Browsing by Author "Linnansaari, Tommi"

Now showing 1 - 20 of 21
  • Thumbnail Image
    Item
    Atlantic salmon (Salmo salar) migrations in a large hydropower reservoir and the regulated Saint John River
    (University of New Brunswick, 2019) Babin, Amanda; Linnansaari, Tommi; Peake, Stephan
    My research focused on evaluating the impacts of the large Mactaquac Generating Station (MGS) reservoir on the migrations of the endangered Outer Bay of Fundy Atlantic salmon (Salmo salar). Salmon respond to flowing waters to determine the direction, timing, and speed of their migrations. A large reach of the Saint John River (SJR) was impounded by the MGS in 1968, transforming the habitat from a freeflowing river to a lacustrine environment with altered and slower flow. I examined all migratory lifestages of Atlantic salmon in the SJR using acoustic telemetry, including pre-smolts, smolts, adults, and post-spawned adults (kelts), as they navigated these environments. Migration rates were compared between the lentic MGS reservoir and the more lotic reaches upriver and downriver of the MGS to assess whether migration is delayed in the reservoir. Nearly all of the tagged salmon experienced migratory delay within the reservoir (medians: smolts 1.3-6.4 d, kelts 3.5-10.5 d, adults 1.5-5.7 d) due to suppressed migration rates (medians: smolts 5.0-13.3 km d[-1 superscript] vs. 15.4-29.3 km d[-1 superscript], kelts 4.4-8.9 km d[-1 superscript] vs. 14.9-36.8 km d[-1 superscript], adults 8.5-20.1 km d[-1 superscript] vs. 19.3-46.9 km d[-1 superscript]). Migration success through the reservoir was higher for downstream migrants (smolts > 81 % and kelts > 82 %) than upstream migrants (adults 47 %). Recommendations informed by these findings with the aim of aiding recovery of this endangered population are given to hydropower and fisheries managers, including: i) changing the spill regime to allow a greater proportion of downstream migrants the option of spillway passage since all but a few smolts and even the earlier kelt migrants were sometimes forced to pass via turbines; ii) constructing a downstream surface-bypass facility which is more economically feasible than increasing spill and is supported by the observed variable passage timing; iii) allowing the free-swim of downstream migrants through bypasses in comparison to a trap-and-haul strategy that was not found to increase survival of smolts; and iv) maintaining trap-and-haul operations for adults migrating upstream of the MGS due to the high proportion of fallbacks and increased energy expenditure from superfluous movements in the reversed direction to the intended migration observed in the reservoir.
  • Thumbnail Image
    Item
    Freshwater migration and behaviour of wild adult Atlantic Salmon (Salmo salar) in the Miramichi River, New Brunswick, Canada
    (University of New Brunswick, 2021) Carrow, Ryan M.; Linnansaari, Tommi
    Historically, the Miramichi River, New Brunswick, Canada, had the largest population of Atlantic Salmon (Salmo salar) in North America but has now failed to consistently meet conservation targets set by Fisheries and Oceans Canada for over two decades. Miramichi River salmon return as mature adults to their natal river in either an early (June/early July) or late (September/October) run group, where they enter the river and migrate upstream to spawning areas. The specific, in-river migratory behaviour of the two temporally distinct runs and the habitats utilized during migration are poorly understood in the Miramichi River. In this thesis, radio telemetry was used to monitor adult migration behaviour and habitat selection for early and late run salmon in the Miramichi River. On average, early run salmon migrated 1.5 river km per day (rkm/d), and selected deep habitat (>0.5 m) with large substrate sizes. Salmon started to use thermal refugia when river temperatures reached 19 °C, and increasingly at temperatures > 22 °C. In autumn, river conditions appeared to delay late run salmon from entering freshwater for weeks. Late run salmon migrated between 1.0 – 2.4 rkm/d on average, selected deep habitat types (>0.5 m) with cobble substrate, spawned between mid-October to late November, and began migrating downstream after spawning. Fisheries managers can use this information for better conservation, restoration and rehabilitation of Miramichi Atlantic Salmon population and their critical habitat.
