The never-ending jellyfish joyride


Whilst the media have run with a series of entertaining headlines (“Sea of deadly jelly lurks, scientist warns“, second only to “jellyfish joyride threatens oceans“), University of Queensland scientist Dr Anthony Richardson issued a grave warning as to the future of the worlds oceans (co-inciding with World Oceans Day). Dr Richardson’s research shows convincing evidence that jellyfish aggregations, associated with overfishing of their main predators and increases in nutrient run-off from fertilisers and sewage, are likely to take over large parts of the worlds oceans in the decades to come.

“Small pelagic fish like sardines and pilchards are being fished out in many places and they eat plankton, which is partly made up of juvenile jellyfish,”

“Nutrient run-off on land causes phytoplankton blooms which produce water with low oxygen which jellyfish can survive but fish can’t.

“As well, a warming ocean associated with climate change sees increasing numbers of tiny flagellates in surface waters, and they are a favourite food of some jellyfish.” (Read More)

Amongst the more impressive of these are the giant Nomura jellyfish (over 2m in diameter, weighing over 200kg), which is already causing problems for fisherman in Japan by clogging nets (click through the image above for a higher resolution photograph). Despite the serious topic, I think Dr Richardson is a definite contender for the best paper title of the year (“The jellyfish joyride: causes, consequences and management responses to a more gelatinous future“, with a subsection entitled “Self-enhancing feedback: the never-ending jellyfish joyride“).