Chitobiase as a surrogate measure of aquatic invertebrate biomass and secondary production in an environmental effects monitoring context

The current techniques used to assess aquatic invertebrate community status in the field are typically labour and time intensive, and therefore the development and implementation of new rapid and cost-effective methodologies is warranted. A proposed option is the enzymatic assay to detect and quantify the rate of production of the molting enzyme chitobiase, which can be used for determining impacts on freshwater aquatic systems. Two case studies were performed at: 1) The Prairie Wetland Research Facility at the University of Manitoba, to determine if a relation exists between measures of chitobiase and aquatic invertebrate biomass in a mesocosm setting, as well as to determine if changes in chitobiase activity could detect impacts to aquatic invertebrate communities from sulfamethoxazole and diluted bitumen and; 2) in the Elk River Valley region of British Columbia, to determine if a positive relationship exists between the rate of chitobiase production and benthic invertebrate biomass in lotic freshwater systems. No significant relationship was observed between the chitobiase measures and invertebrate biomass measures, and no effects of the stressors were detected in the first study. A significant positive relationship was observed between the rate of chitobiase production and benthic invertebrate biomass in the second study. It is recommended that additional studies be performed to further assess the potential of chitobiase activity to be used in an environmental monitoring context.