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Summary

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

This paper summarizes the objectives, activities initiated and approaches used in developing Atlantic salmon stock re-building programmes in three large river systems in northern Finland in order to identify the priorities for research and management for further restoration and rehabilitation steps. Until recently, these historically renowned major salmon rivers have been harnessed for hydropower for 40–60 years without provisions for fish passage. Hydropower companies are obliged to compensate for the losses caused by dam construction by annual fish releases, including juveniles of Atlantic salmon and migratory brown trout. Returning fish are harvested in the designated ‘terminal fishery areas’ at river mouths. Recently, activities aimed at restoring salmonid stocks have started in all these rivers. First fishways at the dams closest to the river mouths were constructed on two rivers, and preliminary projects were completed to review the preconditions for restoration, options for bypassing the dams, and to study the performance of these fishways. New projects incorporating further detailed fishway planning are underway. The various projects have proved successful in bringing together authorities, hydropower companies, local organizations, and expertise from various institutions for a joint effort to tackle these multifaceted and multidisciplinary problems.


Introduction

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

Atlantic salmon (Salmo salar) once reproduced in most Baltic rivers, but various human activities have significantly decreased the number of rivers with salmon runs throughout the Baltic area. River fragmentation through damming, deteriorated water quality and overfishing are the most obvious causes of the decline. Natural, self-sustaining populations currently exist in less than thirty Baltic rivers (e.g. Ranke et al., 1999).

After World War II, most of the important remaining Baltic salmon rivers in Finland, the rivers draining into the Bothnian Bay, were harnessed for hydropower development, and their naturally reproducing salmon populations were lost. During that time, production of electricity was seen as an overriding national interest and generally took precedence over other factors. Local people who endured the loss of self-sustaining salmon populations had no way to articulate their interests and express criticism given the prevailing economic and political situation. Hydro-development planning proceeded on the basis of technical and economic calculations, but environmental and social impacts were given minor or no attention. Loss of salmon meant a dramatic change for local people, both in loss of economic as well as cultural and heritage values of most migratory fish species.

Salmon smolt releases were often directed by the water court decisions as a means to compensate the sea fisheries for losses caused by the extirpation of populations due to hydro-development. These releases, totaling c. 3 million fish annually in the Bothnian Bay area, have provided a lucrative basis for commercial fisheries, both in the offshore areas of the Baltic Main Basin, and coastal fisheries along the Bothnian Bay (Christensen et al., 1994; Karlsson and Karlström, 1994). However, the recent decline in survival of the Baltic salmon post smolts, especially evident in reared salmon (Michielsens et al., 2006), has raised questions about the feasibility of such large-scale releases. A concurrent increase in wild salmon production in the northernmost areas of the Baltic Sea (Romakkaniemi et al., 2003; ICES, 2010) has increased the contribution of wild fish in different Baltic fisheries (Koljonen, 2006), and raised interest in making better use of natural salmon production areas in the regulated rivers.

In recent decades, the demand for recreational use of landscapes and watercourses has been growing due to increased leisure time and urbanization, resulting in an increased environmental consciousness. Prospects of nature-based tourism are thus very promising in many northern regions. At the same time, hydropower development has experienced a revival: Dams and hydropower are once again being promoted as engines for development, poverty alleviation and sustainable, climate-friendly energy generation (Klöpper, 2008; Karjalainen and Järvikoski, 2010). Concurrently, there are policy initiatives, such as the EU Water Framework Directive (European Parliament, 2000), which aim to restore the multi-functionality of riverine ecosystems and landscapes. The Directive guides Member States to aim for good ecological potential even in heavily modified water courses, and to increase citizen participation in watershed management. Together with the need to safeguard biodiversity, these issues have provided additional pressure for the restoration of naturally reproducing populations into the rivers now harnessed for hydropower production.

In this paper, we review the recent attempts to restore salmon populations in three regulated salmon rivers running into the Bothnian Bay (northern Baltic Sea), the rivers Oulujoki, Iijoki and Kemijoki. We summarize the biological, technical and social aspects investigated during recent development projects on these rivers, and highlight the role of multidisciplinary collaboration, networking and social capital as important prerequisites and drivers for these activities.

Study area

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

The rivers Oulujoki, Iijoki and Kemijoki (Fig. 1, Table 1) once produced considerable runs of migratory species: Atlantic salmon, sea trout, Salmo trutta, migratory whitefish, Coregonus lavaretus and river lamprey, Lampetra fluviatilis. These populations also supported extensive fisheries in the rivers, estuaries and the nearby coastal areas. Increased harvest of sea fishing caused a decline of catches as early as the 1900s and dredging of river channels for timber floating destroyed a lot of spawning and nursing areas. Large scale forestry, agriculture and peat extraction resulted in a deterioration of water quality in some tributaries of the rivers Oulujoki and Iijoki; a consequence of their being located in more densely populated areas than the River Kemijoki system further north. The construction of multiple main stem dams equipped with Kaplan turbines on the Rivers Oulujoki and Kemijoki in 1940s and the River Iijoki in 1960s effectively blocked migration corridors for migratory fishes in all three systems.

