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Review of the Effectiveness of Recovery Measures for Southern Resident Killer Whales

Recommendations about priority of Recovery Measures

Review of the Effectiveness of Recovery Measures for Southern Resident Killer Whales

Review of the Effectiveness of Recovery Measures for Southern Resident Killer Whales (PDF, 1.36 MB)

Table of Contents

8.0 Recommendations about priority of Recovery Measures

Based on data from the long term population census program and genetic studies examining paternity patterns in the population, there is no evidence that the SRKW population is recovering. Annual population assessments since 1974 have shown that the number of SRKWs has fluctuated from a low of 71 animals in 1974, to a high of 96 in 1996. As of late 2016, there are 78 animals.

The following sections present recommendations about high priority actions to be taken to address the main threats to the population. These recommendations were made within a limited time frame and a limited review process, and therefore may be further refined in the future.

Recommendations about Prey Availability

A recent review of research to detect poor body condition in the SRKW population concluded that poor body condition is prevalent in some years and that it is associated with subsequent reproductive loss through loss of fetuses as well as mortality of calves. Poor body condition was also associated with mortality of adults, including prime reproductive age females.

In two specific instances, females that died were not only foraging to feed themselves but also to provision calves or orphaned young. The loss of these individuals may increase the risk of mortality for the individuals they provisioned. Both 2013 and 2016 had relatively low catch-per-unit-effort for Chinook salmon returns to the Fraser River, and in both of these years a number of animals in poor body condition died, or if pregnant, did not subsequently produce calves. In most wild populations, food availability is the most common cause of poor body condition (Matkin et al. 2017). Recovery Measures that aim to increase prey availability should be of paramount importance (Table 3). Longer term Recovery Measures that include rebuilding of Chinook stocks should be implemented, and to do so will require integration between Chinook salmon population recovery efforts and DFO Science and Management specifically related to SRKWs. It seems likely that with more focussed attention on possible actions to rebuild Chinook stocks, additional Recovery Measures beyond those identified will become apparent.

Near-term Recovery Measures that aim to provide improved foraging conditions to enhance SRKW foraging success on the existing available Chinook salmon include those that may lead decreased direct competition for prey, or reductions in acoustic impacts on the foraging grounds from vessel traffic. Such areas could provide undisturbed access and space for SRKWs to forage. Strategic fishery planning approaches and Chinook management actions in key SRKW foraging locations could reduce competition with fishers for Chinook in these hot spots. The primary SRKW foraging areas in the Salish Sea have been identified, although less is known of their foraging hotspots in winter areas such as northern Strait of Georgia (Hauser et al. 2007; Hanson et al. 2010a). Examples of approaches to identifying potential areas for restriction of fishing activity and other human activities are available (Hauser et al. 2007; Ashe et al. 2010). More recently, ECHO has applied acoustic mapping and SRKW distribution data to identify areas of high SRKW use that could be targeted for mitigation of acoustic and physical disturbance, which are also important considerations for foraging success. Monitoring and research needed to assess the effectiveness of these actions include trends in the nutritional status of SRKWs, their foraging success, habitat use and ultimately their population size.

Presently NOAA is considering a petition to establish a Whale Protection Zones that would extend 1.2 kilometres offshore of the west side of San Juan Island. The proposed protected area would encompass approximately 26 to 31 square kilometres (about 0.5% of the currently designated US portion of Critical Habitat) and is an area in which SRKWs are estimated to be three times more likely to be engaged in foraging than elsewhere (Ashe et al. 2009; NOAA 2016). Efforts to create areas of reduced acoustic and physical disturbance as well as reduced competition should also be a priority in Canadian waters.

In light of fluctuating herring stocks and changes in ecosystem structure and dynamics, a new management measure has been recommended in support of recovering Chinook salmon by considering Chinook foraging needs. Pacific herring and sand lance constitute an important part of the diet of Chinook in most areas (Healey 1991). DFO has a forage fish policy that could be implemented to consider the ecosystem role of these fish species and their potential importance to the rebuilding of not only Chinook stocks, but ultimately the SRKW population.

