Existential threat to marine life as oceans impacted by global warming

Ratnavali Poosawat, a specialist on ecology at the Department of Fisheries, said: “The oceans absorb approximately 90% of the Earth's heat energy. As global temperatures rise, coupled with the absorption of around 30% of emitted carbon dioxide, this results in a decrease in oxygen levels in the water, leading to the condition known as ‘ocean acidification’.”

Global warming affects wind patterns and impacts the water quality in the oceans, Ratnavali said. When combined with issues from human activities such as "waste" in the oceans, these factors negatively affect marine life. Species that rely on seafood as their food source will face greater difficulties in finding sustenance. Naturally, the human food chain is also affected by the decreasing availability of food sources, Ratnavali added.

On average, sea levels rise by approximately 3.1 millimetres per year, resulting in increasing loss of coastal areas. This impacts crucial marine habitats, including breeding grounds for young marine animals, mating sites for turtles, fish, and shrimp. Coastal fishing communities are also affected. They need to adapt, as failure to do so might lead to job loss and decreased reliance on the ocean due to the unpredictability caused by global warming's impact on weather patterns, also known as "climate chaos”, he said.

In the field of fisheries, addressing the challenges involves sustainable aquaculture practices using valuable resources, as well as implementing Internet of Things (IoT) technology to monitor water quality and temperature in breeding areas. However, controlling the ocean environment is complex due to various factors like global warming and industrial pollution, which can only be managed to a certain extent, Ratnavali explained.

Marine animals have adapted to changing water temperatures and seasons, such as by altering their egg-laying times and the recovery of corals, but around 20-30% of marine species are at risk of extinction due to these changes.

According to Rachawadee Chantara, a veterinarian at the upper Gulf of Thailand Marine and Coastal Resources Research and Development Institute, the fluctuating winds not only affect coastal erosion but also lead to the separation of mother and baby marine animals, particularly those who rely on nursing.

Mature marine animals and sick ones face the risk of dying, resulting in a marine animal tragedy on beaches, mangroves, and sea areas, Rachawadee warned.

Another significant impact of global warming is the water quality in the oceans, particularly in the upper Gulf of Thailand where over 50% of the water is in poor condition or is deteriorating. “This is caused by freshwater released from central regions to the gulf, often resulting in a phenomenon called 'red water' locally,” Rachawadee explained. “Scientifically, it's referred to as eutrophication, a severe oxygen deficiency caused by a combination of factors, including the release of wastewater from households, ships, and agriculture. This leads to nitrogen and phosphorus contamination, promoting rapid growth of plants, which then depletes oxygen levels and turns the water red. The lack of oxygen makes it difficult for fish to access food, leading to death.”

The increased acidity caused by carbon dioxide absorption in the oceans poses a significant threat to marine life with calcium carbonate structures, like corals and shellfish, Rachawadee warned. They struggle to form protective shells.

The Ministry of Natural Resources and Environment has initiated a marine project to promote awareness and participation in addressing plastic waste and to implement modern technologies for monitoring and assessing marine mammal nursing populations, as well as offshore populations. The aim is to enhance protection, conservation, evaluation and recovery of marine resources and coastal areas. A safe ocean and coast means safe human food sources for all, requiring concerted efforts from everyone, Rachawadee said.