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Figure 1.  The three regulated river systems in Northern Finland, the rivers Oulujoki, Iijoki and Kemijoki-Ounasjoki and their watersheds (grey areas); the largest tributary of the Kemijoki, the unregulated River Ounasjoki, is marked off separately. The existing fish passes are indicated at Isohaara (A) and Merikoski (B), and the black circles indicate the locations of hydro-electric dams. Copyrights: Catchments © SYKE; Borders of Finland © SYKE, National Land Survey of Finland license 7/MML/10; Watersheds © Affecto Finland Oy, State Map Centre license L465

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Table 1.    Hydrological characteristics and number of dams and fishways in the rivers Oulujoki, Iijoki and Kemijoki
RiverCatchment area (km2)Lake Percentage (%)Length of main stem (km)Dams/fishwaysa (n)Dischargeb
MQ (m3 s−1)HQ (m3 s−1)NQ (m3 s−1)
  1. aNumber of dams/fishways in the main stem.

  2. bMean 1991–2000; MQ, HQ, NQ = mean, maximum and minimum discharge, respectively.

Oulujoki22 84111.41027/12748480
Iijoki14 1915.71905/018112480
Kemijoki51 1274.32985/160745570

Prior to hydro-development, the annual discharge pattern of all three rivers was originally similar with a peak in late April–early June due to snowmelt and a smaller increase in late autumn. However, the natural spring flood was smaller and later in the River Oulujoki, which has a large central lake (Fig. 1). The regulation practice has changed this discharge pattern considerably, especially in the River Oulujoki, where the lake is used for storing flood waters as a reservoir and the spring flood has practically disappeared (Fig. 2). Daily discharge varies with minimum flows during the night and increasing flows towards the afternoons as of resulting of hydro-peaking practices.

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Figure 2.  Mean discharges (1971–2000) of the regulated rivers Oulujoki, Iijoki and Kemijoki and the unregulated River Tornionjoki located in the same region

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As a consequence of dam construction, the natural salmon stocks have been extirpated in the rivers Oulujoki and Kemijoki. However, since the damming in 1960s, salmon and sea trout stocks have been maintained in the River Iijoki through a live broodstock programme where stocks are renewed using eggs stripped from returning fish, and their genetic diversity are monitored (see Piironen and Heinimaa, 1998). In the River Oulujoki, compensatory releases of salmon smolts originate from a hatchery stock comprising a mixture of genetic material from three Bothnian Bay rivers (Skellefteå, Iijoki and Tornionjoki; in addition, few individuals from the former Oulujoki strain were still available and used when the mixed hatchery stock was established). Hatchery smolt releases in the River Kemijoki mostly originate from salmon stock of the nearby wild salmon river system, the River Tornionjoki, but also include material from the River Iijoki strain. Realized annual smolt releases somewhat vary around the set target figures for annual obligations (Fig. 3). The smolts are released at the river mouths, except in Oulujoki where one-third of the smolts are released below the second dam, 35 km from the river mouth (Fig. 1). Specific salmon fishery areas have been established at the outlets of these rivers. These so called terminal fishing areas have allowed for the effective harvest of hatchery-reared salmon returning to the outlets of the dammed rivers, and salmon fishing regulations for these areas are less restrictive compared with those in other coastal areas.

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Figure 3.  Atlantic salmon smolt releases in the rivers Kemijoki, Iijoki and Oulujoki. Annual obligations of smolt releases are 615 000 individuals for the River Kemijoki, 340 000 for the River Iijoki, and 200 000 for the river Oulujoki

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Technical challenges in fish passage

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

In the River Oulujoki, the first fishway constructed in 2003 opened a route for migratory fish over the Merikoski dam at the river mouth and into a 40-km river stretch including two tributaries. The fishway is a combination of vertical slot sections and a semi natural bypass, and is equipped with a VAKI fish counter and a video camera (Isomaa and Laine, 2008). Fish can be observed through a window in a control room at the upper end of the fishway. The successful first years of the fishway operation with 150–500 salmon and trout entering the river (Table 2) have provoked public pressure for restoring runs of fish, and especially migratory salmonids further into the river. In this river, most of the suitable lotic habitats are located in tributaries running into the 100-km-long main reach, where as many as seven hydropower dams prevent fish access. Detailed planning has been started and a feasibility study has been conducted to determine the optimal fish passage options for each dam.