  • Thumbnail Image
    Item
    Interannual variation in spawning success of striped bass (Morone saxatilis) in the Saint John River, New Brunswick
    (Wiley, 2019-11-08) Andrews, Samuel N.; Linnansaari, Tommi; Leblanc, Nathalie; Pavey, Scott A.; Curry, R. Allen
    Barriers such as dams have been cited as a serious threat to striped bass survival, especially when they affect or impede migration and access to spawning grounds. On the Saint John River, New Brunswick, the installation of the large Mactaquac Dam in the immediate vicinity of a historic striped bass spawning location was suspected to have caused the arrest of striped bass reproduction and the collapse of the native striped bass population. In 2014, juvenile striped bass of confirmed Saint John River origin were documented in the river for the first time since 1979. In the current study, we examined juveniles from 6 years of sampling to determine corresponding years of successful recruitment. We also tracked adult striped bass matching the ancestry of native Saint John River juveniles to determine the timing and location of spawning. Over 5 years, we observed an annual upstream migration by adult striped bass to historic spawning areas near Fredericton, identified a dominant year class of Saint John River origin juveniles reproduced in 2013, and linked the apparent successful production of year classes to definable discharge conditions, that is, extended periods of sustained flow >36 hr downstream from the Mactaquac Dam. The results of this study suggest important first management actions towards recovering and sustaining the re-discovered striped bass population in the Saint John River, New Brunswick.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Mactaquac Aquatic Ecosystem Study Report Series 2015-017, Environmental Considerations for Large Dam Removals
    (Canadian Rivers Institute, 2015) Chateauvert, Adam; Linnansaari, Tommi; Yamazaki, Gordon; Curry, R. Allen
  • Thumbnail Image
    Item
    Mactaquac Aquatic Ecosystem Study Report Series 2015-021, METHODS REPORT: Fish Taging
    (Canadian Rivers Institute, 2015) Gautreau, Mark; Wallace, Ben; Linnansaari, Tommi
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Mactaquac Aquatic Ecosystem Study Report Series 2018-033, PRELIMINARY FISH HABITAT AND COMMUNITY ASSESSMENT RELATED TO THE FUTURE OPTIONS OF THE MACTAQUAC GENERATING STATION
    (2018) Wegscheider, Bernhard; Linnansaari, Tommi; Ndong, Mouhamed; Ogilvie, Jae; Schneider, Matthias; Kopecki, Ianina; Dolson-Edge, Rebecca; Samways, Kurt; Haralampides, Katy; Curry, R. Allen
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Mactaquac Aquatic Ecosystem Study Report Series 2019-050, STATE OF FISH PASSAGE DESIGN FOR THE MACTAQUAC GENERATING STATION
    (2019) Samways, Kurt; Dolson-Edge, Rebecca; Yamazaki, Gordon; Linnansaari, Tommi; Curry, R. Allen
  • Thumbnail Image
    Item
    Monitoring Atlantic salmon (Salmo salar) populations using imaging sonar technology in the Miramichi River
    (University of New Brunswick, 2021-09) Helminen, Jani; Linnansaari, Tommi
    Atlantic salmon (Salmo salar) is an important species culturally and socially, and a target species of multiple fisheries globally. Primarily due to overfishing, water pollution, sedimentation, and damming, Atlantic salmon catches at sea are under a continuing decline; however, the state of different populations varies greatly, and it is important that each population is assessed accurately and independently. In this PhD research, non-invasive imaging SONAR technology was tested for collecting tributary-specific information about migrating fish in the Miramichi River, where the adult Atlantic salmon population is currently monitored using a traditional mark-recapture method. The accuracy and precision of the length measurements using long-range (up to 30m) imaging sonar data was tested and deemed low; however, a Bayesian model was created with capacity to predict the size class of adult Atlantic salmon from the sonar measurements. For efficient analysis of the sonar data, an automated data processing workflow was created. The automation counted the number of migrating fish similarly as different human-generated counts (with mean of differences between -39 % and 65 %). The tail-beat frequencies of three-fish species (Atlantic salmon, striped bass (Morone saxatilis), and American shad (Alosa sapidissima)) were calculated from the sonar data and found significantly (p<.05) different from each other. An automated method was developed showing promising results that can be further developed into models distinguishing different species using sonar data. Finally, underwater camera sampling was used for apportioning species in the sonar data in the Little Southwest Miramichi River. Hourly migration data indicated that both salmon and striped bass were rarely detected during daylight hours. When compared to downstream trap net catches that were adjusted for realistic values from literature (catchability 10 % and 40 % of fish moving to the same tributary), the counts were in close agreement for Atlantic salmon (sonar count 103-130 % of the adjusted trap net catch). To combine all the information gathered throughout the project, a guide was produced for monitoring Atlantic salmon in rivers using imaging sonars. In conclusion, the imaging sonar method provides an efficient and non-invasive method for population assessment in the Miramichi River.
