral bleaching across the seascape

2020 ◽  
Vol 117 (10) ◽  
pp. 5351-5357 ◽  
Author(s):  
Mary K. Donovan ◽  
Thomas C. Adam ◽  
Andrew A. Shantz ◽  
Kelly E. Speare ◽  
Katrina S. Munsterman ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Coral Bleaching ◽  
Nitrogen Availability ◽  
French Polynesia ◽  
Nitrogen Pollution ◽  
Small Scale ◽  
Modeling Framework ◽  
Excess Nitrogen ◽  
Temperature Anomalies

Climate change is increasing the frequency and magnitude of temperature anomalies that cause coral bleaching, leading to widespread mortality of stony corals that can fundamentally alter reef structure and function. However, bleaching often is spatially variable for a given heat stress event, and drivers of this heterogeneity are not well resolved. While small-scale experiments have shown that excess nitrogen can increase the susceptibility of a coral colony to bleaching, we lack evidence that heterogeneity in nitrogen pollution can shape spatial patterns of coral bleaching across a seascape. Using island-wide surveys of coral bleaching and nitrogen availability within a Bayesian hierarchical modeling framework, we tested the hypothesis that excess nitrogen interacts with temperature anomalies to alter coral bleaching for the two dominant genera of branching corals in Moorea, French Polynesia. For both coral genera, Pocillopora and Acropora, heat stress primarily drove bleaching prevalence (i.e., the proportion of colonies on a reef that bleached). In contrast, the severity of bleaching (i.e., the proportion of an individual colony that bleached) was positively associated with both heat stress and nitrogen availability for both genera. Importantly, nitrogen interacted with heat stress to increase bleaching severity up to twofold when nitrogen was high and heat stress was relatively low. Our finding that excess nitrogen can trigger severe bleaching even under relatively low heat stress implies that mitigating nutrient pollution may enhance the resilience of coral communities in the face of mounting stresses from global climate change.

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