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Recovery strategy for the Nooksack dace in Canada

Recovery

Recovery Feasibility

Feasibility CriteriaFootnote 2

1. Are individuals capable of reproduction currently available to improve the population growth or population abundance?

Yes. Breeding adults have been captured recently from all populations.

2. Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?

Yes. Sufficient physical habitat exists to support the three populations that have been surveyed (Bertrand, Pepin and Fishtrap creeks), although up to 70% of it is seriously degraded by sediment deposits or low water levels in late summer. The severity and extent of these problems could be mitigated by reducing ground and surface water withdrawals during sensitive periods, by reducing sediment entry to streams and by managing beaver activity in sensitive habitats. The quantity and condition of available habitat in the Brunette River population is unknown at present.

3. Can significant threats to the species or its habitats be avoided or mitigated through recovery actions?

Yes. Riffle degradation through seasonal drying can be avoided by reducing water withdrawals or flow supplementation. Sedimentation can be reduced through riparian planting, improved agricultural practices, the installation of sediment traps in storm sewer systems, and proper sediment control at mine and construction sites. Riffle loss can be mitigated through habitat restoration and (when necessary) beaver control.

4. Do the necessary recovery techniques exist and are they demonstrated to be effective?

Yes. Techniques to reduce problems of low base flow, sediment deposition and beaver ponding are well known. Monitoring of created riffle habitat has demonstrated that restored habitats are quickly colonized.

Feasibility Assessment

Recovery of Nooksack dace populations to levels ensuring long-term survival is both technically and biologically feasible. However, it is highly likely the species will remain at some risk due to the continued pressure on its habitats from a rapidly growing human population in the Fraser Valley.

Recovery will involve the establishment and/or maintenance of riffle habitat sufficient to maintain a population in each creek. Some management will be required in all three watersheds. It should focus on in-stream flow protection in Bertrand Creek, restriction of beaver impoundment in Pepin Brook, and the restoration of riffle habitat in Fishtrap Creek. Appropriate recovery actions in the Brunette River are unknown pending population and habitat status surveys.

Recovery Goal, Objectives and Corresponding Approaches

Recovery Goal:

To ensure the long-term viability of Nooksack dace populations throughout their natural distribution in Canada.

Recovery Objectives

1. For all currently and historically suitable habitats in native streams to be occupied by 2015.

WatershedHabitat with High Potential Productivity Occupied in 2004 (km)Total Habitat with High Potential Productivity (km)
Bertrand Creek<6.510.0
Pepin Brook<22.8
Fishtrap Creekunknown8.5
Brunette Riverunknownunknown

 

Rationale:

A significant portion of habitat with high potential productivity is not currently occupied, primarily due to riffle degradation or loss to drying, sediment deposition and beaver impoundment. Achievement of interim population recovery targets in the three surveyed watersheds will require that all habitat with high potential productivity be occupied (see objective 2 below). In most cases unoccupied areas could be rendered habitable quickly by increasing water flow, controlling beaver, and/or implementing fish-sensitive drainage maintenance practices.

2. To increase Nooksack dace abundance to target levels in all watersheds by 2015.

Watershed

Area of Riffle

in Potential Habitat Reaches (m2)

Population Target

(excludes young of year)

Bertrand Creek30005700*
Pepin Brook2300**4400*
Fishtrap Creek20303900*
Brunette Riverunknownunknown pending habitat survey

*Assumes an average density of 1.9 Nooksack dace per m2 riffle in suitable habitat (Inglis et al. 1994). Rounded to nearest hundred.

** Based on 1999 survey. By 2001 approximately 200 m2 of riffle was lost to beaver ponding (Pearson 2004a).

Rationale

Ideally population targets would be based on robust population viability analyses. Unfortunately the necessary demographic data is lacking for Nooksack dace. An appropriate guideline for minimum viable population (MVP) size in vertebrate species, based on an extensive review of the scientific literature (Reed et al. 2003; Thomas 1990), is 7000 breeding adults (median value; range 2000-10000). This abundance is considered adequate to maintain genetic diversity and to buffer the population from random variations in survival, and thus to maintain long-term viability in the absence of deterministic factors causing the population to decline.