Table 3. Suggested high priority recovery measures aimed at abating the threat of reduced prey availability and activities to monitor the effectiveness of these measures. The rank for implementing measures is determined based on whether the scope of the measure or the benefits to the population with regards to abating the threat is large or small, and whether its impact in terms of threat abatement is direct or indirect. Timing can be ‘immediate’ (within 1 year), ‘short-term (1-5 years), medium-term (5-10 years) or longer-term (10 + years), and represents the horizon for acquiring the scientific information necessary to implement the measure and for the effects of implementation to become evident, either in terms of a reduction of threat level or benefits to the population. A rank of 1 is given to measures that directly abate most effects from a threat; a rank of 2 is given to measures with a large scope, but with indirect impacts on the threat. Measures to fill data gaps or provide a monitoring function are not assigned scope, impact, timing for improvements, or rank, as they collectively support the implementation of the management-based measures listed.

Recovery Measures Anticipated effectiveness Anticipated timing Rank
Scope Impact Initiate implementation Improvements
Management-based
Plan and manage salmon fisheries in ways that will reduce anthropogenic competition for SRKW prey in important foraging areas during key times (e.g., create protected areas; implement fishery area boundary adjustments and/or closures) or when there are indications of population nutritional stress. Among other things, this will require the formation and formalization of a transboundary working group of science and management representatives from DFO, NOAA, and other technical experts to ensure that SRKW prey needs are incorporated consistently in the management of salmon fisheries for transboundary stocks (e.g. Canada's Policy for Conservation of Wild Salmon, Pacific Salmon Treaty). Large Direct immediate Short-term 1
During years of poor Chinook returns, implement a more conservative management approach than would be used in typical years to further reduce or eliminate anthropogenic competition for Chinook and other important prey in key SRKW foraging areas during key times. Large Direct immediate Short-term 1
Protect and preserve the freshwater habitat of important SRKW prey stocks. Large Indirect Short-term medium-term 2
Implement fisheries management measures that will foster healthy and abundant populations of herring and sand lance to support greater availability of Chinook Large Indirect Short-term Medium-term 2
Data gaps and needs for monitoring
Undertake a catch per unit effort assessment of SRKW foraging effort and success rate to provide information on the efficacy of management actions aimed at reducing prey competition and increasing prey availability in known key foraging areas, and monitor over time.     Short-term    
Assess seasonal and inter-annual changes in body condition and growth of SRKWs to further refine the relationship between nutritional status and prey abundance and/or foraging success to inform management actions aimed at increasing prey availability to SRKWs.>     Short-term    
Continue to refine knowledge of SRKW prey preferences and prey distribution throughout their range and among seasons using methods including acoustic monitoring and dedicated vessel surveys.>     Short-term    
Assess the impacts of disturbance and prey competition from fisheries on foraging success of SRKWs in foraging areas.     Short-term    
Continue to perform a population census each year on the SRKW*
*Note: this research-based activity supports adaptive management of ALL threats and provides an ultimate gauge of the collective efficacy of management actions (i.e., population size and structure), but it only appears in this recommendation table for simplicity.		     Immediate    

Recommendations about Acoustic and Physical Disturbance

Recommendations about Acoustic and Physical Disturbance

Underwater noise is a significant threat to SRKWs, discussed in section 6.2. Under existing conditions, underwater noise from shipping in SRKW habitat in the Salish Sea is already causing a reduction in foraging opportunities for SRKWs and there are expected impacts of this noise on SRKW communication space and on other life processes, (e.g., reproduction, resting, socializing). Further reductions to foraging opportunities are anticipated with future increases in shipping.

The Vancouver Fraser Port Authorities' ECHO program states as the following objective: "to evaluate vessel underwater noise reduction options, this could be used to incentivize ship owners to reduce their vessel noise outputs". This activity should be prioritized to address acoustic disturbance and lost foraging opportunities because it may lead to one of several mitigation options that could and should be employed simultaneously and as soon as possible. A new recommended measure is the coordination of underwater noise evaluation and reduction options between Canadian and US ports and industries to support the regional success of actions to reduce acoustic disturbance to SRKWs in the Salish Sea.

