Oftentimes pet fish are transported from their point of purchase in a plastic bag filled with water. Once home, the fish is removed and placed in a tank of your choice. Now, Heather Hamlin, a marine scientist from the University of Maine in Orono, says that some of these plastic transport bags are unsafe for the fish.
“Hamlin and colleagues discovered that certain plastic bags with FDA food-grade approval leach nonylphenol (NP) in concentrations that are highly toxic to fish,” according to Phys.org. The chemical NP—also found in food packaging, cosmetics and laundry and dish detergents—binds to estrogen receptors. Even at low concentrations, it mimics estrogen, which feminizes and alters fertility in fish, thus threatening their existence. NP also has been found to alter fish immune function and damage DNA.”
As part of the study, Hamlin and her team kept captive-bred orchid dottybacks (Pseudochromis fridmani) in synthetic seawater. Some were kept in Teflon bags, others in plastic bags from two manufacturers or glass bowls. The fish were kept for 48 hours in these environments. The fish that were kept in the Teflon bags and glass bowls survived the full 48 hours. The fish in one of the plastic bags had an 89 percent survival rate. Only 60 percent of the fish in the other plastic bags survived the full 48 hours, and those that did didn’t survive an additional eight days in an aquarium, Phys.org reports.
Because both types of plastic bags were labeled the same way, making it difficult to tell which is more toxic, Hamlin suggests in the video above that if there are alternatives, such as glass, for transporting fish, use them instead.