Water Stewardship Information Sources
| ID | 1236 |
|---|---|
| Citation | Mathews, M, Glova, G and Sampson, T. 2007. Nicola River Watershed Stream Temperatures, July-October 2006. Prepared for Nicola Tribal Association. |
| Organization | Nicola Tribal Association |
| URL | http://www.thinksalmon.com/images/uploads/Critical_Temp_Thresholds-_Final_Report.pdf |
| Abstract/Description or Keywords | The Nicola River, a tributary of the Thompson River, is a sixth order stream, 189 km long, draining an area of 7,227 km2 in the interior of southern British Columbia (Figure 1). Important tributaries to the Nicola for salmonids include the Coldwater River and Spius, Quilchena, Clapperton and Guichon creeks (Walthers and Nener 1998). Historically, the Nicola River was a significant important contributor to interior Fraser River salmonid stocks, particularly early run Chinook and coho salmon and steelhead. Currently, salmonid escapement to the Nicola system is much lower than it was historically, and higher levels are considered essential for survival of these stocks. Excessive exploitation rates, habitat alteration, disruption and destruction from various human activities in the watershed, as well as effects of climate change appear to be contributing to the decline of these fish stocks (DFO 2005). In spite of the importance of the Nicola River, it remains one of the most threatened in the province, mainly due to impacts from forestry, agriculture, irrigation and urban developments. Forestry is the major land use in the area, with harvesting operations and associated road building activities often causing increased levels of suspended sediments in streams from erosion of roads and cutbanks, landslides and soil disturbances (Rood and Hamilton 1995, DFO 1998). Other sources of impacts to flow and water quality in streams include agricultural developments, water diversion, alteration/loss of riparian habitat, linear and urban influences, pipeline construction, and mining activities (Rood and Hamilton 1995, Kosakoski and Hamilton 1982, DFO 1998). There has been considerable loss of riparian vegetation along the Nicola River, which has reduced stream shading and resulted in warmer stream temperatures during summer. Additional thermal stresses are imposed due to flows being reduced by water withdrawals for irrigation and other land uses, resulting in greater daily temperature variations (Walthers and Nener 1997). Also, frequent destabilization of stream banks has resulted in wider channels and shallower waters being more susceptible to warming during summer. Increases in water temperature, if too great, can adversely affect growth, distribution, behaviour, disease resistance, production and ultimately survival of salmonids. Studies by Walthers and Nener (1997) suggest that salmonid production in both the Nicola and Coldwater rivers are constrained by relatively high water temperatures, with the distribution of fish influenced by local variations in water temperatures as fish tend to seek cooler areas with groundwater inflows, shade, and other features. Within the Nicola system, Rood and Hamilton (1995) regarded the mainstem Nicola, the Coldwater River and other important salmonid tributaries as sensitive areas for salmonids due to high water demands, extreme low and high flows, and excessive logging activity. Very little temperature data are available for drainages of importance for salmonids in the southern interior of British Columbia. The primary objective of this study was to collect temperature data at various sites within the Nicola watershed from July through October and assess the suitability of these environments for salmonids with respect to species temperature preferences and tolerances. |
| Information Type | report |
| Regional Watershed | Nicola |
| Sub-watershed if known | Nicola River, Coldstream River, Spius Creek, Maka Creek, Prospect Creek, Spahomin Creek, Quilchena, Guichon, Nuaitch, Shakan, Skuhun |
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| Comments | |
| Project status | complete |
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