Bowermaster’s Adventures: Navigating the hordes of jellyfish

Jellyfish — those gelatinous, stinging, floating-condoms-of-the-sea, the pint-sized boogeyman of the ocean are fast becoming the equivalent of a coal mine’s canaries. Appearing this summer en masse along coastlines around the globe, jellyfish are evidence of just how badly we’re treating the ocean and with painful results.

During the last days of summer jellyfish swarmed the Atlantic coast of Spain stinging hundreds on a single day, sending many swimmers to the hospital. While most of the stinging effects would go away in a week or two, many can still itch months later and sometimes require surgery to remove the affected area.

Dubbed a couple years back by the New York Times as the “cockroaches of the sea,” hordes of jellyfish have been showing up in similar abundances along beaches in New York, France, Japan and Hawaii, stinging innocent passersby and clogging fishing nets.

While jellyfish do little more than float with the currents and sting only when bumped into, last year more than 30,000 Australians were treated for stings, double the year before. Such swarming used to happen on occasion, but last just a couple days. Now some are lasting for weeks. In Spain this summer a fishing boat from the Murcia region reported an offshore swarm of iridescent purple jellyfish spread over a mile.

“Those jellyfish near shore are a message the sea is sending us saying ‘Look how badly you are treating me,’ ” jellyfish expert Dr. Josep-Maria Gili with the Institute of Marine Sciences of the Spanish National Research Council told the New York Times.

Experts believe this is a problem that’s only going to grow in years to come, thanks to a variety of environmental ills bearing down on the ocean simultaneously:

1. GLOBAL WARMING increases sea surface temperatures, which encourage jellyfish growth, as does a corresponding lack of rainfall. Typically freshwater from rain aggregates near shore and helps keeps the jellyfish at a distance; lack of rain due to a changing climate – as they’ve experienced along the European coasts this summer — means jellyfish float closer and closer to shore.

2. COASTAL POLLUTION reduces oxygen levels and visibility in the water, which scares most fish away from the shoreline but is conditions in which jellyfish thrive. While most fish have to see their catch, jellyfish filter food from the water, so eat passively.

3. OVERFISHING eliminates natural predators of jellyfish like tuna and swordfish, which also allows for more plankton growth, which helps the jellyfish proliferate.

One bright note to the boom? Some predict in the not-so-distant future jellyfish may be the only marine life left and thus may become a dietary staple. Savvy scientists, like the University of British Columbia’s Daniel Pauly, believe thanks largely to overfishing that we better start working on some jellyfish recipes … and fast.
Eating jellyfish is already prevalent in some Asian and Third World countries where sea cucumbers and sea urchins – “which live off dirt,” notes Pauly – are already on menus. When Pauly first suggested the notion of jellyfish sandwiches, it was intended as a joke. Not today.

[flickr image via the glorious and well educated Tuan Bui]