EBTJV

Impacts of Exotic Rainbow Trout on Habitat Use by Native Juvenile Salmonid Species at an Early Invasive Stage: The detrimental impact of introduced Rainbow Trout Oncorhynchus mykiss on native communities has been well documented around the world. Previous studies have focused on streams where the invasion has been successful and the species is fully established. In eastern Quebec, the invasion of Rainbow Trout is an ongoing process and, for now, there are few established populations. The presence of two native salmonids in these rivers, Atlantic Salmon Salmo salar and Brook Trout Salvelinus fontinalis, implies a risk of competition for habitat, despite the relatively low density of the Rainbow Trout populations, as all three species are known to use similar resources. In order to evaluate the strength of the interaction between the invading fish and the native species, we sampled nine rivers (five with Rainbow Trout and four free of Rainbow Trout) and characterized the habitat used by the three salmonids at the juvenile stage. River-scale analysis revealed that in invaded rivers, Rainbow Trout were associated with habitats characterized by closer proximity to the shoreline and by increasing shoreline cover. Estimates of habitat niche overlap integrating depth, water velocity, and substrate size revealed that niche overlap between Brook Trout and Atlantic Salmon significantly increased in the presence of Rainbow Trout. Furthermore, the two indigenous species preferred full cover in the absence of Rainbow Trout but in the presence of Rainbow Trout, which also preferred full cover, the indigenous species moved to more open habitats. Rainbow Trout showed a high growth rate, despite a size disadvantage at the beginning of the growing season, as compared with Atlantic Salmon and Brook Trout. It thus appears that even at an early stage of invasion, when its density is still low, Rainbow Trout significantly impact native salmonids.
Located in Science and Data / Brook Trout Related Publications
In-Stream Habitat Restoration in the Meduxnekeag Watershed, Maine: This project will restore 1.9 miles of habitat on the Meduxnekeag River mainstem and 0.25 miles of habitat on its north branch for brook trout within trust land for the Houlton Band of Maliseet Indians. The project will return the river to a more natural, sustainable state of in-stream habitat complexity, increase brook trout habitat quality, and promote interest in future restoration activities.
Located in Projects / 2006 - 2018 Projects / 2013 Projects
In-Stream Habitat Restoration in the Meduxnekeag Watershed, Maine: This project will restore 1.9 miles of habitat on the Meduxnekeag River mainstem and 0.25 miles of habitat on its north branch for brook trout within trust land for the Houlton Band of Maliseet Indians. The project will return the river to a more natural, sustainable state of in-stream habitat complexity, increase brook trout habitat quality, and promote interest in future restoration activities.
Located in Funded Projects / EBTJV Projects
January 2013 NFH Board Meeting Book: This document contains materials associated with the National Fish Habitat Board's January 16, 2013 meeting that was conducted by teleconference.
Located in About EBTJV / National Fish Habitat Board Meetings / 2013 NFH Board Meetings
June 2013 NFH Board Meeting Book: This document contains materials associated with the National Fish Habitat Board's June 25 - 26, 2013 in-person meeting.
Located in About EBTJV / National Fish Habitat Board Meetings / 2013 NFH Board Meetings
Linking movement and reproductive history of brook trout to assess habitat connectivity in a heterogeneous stream network: 1. Defining functional connectivity between habitats in spatially heterogeneous landscapes is a particular challenge for small-bodied aquatic species. Traditional approaches (e.g. mark–recapture studies) preclude an assessment of animal movement over the life cycle (birth to reproduction), and movement of individuals may not represent the degree of gene movement for fecund species. 2. We investigated the degree of habitat connectivity (defined as the exchange of individuals and genes between mainstem and tributary habitats) in a stream brook trout (Salvelinus fontinalis) population using mark–recapture [passive integrated transponder (PIT) tags], stationary PIT-tag antennae and genetic pedigree data collected over 4 years (3425 marked individuals). We hypothesised that: (i) a combination of these data would reveal higher estimates of animal movement over the life cycle (within a generation), relative to more temporally confined approaches, and (ii) movement estimates of individuals within a generation would differ from between-generation movement of genes because of spatial variation in reproductive success associated with high fecundity of this species. 3. Over half of PIT-tagged fish (juveniles and adults) were recaptured within 20 m during periodic sampling, indicating restricted movement. However, continuous monitoring with stationary PIT-tag antennae revealed distinct peaks in trout movements in June and October–November, and sibship data inferred post-emergence movements of young-of-year trout that were too small to be tagged physically. A combination of these methods showed that a moderate portion of individuals (28–33%) moved between mainstem and tributary habitats over their life cycle. 4. Patterns of reproductive success varied spatially and temporally. The importance of tributaries as spawning habitat was discovered by accounting for reproductive history. When individuals born in the mainstem reproduced successfully, over 50% of their surviving offspring were inferred to have been born in tributaries. This high rate of gene movement to tributaries was cryptic, and it would have been missed by estimates based only on movement of individuals. 5. This study highlighted the importance of characterising animal movement over the life cycle for inferring habitat connectivity accurately. Such movements of individuals can contribute to substantial gene movements in a fecund species characterised by high variation in reproductive success.
Located in Science and Data / Brook Trout Related Publications
Lynn Camp Prong Brook Trout Restoration, TN_FY11 Project: This project was focused on removing rainbow trout from Lynn Camp Prong and re-stocking this stream with wild southern Appalachian strain Brook Trout,
Located in Projects / Project Completion Reports
Minimum Benchmark Set of Fish Habitat Conservation Project Prioritization Criteria_2013: The minimum benchmark set of Fish Habitat Conservation Project prioritization criteria are intended to ensure core tenets of the National Fish Habitat Action Plan are considered by Fish Habitat Partnership when ranking projects for funding. Approved by the National Fish Habitat Board, February 27, 2013.
Located in Groups / Steering Committee / National Fish Habitat Partnership
National Conservation Strategies_2013: National conservation strategies are intended as a framework to guide future actions and investment by the FHPs while allowing the FHPs to develop meaningful goals and approaches to conserve fish habitat. Approved by National Fish Habitat Board February 26, 2013.
Located in Groups / Steering Committee / National Fish Habitat Partnership
NFH Board’s FHP Performance Evaluation: This document contains the measures the National Fish Habitat Board uses to evaluate the performance of Fish Habitat Partnerships.
Located in Groups / … / 2014 Steering Committee Conference Call Summaries / December 16, 2014 Steering Committee Conference Call Documents

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