Next week we will discuss the history of changes in the Smith River Philpott tailwater. The physical habitat changes that resulted from 50 years of a high-dam barrier effect, coldwater release, and daily hydropower peaking operations create a highly altered condition from the 'natural' river. Restoration to a reference condition is out of the question within my career time. However, some changes are possible.
Philpott Project has two large turbines rated at 6700 KW and a smaller unit rated at 600 KW. The USACE operates this project and has contract to deliver electric power to the grid and the electric power production is managed by the Southeastern Power Administration. In 2006 Congress authorized a Section 216 Study of operations of Philpott. This study is ongoing with state match of federal funds. For more information click here.
The history of this project and project completion reports are available at the Smith River Project website. In the 1970's the largest trout ever caught in Virginia waters were from the Smith River. The reading by Marcy Anderson and others (in Assigned Readings/Course Documents) describes changes in the wild brown trout population and my lesson will explore other aspects of the habitat. Another little known fact is that the tailwater supports a "small" population of the Federally Endangered Logperch, which would likely benefit from a change in dam operations.
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There is a 2 minute video of sampling on Smith River this past August. Click on http://www.dgif.virginia.gov/video/?video=15
to view
In their article “Historical changes of the brown trout fishery in the Smith River tailwater, Virginia: a case history ,” Anderson et al. 2003, argue that the tailwater brown trout fishery in the Smith River, Virginia has undergone noticeable and, from the angler’s point of view, undesirable changes possibly resulting from angler harvest, water quality changes, or limiting food resources. The researchers used electrofishing data dating back to 1976 and compared the condition of citation fish turned in by anglers and determined that the population has undergone a shift from a great abundance of large individuals to domination by smaller individuals. The condition of citation trout has also declined through the years. The authors admit some lack of data from the period before 1990, possible inefficiencies of electrofishing equipment in capturing large brown trout, as well as only anecdotal evidence surrounding the hypothesized limitation of food resources. The purpose of this article was to document the change in the Smith River fishery and to highlight areas of improvement for future research on tailwater salmonid fisheries.
Anderson, M.A., D.J. Orth, and S.M. Smith. 2003. Historical changes of the brown trout fishery in the Smith River tailwater, Virginia: a case history. Annual Conference of Southeastern Association of Fish and Wildlife Agencies 57: 150-159.
G. M. Buhyoff, C. W. Krause, M. R. Anderson, and D. J. Orth, in their symposium paper ‘Managing a trout tailwater in the presence of a warmwater endangered species’, are convinced that water temperatures in the Smith River tailwater, a function of hydropeaking operations, may be limiting trout growth, as well as spatially restricting the distribution of the endangered Roanoke logperch. They support this assertion by modeling alternative flow scenarios for the Smith River tailwater to determine if there is a temperature regimen that can enhance the growth of brown trout, as well as increase thermal habitat for Roanoke logperch, and similar warmwater species. The authors accept that the direct positive relationship between water temperature and trout growth, as used in their models, is just an assumption, and that continuing studies on the Smith River tailwater using bioenergetics modeling and in situ sampling will determine whether increased temperatures do in fact enhance trout growth. Buhyoff et al. aim to show that the effective management of trout and endemic warmwater species in hydropeaking tailwaters are not necessarily mutually exclusive and also to emphasize the importance of deliberate, informed flow management to alter the ichthyofauna of tailwaters.
Buhyoff G. M., C. W. Krause, M. R. Anderson, and D. J. Orth (2004). Managing a trout tailwater in the presence of a warmwater endangered species, Wild Trout VIII Symposium, 2004.
In their conference paper titled ‘Historical changes in the brown trout fishery in the Smith River tailwater, Virginia: a case history, M. R. Anderson, D. J. Orth and S.M. Smith assert that the brown trout population in the Smith River tailwater has shifted through time to a distribution dominated by a smaller size. They support this view by reviewing historical length and weight data from citation brown trout and citation numbers collected using citation catch records from 1971-2002, in addition to electrofishing data. The authors however accept the fact that more data would be necessary to fully evaluate changes that occurred in the tailwater and reservoir, because due to the absence of electrofishing data on the trout fishery prior to the 1990s, only limited data on the early trout fishery came from citation records. The writers’ main aim is to show the effects of regulation on fish assemblages.