Recovery Measures that aim to identify and then set aside areas that are refuges from noise for SRKWs should be made a priority. Such mitigation options might include slow down zones for vessels, no-go zones for vessels, rerouting shipping traffic, and/or scheduling shipping traffic movements to allow for periods of quiet in important foraging habitat for killer whales. Monitoring and research needed to assess the effectiveness of these actions include determination of trends in nutritional status, foraging success, habitat use and ultimately population size.

To more effectively manage the impacts of anthropogenic disturbance to SRKWs in the Salish Sea, in particular, a rigorous assessment of cumulative effects of existing and planned developments and activities should be undertaken (e.g. Lawson and Lesage 2012). This is already identified as a Recovery Measure in the Action Plan. To support this, Recovery Measures related to monitoring ambient noise in the Salish Sea should continue to be priority activities.

Table 4. Suggested priority recovery measures aimed at abating the threat of acoustic and physical disturbance and activities to monitor the effectiveness of these measures. The rank for implementing measures is determined based on whether the scope of the measure or the benefits to the population with regards to abating the threat is large or small, and whether its impact in terms of threat abatement is direct or indirect. Timing can be ‘immediate’ (within 1 year), ‘short-term (1-5 years), medium-term (5-10 years) or longer-term (10 + years), and represents the horizon for acquiring the scientific information necessary to implement the measure and for the effects of implementation to become evident, either in terms of a reduction of threat level or benefits to the population. A rank of 1 is given to measures that directly abate most effects from a threat; a rank of 2 is given to measures with a large scope, but with indirect impacts on the threat. Measures to fill data gaps or provide a monitoring function are not assigned scope, impact, timing for improvements, or rank, as they collectively support the implementation of the management-based measures listed. Management-based measures denoted by an asterisk also address the threat of ship strikes (discussed in a later section).

Recovery Measures Anticipated effectiveness Anticipated timing Rank
Scope Impact Initiate implementation Improvements
Management-based
*Implement area-specific vessel regulations and/or guidelines (e.g., speed restriction zones, rerouting vessel traffic, altering vessel traffic scheduling to create convoys) that reduce the overall acoustic impact on SRKWs in their habitat, particularly in the Salish Sea. Large Direct Immediate Short-term 1
Implement incentive programs and regulations that result in reduced acoustic footprints of the vessels habitually travelling in and near important SRKW habitat (e.g., through changes in vessel maintenance, application of quieting technologies) and the elimination of the noisiest vessels. Large Direct Immediate Immediate 1
*Identify candidate acoustic refuge areas within foraging and other key areas of SRKW habitat, and undertake actions for their creation Large Direct Immediate Short-term 1
*Increase the distance between SRKWs and pleasure crafts and whale-watching vessels Large Direct Immediate Immediate 1
Establish a transboundary committee to ensure consistency among U.S. and Canadian management actions aimed at reducing shipping noise in the Salish Sea. Large Indirect Immediate Medium-term 2
*Maintain and improve the existing 24 hour hotline (BCMMRN/ORR) for the reporting of acoustic or physical disturbance incidents to ensure timely response and enforcement of whale watching guidelines. Small Indirect Immediate Short-term 2
Data gaps and needs for monitoring
Assess cumulative effects of physical and acoustic disturbance from projects already on-going and those proposed on SRKWs. Do so using an appropriate impact assessment framework for aquatic species.     Short-term    
Develop a noise monitoring system to assess the noise production from individual ships to support the assessment of effectiveness of incentive programs for ship owners and enable enforcement.     Short-term    
Model existing acoustic data to estimate efficacy of potential noise reduction measures such as alteration of shipping lanes, varying ship speed, and coordinating vessel transits by convoy. Validate acoustic modelling efforts by deploying autonomous recorders and comparing measurements with model outputs.     Short-term    
Continue to monitor ambient ocean noise in the Salish Sea and expand the transboundary coverage of calibrated hydrophones to quantify ocean noise throughout the SRKW range     Short-term    
Quantify the impacts of vessel-related physical disturbance and anthropogenic noise and echolocation masking on SRKW foraging success, and compare to areas where mitigation measures have been implemented to assess the effectiveness of those measures and support their adaptation as needed.     Short-term    