  • Thumbnail Image
    Item
    Quantitative modelling of existing and future fish habitat in the Saint John River, NB, Canada
    (University of New Brunswick, 2020) Wegscheider, Bernhard; Linnansaari, Tommi
    The aging Mactaquac Hydroelectricity Generating Station (MGS) on the Wolastoq | Saint John River (SJR) is one of Canada's largest dams and it is reaching the end of its service life. My research focused on quantifying existing and future fish habitat downstream of the MGS, considering current management options to renew the infrastructure in the short-term with a longer-term solution of rebuilding or removing. In detail, my project applied a hydraulic-habitat model to assess habitat change and predicted effects on fish communities for future regulated and climate-induced flow regimes. Fish communities were surveyed and related to habitat characteristics both up- and downstream of the facility, and habitat requirements were defined for three distinct fish assemblages based on meso-scale habitat use and expert opinion. Modelling predictions suggest that dam operation and flow regulation resulted in a general decrease in habitat availability for each fish assemblage when being compared to the historic flow regime prior to the construction of the MGS. Furthermore, under the current dam operation scheme, rheophilic species were predicted to be limited in habitat conditions during the critical summer low flow period, with habitat availability averaging below 20% and never exceeding 30% of the wetted channel area at any day in the time record (1968 to 2015). The implementation of environmental flows ranging around the proposed Q50 flow rate was predicted to minimize the duration of stress events and increase the availability of suitable habitats on a community scale. Similarly, a future climate induced flow regime under a dam removal scenario was predicted to result in improved conditions for fish species. Recommendations informed by this thesis aim to improve habitat conditions for multiple species and are given to hydropower and fisheries managers. Proposed strategies include: i) implementing environmental flows ranging around a Q50 flow rate for the SJR, and ii) continuing fish community monitoring in the SJR and extending surveys to seasons other than the summer period to gain better insights into flow-ecology relationships of imperiled species.
  • Thumbnail Image
    Item
    Remote sensing framework reveals riverscape connectivity fragmentation and fish passability in a forested landscape
    (University of New Brunswick, 2020) Arsenault, Michael Joseph; Curry, Allen; Linnansaari, Tommi
    Fragmentation of stream networks by anthropogenic structures such as road culverts can affect the health of a catchment by negatively affecting the ecosystem's biota, their movements, abundances, and species richness. The challenge for resource managers is the prohibitive costs of locating, evaluating, and remediating problem structures at landscape-scales. There is a need for a framework to perform a desktop, landscape-scale evaluation and prioritization process using existing data that allows managers to make cost and ecologically effective decisions. I present a framework using publicly available LiDAR and orthophotography to locate and identify road crossings and evaluate fragmentation and passability for various fish species at the landscape-scale. My approach provides a valuable and cost-effective means of identifying potential stream crossing issues for multiple management objectives, e.g., fish passage, and thus the approach is an important step in the development of prioritization tools for restoration decisions by resource managers.
  • Thumbnail Image
    Item
    Restoration potential for reproduction by Striped Bass (Morone saxatilis) in the Saint John River, New Brunswick
    (University of New Brunswick, 2019) Andrews, Samuel Nelson; Curry, Allen; Linnansaari, Tommi
    In 2012 the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) listed the Striped Bass (Morone saxatilis) of the Saint John River, New Brunswick, as endangered as part of the Bay of Fundy designatable unit. This listing was due to an apparent rapid collapse and subsequent absence of presumed native origin Striped Bass, juvenile recruitment, and spawning by the species following the completion of the large Mactaquac Dam in 1968. Expert reports hypothesized that alteration in the river flow and temperature regime imposed upon the Saint John River downstream from the Mactaquac Dam were responsible for the disappearance, however, no recovery efforts or exploratory studies were conducted, and the native Striped Bass population was deemed extinct. This dissertation explored the collapse of the Saint John River Striped Bass starting with a complete historic perspective of the species in the Saint John River and concluded with a possible means to recover the population that was once believed to be lost. Within the chapters of this thesis I first summarize the history of Striped Bass in the Saint John River and explore why the current understanding of the species status needs to be updated. I locate and sample juvenile Striped Bass within the Saint John River for the first time since 1979, prove their native ancestry, and monitor their year class success. Native adult Striped Bass matching juvenile ancestry are tagged and tracked to determine the timing and location of their upstream spawning migration and the migrations of non-native adult Striped Bass within the Saint John River are also explored. I summarize information on Striped Bass winter ecology in Canada, then locate and describe four key winter habitats used by Striped Bass in the Saint John River. Finally, I draw a possible connection between the regulated discharges at the Mactaquac Generating Station to the success of Striped Bass juvenile recruitment observed in the Saint John River over six consecutive years of sampling. My general conclusion is that spawning by native Striped Bass in the Saint John River downstream of the Mactaquac Dam has been severely impacted, though not eliminated, by the regulated discharges resulting for power production. These discharge regimes have resulted in infrequently successful year classes, poor recruitment and possible spawning failures; however, spawning by surviving native origin Striped Bass may be recovered through the management of spring discharges. Managing for extended periods of moderate, sustained flow of sufficient volume and duration to keep Striped Bass eggs in suspension during the incubation period may restore successful Striped Bass spawning and juvenile recruitment in the Saint John River, New Brunswick.