Toxicity of Potassium Chloride Compared to Sodium Chloride for Zebra Mussel Decontamination

Abstract

Decontamination of watercraft and/or equipment following exposure to zebra mussels with the use of chemicals is one method of decontamination that has been recommended in the United States by multiple government agencies. The ideal chemical to be used for decontamination would be inexpensive, easily obtained, have no or limited effect on nontarget species, and relatively environmentally friendly. Two chemicals that have been tested are potassium chloride and sodium chloride. The toxicity of each chemical to both adult mussels and veliger larvae was examined. Sodium chloride was less effective at causing mortality than potassium chloride within the exposure periods tested. Adult mussels required an exposure period four times longer to experience complete mortality when exposed to sodium chloride (24h) at a concentration of 30,000mg/L compared to potassium chloride (6h). At a 10,000mg/L concentration, sodium chloride took eight times longer (96h) to cause 100% mortality of adult mussels than potassium chloride (12h). Veligers exposed to 1,250mg/L of potassium choride required a 12h exposure period to cause complete mortality while an exposure period of 18h was required for a 10,000mg/L concentration of sodium chloride to have the same result. To determine if potassium chloride is more advantageous as a decontamination chemical, the cost and chemical availability need to be researched. Received 30 May 2017 accepted 01 Oct 2017 revised 12 Sep 2017.