The Baltic Sea, the North Sea, and Norway’s coastal waters and fjords may soon be filled with jellyfish.
The waters are getting darker, and researchers explain that this could be from overproduction of organic compounds–the perfect recipe for marine areas with fewer fish and more jellyfish.
“This fresh water contains far more colored dissolved organic matter (CDOM) than marine water, so our coastal waters are darkening,” explained Professor Aksnes.
This has likely been occurring over many decades, but evidence suggests that climate change is causing it to accelerate. One of the areas that Aksnes is studying, Lurefjorden, is already heavily populated with the jellyfish Periphylla periphylla.
“Periphylla periphylla is a very light-sensitive jellyfish that thrives best in the world’s very deep marine waters,” Aksnes continued. “But the water in Lurefjorden has now become so murky and dark that it probably is helping this jellyfish to thrive. At the same time, the fjord has become less hospitable as a habitat for important fish species.”
Aksnes explained that another reason for the population shift is that the lower visibility makes it harder for the fish to find their prey.
To learn more:
- Read the full news release from the Research Council of Norway: Darkened fjord waters mean fewer fish, more jellyfish
Copyright © 2012 by Marine Science Today, a publication of Marine Science Today LLC.