Populations of Nooksack dace in each of the four watersheds are essentially independent of one another, with extremely low probability of natural exchange of individuals between watersheds because of the very large distances of unsuitable habitat that separate populations. Natural recolonization of habitat from which a population has been extirpated (rescue effect) is therefore highly unlikely. Each watershed, consequently, warrants a separate recovery target in the low to mid thousands.

High quality habitat in Bertrand Creek supported an average of 1.9 dace/m-2 (n=20, SE = 0.35) in the single available direct estimate of density (Inglis et al. 1994). If all riffle areas in all reaches with habitat with high potential productivity supported this density, total adult abundance would be in the low thousands for each watershed. This suggests that for Nooksack dace in the three surveyed watersheds, the maximum achievable population size is close to the minimum viable population size and that all suitable habitats should be designated critical.

3. To ensure that at least one reach in each watershed supports a high density of Nooksack dace.

Rationale

Within each watershed, individual populations may be structured as metapopulations, with different subpopulations separated by poor quality habitat, and some level of exchange of individuals between sub-populations. Population persistence in such systems is dependent upon the existence of one or more source areas where population growth is positive and densities are high.

Broad Strategies to be Taken to Address Threats

Eight broad strategies have been identified in support of the recovery objectives.

1. ProtectFootnote 3, create and enhance riffle habitat in habitat reaches with high potential productivity.

2. Establish or maintain adequate baseflow in all habitats with high potential productivity.

3. Reduce sediment entry to creeks.

4. Ensure the integrity and proper functioning of riparian zones throughout watersheds.

5. Reduce habitat fragmentation

6. Encourage stewardship amongst private landowners and the general public.

7. Minimize toxic contamination of creeks.

8. Minimize impacts of introduced predators.

In Table 4 these are prioritized, detailed and related to the relevant recovery goals and objectives.

Evaluation

Monitoring and evaluation of a subset of populations will occur each year with the status of each population and watershed being evaluated every five years at minimum. Performance measures for each objective and broad strategy are listed in Tables 5 and 6. Details and priorities of strategy implementation will be provided in one or more Action Plans.

Effects on Other Species

Most recovery efforts will benefit co-occurring native species including steelhead, cutthroat trout, and coho salmon. All three Nooksack dace streams in Canada also contain the Salish sucker (Catostomus sp.), which is also listed as Endangered under SARA. Most of the proposed strategies for Nooksack dace recovery should also benefit Salish sucker, although there is potential for conflict over beaver management. In some cases beaver control and dam removal may benefit a Nooksack dace population by restoring riffle habitat, but harm Salish sucker population by eliminating deep pool and marsh habitat. Recovery activities for the two species will be coordinated in watersheds where they co-occur through the development of one or more multi-species Action Plans. Beaver management will be intended to restore that species’ natural balance in these watersheds. Specific measures of controlling beavers and their dams will be determined in one or more Action Plans.

Approaches to Recovery

An active adaptive management approach (Walters & Holling 1990) should be used in planning and implementing recovery. Whenever possible management actions should be conducted as controlled experiments designed to inform ongoing recovery and action planning. Recovery planning and implementation should occur at the scale of individual watersheds as their populations are isolated from one another and face differing suites of threats in each watershed.

Actions Already Complete or Underway

Landowner Contact and Public Education Programs

A Recovery Implementation Group (RIG) has been formed. The RIG, in cooperation with local stewardship groups, has developed programs to contact landowners in three Nooksack dace watersheds. A public meeting to exchange information was held in each watershed. In addition, colour display posters on Nooksack dace have been given to stewardship groups in Langley for use in public events.

 

Table 4: Broad strategies for Nooksack dace recovery and details of associated research and management activities.Underlined points should not be postponed despite lack of full scientific certainty.
Broad StrategyObj. No.Threats AddressedPrioritySpecific StepsOutcomes or Deliverables
1. Protect, create and enhance riffle habitat in reaches with high potential productivity.1,2,3

Physical destruction of habitat

Riffle loss to beaver ponds

Habitat fragmentation

High

Identify high priority sites for protection, restoration or habitat creation.

Assess benefits of riffle creation and enhancement to Nooksack dace populations.

Estimate current extent of riffle loss to authorized and unauthorized stream and ditch dredging and to beaver activity.

Work with stewardship groups and landowners to identify and implement habitat creation and restoration projects.

Develop best management practices and work plans for habitat reaches with high potential productivity that require drainage maintenance or beaver management.

