Terms of Reference

Recovery Potential Assessment – Fraser River Chinook Salmon (Oncorhynchus tshawytscha) – Eleven Designatable Units

Regional Peer Review – Pacific Region

December 10-12, 2019
Paper #1 – Elements 1-11
Kamloops, British Columbia

Chairperson: Mike Bradford

February 25-27, 2020
Paper #2 – Elements 12-22
Nanaimo, British Columbia

Chairperson: To be determined

Context

After the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses an aquatic species as Threatened, Endangered or Extirpated, Fisheries and Oceans Canada (DFO) undertakes a number of actions required to support implementation of the Species at Risk Act (SARA). Many of these actions require scientific information on the current status of the wildlife species, threats to its survival and recovery, and the feasibility of recovery. Formulation of this scientific advice has typically been developed through a Recovery Potential Assessment (RPA) that is conducted shortly after the COSEWIC assessment. This timing allows for consideration of peer-reviewed scientific analyses into SARA processes including recovery planning.

The following eleven populations of Fraser River Chinook Salmon (Oncorhynchus tshawytscha) were designated as Endangered or Threatened by COSEWIC in 2018 based on population declines (COSEWIC 2018).

1. DU 2, Lower Fraser Ocean Fall population (Threatened): While the calculation of decline rates is complicated by hatchery releases from 1981 to 2004, this fall run of Chinook spawning in the Lower Fraser has declined steadily in abundance. The abundance data over all years was thought to best represent natural spawner abundance. Declines in marine and freshwater habitat quality, harvest and ecosystem modification in the lower Fraser estuary, are threats facing this population.
2. DU 4, Lower Fraser Stream Summer (Upper Pitt) population (Endangered): This summer run Chinook stock spawning in the Pitt River in the Lower Fraser watershed has declined and is now at its lowest recorded abundance. Declines in freshwater and marine habitat quality and harvest are continuing threats to this population.
3. DU 5, Lower Fraser Stream Summer population (Endangered): This summer run Chinook spawning in the Lillooet and Harrison rivers in the Lower Fraser watershed has declined to very low levels. Declines in freshwater and marine habitat quality and harvest are threats facing this population.
4. DU 7, Middle Fraser Stream Spring population (Endangered): This population of spring run Chinook spawning in the Nahatlatch and Anderson watersheds has declined to very low levels. Declines in freshwater and marine habitat quality and harvest are continuing threats to this population.
5. DU 8, Middle Fraser Stream Fall population (Endangered): This population of fall run Chinook spawning in the Seton and Anderson watersheds along the middle Fraser River has declined to very low levels, and the decline is anticipated to continue. Declines in freshwater and marine habitat quality and harvest are continuing threats to this population.
6. DU 9, Middle Fraser Stream Spring population (MFR+GStr) (Endangered): This spring run of Chinook spawning in multiple middle Fraser River tributaries has declined in abundance. Declines in marine and freshwater habitat quality, harvest and pollution from mining activities are threats to this population.
7. DU 10, Middle Fraser Stream Summer population (Threatened): This summer run of Chinook spawning in multiple middle Fraser River tributaries has declined in abundance. Declines in marine and freshwater habitat quality are threats to this population.
8. DU 11, Upper Fraser Stream Spring population (Endangered): This spring run of Chinook spawning in the Salmon and Rausch rivers of the upper Fraser watershed has declined in abundance. Declines in marine and freshwater habitat quality and harvest are threats facing this population. Anticipated changes to North Pacific weather systems that affect groundwater availability, will impact spawning sites and overwinter survival
9. DU 14, South Thompson Stream Summer 1.2 population (Endangered): This summer run of Chinook spawning in the South Thompson River has steeply declined in abundance to a very low level. Declines in marine and freshwater habitat quality and harvest are threats to this population.
10.  DU 16, North Thompson Stream Spring population (Endangered): This spring run of Chinook spawning in the North Thompson River has steeply declined in abundance to a low level. Declines in marine and freshwater habitat quality and harvest are threats to this population. Anticipated changes to North Pacific weather systems that affect groundwater availability, will impact spawning sites and overwinter survival.
11. DU 17, North Thompson Stream Summer population (Endangered): This summer run of Chinook spawning in the North Thompson River has steeply declined in abundance. Declines in marine and freshwater habitat quality and harvest are threats facing this population.

DFO Science has been asked to undertake a Recovery Potential Assessment (RPA), for these 11 populations based upon the national RPA Guidance. The advice in the RPA may be used to inform both scientific and socio-economic aspects of the listing decision, development of a recovery strategy and action plan, and to support decision making with regards to the issuance of permits or agreements, and the formulation of exemptions and related conditions, as per sections 73, 74, 75, 77, 78 and 83(4) of the Species at Risk Act (SARA 2002). The advice in the RPA may also be used to prepare for the reporting requirements of SARA section 55. The advice generated via this process will update and/or consolidate any existing advice regarding these populations of Fraser River Chinook Salmon.