Table 2.    Number of ascending Atlantic salmon and sea trout observed passing the Merikoski fishway in the River Oulujoki in years 2004–2009
 Atlantic. salmonSea trout
2004407117
2005311113
200615339
200726982
200810436
200910248

The first fishway on the River Kemijoki, at the Isohaara dam, was constructed in 1993. It is a combination of a vertical slot and a Denil fishway with two entrances (Laine et al., 1998). The next dam is 20 km upstream and there are no tributaries running into the impoundment between the dams. Hundreds of salmonids and other fish use the Isohaara dam fishway annually in spite of the lack of migrating fish stocks that originate from the river, effective fishing in the river mouth and the simultaneous use of two power houses, one on each shore of the 200 m wide river mouth (Laine et al., 2002a,b). A feasibility study, carried out in the early 2000s, suggested that there is a sound biological basis for constructing fishways to the four additional dams blocking the access to the River Ounasjoki, the major free-flowing tributary of the River Kemijoki, containing vast salmonid production potential (Laine et al., 2002a,b; Fig. 1; Table 3). However, no progress has been possible until very recently. A major problem slowing down the next steps has been securing commitment from the municipalities along the main river with regard to funding and sharing the responsibilities associated with the proposed new fishways. Progress has recently been made along these fronts; an additional fishway in connection with the old Isohaara powerhouse.

Table 3.    Estimates of potential production areas, implemented and planned habitat restoration activities and their costs in the rivers Kemijoki, Iijoki, and Oulujoki. Data from Laine et al., 2002a,b; Mäki-Petäys et al., 2008; Huhtala, 2008
RiverPotential production habitat, haRestoration area, haCostsa Million€Years of implementation
  1. aCosts include mainly measures to compensate for impediments caused by earlier timber floating; habitat restoration in dredged river sections, clearing of river bottom from sinken logs, rehabilitation of water levels in lakes regulated for timber floating, and landscaping of riverside areas.

  2. bRiver Ounasjoki tributary system only.

Kemijokib1900101710.01985–2008
Iijoki700–8004106.01988–2011
Oulujoki50–100650.51995–2012

The mid- and upper reaches of the River Iijoki, above five main stem dams located within the lowest 50 km of the river, include considerable habitat suitable for salmonid spawning and nursery. No fishways have been constructed, but adult salmon trap and transfer operations and restocking of juvenile salmon and sea trout have been initiated in the unregulated sections of the system. Planning fish passage in the River Iijoki has been preceded by an ongoing social survey aimed at developing commonly accepted objectives for restoring migratory fish stocks. After determining the fish passage alternatives that best meet the common objectives, the details of how to technically arrange the fish passage at the individual dams will be decided. Technical options include making use of old river channels below the spillways, constructing fish passage at the hydropower dams, and transferring fish above the dams.

Short term flow regulation, resulting in the reduction of nighttime flow and water level variation in the impoundments presents particular challenges to fish passage. Water level variation can be overcome by either vertical slot fishways that can be effective across a range of water levels (e.g. Larinier, 2002), or by short vertical slot structures in the entrance and exit sections of the proposed fishways. Since there are several successive dams in all three rivers (Fig. 1), fishway efficiency at each dam should be as high as possible to minimize the cumulative effects that delays and failures at individual dams can have. The key elements are optimal entrance and exit locations, sufficient attraction flows and safe downstream passage.

Trapping migrating fish at lower dams and transferring them to the upper river reaches is a cost-effective management option in heavily regulated rivers, although there are constraints such as the dependency on human labor and the limited selection of both target species and number of fish that can be included. The method can, however, be used at least in a supportive capacity during the early stages of stock re-building processes.

Juvenile salmonid habitat assessment and restoration plans

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

The quantity of potential habitat for salmonid production has been estimated based on the total area of the rapids and glide sections (mean water velocity >0.2 m s−1) suitable as spawning and nursery areas. For the rivers Kemijoki, Iijoki, and Oulujoki, the estimates are c. 1900 ha (R. Ounasjoki only), 700–800 ha, and 50–100 ha, respectively (Laine et al., 2002a,b; Mäki-Petäys et al., 2008; Huhtala, 2008; Table 3). In the River Kemijoki, the potential habitat is almost entirely situated in a single, large unregulated tributary, the River Ounasjoki, which enters the main stem above five main stem dams. In the River Iijoki, suitable habitats are found both in the main stem and in the tributaries above the five dams. In the River Oulujoki, four small tributaries provide c. 50 ha of suitable production areas. Depending on the minimum flow and the short-term regulation practice in the River Oulujoki, potential production areas in the main stem may vary between 0 and 50 ha in addition to the 50 ha available in tributaries (Table 3).

Over the past few decades, several stream enhancement programmes have been implemented to increase habitat suitable for salmonids in the rivers Kemijoki, Iijoki and Oulujoki, including costs at c. 16 million Euros (Table 3). These programmes have focused mostly in the upper reaches and tributaries but in some cases activities have been conducted in the main stem of the rivers (Table 3). Dredged reaches of these rivers previously used for log floating were restored using large boulder and cobble structures and opening of closed side channels or channel margins. In addition, cleaning gravel in existing spawning areas, moving of gravel to suitable places, and making new spawning grounds were also performed to increase suitable spawning habitat. Generalized habitat suitability criteria (Mäki-Petäys et al., 2002; Louhi et al., 2008) have been developed for salmon nursery and spawning areas to facilitate the planning and evaluation of these habitat restoration projects.

