Rougheye and blackspotted rockfish complex and longspine thorny management plan 2012: chapter 2

2. Management

The main threat to the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead is population decline as a result of direct and indirect biological resource use. Although there is a lack of knowledge on the relative abundance and distribution of Rougheye and Blackspotted Rockfish, management actions that may reduce the risk of population-level threats should be considered. It is important that the management goal and objectives are set at the species level so as to mitigate the risk of losing unrecognized biological diversity of the Rougheye/Blackspotted Rockfish complex species pair.

2.1 Management Goal

The management goal for the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead is to maintain sustainable populations within each species’ known range in Canadian Pacific waters.

The purpose of the Species at Risk Act (SARA) is to manage species of Special Concern so as to prevent them from becoming listed as Threatened or Endangered. Thus, the management goal focuses on maintaining abundance levels within the species’ known range. Stock status is currently based on relative abundance indices from Fisheries and Oceans Canada (DFO) Science surveys or commercial Catch per Unit Effort (CPUE) to monitor trends in populations (see Section 2.3.3).

As commercial fishing has been identified as the primary threat to these rockfish species, it is important to manage this threat to achieve the management goal. In 2009, the Department began implementation of the Sustainable Fisheries Framework (SFF). The SFF is a toolbox of existing and new policies for DFO and other interests to sustainably manage Canadian fisheries to conserve fish stocks and support prosperous fisheries. One of these policies is the Precautionary Approach, which applies to key harvested stocks managed by DFO.

Applying the precautionary approach to fisheries management decisions entails establishing a harvest strategy that:

  • Identifies three stock status zones – healthy, cautious, and critical – according to upper stock reference points (USR), limit reference points (LRP) and target reference points (TRP);
  • Sets the removal rate at which fish may be harvested within each stock status zone; and
  • Adjusts the removal rate according to fish stock status variations (i.e., spawning stock biomass or another index/metric relevant to population productivity), based on pre-agreed decision rules.

(DFO 2009b)

It will be necessary to address these requirements in future stock assessments (see Section 2.3.3) for the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead, as well as the identified knowledge gap (see Section 1.9) to achieve this management goal (see Section 2.3.3).

2.2 Management Objectives

The following statements are objectives (not listed in order of priority) to support the management goal of these rockfish species:

  1. Maintain the Rougheye Rockfish, Blackspotted Rockfish, and Longspine Thornyhead population ranges in Canadian Pacific waters.
  2. Continue management under the Commercial Groundfish Integrated Program (CGIP), employing management tools when necessary, as indicated by monitoring and assessment of the stocks.
  3. Account for total catch (retained and released) of Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead, and examine species removal trends in commercial fisheries, DFO Science surveys, recreational, and First Nations fisheries.
  4. Enhance existing DFO Science research, where resources and funding are available, to gather more information on stock status, including relative abundance and distribution of each species.
  5. Produce peer-reviewed stock assessments and harvest advice for the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead.
  6. Support and contribute to research that addresses knowledge gaps, as well as the effects of other identified (Table 1) and non-identified threats, on an ongoing basis.

The current management regime (outlined in Section 1.8) regulates the commercial Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead fisheries through the use of individual transferable quotas (ITQ), trip limits and a comprehensive catch monitoring program. Management tools that are available to DFO fishery managers include the use of area and time closures and adjusting species’ Total Allowable Catch (TAC) limits. In addition, fishery management objectives are reviewed every season and included in annual integrated fisheries management plans (IFMP), which are used to guide the management of the fishery (see Sections 2.3.3 and section4).

For example, if a significant decline in the population of Longspine Thornyhead were identified through monitoring and assessment, DFO may reduce the TAC limit for the species and/or implement time/area closures. These harvest guidelines would also be incorporated into annual IFMPs. This approach allows fishery managers to respond to changes in a timely manner, based on the results of monitoring and assessment activities.

Management objectives addressing threats of greatest concern aim to prevent undesirable population decreases and prevent significant alterations in distribution of the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead populations in BC.

2.3 Actions

The following actions (not listed in order of priority) are in support of the management goal and objectives (outlined in Sections 2.1 and section2.2). Many of the actions listed below are currently underway (see Section 1.8).

Although management objective 3 includes First Nations fisheries, non-groundfish commercial fisheries and recreational fisheries, determining catch estimates for Rougheye and Blackspotted Rockfish (rather than for the complex) is more of a priority in the commercial groundfish fishery, as it is the known source of highest mortality for these species.  As there are currently no verifiable catch estimates of the Rougheye/Blackspotted Rockfish complex in the First Nations, non-groundfish commercial and recreational fisheries; management actions for those fisheries focus on gathering catch estimates for the complex.

The synchronization of these listed activities for management, research, and monitoring and assessment will facilitate a multi-species approach to conservation of the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead populations in Canadian Pacific waters and allow for the effective use of available resources. Actions have been recommended where implementation is deemed practical and feasible, and most likely to result in successful conservation of these rockfish populations in BC.

2.3.1 Management

Management actions (A) to address key threats are listed below. Although pollution through toxic spills and waste discharges from ocean-going vessels are listed as a threat to the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead populations, the management of bio-chemical contamination falls under the jurisdiction of Environment Canada and Transport Canada.

