In this episode of Climate Now, we ask how fish farmers in the Mediterranean are adapting to climate change. Warmer water temperatures and lower oxygen levels can hit production hard, so scientists are working with aquaculture experts in Greece to find solutions.
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00:00Hello and welcome to Climate Now and this month we're here in Greece to ask how fish
00:09farmers in the Mediterranean can adapt to climate change.
00:13They're facing a lot of issues here, including rising water temperatures and falling oxygen
00:19levels.
00:20This year is a record, 25.5, this time of year it's a record.
00:28Well that's our story coming up, but first the very latest data from the Copernicus
00:32Climate Change Service.
00:35Globally it was the second warmest September on record, with temperatures 0.7 degrees Celsius
00:41above the 1991 to 2020 average.
00:44In Europe, September will be remembered for the devastating floods from Storm Boris.
00:49This map shows the precipitation anomaly for September, parts of the Czech Republic, Poland
00:54and Germany saw up to three months of rain in a few days.
00:59Well now to our report on the climate change challenges facing the aquaculture industry
01:04here in the Mediterranean, and if we have a quick look at the data we can see that on
01:08average sea surface temperatures across the Mediterranean are rising at 0.4 degrees Celsius
01:14per decade.
01:16And then if we have a look at this map, you can see that everywhere shaded in red faced
01:20its warmest sea surface temperatures on record this summer.
01:24So how are they coping?
01:25Well let's find out more.
01:31This fish farm in the Gulf of Carinthia looks idyllic, yet operations director George Tsatsos
01:37says the warming trend in the Mediterranean is hitting them hard.
01:41Last year, 2023, we had in this farm for two or three days 30 degrees, which was a record
01:48from here.
01:50The higher summer water temperatures are not good for business.
01:54It's a loss because as the temperature increases, the oxygen goes down, and that means we are
02:02forced to reduce feeding, and reducing feeding will lose growth.
02:09This farm produces 400 tonnes of sea bass per month, and to adapt to warming and preserve
02:14productivity, operations are now further offshore.
02:18So the first thing we have to do is to take the farms out on more exports, more open sea,
02:26with bigger depths, stronger currents, and better oxygen, which is quite important.
02:35There are 65 companies operating 328 fish farms in Greece.
02:39It's an important sector for export, which needs to remain sustainable.
02:43So scientists are stepping in to find solutions.
02:49Here in Crete, Nikos Papandrioulakis heads research into how best to rear sea bass in
02:53a warmer climate.
02:55They do so by comparing fish living in different temperature tanks.
03:00And each system has a different temperature.
03:03This is at 26, this is at 28, and this is at 30.
03:0826 degrees Celsius is ideal for raising sea bass, but as soon as the water temperature
03:13rises much higher, they don't put on weight and feed is wasted.
03:17In conditions where the temperature is around 28, 29, the fish grow less, but they also
03:24lose their capacity to transform feed to biomass.
03:29And at 33, 34, there is an almost complete physiological collapse, and the fish are not
03:35able not to grow and not to consume anything.
03:39Nikos and his team have used their observational data to model the fish growth and behavior
03:43and developed two applications.
03:46One uses satellite data and models to predict the oxygen requirements of the fish a few
03:50days in advance to help with feeding.
03:52The other allows fish farmers to test different species and locations against decadal climate
03:57trends.
04:00It is very important that the farmers have appropriate tools to adapt today and to plan
04:07for tomorrow.
04:10On this farm, the situation is evolving rapidly.
04:13They now put fewer fish in each cage, feed them twice a day to reduce oxygen demand,
04:17and use nets with bigger holes to increase water flow.
04:22As we are seeing the temperature going increasing year by year, we can't stay where we are.
04:30We need to, we need to, to act.
04:36Well that's all we have time for, but please head over to euronews.com slash climate now
04:41for more news on how our planet is changing.
04:44I'll see you next time.