Physical habitat restoration of the river channels may be ineffective, however, if continued particle sedimentation from peatlands to streams prevents successful incubation of salmon eggs in the spawning grounds (Laine et al., 2001). Several studies have revealed severe effects of fine sediment on fluvial salmonids, e.g. reduced egg survival (Armstrong et al., 2003) and delayed emergence of alevins (Roussel, 2007). In some of the tributaries of these large regulated rivers, water quality issues may form a bottleneck requiring further actions in the catchment areas. Humic substances and related low pH levels in single tributaries of the Oulujoki and Iijoki and inorganic sediment loads from dredged areas in a second tributary of the Oulujoki are likely limiting salmonid production success (Mäki-Petäys et al., 2008). The sub-catchment problems require further investigation and potentially mitigating actions, e.g. liming and effective control of sediment transportation.

Salmon migration studies

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

In recent years, continued studies focussed on salmon biology with particular emphasis on salmon migrations to address river-specific issues related to re-establishing salmon populations within these systems. The approaches and aims of these studies varied dependent on the characteristics of the individual rivers and the constraints for re-establishing salmonid species in these different river systems. In the River Oulujoki, which has relatively limited spawning and nursery areas for salmonids, the research has focused on migration behaviour and survival of stocked hatchery-reared smolts combined with studies on migratory behaviour of adults ascending the recently constructed Merikoski fishway and within the 40 km stretch of the barrier-free river. The studies have included large-scale radio-tagging of hatchery-reared salmon smolts to investigate optimal timing of release for maximum survival. Video monitoring and radio-tracking of ascending adults was also included to study fishway utility and upstream migratory behaviour to the next hydropower dam (Karppinen et al., 2008), resulting in strategies to optimize smolt release and fishway improvements to maximize survival of upstream migrating salmon and brown trout.

In the rivers Kemijoki and Iijoki, with their abundant spawning and nursery areas above the lower main stem hydropower dams, the migration studies started in 2009 and have focused on evaluating the migration and spawning behaviour of radio-tagged adult salmon trapped at river mouths and transferred above the main stem dams. If it is shown that the transferred salmon remain above the hydropower dams and utilize suitable spawning areas (cf. Erkinaro et al., 2000), this approach could be beneficial in re-starting the natural life-cycle of salmon in both river systems. The transferred salmon could produce offspring that willingly migrate upstream once the fishways are opened in future years. Adult salmon trap and transfer can be seen as a semi-natural way of restoring migratory fish populations and it may decrease the need for large-scale stocking of hatchery-reared juveniles.

Although the problems associated with restoring natural salmonid populations differs significantly among the three rivers, the results obtained from the biological migration studies can at least partly be utilized and applied across all the rivers. This will be beneficial for the allocation of constrained research funds, as all individual experiments will likely not be repeated in all three river systems, and therefore experiences gained at one river will be available for facilitating problem-solving at other rivers. These results will likely be useful for similar restoration programmes elsewhere aiming at re-establishment of migratory fish populations.

Social impact assessment

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

Stakeholder and citizen participation is crucial for the successful process of restoring migratory fish runs and river ecosystems. In the case of heavily modified rivers, restoration is inevitably a lengthy process, and the long-term commitment of different parties to the project and interaction between planners, authorities, stakeholder groups and citizens is therefore of vital importance. Thus, there is a clear demand for approaches that can evaluate multiple issues, interests and values and integrate stakeholder and community concerns into the assessment and decision making processes of river restoration. Restoration planning often suffers from poorly defined objectives, the confusion between objectives and means, and lack of consideration of the impacts of suggested alternatives and measures (Corsair et al., 2009). The ecological and economic benefits of restoration have been increasingly recognized and evaluated, but the analysis and discussion about the social dimensions of restoration efforts and practices are still rare (Aronson et al., 2010).

Over recent decades, social impact assessment (SIA) procedures have developed which provide advanced techniques and methods of prediction and support public participation, impact mitigation, monitoring and management (Vanclay, 2006). In social impact assessment, we have used Multicriteria Decision Analysis (MCDA) approach which helps structuring of decision situations by expressing and analyzing systematically stakeholders’ preferences, comparing alternatives having incommensurable impacts and identifying key trade-offs. For example, in order to support the objective to create a concrete program for restoring migratory fish in the River Iijoki, we applied interactive MCDA in a collaborative process which aimed at finding to an ecologically, socially, and economically sustainable way to return migratory fish stocks. In our decision analysis interview approach (Marttunen and Hämäläinen, 2008) key stakeholder groups, e.g. hydropower company, fishermen, fisheries and environmental authorities and municipalities, are actively involved in the different phases of the work and analysis of the results are realized face-to-face between the analyst and the participants.

Various interest groups often have different and even conflicting objectives concerning river environments and their ecosystem services. In Scandinavian countries high hopes are placed on maintaining even the sparse populations of Atlantic salmon. In coastal areas salmon provide important catches for some commercial or semi-commercial fishers while the inhabitants of the river valleys now see salmon as an essential element in developing tourism around recreational fishing (Haapasaari and Karjalainen, 2010). Furthermore, the salmon management takes place in a context of changing public expectations and a broadening constituent base. Fishery management have been designed to optimize food production, but fishery interests are increasingly heterogeneous, no longer just commercial ones. They represent a wide range of commercial, recreational, and environmental interests. Non-market values of fish stocks – the values of existence and future options – are becoming more significant in fisheries management (Hanna, 2008).

