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<br />1592
<br />
<br />populations would have spawner abundances ranging from
<br />less than 100 to several thousand individuals and would
<br />include most of the freshwater stocks in Canada's inland
<br />lakes and rivers. Generally, spawner-targeted harvesting
<br />of such stocks would impose a risk to their sustainability
<br />high enough to violate conservation requirements.
<br />
<br />The application of conservation
<br />principles
<br />
<br />At the federal level in Canada, two documents guide the
<br />management of fishery resources: the Fisheries Act of
<br />1967 with subsequent revisions, and the Policy for the
<br />Management of Fish Habitat issued in 1986 (Department of
<br />Fisheries and Oceans 1986). The Act imposes the goal of
<br />conservation and protection while the Policy aims for no net
<br />loss of productive capacity of fish habitats. In some
<br />provinces, relevant policy documents have been developed
<br />that are compatible with federal objectives. For example, the
<br />policy documents produced by the Ontario Ministry of
<br />Natural Resources, Direction '90s (Ontario Ministry of
<br />Natural Resources 1991) and the Strategic Plan for Ontario
<br />Fisheries, known as SPOF II (Ontario Ministry of Natural
<br />Resources 1992), embrace an ecosystem approach to man-
<br />aging fisheries.
<br />At a more prosaic level, the application of conserva-
<br />tion principles in the daily work routine of most fisheries
<br />biologists relates to detenninations they make about resource
<br />extraction and development issues. This usually requires
<br />them to develop guidelines or regulations to control harvest
<br />and protect habitat. The natural tendency to provide over-
<br />simplified operational definitions of conservation should
<br />be resisted. For example, adequate local control of exploita-
<br />tion cannot be strictly based on species-specific, provincial
<br />fecundity and productivity standards. Such standards, while
<br />useful first approximations, ignore, of necessity, local cir-
<br />cumstances (see Ontario Ministry of Natural Resources
<br />1982 for an example of how a knowledge of local condi-
<br />tions can be used to modify provincial yield guidelines).
<br />Without this type of evaluation, the standards sanction
<br />harvest levels that approach short-term maximum extraction
<br />rates. Such levels are clearly not sustainable because they
<br />afford a low margin of safety and take no account of tem-
<br />poral and spatial variation in reproductive success.
<br />The primary literature contains a variety of methods
<br />for estimating the optimal sustained yield for individual
<br />fish populations in a water body. These studies also discuss
<br />why harvests in local waters may vary considerably from
<br />predicted values and how yield estimates can be adjusted
<br />to provide a closer match to local conditions. Such esti-
<br />mates do provide useful reference points for establishing the
<br />lower harvest necessary to provide the margin of safety
<br />required to protect stock sustainability. These adjustments
<br />require specific knowledge of the water bodies involved
<br />and the manner of harvesting. For example, allowable yield
<br />should be lower when spawners are targeted for harvest.
<br />Sanctuaries and harvest refuges can be effective tools for
<br />applying conservation principles to management issues,
<br />particularly those involving immediate threats to stock
<br />sustainability. Sanctuaries are water bodies, or parts thereof,
<br />where removal of any fish species is prohibited, either for
<br />
<br />Can. J. Fish. Aquat. Sci. Vol. 52, 1995
<br />
<br />a short period to provide protection to spawning aggrega-
<br />tions or for much longer times to allow for rehabilitation of
<br />fish stocks. Using examples from coastal marine fisheries
<br />and reef fishes in particular, Carr and Reed (1993) define
<br />harvest refuges as areas where harvest of target species is
<br />restricted, and where the intent of rebuilding stocks of
<br />such species is through larval recruitment. It is not clear to
<br />us whether the authors include prohibition within the mean-
<br />ing of restriction. Local circumstances, however, will surely
<br />dictate a large variety of harvest control regimes including
<br />no fishing of target species in some refuges, although fish-
<br />ing for other species mayor may not be allowed. Regard-
<br />less of the type or degree of protection, sanctuary or refuge
<br />status should be withdrawn only when special protection is
<br />no longer required.
<br />Routine monitoring of ecosystem status is critical to
<br />measuring or understanding the status of conservation
<br />efforts. For those resources that undergo harvest, stocks
<br />must be assessed occasionally, harvest must be determined
<br />periodically as a check against sustainable levels, and com-
<br />pliance must be assured. Stock assessment is expensive,
<br />but we see no alternative to a judicious and modest program
<br />of routine monitoring.
<br />Our intent in presenting this perspective on conservation,
<br />vis a vis fish and fisheries, is twofold: to promote an eco-
<br />logical ethic as the foundation for developing a set of con-
<br />servation principles for the management of fisheries
<br />resources in Canada, and to present a set of conservation
<br />principles for fisheries management that will evoke a debate
<br />about just what those principles ought to be. With respect
<br />to the former, we would expect general support from the
<br />fisheries community, but we are under no illusion that the
<br />fisheries community will endorse this preliminary state-
<br />ment of conservation principles. Any subsequent debate
<br />that this article may spark will, however, contribute to a fur-
<br />ther refinement and elucidation of such principles. This
<br />can only benefit the resource, its stewards, and its users.
<br />
<br />Acknowledgements
<br />
<br />We thank Bob Randall of the Department of Fisheries and
<br />Oceans and Mike Jones of the Ontario Ministry of Natural
<br />Resources for their input and insightful criticisms of var-
<br />ious drafts of this paper. We also thank Henry Regier,
<br />Gary Meffe, and an anonymous reviewer for their helpful
<br />comments.
<br />
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