Recommendations regarding environmental contaminants

Chemical Pollutants

Because the SRKWs frequent the industrialized waters of southern British Columbia and northern Washington State, mitigation efforts such as the removal or capping of contaminated sediments in that region, accelerating the rate of compliance with wastewater effluent regulations, and the continued regulation and restrictions on POPs in this region should be priorities. Of the three main threats to SRKWs, the positive effects of reducing the quantity and variety of chemical contaminants entering SRKWs and their habitat, will likely take longest to detect because of the bio-accumulating nature of POPs and the long life span of these animals. Therefore a high priority should be set on implementing and prioritizing management actions in the near term.

While the Canadian Wastewater System Effluent Regulation (2012) is a positive step, as it requires wastewater systems discharging untreated and under-treated wastewater to upgrade to at least a secondary level of wastewater treatment, it is not clear at the time of this review when all facilities that border the Salish Sea in Canada will be required to be compliant. Under the WSER, wastewater systems, such as those in Victoria and Vancouver have upgrade timelines of the end of 2020 and 2030, respectively. Early compliance with the regulations would be beneficial. The transboundary contaminant working group could be used to connect this effort in Canada with regulatory authorities in the US and support the development of consistent mitigation protocols to reduce entry of contaminants into the environment.

Temporal trends (1993–2006) for PBDEs observed in SRKWs showed a doubling time of ˜5 years. PBDEs are not currently examined in ocean disposal assessments but they should be because if even the current sediment quality guidelines available in Canada for PCBs are applied to PBDEs, it can be expected that PBDE concentrations in killer whales will exceed available toxicity reference values by a large margin (Alava et al. 2016).

Efforts to better understand the fate transport, and bioaccumulation of PBDE in the ecosystem and establishment of a PBDE toxicological threshold level in marine mammals and threshold levels for mixtures containing PBDEs and other persistent pollutants, would enable targeted remediation and regulations. There have been some efforts towards this in Puget Sound (see section 6.3); however there does not appear to be a similar process or coordination of effort in Canada. Such efforts will be necessary to assess the effectiveness of actions aimed at reducing contaminants in SRKWs, their prey and their habitat. In that regard it is advisable that an Interdepartmental Regional Advisory Committee and even a transboundary committee be established to set priorities and targets for reduction of chemical contaminants.

Canada does not have an oil spill response plan for marine mammals and their habitat, including SRKWs. Development of such a plan should be a priority.

Biological Pollutants

Health monitoring supported by an effective marine mammal stranding response and reporting network will continue to be important to enable monitoring of health through necropsy and disease testing. While this will not reduce the threat it will continue to inform our understanding of the threat and it could provide a measure of effectiveness of regulations or other management measures that ultimately aim to reduce releases of biological pollutants into the marine environment.

Table 5. Suggested priority recovery measures aimed at abating the threat of chemical and biological pollutants and activities to monitor the effectiveness of these measures. The rank for implementing measures is determined based on whether the scope of the measure or the benefits to the population with regards to abating the threat is large or small, and whether its impact in terms of threat abatement is direct or indirect. Timing can be ‘immediate’ (within 1 year), ‘short-term (1-5 years), medium-term (5-10 years) or longer-term (10 + years), and represents the horizon for acquiring the scientific information necessary to implement the measure and for the effects of implementation to become evident, either in terms of a reduction of threat level or benefits to the population. A rank of 1 is given to measures that directly abate most effects from a threat; a rank of 2 is given to measures with a large scope, but with indirect impacts on the threat. Measures to fill data gaps or provide a monitoring function are not assigned scope, impact, timing for improvements, or rank, as they collectively support the implementation of the management-based measures listed.

