2018-加拿大淡水生物多样性区域（英文版）-2mb

Summary of Freshwater Key Biodiversity Areas in Canada

Core Content

This report outlines the identification of Freshwater Key Biodiversity Areas (KBAs) in Canada, which are critical for the global persistence of freshwater biodiversity. It highlights the importance of these areas in informing species conservation and development planning, particularly in the context of increasing threats to freshwater ecosystems.

Main Points

Freshwater Biodiversity in Canada

• Canada contains 60% of the world's freshwater lakes and 25% of the world's wetlands by area.
• Freshwater habitats include lakes, rivers, and diverse wetlands such as marshes, deltas, and vernal pools.
• Despite its abundance of freshwater habitats, aquatic species diversity is lower in Canada compared to southern nations, due to repeated glaciation events and climatic characteristics.
• Southern Ontario and British Columbia are the regions with the highest species richness and number of threatened species.

Key Biodiversity Areas (KBAs)

• KBAs are sites of global importance for biodiversity but do not require specific conservation actions such as protected area designation.
• 9.4% of 28,226 river/lake sub-catchments were identified as likely to meet KBA criteria.
• 13 freshwater KBAs were confirmed by regional experts, covering 17,707 km².
• These KBAs support 15 globally threatened species (Critically Endangered, Endangered, or Vulnerable) and 6 geographically restricted range species.

Threats to Freshwater Species

• The primary threats identified include:
  • Hydrological alterations from dam construction.
  • Water pollution from agriculture and urbanization.
  • Over-abstraction of surface and groundwater.
  • Invasive species competing with native taxa.
• These threats often spread rapidly through catchments, making localized conservation efforts ineffective.

Conservation Recommendations

• Improve hydrological management of KBAs to ensure environmental flows.
• Implement catchment-wide Integrated River Basin Management.
• Control and eradicate invasive species to reduce their impact on native biodiversity.
• Periodically update Red List assessments and monitor sites to track extinction risk and evaluate the effectiveness of conservation measures.

Key Information

Project Objectives

• The goal was to identify freshwater KBAs in Canada by analyzing data on species distribution, abundance, and conservation status.
• The process involved:
  • Collating data on species (fishes, molluscs, aquatic plants).
  • Identifying sub-catchments with KBA trigger species.
  • Validating through stakeholder consultations.
  • Compiling additional information to support management and planning.

Methodology

• Followed the IUCN draft consultation document (October 2014).
• Used HydroBASINS Level 8 data for sub-catchment delineation, with an average surface area of 616 km².
• Screened sub-catchments using R scripts to identify trigger species and meet KBA criteria.

KBA Criteria and Thresholds

• The following criteria were used to identify KBAs:
  • A1: Threatened biodiversity
    • (b) Site regularly holds ≥0.5% of the global population and ≥5 functional reproductive units of a globally Critically Endangered (CR) or Endangered (EN) taxon.
    • (c) Site regularly holds ≥1% of the global population and ≥10 functional reproductive units of a globally Vulnerable (VU) taxon.
  • B1: Individually geographically restricted species
    • Site regularly holds ≥10% of the global population size/extent of any species.
  • B2: Co-occurring geographically restricted species
    • Site regularly holds ≥1% of the global population/extent of two or more 'restricted range' species; or ≥0.02% of the total number of species in a taxonomic group, whichever is larger.
  • B3: Geographically restricted assemblages
    • ≥5 ecoregion-restricted species; or ≥10% of the species restricted to the ecoregion, whichever is larger.
• Criteria C (Ecological Integrity) and E (Irreplaceability through quantitative analysis) were not applied due to the focus on species-level data.

Existing and Newly Delineated KBAs

• Existing KBAs/Protected Areas were adopted as freshwater KBAs.
• 13 newly delineated KBAs were identified, covering a significant portion of Canada's freshwater biodiversity.
• Many of these areas are within pre-existing protected areas, but existing management units often fail to cover freshwater species adequately.

Species Diversity and Threats

• Canada has:
  • 215 freshwater fish species and 12 subspecies.
  • 54 freshwater mussel species and 4 subspecies.
  • Over 125 freshwater snail species/subspecies.
  • 819 obligate wetland plants.
• 74% of freshwater snails are at risk, compared to 39% of fishes and 48% of crayfishes.
• 15 species are globally threatened (VU, EN, or CR), and 6 species are geographically restricted.
• Six freshwater fish species and infraspecies are now extinct, with half being nationally endemic.

Stakeholder Involvement

• A validation workshop in Toronto (July 2015) involved 13 experts from various sectors.
• The workshop confirmed KBA boundaries and validated the presence of trigger species.
• Site champions were identified to support the management and monitoring of KBAs.

Conclusions and Recommendations

• Freshwater KBAs are essential for strategic conservation planning and sustainable development.
• They should be integrated into national and regional conservation frameworks.
• Integrated River Basin Management is crucial for maintaining ecological flows and protecting biodiversity.
• Invasive species control is a key action to reduce threats to native species.
• Periodic Red List updates and site monitoring are necessary for tracking biodiversity trends and assessing the effectiveness of conservation measures.

Next Steps

• Expand the number of freshwater KBAs through ongoing data collection and analysis.
• Develop conservation policies and management plans based on KBA data.
• Enhance stakeholder engagement and local community involvement.
• Continue research and monitoring to refine KBA identification and improve conservation outcomes.

References and Appendices

• The report was edited by IUCN experts and reviewed by Conservation International and Wildlife Conservation Society.
• ISBN: 978-2-8317-1870-5 (print) and 978-2-8317-1871-2 (PDF).
• DOI: https://doi.org/10.2305/IUCN.CH.2017.16.en.
• Appendix I: Lists of site champions.
• Appendix II: Summary of KBA criteria and thresholds.