Scientist raises red flags about concerning phenomenon causing sharks to move closer to shore: 'New coastal environments'
Sharks and other cartilaginous fish are moving to shorelines in the Sea of Marmara as oxygen amounts fall in deeper waters, Türkiye Today reported.
What's happening?
Pollution and warmer waters have reduced oxygen in the sea's deeper sections. In parts below 200 meters in the eastern area, oxygen is now at zero, said Hakan Kabasakal, fish advisor at World Wide Fund for Nature-Türkiye.
This change pushes sharks and similar fish toward shallow shore areas, where they encounter dangers. These fish need at least 4.5 milligrams of oxygen per liter of seawater to stay alive, but many areas of the Sea of Marmara now have less than 2 milligrams per liter.
"Due to continued deoxygenation in deep waters, these fish can't return, but they also can't thrive in their new coastal environments because of overfishing," Kabasakal explained.
Why is this marine oxygen drop concerning?
When sharks swim to shore, it creates a problem for sea life and people who rely on healthy oceans.
Out of 1,266 known cartilaginous fish, one-third could die out this century if nothing changes. These animals are top hunters in seafood chains, and when they vanish, whole food webs can fall apart.
The issue is bigger than just sharks. Low oxygen creates "dead zones" where most marine animals can't survive. This harms fishing jobs and food sources for towns near the Sea of Marmara.
In a three-year study, scientists observed an initial rise in shore shark numbers, but they then dropped rapidly in 2024. This shows that new areas can't keep these moved fish healthy over time.
For humans, losing these sea animals means fewer natural hunters of pests and less mix of life in waters that coastal towns need for food and jobs.
What's being done about this marine oxygen drop?
Work is growing to help these at-risk fish and boost oxygen in sea waters.
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WWF-Türkiye built a wildlife tracking app called Gozum Dogada (My Eye on Nature) so people can report shark sightings along Türkiye's almost 9,000 kilometers of shore.
"The more data we have, the stronger our conservation efforts become," Kabasakal noted.
Scientists also combat misconceptions about sharks that instill fear instead of fostering care. He's looking at old shark attack records from the Mediterranean Sea to show they happen much less than people think.
If you live by the sea, help by reporting unusual sea life sightings to local nature groups or by using a wildlife app. This gives important information to scientists tracking these changes.
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Yahoo
04-08-2025
- Yahoo
Scientist raises red flags about concerning phenomenon causing sharks to move closer to shore: 'New coastal environments'
Scientist raises red flags about concerning phenomenon causing sharks to move closer to shore: 'New coastal environments' Sharks and other cartilaginous fish are moving to shorelines in the Sea of Marmara as oxygen amounts fall in deeper waters, Türkiye Today reported. What's happening? Pollution and warmer waters have reduced oxygen in the sea's deeper sections. In parts below 200 meters in the eastern area, oxygen is now at zero, said Hakan Kabasakal, fish advisor at World Wide Fund for Nature-Türkiye. This change pushes sharks and similar fish toward shallow shore areas, where they encounter dangers. These fish need at least 4.5 milligrams of oxygen per liter of seawater to stay alive, but many areas of the Sea of Marmara now have less than 2 milligrams per liter. "Due to continued deoxygenation in deep waters, these fish can't return, but they also can't thrive in their new coastal environments because of overfishing," Kabasakal explained. Why is this marine oxygen drop concerning? When sharks swim to shore, it creates a problem for sea life and people who rely on healthy oceans. Out of 1,266 known cartilaginous fish, one-third could die out this century if nothing changes. These animals are top hunters in seafood chains, and when they vanish, whole food webs can fall apart. The issue is bigger than just sharks. Low oxygen creates "dead zones" where most marine animals can't survive. This harms fishing jobs and food sources for towns near the Sea of Marmara. In a three-year study, scientists observed an initial rise in shore shark numbers, but they then dropped rapidly in 2024. This shows that new areas can't keep these moved fish healthy over time. For humans, losing these sea animals means fewer natural hunters of pests and less mix of life in waters that coastal towns need for food and jobs. What's being done about this marine oxygen drop? Work is growing to help these at-risk fish and boost oxygen in sea waters. Do you worry about air pollution in your town? All the time Often Only sometimes Never Click your choice to see results and speak your mind. WWF-Türkiye built a wildlife tracking app called Gozum Dogada (My Eye on Nature) so people can report shark sightings along Türkiye's almost 9,000 kilometers of shore. "The more data we have, the stronger our conservation efforts become," Kabasakal noted. Scientists also combat misconceptions about sharks that instill fear instead of fostering care. He's looking at old shark attack records from the Mediterranean Sea to show they happen much less than people think. If you live by the sea, help by reporting unusual sea life sightings to local nature groups or by using a wildlife app. This gives important information to scientists tracking these changes. 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. Solve the daily Crossword
Forbes
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We've made sharks into monsters
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