Restore
The “Restore” component of the Restoration Framework includes a couple of steps that are dependent on the planning steps. For example, informed by the gap analysis modeling, spatial units need to be delineated within each lake for coregonine species targeted for restoration or conservation. For each spatial unit, threats assessments and population viability analyses will occur. With these planning steps complete, the “restore” steps (described below) can be undertaken by fishery managers.
Restoration Opportunities
The first “restore” step in the Restoration Framework is to consider and propose potential restoration opportunities for each spatial unit. Multiple opportunities or tools could be considered, including undertaking reintroduction of extirpated species, restoring or connecting habitats, or using regulatory authorities to create refuges or otherwise limit fishing mortality.
Reintroduction
Reintroduction of extirpated coregonine species is a critical restoration tool to implement. One method is the rearing of coregonines in the hatchery and releasing them into spatial units targeted for restoration. Current best practices for hatchery rearing seek to minimize potential negative effects of hatchery fish, by maintaining their genetic diversity and seeking to produce fish that are physically and behaviorally similar to wild fish. Another option is to “translocate” or directly transfer fish from one lake to another, assuming that concerns about transferring any diseases can be mitigated.
Habitat
The Council of Lake Committees has recognized that diverse and functional habitats give rise to sustainable fish production, and that the protection and improvement of these habitats should occur systematically, adaptively, cumulatively, and collaboratively. Projects can help evaluate where impaired habitat (e.g., spawning or nursery areas) could still be a threat to restoration success and seek to develop habitat remediation strategies (e.g., building new habitat, cleaning or improving existing habitat, connecting functioning habitats).
Refugia
Refuges or reserves can help conserve or even increase abundance of fish stocks in oceans, estuaries, lakes, and rivers, and have been created to support Lake Trout restoration in the Great Lakes. Should evidence be found that protection from fishing mortality or protection of critical habitat can enhance coregonine restoration, this tool would be considered.
A spawning migration of ciscoes (C. artedi) in the Yellowknife River, Great Slave Lake, NT during October. Credit: Paul Vecsei.
Develop and implement a prioritized and integrated restoration plan
To determine which suite of restoration tools should be implemented, fishery managers will consider the outcomes of the planning methods through an iterative process that ultimately will provide guidance as to which restoration tools would be most effective. For a given spatial unit, the outcome of the threats assessment will determine what factors could be most likely to influence restoration success. With that information, population viability models will evaluate how different restoration scenarios (e.g., improving habitat, how many fish to reintroduce, protection from fishing mortality) could overcome those threats and maximize the probability of restoration success. Fishery managers will consider these planning methods along with logistical constraints (e.g., funding, availability of different sources for reintroduction) and their own policy considerations to finalize a restoration plan and implement it.