Developing an evidence-based toolbox for addressing freshwater biodiversity threats

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About the project

It is well established that freshwater biodiversity is in such a state of decline that we can describe it as a crisis. There is an urgent need to rethink aquatic ecosystem management and to equip practitioners and their partners with the evidence needed to make decisions that will not only halt declines in freshwater biodiversity, but reverse them.

Given the vast size of Canada and its substantial heterogeneity in geology, climate and biogeographic history, it is not surprising that Canada also has rich and diverse freshwater ecosystems. However, even the most remote areas have been affected by human activities. Despite the incredible scientific capacity and knowledge about these ecosystems within academic and non-government organizations—as well as the numerous regional, Indigenous, provincial/territorial and federal bodies tasked with aquatic ecosystem management and protection—freshwater biodiversity threats are ever-present in Canada and there is evidence that pressures are accelerating. Quite simply, the Canadian context demands a made-in-Canada solution that aligns with our governance structures, geography, culture and collective values.

Given the quantity of literature, time constraints of decision-makers and practitioners, and the importance of drawing together primary studies to elucidate common effects and key lessons, well-conducted evidence syntheses (literature reviews) can provide a valuable resource to enable more evidence-based decisions and implementation of effective policy and practice. There is a need to ensure that decision-makers and practitioners working to bend the curve for freshwater biodiversity loss have access to such syntheses that will collectively guide their on-the-ground actions.

Key findings

  • The evidence toolbox is made up of 53 freshwater management interventions and includes 259 evidence syntheses (ranging from publication years 1983-2020).
  • Study sites of included syntheses covered 130 countries. Most studies were conducted in North America (n = 179 [USA], n = 88 [Canada]) and in Australia (n = 87).
  • Fish were the most studied species group across all conservation interventions (38%). Aquatic invertebrates (19%) and amphibians (14%) represented the second and third highest groups examined.
  • In general, most syntheses scored poorly according to Collaboration for Environmental Evidence Synthesis Appraisal Tool (CEESAT) criteria, which assess the rigour of methods, susceptibility to bias and transparency. In most elements of CEESAT criteria, the median score was “red,” indicating that most syntheses did not provide detailed, transparent and systematic methods or reports of limitations. Given the urgency of the freshwater biodiversity crisis, it is troubling to think that much of the evidence being used to inform actions is of low reliability, which could lead to wasted resources and decisions that do more harm than good.
  • Generally, most syntheses scored well according to Relevance and Applicability of Evidence Syntheses to Canada Appraisal Tool (RASCAT) criteria, which assess the relevance and applicability of syntheses to Canadian freshwater decision-makers and practitioners. For most elements of the RASCAT criteria, the median was “gold,” indicating that many elements of included syntheses, and therefore the syntheses themselves, were relevant and applicable to freshwater biodiversity in Canada. This is promising and suggests that the evidence base, although inherently global in scope, can have regional relevance.
  • One area where syntheses scored rather poorly in relevance was their implications for decision-makers and/or practitioners. We strongly encourage future evidence syntheses—not only in freshwater biodiversity—to provide clear, concise and actionable implications, guidance and recommendations to decision-makers and practitioners.

Policy implications

Providing this evidence toolbox is an important step forward in enabling the practitioner, but it will take a more collective effort from many actors (e.g., policy-makers, research community, professional bodies and societies, advocacy groups, NGOs and industry, among others) to help ensure that practitioners have the knowledge, tools and conditions they need to undertake actions to help address freshwater biodiversity threats on a local scale.

  • Policy-makers must ensure that policies pertaining to freshwater biodiversity are created with the best-available science (with help from evidence-based toolboxes to guide that process) and that this is done in partnership with those working within the framework of these policies.
  • Policy-makers need to be certain that ample time, funding and other forms of support are available to practitioners who put policies into action.
  • Provision of enabling conditions is not only the role of policy-makers, but also the responsibility of decision-makers at the organizations that practitioners work within. For NGOs, industry organizations or advocacy groups that focus on freshwater biodiversity objectives, support for freshwater biodiversity and practitioners can be woven into their corporate culture and brand identity.

Further information

Read the full report

Contact the researchers

Steven Cooke, Carleton University;

The views expressed in this evidence brief are those of the authors and not those of SSHRC, NSERC, CIHR and the Government of Canada

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