Invasion of the jellyfish

Jellyfish at Orot Rabin power station, Hadera [Reuters]

The Hollywood version of a post-apocalyptic world consists of hairy, unwashed, human low-lifes sprinkled with higher life forms such as Mel Gibson and Kevin Costner with gills. The reality, of course, would be very different.

We all know bacteria seem to thrive in any environment. So, too, do cockroaches. Now, to that list, it sees we must add jellyfish. Jellyfish are taking over the world. They even do so before the apocalypse, if they maintain their current rate of population growth.

Jellyfish seem to thrive when other marine species do not and they also love warm water. The warmer, the better and global warming is making for an ever increasing jellyfish-friendly marine environment.

The latest country to suffer a population explosion of jellyfish is Israel. Huge swarms of the creatures have driven sunbathers from many of the country’s beaches and the vastness of  their numbers is such that the water inlets of a coastal power station were blocked by them.

Similar incidents have been reported across the Mediterranean region in recent years. Even in the relatively cold waters around Scotland, the nuclear power station at Torness, East Lothian was closed for a period early in July.

The jellyfish’s love of warm water is such that as global sea temperatures increase, their range extends. At the same time, warmer waters are generally nutrient-poor and therefore there is less completion for food from fish which also prey on small jellyfish.

Another factor favouring the jellyfish is ocean acidification. Over the last 250 years, or so, since the growth of industry, the production of carbon dioxide gas has resulted in a take-up by the Earth’s oceans which has caused an increase in pH of approximately 30 percent.

This makes it harder for marine animals to form shells.  Many such creatures feed on jellyfish. They are the main prey of leatherback sea turtles, for instance.

So perhaps, in the near future, Hollywood will consider a follow up to Mad Max and Waterworld. ‘Invasion of the Jellyfish’ could feature Ben Stiller and Cameron Diaz in the leading roles as two cute little jellyfish befriending the last of the sea turtles, perhaps played by Morgan Freeman. Ben and Cameron would be sure to live happily ever after. As for Morgan, that would be a tricky task for the scriptwriters to produce a happy ending.