Typically, when an RPA is undertaken, all 22 different elements are complied into one working paper for review to inform not only a listing decision under SARA, but subsequent recovery planning. For Fraser River Chinook Salmon there will be two separate working papers, presented and reviewed at different times. The two working papers are as follows:

• Working paper #1: Fraser River Chinook Salmon – Elements 1-11.
• Working paper #2: Fraser River Chinook Salmon– Elements 12-22.

Objective

To provide up-to-date information, and associated uncertainties, to address the following elements:

Biology, Abundance, Distribution and Life History Parameters

Element 1: Summarize the biology of Fraser River Chinook Salmon (11 populations).

Element 2: Evaluate the recent species trajectory for abundance, distribution and number of populations.

Element 3: Estimate the current or recent life-history parameters for the 11 populations of Fraser River Chinook Salmon.

Habitat and Residence Requirements

Element 4: Describe the habitat properties that Fraser River Chinook Salmon populations need for successful completion of all life-history stages. Describe the function(s), feature(s), and attribute(s) of the habitat, and quantify by how much the biological function(s) that specific habitat feature(s) provides varies with the state or amount of habitat, including carrying capacity limits, if any.

Element 5: Provide information on the spatial extent of the areas for Fraser River Chinook Salmon distribution (11 populations) that are likely to have these habitat properties.

Element 6: Quantify the presence and extent of spatial configuration constraints, if any, such as connectivity, barriers to access, etc.

Element 7: Evaluate to what extent the concept of residence applies to the species, and if so, describe the species’ residence.

Threats and Limiting Factors to the Survival and Recovery of Fraser River  Chinook Salmon (11 populations)

Element 8: Assess and prioritize the threats to the survival and recovery of the 11 populations of Fraser River Chinook Salmon.

Element 9: Identify the activities most likely to threaten (i.e., damage or destroy) the habitat properties identified in elements 4-5 and provide information on the extent and consequences of these activities.

Element 10: Assess any natural factors that will limit the survival and recovery of the 11 populations of Fraser River Chinook Salmon.

Element 11: Discuss the potential ecological impacts of the threats identified in element 8 to the target species and other co-occurring species. List the possible benefits and disadvantages to the target species and other co-occurring species that may occur if the threats are abated. Identify existing monitoring efforts for the target species and other co-occurring species associated with each of the threats, and identify any knowledge gaps.

Recovery Targets

Element 12: Propose candidate abundance and distribution target(s) for recovery.

Element 13: Project expected population trajectories over a scientifically reasonable time frame (minimum of 10 years), and trajectories over time to the potential recovery target(s), given current Fraser River Chinook Salmon population dynamics parameters.

Element 14: Provide advice on the degree to which supply of suitable habitat meets the demands of the species both at present and when the species reaches the potential recovery target(s) identified in element 12.

Element 15: Assess the probability that the potential recovery target(s) can be achieved under current rates of population dynamics parameters, and how that probability would vary with different mortality (especially lower) and productivity (especially higher) parameters.

Scenarios for Mitigation of Threats and Alternatives to Activities

Element 16: Develop an inventory of feasible mitigation measures and reasonable alternatives to the activities that are threats to the species and its habitat (as identified in elements 8 and 10).

Element 17: Develop an inventory of activities that could increase the productivity or survivorship parameters (as identified in elements 3 and 15).

Element 18: If current habitat supply may be insufficient to achieve recovery targets (see element 14), provide advice on the feasibility of restoring the habitat to higher values. Advice must be provided in the context of all available options for achieving abundance and distribution targets.

Element 19: Estimate the reduction in mortality rate expected by each of the mitigation measures or alternatives in element 16 and the increase in productivity or survivorship associated with each measure in element 17.

Element 20: Project expected population trajectory (and uncertainties) over a scientifically reasonable time frame and to the time of reaching recovery targets, given mortality rates and productivities associated with the specific measures identified for exploration in element 19. Include those that provide as high a probability of survivorship and recovery as possible for biologically realistic parameter values.

Element 21: Recommend parameter values for population productivity and starting mortality rates and, where necessary, specialized features of population models that would be required to allow exploration of additional scenarios as part of the assessment of economic, social, and cultural impacts in support of the listing process.

Allowable Harm Assessment

Element 22: Evaluate maximum human-induced mortality and habitat destruction that the species can sustain without jeopardizing its survival or recovery.

Expected Publications

• Science Advisory Reports
• Proceedings
• Research Documents

Expected Participation

• Fisheries and Oceans Canada (Ecosystems and Oceans Science, and Ecosystems and Fisheries Management sectors)
• Province of BC
• Academia
• First Nations
• Industry
• Environmental non-governmental organizations

References

COSEWIC 2019. COSEWIC assessment and status report on the Chinook Salmon Oncorhynchus tshawytscha, Designatable Units in Southern British Columbia (Part One – Designatable Units with no or low levels of artificial releases in the last 12 years), in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xxxi + 283 pp.