Anderson M. R., D. J. Orth and S.M. Smith (2003). Historical changes in the brown trout fishery in the Smith River tailwater, Virginia: a case study, Proc. Ann. Conf. Southeast. Assoc. Fish and Wildl. Agencies 57: 150-159.
In their case history, “Historical Changes in the Brown Trout Fishery in the Smith River tailwater, Virginia: A case history” Anderson et al. argue that the length, weight and abundance of brown trout below Philpott reservoir has declined since the 1970s when it was recognized as a trophy trout area. The authors examined historical citation trout records and electrofished the tailwater areas to estimate the historical and current size of the largest trout in the tailwaters based on relative stock density and relative weight and showed that a downward trend in both criteria exists. The authors admit that current sampling with electrofishing may not have been completely effective in capturing the largest trout in the tailwaters and that changes in both regulations and fees for citation registration may have affected their data, but that despite these data limitations the decline in size and weight of brown trout is still measurable and significant. The purpose of this article is to discuss the change in the fishery in the Smith River, to state the monetary benefits for improving the fishery, and to propose potential changes in the reservoir (loss of food supply from decline in Alewife populations), change in water quality (eutrophication), and changes in riverine food supply (macroinvertebrates because of the flushing from dam operation) which need to be further examined.
Anderson, M.R., D.J. Orth, and S.M. Smith. 2003. Historical Changes in the Brown Trout Fishery in the Smith River tailwater, Virginia: A case history. Proc. Annu. Conf. Southeast Fish and Wildlife Agencies 57:150-159.
Anderson et al. (2002) used citation records and recent electrofishing samples to demonstrate that the brown trout fishery in the Smith River Tailwater was no longer providing the number and size of quality fish it once did. This fishery peaked in the mid 1970s when it provided many large fish, since then the number of citations has declined as has the size of those fish. They propose several explanations for this: 1) the reservoir had become increasingly oligotrophic, 2) habitat quality for macroinvertebrates in the tail water had declined, and 3) Alewife populations have declined. The authors acknowledge a dearth of data is available to support or challenge these hypotheses.
Anderson, M.A., D.J. Orth, and S.M. Smith. 2003. Historical changes of the brown trout fishery in the Smith River tailwater, Virginia: a case history. Annual Conference of Southeastern Association of Fish and Wildlife Agencies 57: 150-159.
Anderson et al begin by describing the early success of the brown trout tailwater fishery on the Smith River below Philpott Dam, VA. They describe that in 1970’s, the fishery produced high numbers of trophy-sized brown trout. However, they hypothesize that the fishery’s quality has declined since then. They used data from VDGIF citation records and electrofishing records to determine long-term trends of several aspects of the brown trout population. They determined the changes in RSD (230 mm, quality; 300 mm, preferred) and relative weight from 1970 to 1995. They determined that RSD has significantly decreased since 1970. The size of citation trout also decreased. Relative weight also significantly decreased over time. After the implementation of a $4.00 charge for citation issues, the number of citation trout also decreased. Possible causes of the Smith River tailwater fishery decline include overexploitation during the 1970’s, faunal succession in the upstream reservoir, decreased invertebrate production (via dam-related in-stream habitat alteration), and altered productive status of the upstream reservoir. Anderson et al conclude that future impoundment projects must collect large amounts of continuous, detailed data in order to evaluate future problems that may arise. They also believe that more effective methods for capturing brown trout must be implemented in order to evaluate the status of large brown trout that are difficult
In the case study, “Historical changes in the brown trout fishery in the Smith River tailwater, Virginia: A Case History”, Anderson et al. historical citation and modern electro-fishing data from the Smith River brown trout fishery in Virginia to document changes in the brown trout population between 1971 and 2002. The authors concluded that the fishery produced more trophy-sized trout in the 1970s than today and possible reasons for the decline in trophy fish could be competition from stocked rainbow trout, over-fishing, or changes in the trouts’ food-base. Some problems with the study are acknowledged by the authors, including: citation data does not provide an adequate description of the entire population and electro-fishing does not adequately capture larger individuals and these individuals may be missed during recent electro-fishing samples. The purpose of this study was to determine if the number of trophy fish are declining in the fishery and determine possible limiting factors for trout growth so that they may be corrected and the fishery improved.
Anderson, M. R., D. J. Orth, S. M. Smith. 2003. Historical changes in the brown trout fishery in the Smith River tailwater, Virginia: A Case History. Proc. Annu. Conf. Southeast Fish and Wildlife Agencies 57:150-159
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