Scientists in South Korea have developed autonomous robots designed to kill jellies by the thousands. These floating ocean drones are given the GPS coordinates of a jelly bloom, and then move through in a synchronized formation. The propeller blades draw the jellies into a propeller/grinder, where the animals are torn apart or cut up to later die of fatal wounds. So far, “The field test results show that three assembly robots operating at 4 knots (7.2km/h) disposes jellyfish at the rate of about 900kg/h” says their website.
Now, you’ve probably guessed I like jellies. I’ll just get that right out there from the start. I do concede, however, that jellies are a major economic issue in some areas and that as a society we should work toward a solution. Ok. Good. Now, for many species, this method is going to make the problem ten times worse. Here is why:
All stinging nettle jellies (read: the ones that tourists hate the most) spawn by releasing eggs and sperm into the water. When researchers and aquarists can’t figure out how to induce spawning naturally, they remove small pieces of the gonad from healthy animals, and preform in vitro fertilization– mixing eggs and sperm from the gonad in a dish– to achieve fertilization. So when you chop up these jellies, you’re effectively releasing all their eggs and sperm into a massive soup. You’ll then get a bunch of larvae, which will settle on the sea floor and do what jelly larvae do best– metamorphose into sea anemone-like little polyps. These polyps, no larger than a bread crumb, can live for years on the sea floor. One polyp can clone itself hundred of times. Each clone can produce hundreds of jellyfish. You get my drift? So for every one jelly you kill, there may be thousands to replace it the following year.
I think this solution could work for some species, such as those that brood their young. But much more information is needed on the life cycle of many animals before we’ll know for sure. In the meantime, best to check what species you’re going to drive robots through before you do a killing sweep, otherwise next year you’re gonna need much bigger robots…