Water Stewardship Information Sources
| ID | 1484 |
|---|---|
| Citation | Rae, R and Andrusak, H. 1996. Ten-Year Summary of the Okanagan Lake Action Plan. BC Ministry of Environment. |
| Organization | Ministry of Environment |
| URL | http://www.obwb.ca/fileadmin/docs/olap_10yrsummary.pdf |
| Abstract/Description or Keywords | The number of kokanee salmon in Okanagan Lake declined substantially during the 1980s. In 1995, the recreational fishery for kokanee was closed, and in 1996, the Okanagan Lake Action Plan (OLAP) began with the objective of rebuilding and maintaining the diversity of wild kokanee stocks in Okanagan Lake. OLAP set out to collect information about the food web in Okanagan Lake in order to better understand the ecosystem. This work entailed measuring the characteristics of the water (limnology) and the algae, zooplankton, and kokanee populations. With a better understanding of the lake ecosystem, OLAP then began several major initiatives to help recover the kokanee population. These initiatives included protection and restoration of stream and shore habitat, control of the introduced mysid shrimp through an experimental shrimp fishery, and investigation of a possible nutrient imbalance in the lake. OLAP has achieved a remarkable amount in its first ten years of kokanee recovery on Okanagan Lake. Biologists now have a much better understanding of the factors involved in the kokanee decline, and they have made progress in many key areas. Key results produced by OLAP include: Confirmed that Okanagan Lake is very unproductive due to nutrient deficiencies (phosphorus and nitrogen) resulting in low algae productivity. Detected that Okanagan Lake suffers from nitrogen deficiency during the algae growing season in wet years. Determined that blue-green algae dominate the algae population and that they are a poor-quality food source for cladoceran zooplankton. Identified that mysid shrimp and juvenile kokanee prefer cladoceran zooplankton, which appear to have low nutritional content due to the kind of algae the lake grows. Determined that juvenile kokanee are limited by poor growing conditions in the lake, resulting in low survival. Confirmed that the stream- and shorespawning kokanee are genetically distinct. Determined that kokanee spawners declined for three decades from nearly 1 million to only 10,000 before recovering somewhat in the 2000s to more than 200,000. Improved stream flows on three important spawning streams. Developed and began implementing a restoration plan for Mission Creek. Improved lake level regulation to protect shore-spawning kokanee. Developed a limited commercial fishery for mysid shrimp. fisheries, aquatic habitat, salmonids, water quality |
| Information Type | report |
| Regional Watershed | Okanagan |
| Sub-watershed if known | Okanagan Lake |
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| Comments | |
| Project status | complete |
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