Is ambient chitobiase activity a monitoring tool for impacts on secondary production in lotic systems?

• Published in: Canadian journal of fisheries and aquatic sciences 2009-08, Vol.66 (8), p.1274-1281
• Main Authors: Conley, Justin M, Schorr, Mark S, Hanson, Mark L, Symes, Steven J, Richards, Sean M
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Aquatic biology; Aquatic environment; Aquatic sciences; Arthropods; Biological and medical sciences; Chitin; Contaminants; Contamination; Enzymes; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Outfalls; Plankton; Polymers; Properties; River basins; Sewage treatment; Sewage treatment plants; Surface water; Synecology; Wastewater treatment plants; Water analysis; Water depth; Water sampling; Water treatment; Zooplankton
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/F09-092

Chitobiase is one of two enzymes responsible for cleaving the chitin polymers that form arthropod exoskeletons and has been found to be predictive of secondary production for marine and freshwater zooplankton. Since chitobiase is released into water during molting by aquatic arthropods, it is possible that ambient chitobiase activity may be a useful proxy of secondary production in aquatic systems. In the present study, surface water samples from the upper Tennessee River basin, USA, were collected and analyzed for chitobiase to determine how enzyme levels vary with season, water depth, and proximity to sewage treatment outfalls. Additionally, chitobiase activity was correlated with three pharmaceutical compounds to assess if changes in chitobiase activity were associated with contaminants derived from sewage treatment plants. Chitobiase activity was significantly (p < 0.05) elevated in the fall relative to other seasons. Further, chitobiase activity displayed significant positive correlation (p < 0.05) between surface and subsurface samples and was negatively correlated (p < 0.05) with pharmaceutical concentrations in summer samples. These results indicate the potential for chitobiase as an assessment tool in estimating secondary production and as an ecotoxicological indictor.