Recovery Measures Anticipated effectiveness Anticipated timing Rank
Scope Impact Initiate implementation Improvements
Management-based
Adequately enforce existing, and/or newly added or expanded, Canadian regulations aimed at reducing toxic chemical compound discharges at the source. Large Direct immediate Longer-term 1
Accelerate the rate of compliance with the Canadian Wastewater System Effluent Regulation (2012) in wastewater treatment facilities that border the Salish Sea Large Direct Short-term Medium-term 1
Use best currently available knowledge of SRKW distribution, foraging behavior, and their food web to ensure that assessment and remediation plans for contaminated sites will reduce the risk of lifetime contaminant exposure in SRKWs. Small Indirect immediate Longer-term 2
Review policies and best management practices for ocean dredging and disposal at sea and modify them to include an examination of PBDEs, as well as any other necessary modifications, to minimize SRKW contaminant exposure. Large Direct immediate Longer-term 1
Identify programs that mitigate small scale and/or chronic contaminant spills and leaks and provide support to them (e.g., financially, in-kind). If none exist, design and implement an ongoing program that focuses on mitigating small scale and/or chronic spills and leaks in SRKW habitat. Small - Large Direct Short-term Short-term 1
Develop a spill response plan including training, equipment, and deterrence methods and ensure that the protection of SRKWs and their habitat is made a high priority in spill response and monitoring protocols in Canada. Large Indirect Short-term Short-term 2
Form an interagency contaminants working group to identify roles and responsibilities for actions to reduce the impacts of contaminants on SRKWs and their environment. The group should also set targets for reduction of chemical contaminants (e.g., PBDEs) and the priorities and timelines for reaching those targets. Large Indirect Short-term Longer-term 2
Data gaps and needs for monitoring
Quantify current contaminant concentrations in SRKW prey and refine the analysis of contaminant intake by SRKWs using current information on their feeding ecology.     Short-term    
Conduct a risk assessment of different chemical contaminants of concern in SRKWs, their prey, and their habitat.     immediate    
Identify and monitor contaminants of concern (e.g. flame retardants, pharmaceuticals and personal care products, PBTs, hydrocarbons) in SRKWs, their prey, and their habitat.     Short-term    
Conduct a pathway-based risk assessment to assess the risk of biological pollutants from various pathways of introduction, such as agricultural runoff, sewage effluent, and wildlife rehabilitation facilities.     Short-term    
Determine the efficacy of the new regulations for PBDEs under the Canadian Environmental Protection Act (CEPA) by monitoring PBDE trends in indicator species in SRKW habitat.     Short-term    
Establish a PBDE toxicological threshold level in marine mammals to support regulations and the prioritization of targeted remediation efforts.     Longer-term    
Establish a monitoring program for pathogens and biological pollutants to evaluate long-term trends in SRKWs and their prey. This would include maintaining an effective marine mammal stranding response and necropsy network*.
*Note: this research-based activity supports the monitoring of ALL threats over time which can guide threat mitigation efforts and enable assessment of the collective efficacy of management actions over time, but it only appears in this recommendation table for simplicity.		     Short-term    

Recommendations regarding Ship Strikes

Two measures are recommended that aim to reduce and detect the threat of ship strikes. First, candidate ship slow down zones should be developed and tested, which would primarily be aimed at reducing underwater noise in SRKW habitat, but which could secondarily serve to reduce ship strike risk (see Table 4). Other measures could include slow down zones on known routes of scheduled large vessel movement (e.g. ferry routes), or development of a mariner alert system based on visual and/or acoustic identification of whales in an area. The efficacy of such measures to avoid collisions with killer whales is not certain at this time, but they should be piloted and monitored to determine their efficacy. Concurrently, performing necropsies consistently and the maintenance of an effective stranding and reporting network are vital to be able to document ship strike incidents resulting from this threat (see recommendation in Table 5) – this is in fact the mechanism through which the recent incident that resulted in the death of J34 came to light. Often carcasses are not found and therefore causes of mortality of missing animals cannot be determined. Continued support and improvement to a stranding and reporting network and necropsies should be a priority as it helps detect and track the impact of the ship strike threat, as well as other threats such as biological pollutants.

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