Texas State Aquarium has been awarded more than US$1m (€900,000, £803,000) in damages after losing more than a tenth of its fish when a mislabelled lethal chemical was introduced to its tanks rather than a parasite treatment.

The incident, which happened in April 2015, occurred when a chemical introduced to the tank labelled trichlorfon was actually hydroquinone – a lethal carcinogen used primarily for film processing and as an additive for paint and motor fuel.

All but two of more than 400 fish in the aquarium’s Islands of Steel exhibit died as a result – around 13 per cent of the aquarium’s total collection.

The aquarium filed the suit against Florida-based Fishman Chemical in May 2015 when an investigation by Summit Environmental Technologies confirmed that the chemical shipped to the aquarium in a container labeled trichlorfon was indeed hydroquinone.

Following the tragedy, more than 130 new fish were been donated by aquariums across the country, representing 30 different species. Among those lost were a sand tiger shark, tarpon, grouper, lionfish, jack crevalle, a balloon fish, redfish and many other smaller species.

“I’m relieved that this episode is behind us,” said Texas State Aquarium president and CEO, Tom Schmid.

“It was important for us to file this federal lawsuit so that there is no question in the public’s mind as to what happened here, and more importantly, by bringing this to light, hopefully we can help prevent something like this from happening at another aquarium.”