Corals are, in many ways, the trees of the seas. They generate oxygen, provide habitats for animals and protect their environments from extreme weather. They also bring many benefits to humans, including creating livelihoods such as tourism.
But bleaching and death are widespread as a result of higher ocean temperatures, low oxygen and increased carbon dioxide — all caused by climate change. Rising sea levels and more frequent extreme weather speeds up coastal erosion and the flow of minerals and nutrients into sea water, causing algal blooms that harm corals.
I was captivated by the beauty of coral reefs when I went scuba diving for the first time on Phuket Island, Thailand, in 2016. In this picture from last year, I was collecting coral samples (which I do several times a year) at Kham Island in southern Thailand, to study how low oxygen levels affect them. Those levels, and the impacts of ocean acidification, are the subject of the PhD I’m doing at Prince of Songkla University. After I graduate, I hope to keep investigating corals so that I can help to better protect them and the marine environment.
In a study published this year, my colleagues and I measured the effects of increasing the water temperature by 3 °C, lowering the oxygen content, or both, on the growth rates of three coral species. In most cases, growth slowed (T. Jain et al. J. Mar. Sci. Eng. 11, 403; 2023). Warmer water and low oxygen also mostly reduced the density of symbiotic algae in the coral and their ability to photosynthesize efficiently.
Fishing and tourism can also harm corals, but we cannot just ban these pursuits, which provide important livelihoods. In the future, I hope that I and other scientists will be able to supply data on the consequences of various human activities, to be fed into models of coral stress and ocean health.
Protecting ocean environments is a crucial job for everyone, not just those who live in coastal areas.
Source: Ecology - nature.com
