Impact of the 3rd Global Coral Bleaching Event on the Western Indian Ocean in 2016 (original) (raw)

The Third Global Coral Bleaching Event on the Marginal Coral Reefs of the Southwestern Indian Ocean and Factors That Contribute to Their Resistance and Resilience

Diversity

Coral reefs reach their southernmost limits in the southwestern Indian Ocean in Maputaland, South Africa. Here, we investigate the recent global coral bleaching event of 2016, the thermal dynamics of these marginal high-latitude reefs and the potential environmental factors regulating the responses of coral communities. Pre-, peak- and post-bleaching surveys of over 9850 coral colonies from 29 genera were undertaken over 3 years across 14 sites spanning 120 km of coastline using point-intercept and visual bleaching index survey methodologies. Bleaching data were related to several environmental variables including temperature, degree heating weeks (DHW), depth, latitude, and upwelling intensity. These reefs have experienced a history of relatively low thermal stress based on DHW. Long-term in situ temperature records nevertheless showed no obvious trend of increase. In situ temperatures also displayed poor relationships, with temperatures predicted by the Representative Concentratio...

Coral reef degradation in the Indian Ocean. Status reports and project presentation 2000

2000

The temperatures of the world's oceans are increasing at an accelerating rate. Recent estimates indicate that the magnitude of these increases might be as much as several degrees over the next century and undoubtedly, the impacts of these changes on the Earth's ecosystems are likely to become increasingly obvious. Coral reefs have already shown dramatic responses to the increasing ocean temperatures.

Coral bleaching in the Indian Ocean islands: ecological consequences and recovery in Mdagascar

2000

During the period from January to August 1998, the largest coral bleaching event and subsequent mortality ever recorded had a huge ecological impact on coral reefs throughout the Indian Ocean. This event corresponded to increased seawater temperatures due to an ENSO phenomenon (Wilkinson, 1998). The full extent of the socio-economic impacts will depend on the recovery capacity of corals which, in many locations, are seriously threatened by

Coral Bleaching and Associated Mortality at Mayotte, Western Indian Ocean

2016

Abstract—Bleaching and associated coral mortality were assessed on fringing and barrier reefs on the north and east coasts of Mayotte from 1-24 May 2010. Major bleaching was encountered; nearly 80 % of the corals were bleached or dead (covered with thin algal overgrowth) on fringing reefs along the north coast, and 50 % and 35 % of the corals were bleached or dead at two sites on the east coast. The observations revealed spatial and temporal heterogeneity in the extent of the bleaching and mortality. The genera that appeared most susceptible to bleaching were Pocillopora and tabular Acropora, while Porites seemed to have suffered the least. Observations on the bleached genera were consistent with those made during the 1997-1998 bleaching event.

Climate Change Induced Thermal Stress Caused Recurrent Coral Bleaching over Gulf of Kachchh and Malvan Marine Sanctuary, West Coast of India

Climate Change in Asia and Africa - Examining the Biophysical and Social Consequences, and Society's Responses

Coral reefs are one of the most sensitive, productive, and invaluable biological resources on the earth. However, coral reefs are facing unprecedented stress due to ongoing climate changes and intensified anthropogenic disturbances globally. Elevated Sea Surface Temperature (SST) has emerged as the most imminent threat to the thermos-sensitive reef-building corals. The 2010–2014-2016 El Niño Southern Oscillation (ENSO) caused prolonged marine heat waves (MHWs) that led to the most widespread coral bleaching and mortality in the tropical Indi-Pacific regions. Coral bleaching prediction is vital for the management of the reef biodiversity, ecosystem functioning, and services. Recent decades, satellite remote sensing has emerged as a convenient tool for large-scale coral reef monitoring programs. As thermal stress is a critical physical attribute for coral bleaching hence, the present study examines the effectiveness of the elevated SSTs as a proxy to predict coral bleaching in shallow...

Coral bleaching due to increased sea surface temperature in Gulf of Kachchh Region, India, during June 2016

2019

The 2015-2016 E1 Niño Southern Oscillation event was one of the extreme climate events which elevated the sea surface temperature (SST) of tropical oceans, which in turn increased the level of thermal stress on corals. Coral bleaching event is mainly caused due to high positive SST anomaly, i.e., when SST exceeds its normal summer maxima. Corals in the Gulf of Kachchh region of Gujarat earlier experienced coral bleaching events during 1988, 2010 and 2014. For this study, SST was derived from NOAA OISST data set which is available daily at 0.25° global grids from 1982 to present. The climatologically warmest month for the Gulf of Kachchh region is June when the maximum monthly mean temperature is 29.31°C, as observed from NOAA OISST. The present study focuses on monitoring daily SST anomalies during summer 2016 for the Gulf of Kachchh reefs and field observations on early responses of coral bleaching from Laku Point reef, a site known for high coral diversity. It was found that in su...