The key to clean water and sustainable fisheries is to follow nine guiding principles of water management, says a team of Canadian biologists.
Fish habitats need ecosystems that are rich in food with places to hide from predators and lay eggs, according to the framework published today in the journal Environmental Reviews.
Humans have put key freshwater ecosystems at risk because of land development and the loss of the vegetation along rivers and streams, says John Richardson, a professor in the Dept. of Forest and Conservation Sciences at the University of British Columbia, one of 15 freshwater biologists who created the framework to help protect fish and ecosystems into the future.
"Fish are strongly impacted when nutrients, sediments or pollutants are added to their habitat. We cannot protect fish without maintaining a healthy freshwater ecosystem," says Richardson, who led the policy section on protecting fish habitats. Other policy sections addressed areas such as climate change and biodiversity.
Connecting waterways are also critical for healthy ecosystems, says Richardson. "If fish can't get to breeding or rearing areas because of dams, culverts, water intakes or other changes to their habitats, then the population will not survive," he says.
With more pressure on Canada's freshwater ecosystems, Richardson and his colleagues wanted to create a framework of evidence-based principles that managers, policy makers and others could easily use in their work. "It's a made in Canada solution, but the principles could be applied anywhere in the world," he says.
Healthy freshwater ecosystems are shrinking and reports suggest that the animals that depend on them are becoming endangered or extinct at higher rates than marine or terrestrial species, says Richardson. Humans also depend on these ecosystems for basic resources like clean drinking water and food as well as economic activity from the natural resource sector, tourism and more.
The components of a successful management plan include:
- Protect and restore habitats for fisheries
- Protect biodiversity as it enhances resilience and productivity
- Identify threats to ecosystem productivity
- Identify all contributions made by aquatic ecosystems
- Implement ecosystem based-management of natural resources while acknowledging the impact of humans
- Adopt a precautionary approach to management as we face uncertainty
- Embrace adaptive management -- environments continue to change so research needs to be ongoing for scientific evidence-based decision making
- Define metrics that will indicate whether management plans are successful or failing
- Engage and consult with stakeholders
- Ensure that decision-makers have the capacity, legislation and authority to implement policies and management plans.
These recommendations are based on nine principles of ecology:
- Acknowledge the physical and chemical limits of an ecosystem
- Population dynamics are at work and there needs to be a minimum number of fish for the population to survive
- Habitat quantity and quality are needed for fish productivity
- Connecting habitats is essential for movement of fish and their resources
- The success of freshwater species is influenced by the watershed
- Biodiversity enhances ecosystem resilience and productivity
- Global climate change affects local populations of fish
- Human impacts to the habitat affect future generations of fish
- Evolution is important to species survival
- Nicolas W.R. Lapointe, Steven J. Cooke, Jack G. Imhof, Daniel Boisclair, John M. Casselman, R. Allen Curry, Otto E. Langer, Robert L. McLaughlin, Charles K. Minns, John R. Post, Michael Power, Joseph B. Rasmussen, John D. Reynolds, John S. Richardson, William M. Tonn. Principles for ensuring healthy and productive freshwater ecosystems that support sustainable fisheries. Environmental Reviews, 2013; 1 DOI: 10.1139/er-2013-0038
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