Kalain Hosein
The entire Caribbean region has been placed under a Coral Reef bleaching watch or warning as ocean temperatures across the Caribbean continue to warm.
According to the latest United States National Oceanic and Atmospheric Administration (NOAA) report, Trinidad and Tobago is under a Bleaching Alert Level 2 for up to eight weeks through November. For an Alert Level 2, widespread bleaching and some mortality is expected.
Trinidad and Tobago’s Institute of Marine Affairs have already observed bleaching in coral reefs in Charlotteville. Coral reef monitoring conducted by IMA has shown up to 50% coral loss from the 2010 bleaching alone, with minimal recovery to date due to chronic ailments, such as pollution and overfishing, that limit the natural recovery processes.
According to the International Union for Conservation of Nature (IUCN), anthropogenic greenhouse gas emissions have caused an increase in global surface temperature of approximately 1°C since pre-industrial times. This has led to unprecedented mass coral bleaching events, which – combined with growing local pressures – have made coral reefs one of the most threatened ecosystems on Earth.
Coral reefs harbor the highest biodiversity of any ecosystem globally. Despite covering less than 0.1% of the ocean floor, reefs host more than one-quarter of all marine fish species and many other marine animals. Additionally, reefs provide a wide variety of ecosystem services such as subsistence food, protection from flooding, and sustaining the fishing and tourism industries. Their disappearance will therefore have economic, social, and health consequences.
Trinidad and Tobago’s maximum surface temperatures have become warmer in the last several decades and warmed by an average of 0.24°C per decade since 1946, according to the Trinidad and Tobago Meteorological Service. In fact, since 1981, each decade has been warmer than the 20th century average of 31.1°C. Higher temperatures are expected to contribute to higher evapotranspiration under a warming climate, resulting in increased aridity and more severe agricultural and ecological droughts.
The Intergovernmental Panel on Climate Change notes that the frequency and intensity of marine heatwaves in some areas of the Indian, Pacific, and Atlantic Oceans have increased. These high surface temperatures are also contributing to ocean acidification. According to the report, marine heatwaves and ocean acidification will increase with global warming of 1.5°C and even more significant increases at 2°C.
When conditions such as the temperature change, corals expel the symbiotic algae living in their tissues, responsible for their color, a spike of 1–2°C in ocean temperatures sustained over several weeks can lead to bleaching, turning corals white. If corals are bleached for prolonged periods, they eventually die. Oceanic heat stress and acidification will fundamentally change our marine ecosystems and potentially wipe out coral reefs like the Buccoo Reef in Tobago.
T&T’s Institute of Marine Affairs encourages those that spot coral bleaching to report any signs to the IMA via their app, SeaiTT. Just over a month ago, the IMA observed the spawning of the endangered Elkhorn coral in T&T’s waters.