Protection of habitats with high potential productivity through stewardship agreements, conservation covenants or acquisition of lands containing habitats with high potential productivity.

Riffle creation/enhancement projects identified and developed.

Public education materials on importance of riffle habitat to fish developed and distributed to landowners.

Advice on Nooksack dace habitat requirements and beaver management available to local stewardship groups and agency staff involved in habitat work.

2. Establish and maintain adequate baseflow in all habitats with high potential productivity.1,2

Seasonal Lack of Water

Habitat fragmentation

High

Identify watersheds vulnerable to inadequate baseflow for Nooksack dace.

Develop water balance models for watersheds.

Establish biologically-based minimum in-stream flows for habitats with high potential productivity.

Develop wetland restoration projects in vulnerable watersheds.

Investigate need and feasibility of supplementing baseflow with well water.

Develop and distribute public education materials on impacts of water use on fish and wildlife to landowners and public.

Water balance model showing relative influences of groundwater extraction, surface water extraction, and gravel removal on baseflow for each vulnerable watershed.

Objectives for present and future water management in vulnerable watersheds (baseflow and water withdrawal).

Adequate water rights for conservation purposes in established and vulnerable watersheds.

3. Reduce sediment entry to creeks.1,2Sediment depositionHigh

Estimate levels of sediment in riffles that are harmful to Nooksack dace.

Map, assess and prioritize mitigation for riffle sedimentation in all watersheds.

Work with landowners, municipal governments, and stewardship groups to prevent, mitigate and restore sediment degradation of riffles from urban, agricultural and industrial sources.

Develop and distribute public education materials on sediment impacts on fish and wildlife to landowners.

Maximum recommended levels of sediment content established for habitat riffles with high potential productivity.

Restoration of degraded riffles completed at high priority sites.

Mitigation projects to reduce sediment entry completed (e.g. riparian planting, stormsewer retrofits, improved settling ponds).

4. Ensure the integrity and proper functioning of riparian zones throughout watersheds.1,2,3

Sediment deposition

Physical destruction of habitat

Toxicity

Hypoxia

High

Conduct riparian assessments of habitat reaches with high potential productivity as the basis of proposed riparian buffer widths.

Identify, prioritize and develop riparian planting or other projects in cooperation with landowners, stewardship groups and government agencies.

Develop and distribute public education materials on riparian reserve strips to landowners

Riparian planting projects completed in high priority areas.

Educational materials developed and included in landowner contact programs and other public education applications.

5. Reduce habitat fragmentation.1,2Habitat FragmentationMed.

Assess the ability of different life history stages to cross different types of barriers.

Identify permanent/seasonal barriers and prioritize for mitigation.

Use of strategically located restoration projects to eliminate barriers and provide ‘stepping stones’ for dispersal to other riffle-rich reaches.

Advice on prioritizing restoration projects available to local stewardship groups and agency staff involved in habitat work.

6. Encourage stewardship amongst private landowners, local governments and the general public.  Med.

Give presentations and field tours on Nooksack dace and watershed ecology to local stewardship groups, schools and others.

Advise stewardship groups, agency staff, and consultants involved in habitat work on Nooksack dace habitat requirements.

Increased awareness of Nooksack dace and local stream ecology among public.

Nooksack dace habitat features incorporated into in-stream works undertaken for other purposes.

7. Minimize toxic contamination of creeks.1,2,3ToxicityMed.

Estimate extent and severity of toxic contamination of creeks.

Work with municipalities to identify, prioritize and develop projects to improve storm water treatment.

Increase width and continuity of riparian reserve areas on agricultural lands (see strategy 3).

Develop and distribute public education materials on pesticide/herbicide impacts on fish and wildlife to landowners.

Stormwater treatment projects completed at high priority sites.

Riparian planting projects completed in high priority areas.

Educational materials developed and included in landowner contact programs and other public education applications.

8. Minimize impacts of introduced predators.1,2,3Increased predationLow

Document distribution and densities of introduced predators in each watershed.

Assess impact of riffle loss to drying on predation risk.

Develop and distribute public education materials on potential impacts of introduced predators on native species to landowners and recreational fishers.

Introduced predator distributions mapped in each watershed.

Educational materials developed and included in landowner contact programs and other public education applications.

