• 2 months ago
Every day, marine biologist Gerwin Gretschel observes how rapidly the Mediterranean Sea is changing. At his diving school, people learn about the dangerous marine effects of climate change.
Transcript
00:00Gerwin Gretschel gets ready for his next dive.
00:04He's explored the waters in Croatia's Valsalina Bay many times already.
00:08The Austrian marine biologist first started diving here 35 years ago.
00:13I can say with certainty that the first 20 or maybe 25 years since I first came here,
00:22there were hardly any changes.
00:27But the last 6 to 10 years, there has been an incredible amount of change.
00:33Now there are changes almost every month.
00:40Above the water, everything is like it's always been.
00:43Blue skies, crystal clear water and people relaxing by the sea.
00:50But underwater, it's clear what Gretschel means.
00:54Until a few years ago, the bay was home to seagrass meadows, a habitat for hundreds of
00:59underwater species.
01:02They're known as the lungs of the sea and key to maintaining the ecological balance.
01:15Today, Valsalina Bay is an underwater desert.
01:20No vegetation, no seagrass meadows.
01:23The marine habitat has vanished in just a few years, with dramatic consequences.
01:31Biodiversity loss means we humans are in danger of suffocating in our own filth because nature
01:36is no longer able to regenerate what we have polluted.
01:45Scientists are also worried because the Mediterranean is warming quicker than any other sea in the
01:49world.
01:52As a result, more and more marine species are colonizing the Adriatic that don't belong
01:57here.
02:01Like the blue crab.
02:04It's a direct competitor to the sponge crab, which gives it the edge when hunting prey.
02:16The fishers, on the other hand, like the blue crab, as restaurants pay good money for them.
02:22But they still don't make up for the drop in fish stocks in recent years.
02:26Today, local fisher Marinko Lapov is out with his small boat that once belonged to his father.
02:34It used to be much better. There was a lot more fish and fewer fishes. It was much more
02:40profitable.
02:43Recently, someone caught a highly poisonous puffer fish not far from here. It's normally
02:50found in tropical waters.
02:54Now there's puffer fish here. They say it's poisonous. You can eat anything usually, but
03:00people don't know this fish. Now we have to look up what kind of fish we've caught on
03:05our phones.
03:10Learning about the world's seas is the only thing that can help combat these issues in
03:14the long term. Gretschel has been running the Pula Marine School for years. The private
03:20institution teaches children and young people about the underwater world, including seagrass
03:25meadows.
03:29They take the youngsters snorkeling in the next bay, where a few seagrass meadows can
03:33still be found. For many, it's the first time exploring the underwater world.
03:45It was really interesting to see it all. It was great. We also saw a spider crab and another
03:52fish, but I don't know what it's called.
03:58The Pula Marine School sponsors research too. Two doctoral students currently work here.
04:05They're investigating the influence of artificial light, for example from the shoreline, on
04:09brown algae.
04:12With this project, we are surrounded with something that is so close to us, and we actually
04:16don't know, we know so little. So for me it's very interesting to actually be part of the
04:20project where we are searching for results and data for something that is so close.
04:28Croatia depends on tourism. Visitors are drawn to its thousands of islands and almost 2,000
04:34kilometer long coastline. But there's a dark side too. Booming construction, environmental
04:40pollution, inadequate infrastructure. So far, the Adriatic is still putting up with it.
04:48The sea has its own laws that don't apply on land. And we always measure ourselves against
04:55those laws of the land. Anything we destroy out here, we can no longer repair. The only
05:01thing we can do is to quickly leave it alone and hope that the sea will regenerate.
05:10The marine school recently got an aquarium, so youngsters can see what a perfectly intact
05:15marine ecosystem might look like.

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