A1.    Continue the current management regime of the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead, including 100% catch monitoring and other management tools (where necessary and applicable) in the commercial groundfish fishery, while working to develop methods to obtain catch estimates for Rougheye and Blackspotted Rockfish.

A2.    Work with other commercial fishing sectors to develop methodologies to account for bycatch of the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead in commercial non-groundfish fisheries.

A3.    Incorporate all catch on research surveys into future DFO Science Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead stock assessments.

A4.    Continue existing work with DFO recreational fisheries management and stakeholders to improve catch monitoring and reporting methods, including species identification in BC recreational fisheries.

  1. Include the Rougheye/Blackspotted Rockfish complex in the recreational creel survey.
  2. Include species identification tools for the Rougheye/Blackspotted Rockfish complex in DFO’s Tidal Waters Fishing Guide for recreational harvesters.

A5.    Improve catch monitoring and reporting methods in First Nations Food, Social and Ceremonial (FSC) fisheries.

  1. Continue existing work with Aboriginal Fisheries Strategy (AFS) managers to improve catch monitoring and reporting methods.
  2. Develop species identification tools to help First Nations identify the Rougheye/Blackspotted Rockfish complex among other rockfish catches.

2.3.2 Research

The following areas are those that have been identified as a priority for research actions to address key knowledge gaps in species biology and other identified and non-identified threats to the species. In addition, research efforts to address data deficiencies will assist management actions for these rockfish species. Other potential areas for research have been listed in previous sections of this management plan (See Section 1.9). Fisheries and Oceans Canada will lead the following research where feasible.

A6.    Improve existing DFO Science research surveys for Longspine Thornyhead, where funding and resources are available, by increasing the number of tows in deep strata (e.g., 500-1200 m).

A7.    Take genetic samples of the Rougheye/Blackspotted Rockfish complex on all DFO Science surveys that currently encounter these species. Samples should come from all area-depth strata in which the complex is caught.

A8.    Develop a set of protocols to acquire biological (including genetic) samples from commercial catch of the Rougheye/Blackspotted Rockfish complex.

A9.    Investigate further the potential impacts of climate change to the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead populations and their habitat in Canadian Pacific waters (e.g., habitat compression due to expansion of hypoxic zones).

2.3.3 Monitoring and assessment

A10.  Conduct an analysis to identify gaps in data that are necessary to conduct comprehensive stock assessments of the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead; implement programs to rectify the data shortfalls.

A11.  Ensure that Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead stocks are prioritized for DFO Science assessments through the implementation of the groundfish science assessment strategic plan.

A12.  Review the Rougheye/Blackspotted Rockfish complex and Longspine Thornyhead abundance trends to monitor the status of the stocks on an annual basis and report in the Groundfish Integrated Fisheries Management Plan (IFMP).

2.3.4 Monitoring and assessment methods

The following highlights the methods that will be used to monitor the conservation of the species and the implementation of the management plan. The research, monitoring, and assessment actions identified in the previous sections (2.3.2 and 2.3.3) will assist in the monitoring of Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead population trends and abundance in Canadian Pacific waters.

Commercial Groundfish Integrated Fisheries Management Plan (IFMP)

The commercial groundfish IFMP, which is reviewed and issued annually or bi-annually, provides a management tool to communicate harvest guidelines to commercial groundfish harvesters. It identifies the main objectives and requirements for the Canadian Pacific groundfish fishery as well as the management measures used to achieve these objectives.

The management objectives for the Rougheye Rockfish, Blackspotted Rockfish and Longspine Thornyhead outlined above (see Section 2.2) will be incorporated into future annual commercial groundfish IFMPs to guide the management of these species. Through this process, fishery managers will be able to annually or bi-annually review and assess the implementation of the management objectives identified in this Management Plan.

Monitoring of Rougheye Rockfish and Blackspotted Rockfish Populations

Since the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) Stock Status Report for the Rougheye/Blackspotted Rockfish complex was published in 2007, DFO Science has added new index points to the various DFO Science research survey series.

DFO Science will continue to gather Rougheye Rockfish and Blackspotted Rockfish data from the various DFO Science surveys to monitor and assess population trends and abundance. In addition, when sufficient genetic samples of the rockfish complex are gathered, DFO Science should be able to determine proportions of Rougheye Rockfish and Blackspotted Rockfish in Canadian Pacific waters. These ratios might also be useful in disaggregating historic catches where only Rougheye Rockfish were reported.

Monitoring of Longspine Thornyhead Populations

Due to the deep, offshore distribution of Longspine Thornyhead, it is not economically feasible to conduct directed research surveys for this species alone. Where funding is available, survey tows in deep strata (500-1200m) should be added or increased in existing DFO Science research surveys. The additional data in conjunction with commercial catch per unit effort (CPUE) can be used to monitor and assess stock abundance for Longspine Thornyhead.

Challenges in Ageing

The inability to easily and economically age Longspine Thornyhead may render assessments for this species more uncertain because they are limited to using production models. When age data are available, age structured models usually provide more reliable estimates of population status. For the Rougheye/Blackspotted Rockfish complex, ageing otoliths via break-and-burn results in a high degree of imprecision (± 5 y, Shayne MacLellan, DFO, pers. comm., supervisor of the PBS fish ageing laboratory, 2010). Ageing error won’t disable an age structured model, but it probably increases the uncertainty of the results.

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