Live reef fish displaying physiological evidence of cyanide poisoning are still traded in the EU marine aquarium industry.

The illegal use of cyanide poisoning to supply live reef fish to several markets is one of the main threats to coral reefs conservation in the Indo-Pacific. The present study performed the first survey ever monitoring the marine aquarium trade in the EU for the presence of physiological evidence consistent with cyanide poisoning in live reef fish. This survey was also the first one worldwide employing a non-invasive sampling approach. Nearly 15% of the fish screened displayed physiological evidence of being illegally collected using cyanide poisoning (by testing positive for the presence of the thiocyanate anion (SCN-) in their urine). The efforts promoted so far to completely eradicate cyanide caught fish from the marine aquarium trade have not been effective, as our results suggest that their prevalence in the trade is in line with data reported nearly two decades ago. A new paradigm is urgently needed to effectively ban cyanide caught fish from the marine aquarium trade.