Were salmon-killing jellyfish produced by global warming?
The appearance of a massive swarm of jellyfish, and their subsequent decimation of an Irish salmon farm, are this week being blamed on global warming.
Stock worth £1million were suffocated in their cages by the swarm, which is estimated to have covered 25 square kilometres of sea and been up to 10 metres thick. The fish farm's director said “It was unprecedented, absolutely amazing. The sea was red with these jelly fish and there was nothing we could do about, it, absolutely nothing.” says Northern Salmon Company managing director, John Russell (Telegraph). The full story is on The Great Beyond.
This isn't the first time climate change has been linked to jellyfish outbreaks. Last summer, the same jellyfish (Pelagia notiluca) was spotted in unusually high concentrations in the Mediterranean, again prompting speculation about impacts of sea temperature rise (New Scientist). Reuters reported that a volunteer campaign had removed eight tons of jellyfish from the Spanish coastline. Both reports mention temperature and decline in preditors as causes.
A recent study linked increasing populations of jellyfish in the North Sea to climate change and predicted that more jellyfish would appear over the next 100 years.
If the two events are truly linked the UK's salmon industry may have to be added to the list of climate change victims.
Daniel Cressey and Anna Barnett