The world’s oceans are becoming noisier thanks to pollution, with potentially harmful effects for whales, dolphins and other marine life, US scientists said in a study published on Sunday.
Low-frequency sound in the ocean is produced by natural phenomena such as rain, waves and marine life, and by human activities such as sonar systems, shipping and construction.
The sound is absorbed mainly through the viscosity of the water and the presence of certain dissolved chemicals, the report published in the science journal Nature said.
The concentration of chemicals that absorb sound in the oceans, however, has declined as a result of ocean acidification, in turn caused by rising concentrations of carbon dioxide. Rising levels of carbon dioxide come from human activity, such as shipping, with the number of ships roughly doubling over the past 40 years, the scientists said.
This was in turn increasing the acidity of the ocean, shown by a lowering of its pH levels, they said.
Using model simulations, the scientists found that increases in acidity could reduce seawater sound absorption by as much as 60 percent by 2100 in high latitude oceans.
Concern about the negative effect of the sea’s increased acidity had previously been concentrated on the reduced rate of calcification, such as in coral reefs.
“However, a less anticipated consequence of ocean acidification is its effect on underwater sound absorption,” the authors said. “A decrease in seawater pH lowers sound absorption in the low-frequency range and, as a result, leads to increasing sound transmission.”
Future global warming may further decrease the ocean’s sound absorption capacity at certain frequencies, the study said.
“High levels of low-frequency sound have a number of behavioral and biological effects on marine life,” it added.
This included tissue damage, mass stranding of mammals, such as whales, and temporary loss of hearing in dolphins, the report said.
Marine species had adapted to varying levels of noise, but the consequences of the sea’s decreased ability to absorb sound were uncertain and required further research, the scientists said.
Also See: Whither the response to climate change?
DEADLOCK: Putin has vowed to continue fighting unless Ukraine cedes more land, while talks have been paused with no immediate results expected, the Kremlin said Russia on Friday said that peace talks with Kyiv were on “pause” as Ukrainian President Volodymyr Zelenskiy warned that Russian President Vladimir Putin still wanted to capture the whole of Ukraine. Meanwhile, US President Donald Trump said that he was running out of patience with Putin, and the NATO alliance said it would bolster its eastern front after Russian drones were shot down in Polish airspace this week. The latest blow to faltering diplomacy came as Russia’s army staged major military drills with its key ally Belarus. Despite Trump forcing the warring sides to hold direct talks and hosting Putin in Alaska, there
North Korea has executed people for watching or distributing foreign television shows, including popular South Korean dramas, as part of an intensifying crackdown on personal freedoms, a UN human rights report said on Friday. Surveillance has grown more pervasive since 2014 with the help of new technologies, while punishments have become harsher — including the introduction of the death penalty for offences such as sharing foreign TV dramas, the report said. The curbs make North Korea the most restrictive country in the world, said the 14-page UN report, which was based on interviews with more than 300 witnesses and victims who had
COMFORT WOMEN CLASH: Japan has strongly rejected South Korean court rulings ordering the government to provide reparations to Korean victims of sexual slavery The Japanese government yesterday defended its stance on wartime sexual slavery and described South Korean court rulings ordering Japanese compensation as violations of international law, after UN investigators criticized Tokyo for failing to ensure truth-finding and reparations for the victims. In its own response to UN human rights rapporteurs, South Korea called on Japan to “squarely face up to our painful history” and cited how Tokyo’s refusal to comply with court orders have denied the victims payment. The statements underscored how the two Asian US allies still hold key differences on the issue, even as they pause their on-and-off disputes over historical
CONSOLIDATION: The Indonesian president has used the moment to replace figures from former president Jokowi’s tenure with loyal allies In removing Indonesia’s finance minister and U-turning on protester demands, the leader of Southeast Asia’s biggest economy is scrambling to restore public trust while seizing a chance to install loyalists after deadly riots last month, experts say. Demonstrations that were sparked by low wages, unemployment and anger over lawmakers’ lavish perks grew after footage spread of a paramilitary police vehicle running over a delivery motorcycle driver. The ensuing riots, which rights groups say left at least 10 dead and hundreds detained, were the biggest of Indonesian President Prabowo Subianto’s term, and the ex-general is now calling on the public to restore their
RSS