Based on social impact assessments undertaken on the rivers Kemijoki, Iijoki and Oulujoki, it seems that interest conflicts and cognitive conflicts are the most evident types of conflicts in the context of returning migratory fish in heavily regulated rivers. In the case of an interest conflict, what is at stake is the distribution of losses and gains. The parties may agree on facts and values, but perhaps disagree on how to balance the costs of building fish ladders with the loss of electricity generation due to the water ‘lost’ in the fish pass, or on how to reorganize fishing regulations and reallocate catches between estuaries and up-river areas in the future.

In the rivers Kemijoki and Iijoki, efforts to start the restoration of migratory fish populations were made in the late 1990s. However, at that time there was insufficient common will or agreement between different interest groups to pursue the initiative. SIA in the Kemijoki case showed that a conflict between locals living at the river mouth and those inhabiting the valley further upstream was especially evident (Ponnikas and Reinikainen, 2002). Over the present decade, societal pressures, e.g. from environmental policies, for restoring riverine ecosystems have became stronger. As a consequence, new efforts have been launched. The first success of the new century was the Merikoski fishway on the River Oulujoki. The migratory fish restoration projects on the Rivers Iijoki and Kemijoki are now also seen as regional ‘flagship’ projects in restoring river ecosystems. Salmonid fish species are considered as indicators of good ecological status of a river, and provide valuable potential for fishing tourism and recreation.

The results from the River Oulujoki indicated that local residents and most stakeholder groups had a broad view of the restoration programme and the river ecosystem. They recognized not only the fishery values, but also the scenic values, recreational possibilities, and better image for municipalities, which might attract tourists and new inhabitants, and help the development of the business sector. The value of ecosystems and the river environment as a whole (as an environmental good) is increasing among citizens and all stakeholder groups (Karjalainen and Reinikainen, 2008).

The SIA process in the River Oulujoki showed that the conflict between hydropower and other interests were actually less than that perceived at the beginning of the project. It was predicted that the hydropower company would hamper the whole idea of restoring salmon runs by driving a hard bargain for building fish ladders and in relation to river regulation and stream flow issues. In all cases the use of SIA has helped to generate a shared understanding about the project goals and made the aims and values of different stakeholders more visible and transparent. The results can be utilized to identify the most acceptable and feasible alternatives for restoring migratory fish runs.

Conclusions and future prospects

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

Restoration of fluvial habitats and their biota is currently a world-wide trend and phenomenon as well as a booming enterprise (see Palmer et al., 2007) reflecting a growing awareness of aquatic ecosystem degradation. Programs aiming at salmonid stock re-building have been started in many countries; some already have considerable history behind them, but increasing interest in restoration projects has been evident especially in recent years. Long-term restoration efforts in New England rivers in USA have mostly started as single-species projects with an interest in Atlantic salmon, but have gradually evolved to multi-species diadromous fish restoration programmes (Gephard, 2008). Similarly, despite separate projects on single migratory species, the large-scale restoration of the River Rhine ecosystem in central Europe comprises a multi-species approach (e.g. Raat, 2001). The most comparable situations with our study areas can be found in northern Sweden, on the other side of the Gulf of Bothnia. Restoration activities in northern Swedish rivers have focused on challenges in both upstream migration of returning adults (Lundqvist et al., 2008) and downstream guidance of juvenile and spent individuals (Ferguson et al., 2008) of Baltic salmon and sea trout. These projects face very comparable challenges with those in our rivers, e.g. fishway solutions, passage beyond dams and through turbines, and conflicts with current stocking and fishing policies. As concluded by Lundqvist et al. (2008), problems to bypass the hydropower dams in their search for natural spawning areas is in conflict with sustainable management of the anadromous fish populations. One major question is the very high fishing pressure on both reared and wild salmon in the feeding areas in the Baltic Proper, and on the returning route along the coasts of the Gulf of Bothnia (cf. Romakkaniemi et al., 2003; ICES, 2010). These factors highlight the importance of local, but also national and broad-scale international long-term solutions to facilitate re-building and maintenance of viable salmon populations in future.

