| Abstract/Description or Keywords |
The Middle and North Fraser Habitat Management Areas encompass a very large area and some extremely productive fish habitats, including the spawning grounds of the famous Stuart River and Horsefly River sockeye salmon. The Middle Fraser HMA provides a migratory corridor for numerous runs of all five anadromous salmon species, both as juveniles heading towards the sea, and as adults returning to spawning grounds. It also has numerous small tributaries that collectively support all five species of anadromous salmon. The Nechako, Stuart-Takla, and Upper Fraser HMAs support two species of anadromous salmon, sockeye and chinook. The Quesnel HMA supports sockeye, chinook, pink, and coho populations. The Middle and northern Fraser HMAs contain three large urban/industrial centers, which are Prince George, Williams Lake and Quesnel. Prince George and Quesnel are both located adjacent to the Fraser River at the confluence of major tributaries (the Nechako and Quesnel Rivers respectively). There are numerous small towns along the Fraser Mainstem and tributaries, and apart from these settlements the HMAs are sparsely populated. A large number of data were available for several sites in the Fraser River mainstem in the Middle and Upper Fraser HMAs. However, there has been relatively little water quality sampling of salmon-bearing watersheds in the other HMAs addressed here, with the exception of a few of the larger tributaries. Because water quality data were not available for many of the salmon-bearing tributaries, assessments of potential impacts to these systems were largely based on land use information. The largest urban/industrial centers generate both point sources and non-point sources of impacts to water quality, and negatively affect fish habitat. The largest permitted discharges from the HMAs include effluents from five pulp mills (three near Prince George in the Upper Fraser HMA and two at Quesnel in the Middle Fraser HMA), and treated sewage from Prince George. All of these effluents are discharged to the Fraser River mainstem. The pulp mill effluents were formerly of concern due to the persistent organic contaminants that they contained. Primary production is limited by the high suspended sediment levels that are characteristic of the river, hence nutrients present in these effluents are not considered problematic. Temperature may be one of the main outstanding water quality issues associated with the pulp mill effluents today. Very large volumes of effluent are discharged continuously, at up to 38°C. During some summers water temperatures in the Fraser mainstem reach levels that cause significant pre-spawning mortality in salmon. Any warming influences on the river should be treated with concern when river temperatures are resulting in pre-spawning mortality. The 23 salmon-bearing watersheds of the Middle Fraser HMA have experienced relatively little human development. Consequently, the water quality of few of these Fraser River tributaries were considered to be significantly affected. Of these streams, four are considered to be significantly impacted by urban development, in addition to the Fraser mainstem, and three are significantly impacted by logging. Narcosli Creek is the only salmon-bearing stream in the HMA with significant impacts from agriculture. Ten of the 23 streams had very low natural summer low flows. Fortunately, with the relatively low level of human development there are not excessive demands for water within the HMA, which would exacerbate natural low flow problems. Water quality sampling in the Middle Fraser HMA has largely been focussed on the Fraser River mainstem and the San Jose River watershed. Numerous other sites have been sampled a relatively small number of times, usually in the vicinity of a permitted waste discharge to surface waters. For many of the salmonbearing tributaries to the Middle Fraser HMA water quality data were not available at all, and assessments were based on information available about land use. In the Middle Fraser HMA efforts should be directed at maintaining the integrity of salmon-bearing watersheds, as well as protecting existing flows in streams that experience natural low flow problems by limiting water withdrawals and protecting the natural hydrology of these systems. Within the Nechako HMA there are twelve salmonbearing streams in addition to the Nechako River mainstem. Water quality sampling of the Nechako River has been relatively extensive downstream from Fort Fraser, both geographically and in terms of the number of samples collected at several of the sampling sites. Some data were also available for the Endako watershed, but little or no data were available for other salmon-bearing watershed in the HMA. Both the hydrology and water quality of the Nechako River have been significantly affected by the damming of the headwaters. Impoundment of the headwaters results in relatively low suspended sediment levels in released water. In addition, water released from the Skins Lake Spillway tends to be relatively warm during summer months. Warm water releases combined with reduced flows result in Nechako River water temperatures that are dangerously warm for salmonids during summer months. The apparent accumulation of mercury in some fish species in the Nechako Reservoir is also of concern. Urban and industrial development affect water quality and fish habitat of the Nechako River at Vanderhoof and Prince George. Agriculture significantly impacts water quality and fish habitat in some areas of the Nechako Strategic Water Quality Plan and Chilako systems. Natural summer low flows are considered problematic for fish in three tributaries to the Nechako, and two of these three also experience further pressure on flows from water withdrawals. Timber harvesting is the most significant land use issue in the HMA, and impacts water quality and fish habitat in six of the 12 salmon-bearing Nechako River tributaries. There may be a need for increased enforcement action pertaining to forestry activities in the area. The Stuart-Takla HMA supports some of the largest sockeye populations in B.C, as well as chinook salmon. Sockeye spawn in the numerous relatively small tributaries of the system, and rear in