Water quality and shellfish management in tillamook bay, Oregon

Abstract

The contamination of shellfish by pathogenic bacteria and viruses is a concern of shellfish producers, distributors, and consumers. To address these water quality concerns, the National Shellfish Sanitation Program has classified shellfish growing waters as approved, conditionally approved, or prohibited. The Tillamook estuary is one of Oregon's primary shellfish harvest areas. Degradation of water quality in Tillamook Bay has been linked to oyster bed closures, declines in salmonid populations, and decreases in recreational use of estuarine resources. In this study, water quality concerns related to shellfish management are addressed by examining the patterns of fecal coliform bacteria (FCB) concentration in Tillamook Bay. A oneway analysis of variance was used to compare log‐transformed FCB concentrations in prohibited, restricted, and conditional shellfish management areas. We found (I) a difference in Tillamook Bay water quality between all three areas and (2) a change in FCB concentrations through time in each management area. Since the designation of shellfish management areas affects the economy and public health, monitoring practices need to be reevaluated in order to draw more refined conclusions about water quality trends in Tillamook Bay.