Science Advisory Report  2012/063

Science Advice to Support Development of a Fisheries Protection Policy For Canada

Summary

• This Science Advisory Report (SAR) provides advice to policy and management primarily regarding scientifically significant terms in the amended Fisheries Act (2012). In respect of commercial, recreational or Aboriginal (CRA) fisheries, policy-makers sought scientific definitions for “the sustainability and ongoing productivity”, the “fish that support” such CRA fisheries, and “the contribution of the relevant fish”.  The scientific advice provided is organized accordingly.

“Sustainability and Ongoing Productivity”:

• Productivity is determined by vital rates (e.g. reproduction, growth and survival) and life history characteristics (e.g. fecundity, age at maturity) that determine the fish production rate, that is, the growth in population biomass per unit area per unit time. Yield is a function of fish production. Fisheries productivity is sustained yield of all CRA fishery species.
• The Federal Sustainable Development Act indicates that sustainability “means the capacity of a thing, action, activity, or process to be maintained indefinitely”. The ecological concept of sustainability recognizes that populations fluctuate over time. Sustainable development does not preclude short-term or transitory impacts on the environment, but threats should be managed to avoid, mitigate or offset impacts such that there is a reasonable expectation of avoidance of serious adverse impacts or recovery from unavoidable impacts within a biologically reasonable period of time.
• The ecological concepts of ecosystem productivity, biodiversity and resilience are linked. A more diverse ecosystem tends to have higher overall productivity and to be more resilient to natural or anthropogenic perturbation than a less diverse ecosystem. In fisheries, habitat complexity and population diversity have been shown to positively correlate with both production and yield, supporting on ecological grounds the consideration of both direct and indirect links between habitat features and productivity of CRA fishery species, and evaluating impacts of projects on multiple scales.
• It is rare to measure all components of productivity.  A pragmatic approach can take advantage of existing surrogates which range from habitat-based approaches for a smaller-scale work, undertaking or activity (w/u/a) to productivity-based approaches (using proxies for productivity) for larger ones.

“Fish that Support a CRA Fishery”:

• The support functions of an ecosystem are those functions which are essential for sustaining the production of CRA fishery species within the bounds of natural variability, over short- and long-term temporal scales.
• Support functions and “supporting fish” populations which affect the productivity of CRA fishery species may occur in areas outside of the distribution of the CRA fishery species and be connected to the CRA fishery species through food webs, inter-dependencies of sub-populations of a species and movements or migrations.
• On ecological grounds to be a species that “supports” fish that are part of a CRA fishery (in the sense of Section 35 of the Fisheries Act), two conditions have to be met.  Firstly, the productivity of the fish that are part of CRA fisheries has to be impacted by changes in status of the species that “supports” them in a consistent manner.  Secondly, there would be few or no ways that the ecological functional role of the supporting species would be fulfilled by other species more resilient to impacts of the w/u/a. 
• Two important support functions that arise from direct interactions with CRA fishery species are (i) the roles of key prey species and (ii) any species that create biogenic habitats (i.e. habitats created by the bodies or behaviors of organisms) that the CRA fishery species requires to complete its life cycle and contribute to the ongoing productivity.
• In addition to the direct support functions provided by key prey and structure-forming species, the dynamics of some ecosystems (and hence the productivity of CRA fishery species) may depend on certain other ecological functions provided by these or other species. 

“Contribution of the Relevant Fish”:

• The “contribution of the relevant fish to the ongoing productivity of commercial, recreational or Aboriginal fisheries” is measured by the impact that would be expected on the productivity of CRA fishery species if the change (associated with a w/u/a) to the potentially affected species or habitats takes place. The affected species or habitats include the fish that are part of the fisheries and their habitats, and the fish that support the fisheries and their habitats.
• Contribution can be conceptualized as a relationship between the productivity of the fishery and the state of the affected species or habitats. The shape of this relationship, the potential presence and position of inflection points and its slope can inform management decisions about risks associated with changes to the state of the affected species or habitats.
  Application of the contribution framework to support decisions within a precautionary framework requires the following five pieces of information:
1. understanding how overall productivity depends on the affected species or habitats,
2. the “current” state (i.e., the state before the w/u/a commences) of the potentially affected species or habitats,
3. resilience of fish productivity to perturbations of the affected species or habitats,
4. how the proposed w/u/a may alter the state of affected species or habitats, and
5. uncertainties about the relationship, the current state of affected species or habitats, the potential impacts of the w/u/a, and, when applied, the effectiveness of avoidance and mitigation measures.
• Comprehensive data will rarely be available to fully parameterize functions and positions for (a) – (c), to quantify (d) precisely, and to quantify uncertainty (e) for specific places and the fisheries in those places.  However there is substantial research and expert knowledge of scientists, managers, and related professionals. These can inform development of default forms for the functional relationships between productivity and state of the affected species or habitats, and provide general guidance to support decision-making.
• Use of this framework does not make the decisions automatic.  However, it provides a structure for organizing information and bringing consistency to decision making.

This Science Advisory Report is from the national advisory process of August 29-31, 2012, on “Science guidance for Fisheries Protection Policy”.  Additional publications from this process will be posted as they become available on the Fisheries and Oceans Canada Science Advisory Schedule.

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