Fish in a new climate
Will oysters be able to survive climate change and the expected rise of water temperatures in seas and oceans across the globe? Our Futuris programme brings you the answers.
Euronews correspondent Julian Lopez Gomez asks an important question: “Will oysters be able to survive global warming?
By the end of the century, seawater temperatures could rise between 2 and 4 º centigrade, according to the most pessimistic forecasts of the International Panel on Climate Change (IPCC) . What would be the consequences on fish and shellfish with a high commercial value? The search for answers is driving scientists to places like the Portuguese Institute for Sea and Atmosphere in Portugal.
Marine biologists here want to understand how rising levels of temperature, salinity and acidity in the water may affect the physiology of oysters.
They already have some ideas but the news isn’t good for oyster farmers.
Domitilia Matias is a Marine Biologist from the Portuguese Institute for Sea and Atmosphere. She told Euronews what happens when the water temperature rises: “In warmer waters, oysters dramatically increase their filtering activities. Their metabolism speeds up. And this continuous filtering effort absorbs a lot of their energy. This affects their growth; the length of their shells may become smaller and their bodies may accumulate less weight”.
Samples are taken from these waters to the labs for further analysis.
Researchers also want to understand if and how warmer temperatures can affect oysters´ reproductive cycles – and the implications in the long run.
Domitilia Matias is looking at the problem: “We’re evaluating the impact of those rising temperatures in the reproductive cycles of the species. And then we’ll also study if the eggs resulting from these reproductive cycles in warmer waters are viable or not”.
Oysters and other species of high commercial value are being studied in a European research project aimed at understanding how climate change will influence Europe’s fish and shellfish resources – and how the industry can adapt to those changes.
Myron Peck is a Biological Oceanographer from the University of Hamburg and also the Ceres Project Coordinator. He spoke to Euronews about some of the results of his data and research. “So we can predict how fast the fish are going to grow, what ultimately might happen to certain population stocks. And then we also have some economic modeling involved, and that is where we can look at the effects on farmers or fishermen”.
Elsewhere in northern Poland, a nearby power plant heats the water which runs through a unique experimental aquaculture farm.
Researchers study how carp, a key local fish resource, adapt to a warmer environment.
And even here, scientists say that the news is challenging.
Jacek Sadowski is a Fish Nutritionist from the West Pomeranian University of Technology. He has some concerning news for farmers.
“The warmer the water, the more stressed the whole physiology of the carp becomes. And this stress makes them more vulnerable to attacks from viruses and bacteria”.
Commercial aquaculture farms are involved in the research effort. This one produces some 25 tons of carp, perch, tench and pikes each year.
Farm managers say scientific knowledge will help them minimise risks and maximise the potential benefits.
Ichthyologist Mateusz Gzyl from the Inskie Centrum Rybactwa told Euronews: “We know warmer waters may affect the growth of fish. But our clients demand large carp, on average 2 or 2.5 kilos in weight. Understanding climate change patterns can allow us to develop more efficient feeding strategies to help our carp thrive”.
Researchers use these field activities to create models that assess the risks, vulnerability and adaptive capacity of the species studied.
The video on this page was prepared in collaboration with Euronews for the Futuris programme.