The South Korean ocean’s average temperature has been on a steady increase since 2010 and the rise is higher than the global average, the country’s meteorological authority said.
The ocean absorbs most of the excess heat from greenhouse gas emissions, leading to rising ocean temperatures. Since 1971, the global ocean has absorbed 90 percent of the excess heat added to the atmosphere by burning fossil fuels and other human activities.
Rising ocean temperatures affect marine species and ecosystems, leading to coral bleaching and the loss of breeding grounds for marine fishes and mammals. Ocean warming also affects humans by threatening food security, making waves more powerful, raising global sea level because water expands when it warms, and causing the loss of coastal protection.
In January, the Korea Meteorological Administration released a report that studied the ocean climate from 1981 to 2020, which found that the global ocean average temperature rose by 0.12℃, while the Korean temperature increased by 0.21℃, almost double the global value. The East Sea showed the highest increase rate during the study period.
The report also revealed that the ocean temperatures had increased in recent years, with five out of the 10 warmest years occurred between 2001 and 2020. Wave heights also increased correspondingly, as seven out of 10 highest years were also from the recent year category.
“The impact of climate change is appearing not only on land but also in the ocean,” Park Kwang-suk, administrator of the Korea Meteorological Administration, said in a statement. “And its impact (in the ocean) is increasing in the recent years.”
This is not the first time that a government agency reported the ocean is getting warmer. Last March, the Ministry of Ocean and Fisheries stated that the temperature increased between 2015 and 2020.
The ministry added that the higher temperature has shifted marine species’ habitats. For example, conchs used to live along the southern coast at 35 degrees north latitude in 2011, but they have moved to 37 degrees north latitude recently, and ghost crabs that used to live around the eastern water migrated slightly to the south.
The impact of ocean warming does not end there. Han In-sung, a researcher at the National Institute of Fisheries Science, said that a rise in temperature can affect the marine ecosystem in many different aspects.
“Stationary marine species may move their habitats northwards and migratory fish species, which mostly are valued as a food source, will change their migration paths,” Han wrote in an article published in 2018.
Ocean warming causes fluctuation in the amount of catches, as it can impact the spawning season of fish species. “The temperature change affects the spawning season and spawning fields of primary fish species as it can impact their physiology and ecology,” Han wrote.
In fish farms, a higher temperature can cause the mass mortality too.
Warmer waters can affect the shipping industry too, because a higher temperature influence the intensity of typhoons. “The power of typhoons can be significantly affected by the trend of surface water temperature in their paths,” Han wrote.
“Higher degrees in the East China Sea’s surface temperature had a great influence in (intensifying) typhoons like Typhoon Rusa and Typhoon Maemi that struck Korean Peninsula in 2002 and 2003 respectively.”
Han believed that the government should lead the way in mitigating risks.
“In order to respond to long-term seawater temperature changes, the government should provide long-term solutions to manage marine resources efficiently, based on accurate estimates and predictions,” he wrote.
Park said the Korea Meteorological Administration will serve as a watchdog of climate change and provide up-to-date information to the public.
“The Korea Meteorological Administration will produce detailed ocean temperature change scenarios,” Park said. “Based on the scenarios, we will evaluate the impact for different industries and fields, including fishing and disaster prevention.”
Photo credit: iStock/ zkruger. Female divers in the Korean province of Jeju, whose livelihood consists of harvesting a variety of mollusks, seaweed and other species from the ocean. The majority are above 50 years old with the oldest being 80.