Monday 10 April 2017

Lionfish a go go

There I was talking two years ago about the the beautiful but poisonous koraalduivel lionfish Pterois volitans [R with a scuba-diver for scale: it's about as big as your head] as an invasive species in Florida. I knew this voracious predator quite well when I worked in the Zoo in Rotterdam cleaning aquaria and sweeping the floor. I mentioned the species recently as an example of why releasing pets into your back garden when you are bored with them is a Bad Idea. I've been having a bit of an update on lionfish and what can be done about them. Here's an map for the status of the problem, each dot from Connecticut to Curacao is a sighting of feral lionfish:
There is no hardship which people won't go through, no ingenuity they won't mobilise if they can make money out of something.  A market is often a far better incentive than a bounty. Bounties didn't work for foxes Vulpes vulpes in Victoria, Oz; they didn't work as well as a hideous virus for 'controlling' Tasmanian Devils Sarcophilus harrisii.
  • In my original post and here's a video, it is suggested that selective culling can make inroads. It's a sport now, you can go down scuba in the Caribbean and go hunting.
  • But that only works down to the scuba depth limit of, say, 50m. Below that is where most of the lionfish hang out and breed. So ingenious engineers are developing a sort of sub-aqua drone that gets up close and personal and delivers a fatal electric shock.
  • Of course the American way is to modify your Glock pistol to shoot lionfish underwater and get reported by Fox News. Not so very patriotic though to use an Austrian handgun, hmmm.
  • Q. can you train sharks to eat lionfish? A. not very well.
  • If you can get past the poisonous spines, the flesh of Pterois is said to be tasty and you aren't getting the added frisson of dicing with death as you are with fugu Takifugu rubripes. With lionfish you just have to remove the rather obvious dorsal spines; with fugu you have to carefully remove all traces of liver, eyes, ovaries and skin if it is to be safe to eat. For spine cutting to prepare liondish you need tin-snips, puncture-proof gloves, 20 seconds and the ability to count up to 13. For fugu you need a licence and three years training. The Emperor of Japan is forbidden to eat fugu out of concern for his safety.  
  • There is also a cunning plan in Belize to get added value from the carcass by making jewellery out of the brightly stripes fins.
We don't have to kill every Atlantic-side lionfish, we just have to bring their numbers into line with a bit of judicious disease or predation to give the local fish a fair chance of getting their own genes into the next generation. Shouldn't be too difficult of a task: we've reduced cod morue bacalau Gadus morua from being so numerous that you could walk across their backs from one skiff to another to almost an endangered species. 

1 comment:

  1. It's taking many years but the cod are returning to Newfoundland. Largest industrial layoff in Canada as a result of the cod fishery closure in 1992.