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El Nino is a state of the ocean and atmosphere in the tropical Pacific Ocean appearing every two to seven years with various strengths, and lasting six to eighteen months. The 2015-16 El Nino is the strongest ever recorded, smashing the previous record from 1997-98. Sea surface temperatures averaged 2.38° Celsius above the norm, surpassing December 1997, which was 2.24°C above normal. The National Oceanic and Atmospheric Administration (NOAA) declared last year El Nino event, the third global coral bleaching in history. This event is responsible in major changes in oceanic living conditions and temperatures, some of which are brought upon by our actions.
Endangered Species International (ESI) monitors, manages, and protects coral reef sites in the Coral Triangle (Southeast Asia). Our conservation efforts are happening where it is most needed and has been proven to lessen the negative impacts from El Nino.
In the Coral Triangle, the first reported observation of bleaching due to the 2015 El Nino was reported in May 2015 from Tubbataha Reefs Natural Park (Philippines). However, ESI recorded coral bleaching from rising surface water temperatures as early as May 2015 at various sites (Mindanao and Negros) in the Philippines. In October 2015, most sites having experienced coral bleaching and poor protection lost between 70 and 98 percent of corals. Sites resilient to the 2015-16 El Nino bleaching event were those with stronger water currents (therefore lower water temperature) and better protection and management against human impacts. At those sites, most surface coral species (usually not submerged at very low tides) were heavily impacted by El Nino, however, corals in deeper waters were usually preserved from bleaching.
During mass coral bleaching, water temperature increases above a critical threshold, typically over a large area. Under these stressful conditions, corals begin to lose their algae called zooxanthallae, eventually appearing 'bleached'. Should temperature stress continue, corals are likely to die. Where mass coral bleaching causes high levels of coral mortality, these ecosystems typically take years to decades to recover if no other addition impacts occur.
Reef-building corals have inhabited shallow tropical waters for over 200 years. However, they are experiencing a dramatic decline worldwide due to human activities. 85% of reefs in the Coral Triangle are classified as threatened, significantly higher than the global average of 60%. ESI has been involved in many fronts to save coral reefs from human impacts and support their recoveries. Coral communities are resilient to catastrophic disturbances like El Nino if they are not exposed to chronic stressors like overfishing, sedimentation, and pollution.
Join us to support healthy coral reefs thrive, to help unhealthy coral reefs recover, and to preserve the ocean.
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