Do Not Mess With Fish 236,

and you thought fish were fun!

but not when they are caught with cyanide! regrettably the illegal in many countries practise continues today, in the aquatic trade an ongoing problem has been with fish that are caught with cyanide, it is easy and quick to use but has the most damaging of side effects, first let me explain the fishermen drop tabs of the substance into water bottles, which are then used to squirt clouds of the toxin into the coral crevices fish like to hide in. Some fish die on contact, but most are stunned for a period of about 20 minutes. That's more than enough time for the fishermen to scoop them up or even break apart the coral to get at any fishes hiding within, it’s also cheap. “Any time you have mining you’ll have cyanide around,” says Andrew Rhyne, a biologist at Roger Williams University in Rhode Island. What’s more, the middlemen who buy fish off of the fishermen often supply the cyanide tabs at little or no cost to the fishermen themselves, but the biggest problem with cyanide is that it’s difficult to detect. If you or I were to take a look at a cooler full of blue tangs fresh off the coral reef, there’d be no immediate way to know whether the fish were caught with cyanide, typically fish caught with cyanide can die in a matter of days or live to up to 6 weeks after exposure,

so not only does cyanide ultimately kill the fish it destroys the coral reef as well, for years a easy to administer and portable cyanide detector kit has been wanted by the aquatic trade to help stop the flow of cyanide caught fish, enter Ethan Kocak and Clifford Murphy, who together are developing a handheld test that would be both cheap to produce and easy to use in the field. And the way it works is pretty cool, when a fish gets hit with a squirt of cyanide solution, its liver immediately begins trying to neutralise and remove the compound. First it metabolises it; then it converts it into something called thiocyanate. The fish then ejects the thiocyanate in its body just as you and I might expel toxins: It pees the thiocyanate out, “You can actually tell if someone is a smoker based on a very similar test,” says Rhyne. All you have to do is look at their secretions—urine, saliva, etc—and you’ll find thiocyanate, other groups have been working to streamline this detection process, but Rhyne and Murphy have created a portable prototype that uses modified electrodes to detect thiocyanate at incredibly low levels: between one and five parts per billion. Right now, there are two hurdles the scientists want to overcome before they get this test to market. The first is to get the tests to the point where each handheld test detects at the same sensitivity as the next, the second, naturally, is money, hopefully both hurdles can be overcome, so in a few years’ time you may see labels in aquatic stores stating, “Cyanide Free” rather like we are used to seeing in stores that advertise organic produce, grass-fed beef or cage-free chickens, if fishermen can sell "Cyanide-Free Fish" for a higher price, and we can keep that label honest with a better detector, then everybody wins. In fact, the fishermen would win twice, because they’d no longer have to spend every day snorkelling through clouds of poison with bare skin and no protective equipment, “I think the fishermen get left out a lot of times. They get made into bad guys because they’re using cyanide. But these aren’t bad people,” says Rhyne, who has travelled to Indonesia many times. “They aren’t driving really fancy cars. These are people just trying to feed their family.”