Handheld device could help clamp down cyanide fishing


Scientists are working on a handheld device that they claim will detect cyanide fishing thereby enabling authorities to clamp down this destructive practice that not only leaves toxins in the water body, but also damages coral reefs and marine ecosystems.

The practice of cyanide fishing involves spraying of cyanide near coral reefs. This toxin quickly and cheaply stuns ornamental fish thereby making it easy for fish catches to scoop them easily and then supply it to pet stores.

While many countries have already banned this particular practice of fishing, people still follow this practice at many places; however, it is not always easy for authorities to track the perpetrators and clamp down cyanide fishing.

A new study however has found a way to detect such fishing. The idea is to forensically determine whether the fish being brought on the shore has been caught by cyanide fishing or not. This forensic determination can be carried out by a portable device says the team behind the study which is looking to find an alternative to the current methods of pre-treatment and testing that are not only expensive, but also time consuming.

To develop the portable sensor, the team including Andrew Rhyne, Ph.D., Roger Williams University in Rhode Island, looked into an electrochemical platform that uses porphyrins to bind thiocyanate. Porphyrins are organic molecules, and many of them are naturally occurring. One example is heme, the pigment in red blood cells. And thiocyanate is a metabolite secreted by fish that have been exposed to cyanide.

To make the electrodes, researchers attached metalloporphyrins — porphyrins with a metal in the center — to a substrate, and exposed the resulting sensor to water collected from nearby Narragansett Bay. The water samples were spiked with varying levels of thiocyanate. When thiocyanate attaches to the porphyrins, their chemistry and colors change — just as purple heme turns red when oxygen binds to it.

Researchers say their tests revealed the sensor’s ability to detect the thiocyanate, even in untreated salt water. Undergraduate researcher Connor Sweet is continuing the project, testing different metalloporphyrins and developing a consistent method for making the electrodes, which he currently does by hand. Engineering student Charles Flynn is working on the electronics side, developing a hand-held device to accommodate the sensor technology. The team will test the method on water samples from treated fish. They say if those results are promising, they could have a prototype ready in one to two years.