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Recovery strategy for the blue whale (Balaenoptera musculus), Northwest Atlantic population, in Canada

2. Recovery

2.1 Recovery feasibility

The recovery of the Northwest Atlantic blue whale population is feasible. This population’s extensive distribution range goes far beyond Canadian jurisdiction and therefore limits the scope of this recovery strategy. Adequate protection throughout this population’s entire distribution range requires international efforts, both new and continuing. The following criteria were considered to determine whether recovery was feasible:

  1. There are individuals able to reproduce: The number of adult blue whales seems sufficient to increase population growth rate or abundance, despite uncertainties in terms of growth rates and the overall number of blue whales in the Northwest Atlantic (Sears and Calambokidis, 2002). More than 400 blue whales have been photo-identified in the Estuary and Gulf of St. Lawrence since 1979 (R. Sears, Mingan Island Cetacean Study (MICS), personal communication). This species’ survival rate, whose longevity exceeds 80 years (Yochem and Leatherwood, 1985; Sears, 2002) is estimated at 97.5% in the Gulf of St. Lawrence (Ramp, et al., 2006). In addition, since 1994 (except for 2006), at least one mother-calf pair has been sighted every year in the Estuary and Gulf of St. Lawrence, which indicates a certain level of reproductive activity.

  2. There is sufficient suitable habitat available to support the species: The blue whale is a migratory species that occupies a vast distribution range in which limited habitat availability initially does not appear to be an issue for the population’s survival. According to available information, the blue whale uses Canadian coastal and pelagic Atlantic waters in the summer to feed. In order to fulfill its energy requirements, the blue whale must feed in areas with high krill densities (Brodie, et al., 1978; Kawamura, 1980; Croll, et al., 2005). Many such areas that could constitute feeding areas for blue whales have been identified in the Estuary and Gulf of St. Lawrence. These potential feeding areas could be protected or restore (e.g. noise reduction) to ensure their availability for blue whales.

  3. Significant threats to the population or to its habitat can be avoided or mitigated with recovery measures: Several significant threats to the species and its habitat can be avoided or mitigated by recovery actions such as the moratorium on forage species and approach distances for whale-watching activities. For blue whale habitat in Canadian waters that shows some deterioration, such as the head of the Laurentian Channel, most of the disruptive elements such as noise and disturbances, are caused by humans. There are ways to mitigate the impacts of these disruptive elements in order to improve habitat quality for the blue whale. These measures can be effective providing sufficient resources are invested in education and raising awareness as well as in control and implementation.

2.2 Recovery goal

In order to ensure the survival and recovery of the blue whale population in the Northwest Atlantic, this recovery strategy’s goal is to reach a level of 1000 mature individuals. This recovery target corresponds to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) criteria for marking down the blue whale population from a status of “endangered” to a “no at risk” status. This target based on COSEWIC criteria was chosen over the precautionary approach implemented by the Department of Fisheries and Oceans Canada (DFO) for managing various marine resources (DFO, 2006; Hammill and Stenson, 2007), which proposes a threshold target of 70 % from the maximum historic population size.

The best historic blue whale population size estimates were from hunting data analyses, which suggest a population size between 1100 and 1500 individuals before intensive hunting began (Sergeant, 1966; Allen, 1969). Sergeant (1966) estimated that between 1898 and 1915, approximately 1500 blue whales were hunted by the whaling stations located in Newfoundland and in Labrador. Allen (1969) concluded after comparing blue whale and fin whale yield indices that the initial population of blue whales was slightly more than 1100 individuals. However, experts believe these estimates of historic population size might represent only a fraction of the entire Northwest Atlantic population. By using the precautionary approach, the recovery target would have been around 1050 mature and immature individuals (70% of 1500 individuals), a slightly lower target than the one proposed (1000 mature individuals). The recovery team preferred using a target of 1000 mature individuals because applying a precautionary approach on a likely underestimate of the maximum historic size seemed less judicious. However, it is difficult to estimate the time necessary to reach this target owing to the knowledge gaps on the present population structure.

2.3 Recovery objectives

In order to reach the recovery goal, three objectives were established for the next five years:

  1. Define and undertake a long term assessment of the number of Northwest Atlantic blue whales, the structure and trends of the population, and determine their range as well as their critical habitat within Canadian waters.
  2. Implement control and follow-up measures for activities which could disrupt the recovery of the blue whale in its Canadian range by prioritizing the following actions:
    • 2.1 first, reducing anthropogenic noise (e.g., seismic exploration) and protecting food resources;
    • 2.2 second, reducing disturbance from anthropogenic activities (e.g., whale-watching), reducing the risk of accidents associated to collisions as well as other human activities (e.g., fisheries and by-catch) and by reducing toxic contamination in the marine environment, which may have an impact on blue whales.
  3. Increase knowledge concerning the principal threats to the recovery of the blue whale in Canadian waters, such as anthropogenic noise, the reduced availability of food resources, anthropogenic activities that can lead to disturbance, injuries or mortality (e.g., whale-watching activities, shipping traffic, coastal and offshore developments) and contamination, in order to determine their true impact and identify effective measures to mitigate the negative consequences for this population’s recovery.