The present obligations for releasing migratory fish at the river mouths of the regulated rivers in northern Finland are based on legal decisions, which aim to compensate for the lost harvest to the fishermen at the river mouth and in nearby coastal areas. This policy is not supporting restoration of migratory salmonid stocks and biodiversity in the rivers, and, for instance, the apparent declining trend in returning fish at the Merikoski fishway (Table 2) raise concerns about the stocking practices. Marked changes in the current legal system in relation to compensatory releases and terminal fishery areas are needed if migratory routes and populations of salmonid populations are to be restored, especially if naturally reproducing self-sustaining populations are the desired target. Altering stocking obligations is possible but not easy, and there are questions about the ownership of the water areas and emerging conflicts of interest between sea and riverine fishermen. A broad socio-economic research and collaborative planning methods are of utmost importance to help inform the process onward on local and regional scales, but political decisions are needed on national and international scales. It should be remembered that the current legal situation with the release obligations and terminal fishery areas has not allowed a true kick-off for the stock-rebuilding in these rivers. Therefore no actual results of the restoration success are available as of yet, although various background investigations and pilot studies have been carried out or are underway. In addition, relevant objectives of restoration may vary within the rivers; the target levels for natural salmonid production being considerably higher for the rivers Kemijoki (Ounasjoki) and Iijoki compared to those for the River Oulujoki, simply because of very different amounts of suitable fluvial habitat available (Fig. 1; Table 3).

Juridically, fishways can be constructed either on a voluntary basis or by changing the present stocking obligations. The latter option may entail a long and complicated legal process, which is why the voluntary basis must be favored whenever possible. Granting the permission for a voluntary fishway construction assumes that an agreement through negotiations can be reached with the owner of the power station on such issues as the amount of water that can be guided into the fishway, and the type and location of the fishway. In this case, there is no need to change the fish stocking obligation but this option could be included in the negotiations. Potential funding sources for the fishway construction include the European Regional Development Fund, the State, municipalities and hydropower companies.

Social impact assessments at the three Bothnian Bay rivers have revealed that overall interest in, or success of fish stock restoration programmes does not rely entirely on fishery values and performance. The overall value of the natural environment, including the habitat connectivity, biological diversity and genetic diversity, has been given increased focus and importance in recent years. For instance, the river basin management plans based on the European Water Framework Directive define that it is not possible to reach the target of a good ecological status in the rivers Kemijoki and Iijoki without an open fish migration route. However, progress in meeting these objectives has faced hindrances such as the slow processes of obtaining legal permissions for the actions and the difficulty in developing consensus among the stakeholders as how to proceed. Nevertheless, the broad, overall objectives of the restoration programmes are typically accepted and agreement has been reached among stakeholders on common interests, targets and values. Close collaboration has facilitated building up trust and social capital, which are needed prior to concrete actions (e.g. constructing fish ladders, restocking salmon, restoring habitats, regulating fishing, etc.). In the case of Oulujoki, a workshop at the end of the feasibility study revealed that stakeholders had developed a common will to proceed thereby demonstrating a social learning process leading to concrete results.

Decision making in restoration projects can be complex and seemingly intractable, mostly because of the inherent trade-offs between sociopolitical, ecological, and economic factors, as shown in this paper. We argue that interdisciplinary research and collaborative planning are the key tools for gaining success in restoration efforts. During the programmes described here, the collaborative potential for salmonid restoration at the rivers Oulujoki, Iijoki and Kemijoki has clearly been improved by the interactive cooperation between the interest groups, stakeholders, institutions, and authorities. Through these interactions, the best practices, techniques and experiences have been developed and shared to tackle these multifaceted and multidisciplinary problems. Valuable insights have also been gained through contacts with international experts. In the future phases of these programmes, the challenge will be to further improve the stakeholder involvement and interdisciplinary nature of the collaboration. There is also a need to systematically and comprehensively compare alternative scenarios of varying salmonid population abundance along ecological, social, cultural and economic dimensions.

The cross-disciplinary approach taken in the Gulf of Bothnian rivers presented in this paper is hopefully an useful example to others struggling with the complex challenges of migratory fish restoration in heavily regulated river systems. The problems and circumstances may vary between individual cases, rivers and countries, but the basic challenges are typically fairly similar, requiring broad, multidisciplinary actions, and long-term commitments.

Acknowledgements

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References

This paper is a contribution of the two development projects in the rivers Oulujoki and Iijoki, supported by European Regional Development Fund, State of Finland, cities and municipalities in the river catchments, hydropower companies Pohjolan Voima and Fortum Power and Heat, the Councils of Oulu and Kainuu Regions, and the regional fishery authority in the Kainuu Centre for Development, Transport and the Environment. Support and funding for the River Kemijoki project has been provided by the Lapland Centre for Development, Transport and the Environment, and the Kemijoki Oy hydropower company. We owe special thanks to many persons who have acted in crucial roles in these projects, especially Jermi Tertsunen, Petri Karppinen, Pirkko-Liisa Luhta, Mikko Jaukkuri, Olli van der Meer, Maare Marttila, Jarmo Huhtala, Jukka Viitala, and Markku Vierelä.