 

Table 5: Performance measures for evaluating the achievement of objectives.
ObjectivesProcess Performance MeasureBiological Performance Measure
1. For all currently and historically utilized habitats in native streams to be occupied by 2015.Habitat with high potential productivity identified and occupancy evaluated in all watersheds.Proportion of habitat with high potential productivity occupied.
2. To increase Nooksack dace abundance to target levels in all watersheds by 2015.

Development of a monitoring protocol for population abundance.

Abundance surveys completed in all watersheds.

Estimated population size relative to target population.
3. To ensure that at least one reach in each watershed supports a high density of Nooksack dace.Abundance surveys completed in all watersheds.Number of reaches where catch-per-unit-effort exceeds 0.8 Nooksack dace per standard Gee-trap (24 h set, n&gt;10)

 

Table 6: Performance measures for evaluating the success of broad recovery strategies.
Broad StrategiesProcess Performance MeasureBiological Performance Measure
Protect, create and enhance riffle habitat in habitat reaches with high potential productivity.

Area of riffle habitat restored, created or protected.

Number of landowners and others reached in public education and consultation programs.

Area of riffle protected, restored or created in habitat reaches with high potential productivity.

Establishment or significant growth of populations in habitat reaches with high potential productivity containing protected, created or enhanced riffles.

Establish and maintain adequate baseflow in all habitats with high potential productivity.

Minimum discharges for maintenance of Nooksack dace habitat established in vulnerable watersheds.

Discharge monitored in vulnerable watersheds.

Minimum discharges exceeded in vulnerable watersheds.
Reduce sediment entry to creeks.

Major sources of sediment entry to each watershed identified.

Major sources of sediment entry addressed.

Area and proportion of habitat with high potential productivity affected by sediment deposition.

Establishment or growth of Nooksack dace populations in habitat reaches with high potential productivity where sediment deposition has been addressed.

Ensure the integrity and proper functioning of riparian zones throughout watersheds.

Length and area of riparian habitat restored in each watershed.

Proportion of habitat with high potential productivity for which a riparian assessment has been completed.

Proportion of habitat with high potential productivity for which the results of a riparian assessment have been adopted.

Length and proportion of habitat with high potential productivity with greater than 5, 10, and 30 m of riparian reserve.

Establishment or significant growth of Nooksack dace populations in habitat reaches with high potential productivity with restored riparian reserve strips.

Reduce habitat fragmentation.Permanent and seasonal barriers to movement mapped in each watershed.

Quantity of habitat reconnected by removal of barriers.

Establishment or growth of Nooksack dace populations in habitat reaches with high potential productivity where habitat fragmentation has been addressed.

Encourage stewardship amongst private landowners and the general public.

Number of non-government organizations /individuals involved in recovery activities.

Number of stewardship agreements/conservation covenants signed to protect habitat with high potential productivity.

Number of landowners and others reached in public education and consultation programs.

Length of habitat with high potential productivity protected or restored on private land or with public involvement.

Establishment or growth of Nooksack dace populations in habitat reaches with high potential productivity on stewarded lands.
Minimize toxic contamination of creeks.

Sources of toxic contamination identified.

Sources of toxic contamination addressed.

Area and proportion of habitat with high potential productivity affected by contamination.

Establishment or growth of Nooksack dace populations in habitat reaches with high potential productivity where toxic contamination has been addressed.

Minimize impacts of introduced predators.Extent of habitat with high potential productivity occupied by introduced predators mapped.

Proportion of habitat with high potential productivity containing introduced predators.

Correlation of establishment or growth of Nooksack dace population with introduced predator absence.

 

Statement of When An Action Plan Will Be Completed.

Within two years of posting the final recovery strategy, one or more Action Plans will be developed, including one or more multi-species Actions Plan for Nooksack dace and Salish sucker. The plans will include descriptions of programs, plus a timeline of programs with estimated budgets, and will encompass a timeframe of at least five years. More detailed plans are being prepared for each of the inhabited watersheds as resources and partnership opportunities become available.

Footnotes

Footnote 2

Draft Policy on the Feasibility of Recovery, Species at Risk Act Policy. January 2005.

Return to footnote 2

Footnote 3

Protection can be achieved through a variety of mechanisms including: voluntary stewardship agreements, conservation covenants, sale by willing vendors on private lands, land use designations , and protected areas.

Return to footnote 3