2.4 Approaches recommended to meet recovery objectives

2.4.1 Recovery planning

To achieve these objectives, several approaches are recommended, grouped in three broad strategies: “research and monitoring”, “conservation” and “awareness and education” (Table 1). Recommended approaches to meet objectives are presented in table format along with related performance measures. Performance measures allow for an assessment of progress in reaching the listed recovery objectives for the Northwest Atlantic blue whale population. These will help determine whether the recovery approaches used have a positive impact on the blue whale population, assess whether or not the objectives are being reached, report on the progress, and finally evaluate the objectives in order to improve them.

 

Table 1. Recovery Planning Table and performance measures (Objective 1. Assess the number of Northwest Atlantic blue whales, the structure and trends of the population, and determine their Canadian range)
ObjectivesBroad strategiesThreat(s) addressedRecommended approaches to meet recovery objectivesPerformance measures
UrgentResearch and monitoringAllDevelop and implement a Northwest Atlantic blue whale population monitoring program.
  • Data acquisition on population size, structure and dynamics within Canadian waters.
  • Development of multiple temporal and spatial frequentation change indicators and implementation of a monitoring based follow-up system.
  • A monitoring program is joined to international programs in order to acquire a uniform and extended spatial and temporal coverage.
UrgentResearch and monitoringAllBetter understand the biological and physical processes that influence the life cycle of blue whales.
  • Number of publications and studies on the biological and physical processes that influence the life cycle.
  • Number of management measures stemming from these studies.
UrgentResearch and monitoringAllAnalyze existing and newly acquired data in order to identify high concentration areas or areas that are regularly visited by blue whales and periods of intensive habitat use.
  • Identification of the boundaries of the seasonal distribution range (in particular feeding, reproduction and wintering areas), periods of intensive habitat use, and critical blue whale habitat and its degree of sustainability
NecessaryResearch and monitoringAllEncourage the implementation and continuation of marine mammal observation networks.
  • Functional network of marine mammal observers and database.

 

Table 1 (cont.). Recovery Planning Table and performance measures (Objective 2. Implement control and follow-up measures for activities which could disrupt the recovery of the blue whale in its Canadian range)
ObjectivesBroad strategiesThreat(s) addressedRecommended approaches to meet recovery objectivesPerformance measures
UrgentConservationNoiseImplement adequate mitigation measures for all inshore and offshore projects within the range of the blue whale.
  • Percentage of noise reduction from anthropogenic sources (e.g. seismic exploration, military operations, explosions, drilling) within the Canadian portion of the range.
UrgentConservationNoise and collisionsMinimize blue whale exposure to vessel noise and risk of collisions in the areas known to be frequented by blue whale.
  • Protection measures have been put in place in the shipping lanes that were found to be problematic.
UrgentConservationPrey availabilityPromote the continuation of the moratorium on the exploitation of forage species to prevent further strain on their food resources.
  • The moratorium on the exploitation of forage species is maintained.
UrgentAwareness and educationNoise and collisionsRaise awareness of boaters, ship owners and other industries that generate high noise levels of their negative impact on the blue whale population.
  • Target audiences have been identified and appropriate activities to raise awareness on technologies or alternate behaviours in order to reduce the production and the propagation of noises as well as risks of ship strikes were carried out.
  • Efficiency of awareness campaigns to change behaviours and maintain new behaviours.
  • Sources of information on technologies and best practices to reduce production and propagation of underwater noise are available to industries and ship owners.
NecessaryConservationAllDesignate Marine Protection Areas (MPA) in the range of the blue whale
  • Designation of the St. Lawrence Estuary marine protected area (MPA) and of the Manicouagan MPA.
NecessaryConservationWhale-watchingReview, adopt and implement the Marine Mammals Regulations and the Marine Activities in the Saguenay–St. Lawrence Marine Park Regulations to better protect blue whales against anthropogenic disturbances within their range
  • Implementation of the new Marine Mammals Regulations to better protect blue whales, in particular by maintaining a distance requirement of 400 m with blue whales, for all boats within Canadian waters.
  • Improvement of surveillance of marine tours within known areas of occurrence during the tourism high season.
NecessaryConservationWhale-watchingImprove the decision-making process for issuing permits for research or activities requiring approaches of less than 400 m.
  • Establishment of rules and a centralized decision-making committee, one-stop service for all jurisdictions, to assess the relevance, methods and licensing for activities targeting whales or their critical habitat.
NecessaryConservationAll, whalingEnhance Canadian participation in international conservation efforts for marine mammals in general, and for blue whales in particular.
  • Number of Canadian initiatives in the international effort for marine mammal conservation.
  • Maintaining the moratorium set by the International Whaling Commission.
NecessaryAwareness and educationWhale-watchingRaise the awareness of whale-watching activity enthusiasts, recreational boaters and the general public to the issue of blue whale disturbance.
  • Target audiences have been identified and appropriate activities to raise awareness were carried out.
  • Efficiency of awareness campaigns to change behaviours and maintain new behaviours.
UsefulConservationSpills, epizootics and algal bloomsIn known areas of occurrence of blue whales, implement contingency plans in order to reduce damages which can be caused by toxic spills, epizootics and algal blooms.
  • Contingency plans in the case of toxic spills, epizootics or algal blooms have been written when necessary and are updated regularly.
UsefulConservationAccidental entanglement in fishing gear or entrapment in iceEncourage the maintenance of activities conducted by the Quebec Marine Mammal Emergency Response Network and develop a warning system when conditions are likely to trap blue whales in the ice during spring for the southwest part of Newfoundland.
  • Number of effective and successful responses to entanglement in fishing gear or entrapment in ice contributing to blue whale survival.
UsefulConservationContaminantsStart an extensive pollution reduction program aimed at the various sources of pollution.
  • Percentage reduction of contaminant concentrations in the environment and the tissues of blue whales.
  • Percentage reduction of emissions by source (waste disposal areas, landfills, sewage treatment plants, industries, etc.) and by pollutant type.