References

  1. Top of page
  2. Summary
  3. Introduction
  4. Study area
  5. Technical challenges in fish passage
  6. Juvenile salmonid habitat assessment and restoration plans
  7. Salmon migration studies
  8. Social impact assessment
  9. Conclusions and future prospects
  10. Acknowledgements
  11. Conflict of interests
  12. References
  • Armstrong, J. D.; Kemp, P. S.; Kennedy, G. J. A.; Ladle, M.; Milner, N. J., 2003: Habitat requirements of Atlantic salmon and brown trout in rivers and streams. Fish. Res. 62, 143170.
  • Aronson, J.; Blignaut, J.; Suzanne, N.; Milton, J.; Maitre, D.; Esler, K. J.; Limouzin, A.; Fontaine, C.; de Wit, M. P.; Mugido, W.; Prinsloo, P.; van der Elst, L.; Lederer, N., 2010: Are socioeconomic benefits of restoration adequately quantified? a meta-analysis of recent papers (2000–2008) in Restoration Ecology and 12 Other Scientific Journals Restor. Ecol. 18, 143154.
  • Christensen, O.; Eriksson, C.; Ikonen, E., 1994: History of the Baltic salmon, fisheries and management. ICES Coop. Res. Rep. 197, 2339.
  • Corsair, H. J.; Ruch, J.; Zheng, P. Q.; Hobbs, B. F.; Koonce, J. F., 2009: Multicriteria decision analysis of stream restoration: potential and examples. Group Decis. Negot. 18, 387417.
  • Erkinaro, J.; Karppinen, P.; Mäkinen, T.; Kaukoranta, M.; Popov, N.; Lupandin, A., 2000: Restoring the Atlantic salmon stock of the River Tuloma – a pilot experiment using transplanted radio-tagged adult salmon. In: Advances in fish telemetry. A. Moore and I. C. Russell (Eds). CEFAS, Lowestoft, pp. 229235.
  • European Parliament, 2000: Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal L 327, 22 December 2000.
  • Ferguson, J. W.; Ploskey, G. R.; Leonardsson, K.; Zabel, R. W.; Lundqvist, H., 2008: Combining turbine blade-strike and life cycle models to assess mitigation strategies for fish passing dams. Can. J. Fish. Aquat. Sci. 65, 15681585.
  • Gephard, S., 2008: Restoring Atlantic Salmon (Salmo salar) to New England. In: Saving biological diversity. balancing protection of endangered species and ecosystems. R. A. Askins, G. D. Dreyer, G. R. Visgilio and D. M. Whitelaw (Eds). Springer, New York, pp. 7584.
  • Haapasaari, P.; Karjalainen, T. P., 2010: Formalizing expert knowledge to compare alternative management plans: sociological perspective to the future management of Baltic salmon stocks. Mar. Policy 34, 477486.
  • Hanna, S., 2008: Institutions for managing resilient salmon (Oncorhynchus spp.) ecosystems: the role of incentives and transaction costs. Ecol. Soc. 13, 35. [online] URL: http://www.ecologyandsociety.org/vol13/iss2/art35/.
  • Huhtala, J., 2008: From log floating to fishery rehabilitation – Examples of the impacts of obligatory post log floating rehabilitation on the fishing economy. The Finnish Environment 29, 105 pp (In Finnish with an English abstract).
  • ICES, 2010: Report of the Baltic Salmon and Trout Assessment Working Group (WGBAST). ICES CM 2010/ACOM:08, 253 pp.
  • Isomaa, M.; Laine, A., 2008: The ascent of salmon and sea trout in the Merikoski fishway. In: Will salmon return to the River Oulujoki? Final report of Oulu and Lososinka river surveys 2006–2007. A. Laine (Ed.). The Finnish Environment 5, 95100. (In Finnish with an English abstract).
  • Karjalainen, T. P.; Järvikoski, T., 2010: Negotiating river ecosystems: impact assessment and conflict mediation in the cases of hydro-power construction. Environ. Impact Assess. Rev. 30, 319327.
  • Karjalainen, T. P.; Reinikainen, K., 2008: The social preconditions and effects of restoring migratory fish at the River Oulujoki. In: Will salmon return to the River Oulujoki? Final report of Oulu and Lososinka river surveys 2006–2007. A. Laine (Ed.). The Finnish Environment 5, 1831. (In Finnish with an English abstract).
  • Karlsson, L.; Karlström, Ö., 1994: The Baltic salmon (Salmo salar L.): its history, present situation and future. Dana 10, 6185.
  • Karppinen, P.; Marttila, M.; Jaukkuri, M.; Annala, M.; Männistö-Vetoniemi, K.; Heikkinen, S.; Jørgensen, S.; Vähä, V.; Erkinaro, J., 2008: Telemetry studies on salmon and pike in the lower part of the River Oulujoki. In: Will salmon return to the River Oulujoki? Final report of Oulu and Lososinka river surveys 2006–2007. A. Laine (Ed). The Finnish Environment 5, 8594. (In Finnish with an English abstract).
  • Klöpper, Y., 2008: Southeast Asian water conflicts – from political geography perspective. Asia Eur. J. 6, 325343.
