Abstract
Objective
Translocations have increased in recent years to aid in species recovery efforts. This includes translocations outside of species’ historical distribution, where threats are less severe. One candidate species for translocation is the Bull Trout Salvelinus confluentus, but few examples of successful translocations (re-establishment or range expansion) have been documented. Here, we describe an example in which 63 Bull Trout were translocated in 1987 to establish a population in fishless Marie Lake, Alberta.
Methods
The translocation was monitored through multiple sampling events over the course of 33 years. Sampling techniques included backpack electrofishing, angling, and water quality and habitat assessments.
Result
A population estimate suggested that Bull Trout increased by at least fourfold over the first 12 years; fish reached large sizes (692 mm fork length) and old ages (13 years), and the population had multiple age- and length-classes, including juveniles. Bull Trout also had become established within at least 13 km of river outside of Marie Lake by 2019.
Conclusion
Although a naturally reproducing population of this at-risk species was established, numerous factors were not considered within this translocation initiative. Most importantly, nonadfluvial Bull Trout from a disparate source population located about 4000 river kilometers away were used for the translocation. Our case study represents a rare example of a successful Bull Trout translocation and highlights considerations that should occur prior to future translocations that are intended to aid in species recovery and preservation.
Impact statement
This is the first documentation of a successful Bull Trout translocation to fishless waters and one of only a few successful translocations attempts for this species. We believe that the information provided will assist decision making for future conservation translocations.
Find the full paper here (open access)
Citation
Kissinger, B. C., Sullivan, M. G., Paul, A. J., Meinke, A., & Post, J. (2024). Establishment of Bull Trout in a previously fishless subalpine lake by translocation. North American Journal of Fisheries Management, 00, 1–1. https://doi.org/10.1002/nafm.10989
