Terms of Reference

Cumulative Effects Assessment for Northern and Southern Resident Killer Whale Populations in the Northeast Pacific

Regional Peer Review Process – Pacific Region

March 12-14, 2019
Nanaimo, British Columbia

Chairperson: Gilles Olivier

Context

Under the Species at Risk Act (SARA), the federal government has a commitment to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened. The Minister of Fisheries and Oceans Canada is the competent minister for the recovery of aquatic species at risk.

Three distinct ecotypes of killer whales (Orcinus orca) inhabit the waters off the Canadian Pacific coast: offshore, transient (or Bigg’s), and resident. The resident fish-eating ecotype is further divided into the Northern and Southern Resident Killer Whale populations (NRKW and SRKW). These two populations were listed as Threatened (NRKW) and Endangered (SRKW) respectively under the SARA in 2003. A cumulative effects assessment (CEA) is required in order to address recovery measure 11 in the SARA Action Plan for these populations (DFO 2017a). This recovery measure states “Assess cumulative effects of potential anthropogenic impacts on Resident Killer Whales using an appropriate impact assessment framework for aquatic species”. Cumulative effects are the combined, incremental impacts that threats/stressors from multiple human activities can have on an individuals, populations, communities and ecosystems through space and time. The three primary threats to NRKW and SRKW have been identified as:

1. reduced prey availability,
2. acoustic and physical disturbance, and
3. environmental contaminants (DFO 2017a).

Fisheries and Oceans Canada (DFO) Species at Risk Program has requested that Science Branch provide an assessment of the cumulative effects of the three primary anthropogenic threats on NRKW and SRKW populations. To date, most research on threats to killer whales has studied these threats in isolation, for instance focusing solely on acoustic disturbance or availability of prey. Cumulative effects assessments evaluate the effects of multiple threats by transforming impacts into a single currency or metric, thereby allowing for comparisons among threats and their combined impact on long-term population viability. In collaboration with U.S. and Canadian marine mammal and science experts, this study will update and advance upon previous methods of analysing the three primary threats to Resident Killer Whales (Lacy et al. 2017). For example, the current study will evaluate the threat of acoustic disturbance posed by both commercial as well as recreational vessels and include updated salmon abundance data on the specific stocks which NRKW and SRKW prey upon. New contaminants research, such as that from Simon Fraser University and Washington State Department of Fish and Wildlife, will be considered to improve the treatment of contaminants in the model.

The species-focused cumulative effects assessment will be composed of two phases. The first phase is the development of a Pathways of Effects (PoE) conceptual model describing the impacts of threats on the mortality and fecundity of the species. The second phase involves the parameterization of the impacts (e.g. effect size for each threat and its impact on vital rates) and conducting a quantitative population viability analysis (PVA) to assess the cumulative effects. This project will build upon the methods and results of previous work (Taylor & Plater, 2001; Ward et al 2009; Velez-Espino et al 2014; Williams et al 2017; Lacy et al.2017) and include recent research advances. The effects of low probability high impact events, such as catastrophic oil spills, are out of scope for this assessment. In addition, potential mitigation measures and management actions will not be evaluated. More information on ongoing initiatives to help recover killer whales can be found on the DFO website (DFO 2019).

The cumulative effects assessment arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) further expands the cumulative effects tools available for DFO, and the advice may be used to inform the SARA program in its effort towards survival and recovery of these two populations. This study provides an opportunity to incorporate best available science into a single assessment that includes all three threats, the interactions between them, and the resulting long-term impacts on the population.

Objective

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below. The structure of the pathways of effects model and the data inputs for the quantitative population viability analysis will be reviewed, as recommended in DFO 2012 and undertaken in DFO 2014, and DFO 2017b.

Murray, C., Hannah, L., Locke A. et al.  Cumulative Effects Assessment for Northern and Southern Resident Killer Whale Populations in the Northeast Pacific. CSAP Working Paper 2017SAR01

The specific objectives of this review are to:

1. Review the individual components of the quantitative analysis for the NRKW and SRKW cumulative effects assessment, namely;
1. pathways of effects (PoE) conceptual model, and
2. quantitative population viability analysis (PVA); and
3. assess the biological relevance and the applicability of each component to adequately reflect current best knowledge regarding threats and the interaction of the three priority threats outlined in the recovery plan.
2. Review the resultant cumulative effects assessment for resident killer whales and provide guidance regarding the utility and applicability of the approach for future applications, including limitations (if any) in its use for other populations and species where there may be data deficiencies.
3. Examine and identify uncertainties in the data and methods and highlight knowledge gaps for future research. 

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (Species At Risk, Fisheries Protection Program, Oceans, Ecosystems and Oceans Science, and Ecosystems and Fisheries Management)
• Federal Government (Environment and Climate Change Canada, Transport Canada)
• First Nations
• Province of British Columbia
• Academia
• Industry representatives (Shipping industry, Fishing industry, Whale watching industry)
• Environmental non-government organizations

References

DFO. 2012. Risk-based Assessment Framework to Identify Priorities for Ecosystem-based Oceans Management in the Pacific Region. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2012/044.

DFO. 2014. Pilot application of an ecological risk assessment framework to inform ecosystem-based management in the Pacific North Coast Integrated Management Area. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2014/026.

DFO. 2017a. Action Plan for the Northern and Southern Resident Killer Whale (Orcinus orca) in Canada. Species at Risk Act Action Plan Series. Fisheries and Oceans Canada, Ottawa. v + 33 pp.

DFO. 2017b. A framework for assessing vulnerability of biological components to ship-source oil spills. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep 2017/032.

DFO 2019. Protecting Canada's Endangered Whales. Last accessed January 14, 2019.

Lacy, R.C., Williams, R., Ashe, E., Balcomb III, K.C., Brent, L.J.N., Clark, C.W., Croft, D.P., Giles, D.A., MacDuffee, M., and P.C. Paquet. 2017. Evaluating anthropogenic threats to endangered killer whales to inform effective recovery plans. Scientific Reports 7: 14119(1): 2045-2322pp.

Taylor, M.F.J. and B. Plater. 2001. Population viability analysis for the southern resident population of the killer whale (Orcinus orca). Center for Biological Diversity Electronic Resource.

Vélez‐Espino, L.A., Ford, J.K., Araujo, H.A., Ellis, G., Parken, C.K. and Sharma, R., 2015. Relative importance of Chinook salmon abundance on resident killer whale population growth and viability. Aquatic Conservation: Marine and Freshwater Ecosystems, 25(6), pp.756-780.

Ward, E.J., Holmes, E.E. and Balcomb, K.C., 2009. Quantifying the effects of prey abundance on killer whale reproduction. Journal of Applied Ecology, 46(3), pp.632-640.

Williams, R., Lacy, R.C., Ashe, E., Hall, A., Lehoux, C., Lesage, V., McQuinn, I. and Pourde, S., 2017. Predicting Responses of St. Lawrence Beluga to Environmental Change and Anthropogenic Threats to Orient Effective Management Actions. Canadian Science Advisory Secretariat.