 

Table 1 (cont.). Recovery Planning Table and performance measures (Objective 3. Increase knowledge concerning the principal threats to the recovery of the blue whale in order to determine their true impact and identify effective measures to mitigate the negative consequences for this population’s recovery)
ObjectivesBroad strategiesThreat(s) addressedRecommended approaches to meet recovery objectivesPerformance measures
UrgentResearch and monitoringContaminantsEvaluate contaminant concentrations in blue whale tissues, its food and its environment.
  • Number of publications and studies on the main sources of pollution, on contamination levels and on main contaminants.
  • Number of management measures stemming from these studies.
UrgentResearch and monitoringPrey availabilityImplement a research and monitoring program to fill in the knowledge gaps in terms of zooplankton and other prey (distribution/concentration/variability) of the blue whale.
  • Number of publications and studies on the carrying capacity of habitat as well as the distribution of forage species, fluctuations in abundance and the factors responsible for these fluctuations.
  • Number of management measures stemming from these studies.
UrgentResearch and monitoringNoiseIdentify/characterize noise sources and levels in different areas of the blue whale distribution range and assess the degree of exposure to the noise, particularly in the known areas of occurrence.
  • Number of noisy areas and noise sources identified.
  • Number of publications and studies on the impacts of noise on blue whales.
  • Number of management measures stemming from these studies.
UrgentResearch and monitoringAllImplement a blue whale carcass necropsy program in eastern Canada in order to routinely identify the causes of mortality.
  • Number of publications and studies on causes of mortality and the overall health status of individuals.
  • Number of management measures stemming from these studies.
NecessaryResearch and monitoringNoiseStudy reactions of blue whales when exposed to various noise sources in various contexts.
  • Completion of an assessment report on the circumstances leading to the most significant noise impacts on blue whales.
NecessaryResearch and monitoringPrey availabilityStudy the feeding behaviour and diet of blue whales.
  • Number of publications and studies on the feeding behaviour and diet of blue whales.
  • Number of management measures stemming from these studies.
NecessaryResearch and monitoringAllStudy the impact of various anthropogenic activities on the feeding behaviour and distribution of blue whales.
  • Number of publications and studies on impacts of various threats (e.g., whale-watching, shipping traffic, coastal or offshore development) on the feeding behaviour, diet and energy requirements of blue whales.
  • Number of management measures stemming from these studies.
UsefulResearch and monitoringNoise and prey availabilityStudy the impact of loud noise on the aggregation of prey in blue whale feeding areas.
  • Completion of an assessment report on the impact of loud noise on the availability and aggregation of prey in blue whale feeding areas.

2.5 Critical habitat

Critical habitat is defined by SARA as the habitat that is necessary for the survival or recovery of a listed wildlife species. This critical habitat must be identified in the recovery strategy or in an action plan for the species (s. 2). Identifying the critical habitat is mandatory within the framework of a recovery strategy for an endangered species such as the blue whale (Sections 41 and 49). When the critical habitat has not been clearly identified, a research schedule leading to its identification must be included in the recovery strategy. After the critical habitat has been identified, measures must be applied to protect this habitat (ss. 57–63) as SARA prohibits the destruction of any part of the critical habitat of a wildlife species listed as endangered.


