Terms of Reference

Defining Distinct Nearshore Marine Biotopes Coastwide in British Columbia, Canada

Regional Peer Review - Pacific Region

March 3-4, 2025

Nanaimo, BC

Chairperson: Cher LaCoste

Context

In recent years, there have been a number of marine-use planning initiatives in British Columbia (BC) that have ranged from emergency response planning due to increased transportation of petroleum products to the development of a marine protected area network. Relatively little is known regarding shallow (0-20 m depth) benthic habitat types and associated marine benthic invertebrate and algae communities along the BC coast, most of the work having concentrated on species of commercial interest. The nearshore habitat types and community composition represent a data gap that needs to be addressed in order to provide scientific support to marine-use planning initiatives.

To make informed decisions regarding the management and conservation of marine species, scientists and managers frequently require detailed information on the distribution and habitat requirements of those organisms. Unfortunately, our knowledge of the distribution of many marine species is quite limited, inhibiting our ability to effectively manage and protect vulnerable species and ecosystems. Factors that contribute to our lack of knowledge include limited opportunities for observation, poor detectability in the marine environment, and the expense and difficulty of conducting studies on species that inhabit areas far from easily accessible coastlines. Consequently, management decisions must often be made before detailed surveys can be conducted, or for areas where it is difficult or infeasible to conduct research.

In the Pacific Region, many current stock assessment survey methods do not generate the data required for ecosystem-based stock status assessment. The historical single species approaches used for commercial fisheries were designed to determine abundance and distribution of species, not to assess stock status or their habitats (with a few exceptions). Habitats are spatially recognizable areas where the physical, chemical, and biological environment is distinctly different from surrounding environments (Kostylev et al, 2001). Using the word ‘Habitat’ however is problematic as it usually refers to the area occupied by a given species. Therefore, we will be using ‘biotopes’ which are combinations of physical (wave\swell exposure, currents, terrain) and chemical water property data (temperature, salinity) and associated biological communities (DFO 2013). This definition is a better fit for the outputs of the analysis that will be presented. Defining nearshore biotopes needs to be data driven and therefore reproducible. In the marine environment very few distribution models go beyond single species presence/absence, and biotopes have not been defined due to challenges with data collection and survey design. To fill this gap, Fisheries and Oceans Canada (DFO) initiated a Benthic Habitat Mapping (BHM) survey in 2013. The purpose of the BHM dive survey is to collect data to document substrate types and associated algae and marine invertebrate species to map benthos along the nearshore region of the BC coast.

DFO Biodiversity Program, Ecosystem Management Branch, has requested that Science Branch provide tools to identify where species and species groups vulnerable to oil are present. The vulnerability of individual species and species groups has already been determined (DFO 2024); however, the distribution of most of these species and species groups are unknown and represent a significant gap in order to respond effectively to an emergency incident. The analysis of the BHM data will be used to fill this gap; i.e. define and map the biotopes throughout the Pacific Region. This biotope level approach will streamline the current emergency response process and improve the efficiency of responses to oil spill incidents. This outputs will also be useful for other applications such as Marine Spatial Planning and Marine Protected Areas identification. It will also help to optimize the Benthic Habitat Mapping surveys that have been ongoing since 2013.

Objectives

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below.

• Lessard, J., Park, A., Thompson, P., et al. 2025. Defining Distinct Nearshore Marine Biotopes Coastwide in British Columbia, Canada. CSAS Working Paper.

The overarching goal and specific objectives of this research document are to define distinct nearshore marine biotopes (combination of species communities and environmental factors) in British Columbia located between the high water line and the 20 m depth contour. Specifically:

1. Define the number of biotopes
2. Define the spatial distribution of each biotope
3. Define the species that characterize these biotopes
4. Define the environmental characteristics of each biotope
5. Quantify certainty about the distribution of each biotope
6. Recommend how to interpret, including limitations, and use this information

Expected Publications

• Science Advisory Report
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, and Ecosystems
  and Fisheries Management sectors)
• Provincial/Territorial jurisdictions (e.g. Province of BC, Environment and Climate Change
  Canada, Parks Canada)
• Academia (e.g. Simon Fraser University)
• Indigenous communities/organizations (e.g. Council of Haida Nation)

References

• DFO. 2024. Application of a Framework to Assess Vulnerability of Biological Components to Three Oil Categories (Diesel and Gasoline, Bunker C, and Diluted Bitumen) in the Marine Environment in the Pacific Region. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2024/024.
• DFO. 2013. Key elements in the development of a hierarchical marine ecological classification system to support ecosystem approaches to management in Pacific Canada. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2013/065.
• Kostylev, V.E., Todd, B.J., Fader, G.B.J., Courtney, R.C., Cameron, G.D.M., Pickrill, R.A. 2001. Benthic habitat mapping on the Scotian Shelf based on multibeam bathymetry, surficial geology and sea floor photographs. Mar. Ecol. Progr. Ser. 219: 121-137.