Science Response 2016/044

Review of Dive Survey Methods for Northern Abalone in British Columbia

Context

Northern Abalone (Haliotis kamtschatkana) populations have been surveyed by Fisheries and Oceans Canada (DFO) since 1978 in British Columbia (BC) using the Breen survey method (Breen and Adkins 1979); the original survey method used during the commercial fishery to assess populations at index sites.  Since 2001, two new survey methods were developed: random transect (Lessard et al. 2002) and plot (Lessard et al. 2007).  Each survey method was developed with different objectives, such as long-term monitoring, population distribution assessments, impact monitoring, or monitoring rebuilding efforts.  All three methods produce an estimate of Northern Abalone density with associated error, but each method has trade-offs.

Defining the survey objectives is essential to determining which survey method (Breen, transect or plot) to select.  Each method was designed to answer specific questions and, as such, no protocol is inherently better than the others.  However, certain methods can be better suited to answer specific types of questions.  Once the objectives of a survey have been defined, the most suitable survey method can be selected and a specific survey design can be implemented (i.e.  selection of survey locations).  This report provides an overview of each survey protocol, the strengths and weaknesses of each protocol, and discusses its application and suitability in relation to specific survey objectives. 

DFO Species at Risk (SARA) program has requested guidance on the selection and use of appropriate survey methods for Northern Abalone.  This information will support First Nations and other stakeholders to ensure surveys are executed consistently and in a manner such that data can be used to reliably assess population densities and monitor species recovery.  Specifically, this Science Response provides information on the following objectives:

1. Describe the existing DFO Northern Abalone survey methods: Breen Survey Method (Breen and Adkins 1979), Transect Survey Method (Lessard et al. 2002, 2007) and Plot Survey Method (Lessard et al. 2007).
2. Review the strengths and weaknesses of each method, and describe the appropriate application for each method.
3. Provide guidance on the information required for developing a survey design.

This Science Response results from the Science Response process of March 11, 2016 on the Review of British Columbia Northern Abalone Survey Methods. 

Complete document (PDF, 374 KB)

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