Takla, Trembleur, and Stuart Lakes. Much of the Stuart-Takla HMA is presently undeveloped, hence the water quality of few of the 44 salmon-bearing systems in the HMA are believed to be affected. Water quality data is very limited within this HMA. Some water quality sampling has been done in the area of Fort St. James. As little or no data were available for most of the salmon-bearing streams in the HMA, assessments of impacts to water quality were based almost entirely on land use information. Urban and agricultural development, and water withdrawals do not significantly affect water quality in any of the salmon-bearing systems of the Stuart- Takla area. Very low summer flows in 33 of the 44 salmon-bearing systems give rise to the biggest water quality concern in the HMA, which is high summer water temperatures. DFO must work with other agencies and proponents to ensure that water withdrawals do not further aggravate summer low flow problems, and that the natural hydrology of these systems is not disrupted by land development. The 38 salmon-bearing streams in the Upper Fraser HMA support mainly chinook salmon, however, the Bowron River also supports sockeye. The only large population center in the HMA is a portion of the City of Prince George. Several small towns are located adjacent to the Fraser River, however, there is very little human settlement in tributary watersheds. Relatively few water quality data were available for the Upper Fraser HMA, except for the Hansard and Red Pass stations, which have been extensively sampled. Based on available land use information, none of the salmon-bearing tributary watersheds were considered to be affected by urban development, and only three tributaries were assessed as being significantly impacted by agriculture. Water withdrawals are not problematic in any of the salmon-bearing systems and in general, natural summer low flows are adequate to meet fish needs - except three which do experience very low summer flows. Compared with other land uses, timber harvesting exerts by far the greatest pressure on salmon streams in the HMA, with 15 of 38 streams significantly impacted by logging. The Quesnel HMA contains 28 salmon-bearing streams, which collectively support chinook , pink, and coho salmon, in addition to large sockeye populations. Summer low flows are mostly adequate to support fish requirements, with only 3 of 28 systems experiencing summer low flow problems. Water withdrawals result in significant pressures on fish in two of the 28 streams. The Quesnel HMA is sparsely populated. Apart from the City of Quesnel, there are only a few small towns within the HMA. The lower Quesnel River is the only salmon-bearing system with significant impacts from urban development on water quality and fish habitat, and these impacts are localized around the urban/industrial center of Quesnel. Agricultural development, primarily ranching, covers a significant portion of the land base within the HMA, but only three salmonbearing systems are significantly affected by this land use. Placer mining also affects fish habitat and water quality in the Quesnel HMA, mainly in Hixon and Naver Creeks. DFO is now working to promote education and awareness with proponents to reduce impacts of placer mining on fish habitat and water quality. Timber harvesting is the predominant land use in the Quesnel HMA, and was determined to cause significant impacts to water quality and fish habitat in 9 of the 28 salmon streams. Logging activity was very intensive from 1990-1996, when the area harvested amounted to one-third of all the logging in the previous 30 years. Continuation of this rate of cutting may lead to harmful alterations of the hydrology in salmon streams, as well as an increase in the other types of impacts associated with logging. Overall, the North Fraser HMAs have experienced relatively little human development compared to the Lower Fraser and Thompson HMAs. Furthermore, it is evident from water quality data and Stream Summaries for salmon-bearing systems in the more developed HMAs that current approaches to resource management are not adequately protecting water quality in a manner that ensures sustainable fish populations and healthy aquatic ecosystems. In the Middle and North Fraser HMAs, there remains an opportunity to protect many salmon-bearing systems through watershed management approaches that proactively address cumulative impacts on water quality and fish habitat. Recommendations provided in Chapter 9 identify options for addressing existing water quality problems, and preventing development of further impacts. Effectiveness will fall short of the benefits of comprehensive watershed management without jurisdictional barriers. Successfully protecting ecosystem integrity so that healthy fish populations are sustained will likely require a shift from resource-based management that typically seeks to maximize short-term economic benefits, to ecosystem-based watershed management approaches. Degradation of water quality results from a complex interaction of human activities and land uses. Unfortunately, the control of these uses and activities is broken into many jurisdictions. Agencies make decisions daily about matters that can have a direct influence on water quality and aquatic habitats without consideration being given to ecosystem sensitivity. To properly manage water quality, a long term and integrated approach is required. The structures necessary to Implement such an approach are inadequate or nonexistent. Protecting and/or restoring the ecological integrity of watersheds to sustain healthy fish populations requires multi-agency cooperation and political will. It also requires strong public support to pressure all levels of government for change, for example a shift towards ecosystem management, and improved practices from all of the stakeholders. While the negative effects resulting from the actions and choices of individuals may be small, collectively the impacts of human activities on water quality and fish habitat can become large. Significant efforts to educate the public about how to minimize their impacts on water quality and aquatic habitats will be key to protecting existing water quality and fish habitat values in the Middle and North Fraser HMAs. |
