Microorganism Survival in Ice‐Covered Marine Environment

The concentration of microorganisms in the vicinity of a submerged marine outfall is governed by dilution and decay processes. Dilution is a physical process related to the hydraulic characteristics of the site. Decay of microorganisms is a highly complex process involving chemical, physical, and biological processes. Although the microorganism decay process has long been recognized, it is still poorly understood. The few studies of microorganism survival in cold climates deal mostly with freshwater environments. The study reported herein involved investigations of microorganism survival under ice‐covered conditions from a submerged marine wastewater outfall in Rankin Inlet, Northwest Territories, Canada. Microorganism sampling and analyses for total and fecal coliforms and fecal streptococci were conducted. After accounting for physical dilution by developing a simple mixing model based on dye tracer tests, the data indicated that microorganism decay rates were significantly lower than those reported in more temperate climates. Observed decay rates were similar to those reported in ice‐covered rivers.