  • Koljonen, M.-L., 2006: Annual changes in the proportions of wild and hatchery Atlantic salmon (Salmo salar) caught in the Baltic Sea. ICES J. Mar. Sci. 63, 12741285.
  • Laine, A.; Kamula, R.; Hooli, J., 1998: Fish and lamprey passage in a combined Denil and vertical slot fishway. Fish. Manage. Ecol. 5, 3144.
  • Laine, A.; Heikkinen, K.; Sutela, T., 2001: Incubation success of brown trout (Salmo trutta) eggs in boreal humic rivers affected by peatland drainage. Arch. Hydrobiol. 150, 289305.
  • Laine, A.; Jokivirta, T.; Katopodis, C., 2002a: Salmon and sea trout passage in a regulated northern river – fishway efficiency, fish entrance and environmental factors. Fish. Manage. Ecol. 9, 6577.
  • Laine, A.; Niva, T.; Mäki-Petäys, A.; Erkinaro, J., 2002b: Will salmon leap into the River Ounasjoki? The return of salmon to the Rivers Kemijoki and Ounasjoki. Section III: bases in fish biology Lapland Regional Environment Centre, Regional Environmental Publications 271, 127199.
  • Larinier, M., 2002: Pool fishways, pre-barrages and natural bypass channels. Bull. Fr. Peche Piscic. 364(suppl.), 5482.
  • Louhi, P.; Mäki-Petäys, A.; Erkinaro, J., 2008: Spawning habitat of Atlantic salmon and brown trout: general criteria and intragravel factors. River Res. Appl. 24, 330339.
  • Lundqvist, H.; Rivinoja, P.; Leonardsson, K.; McKinnell, S., 2008: Upstream passage problems for wild Atlantic salmon (Salmo salar L.) in a regulated river and its effect on the population. Hydrobiologia 602, 111127.
  • Mäki-Petäys, A.; Muotka, T.; Huusko, A.; Erkinaro, J., 2002: Transferability of habitat preference criteria of juvenile Atlantic salmon (Salmo salar). Can. J. Fish. Aquat. Sci. 59, 218228.
  • Mäki-Petäys, A.; Marttila, M.; van der Meer, O.; Tertsunen, J.; Isomaa, M.; Louhi, P.; Havumäki, M.; Shirokov, V.; Shurov, I.; Erkinaro, J., 2008: Juvenile salmon production areas in the river Oulujoki system. in: Will salmon return to the River Oulujoki? Final report of Oulu and Lososinka river surveys 2006–2007. A. Laine (Ed). The Finnish Environment 5, 5670. (In Finnish with an English abstract).
  • Marttunen, M.; Hämäläinen, R. P., 2008: Decision analysis interviews in supporting collaborative management of a large regulated water course. Environ. Manag. 42, 10261042.
  • Michielsens, C. G. J.; McAllister, M. K.; Kuikka, S.; Pakarinen, T.; Karlsson, L.; Romakkaniemi, A.; Perä, I.; Mäntyniemi, S., 2006: A Bayesian state-space mark-recapture model to estimate exploitation rates in mixed-stock fisheries. Can. J. Fish. Aquat. Sci. 63, 321334.
  • Palmer, M.; Allan, J. D.; Meyer, J.; Bernhardt, E. M., 2007: River restoration in the twenty-first century: data and experiential knowledge to inform future efforts. Restor. Ecol. 15, 471482.
  • Piironen, J.; Heinimaa, P., 1998: Preservation programs for endangered fish stocks in Finland. In: Action before extinction. An international Conference on Conservation of Fish Genetic Diversity. B. Harvey, C. Ross, D. Greer and J. Carolsfeld (Eds). World Fisheries Trust, Vancouver, BC, pp. 105113.
  • Ponnikas, J.; Reinikainen, K., 2002: Social impact assessment. In: Will salmon leap into the River Ounasjoki? The return of salmon to the Rivers Kemijoki and Ounasjoki. Lapland Regional Environment Centre, Regional Environmental Publications, 271, 127199.
  • Raat, A. J. P., 2001: Ecological rehabilitation of the Dutch part of the River Rhine with special attention to the fish. REGUL RIVER: Res. Manag. 17, 131144.
  • Ranke, W.; Rappe, C.; Soler, T.; Funegård, P.; Karlsson, L.; Thorell, L., 1999: Baltic salmon Rivers – status in the late 1990s as reported by the countries in the Baltic Region. International Baltic Sea Fishery Commission (IBSFC). Baltic Marine Environment Commission – Helsinki Commission (HELCOM). The Swedish Environment Protection Agency. The Swedish National Bord of Fisheries. 69 pp.
  • Romakkaniemi, A.; Perä, I.; Karlsson, L.; Jutila, E.; Carlson, U.; Pakarinen, T., 2003: Development of wild Atlantic salmon stocks in the rivers of the northern Baltic Sea in response to management measures. ICES J. Mar. Sci. 60, 114.
  • Roussel, J.-M., 2007: Carry-over effects in brown trout (Salmo trutta): hypoxia on embryos impairs predator avoidance by alevins in experimental channels. Can. J. Fish. Aquat. Sci. 64, 786792.
  • Vanclay, F., 2006: Principles for social impact assessment: a critical comparison between the international and US documents. Environ. Impact Assess. Rev. 26, 314.