The warmest ocean in the world is getting hotter, causing problems for blue whales, the planet's largest creatures, according to a report from Mongabay.
What's happening?
Blue whale sightings are decreasing off the coast of Sri Lanka, a rare permanent abode for the marine mammal. The warmer waters aren't cooled by the Arctic Ocean, making it ideal for breeding and feeding. But Mongabay, the World Wildlife Fund, and others reported that pollution, shipping traffic, whale tourism disturbances, and sea temperature rises are among factors that could be reducing their numbers in the North Indian Ocean.
A cargo ship carrying tons of toxic plastic pellets that burned and sank didn't help, per the report. But experts are tagging hotter water as a key culprit.
"Sri Lanka's leading marine researchers agree that increasing sea temperatures in the North Indian Ocean, warming at the fastest rate of any of the world's oceans, have likely pushed the whales to new waters," Mongabay summarized.
WWF reported that before whaling there was a robust global blue whale population of around 250,000. Now there are likely under 25,000. Sightings, and even whale sounds, have been declining in the North Indian Ocean for years. Mongabay reported four sightings this season. There were 729 observed in 2015. Some were likely the same whale counted multiple times, all per the report.
Why is the decline important?
It's a sober example about how human actions impact the planet. Pollution and ocean warming are taking a toll on species around the world, including other types of whales.
The North Indian Ocean is typically a balmy 66 degrees to 82 degrees Fahrenheit, which is part of the reason why the blue whales don't migrate away. But the temperature has increased by 1.8 degrees since 1950. It's also impacting monsoon seasons, among other changes, according to Mongabay and World Atlas.
Warming waters influence plankton abundance, a blue whale food source. The experts said that whales could be leaving in search of more food, in addition to being scared off by tourists and other ships, though marine biologist Asha de Vos said she doesn't think shipping is the entire reason.
"I recognize that shipping was heavy and was potentially leaving impacts. However, it is a little unusual for them to suddenly go from being in high numbers to low overnight due to shipping," she said.
Biologist Ranil Nanayakkara added: "Whales are nomadic. They travel around wherever there's productivity, wherever there's food they can return to, just like you and me. They will keep going back to places where there is food."
TCD Picks » Upway Spotlight
💡Upway makes it easy to find discounts of up to 60% on premium e-bike brands
|
How concerned are you about the plastic waste in our oceans? Click your choice to see results and speak your mind. |
Extremely 😫 The U.S. Environmental Protection Agency reported that warming waters can impact fishery health, encouraging the presence of invasive species. This can impact our food supply, as well.
Nanayakkara said he hopes the blue whales have found a place with plenty to eat.
"Who knows, one day they might come back," the expert noted.
What's being done about ocean warming?
Experts said that studies are underway or planned to analyze whale whereabouts as well as their food supply. Redirecting shipping away from the meal locations could help. But getting buy-in for protections has been challenging.
Ocean warming is associated with the planet's overheating, a result of nearly two centuries' worth of fossil fuel use, according to NASA. Advocacy, buying and using cleaner products, and simple actions around the house are all part of the solution.
Replacing a home's worth of old light bulbs with better LEDs can save you $600 a year while producing five times less air pollution, as one example.
Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