2.5.1 Identification of the species’ critical habitat

At the time of drafting this recovery strategy, the best available information does not allow the identification of the critical habitat for the blue whale. There are knowledge gaps regarding the Northwest Atlantic blue whale population habitat that could be considered “critical”. For marine mammals, Harwood (Harwood, 2001) suggests that the critical habitat be established in terms of functional ecological units in order to ensure feeding and reproductive success. This recovery strategy identifies the areas where knowledge acquisition will be necessary in order to complete the identification of blue whale critical habitat.


2.5.2 Schedule of studies to identify critical habitat

The information available concerning feeding and reproductive areas for the Northwest Atlantic population is currently sparse. Because available data indicates the blue whale uses Canadian coastal and pelagic Atlantic waters in the summer to feed, research to identify critical habitat within Canadian waters will focus on blue whale distribution and feeding areas (Table 2). This species’ restricted diet and its feeding method suggest that krill concentration areas, whose formation seems to depend on the interaction between hydrodynamic circulation and submarine landform, are the blue whales’ preferred feeding areas. As a result, studies will be required to identify and validate krill aggregation areas in the Gulf of St Lawrence and the Canadian continental shelf, and to determine and characterize blue whale feeding areas within Canadian waters, in order to gain the knowledge needed to identify blue whale critical habitat. These studies are currently underway, for details on the projects please see section 1.6.3.

 

Table 2. Schedule of studies to identify critical habitat
Research objectiveActivity DescriptionDue date
Improve knowledge of blue whale distribution.
  • Determine blue whale seasonal distribution in Canadian waters.
  • Determine distribution in areas where there are few or no data such as off the coast of Newfoundland and Labrador, the Scotian Shelf, the Eastern and Sourthern parts of the Gulf of St. Lawrence.
2014
Improve knowledge of feeding areas
  • Determine and characterize blue whale feeding areas within Canadian waters.
  • Identify and validate krill aggregation areas in the Estuary and Gulf of St. Lawrence and the Canadian continental shelf.
  • Study physical and biological processes that influence krill aggregation and abundance.
2014

2.6 Existing and recommended approaches to habitat protection

As mentioned in Section 1.6.2 Habitat protection measures, awareness raising and other measures, a marine park was created in 1998 in the St. Lawrence Estuary. Under the Oceans Act, marine protected areas have been created, The Gully MPA located on the Scotian Shelf, or are being developed, the St. Lawrence Estuary and Manicouagan MPA. In addition, the Fisheries Act protects marine mammal habitat by prohibiting any operation or undertaking that would cause the harmful alteration, disruption or destruction of fish habitat (a term that includes marine mammals under this Act).

A moratorium on new permits for the harvest of unexploited forage species (including krill) ordered by the Minister of Fisheries and Oceans has been in place since 1998. This moratorium allows in part for the protection of an important part of the habitat of the blue whale, its food.

2.7 Effects on other species

Thirteen cetacean species visit the Estuary and the Gulf of St. Lawrence, of which eight are toothed whale species (odontocete) and five are baleen whale species (mysticeti) (Appendix 2). In addition, at least nine other odontocete species visit the Canadian Atlantic coast and one species, the grey whale (Eschrichtius robustus) is extirpated from the Canadian Atlantic coast. Therefore, studies within the framework of this recovery strategy, such as impact studies on anthropogenic activities, and proposed mitigation measures, such as restrictive measures for whale-watchers, can also be beneficial for some of the species visiting the Estuary and the Gulf of St. Lawrence and Canadian Atlantic coast. If the blue whale population increased from 250 to 1000 individuals, krill could become less abundant, which could affect the entire food chain. However, the targeted population objective, 1000 mature individuals, is in line with the blue whale stock status before commercial whaling.

2.8 Statement on action plan

A blue whale (Northwest Atlantic population) recovery action plan will be developed within 5 years, by 2014 at the latest. Meanwhile, many of the recommended approaches proposed in this recovery strategy, notably those related to research needs, can be initiated and pursued even in the absence of a formal action plan. The action plan will include a schedule and specific details for implementing the recovery strategy and will include measures for implementing and monitoring the recovery, solve issues pertaining to threats and work towards meeting the objectives. The action plan will also include the identification of critical habitat, to the extent possible, and examples of activities that are likely to lead to their destruction or degradation. It will also include recommendations aimed at protecting critical habitat and will report on any portion of critical habitat that is not already subject to protection. However, if knowledge regarding the identification of critical habitat is acquired before the drafting of an action plan, the designation of critical habitat will be made before the five-year timeline.

Introduction