Research Document - 2010/006

Evaluation of Survey Methodologies for Monitoring Olympia Oyster (Ostrea lurida Carpenter, 1864) Populations in British Columbia

By T. Norgard, S. Davies, L. Stanton and G.E. Gillespie

Abstract

Olympia oysters were harvested commercially from the late 1880s to 1930 when stock declines and a shift in market preference ended the fishery. In 2000 they were listed as a species of special concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and under the Species at Risk Act (SARA) in 2003. As a requirement of SARA a management plan for the Olympia oyster was completed in 2009. One of the required actions identified was the development of survey protocols to measure their relative abundance along the BC Coast. This paper reviewed seven different survey protocols and tested four of them in the field. The results from these reviews have lead to recommendations on survey protocols depending on the population structure and density. On beaches where Olympia oyster populations are discrete or scattered a Two-Stage design with some GPS mapping should be employed. The number of quadrats used at each beach should range from 50 to 100 depending on the population density. On beaches where Olympia oysters are in extremely low abundance (a few individuals under rocks) or in complex habitats such tidal pools or along rock walls, a visual assessment of these populations will be necessary.

Complete document (PDF, 998 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.