Veillard, M.F.*, Ruppert, J.L.W.*, Tierney, K., Watkinson, D., and M.S. Poesch. (2017) Comparative swimming and station-holding ability of the threatened Rocky Mountain Sculpin (Cottus sp.) from four hydrologically distinct rivers. Conservation Physiology 5: 1-12.

Abstract:

Hydrologic alterations, such as dams, culverts or diversions, can introduce new selection pressures on freshwater fishes, where they are required to adapt to novel environmental conditions. Our study investigated how species adapt to natural and altered stream flow, where we use the threatened Rocky Mountain Sculpin (Cottus sp.) as a model organism. We compared the swimming and station-holding performance of Rocky Mountain Sculpin from four different hydrologic regimes in Alberta and British Columbia, including the North Milk River, a system that experiences increased flows from a large-scale diversion. We measured the slip (Uslip) and failure (Uburst) velocities over three constant acceleration test trials. Uslipwas defined as the point at which individuals required the addition of bursting or swimming to maintain position. Uburst was defined as the point at which individuals were unable to hold position in the swimming chamber through swimming, bursting or holding techniques without fully or partially resting on the electrified back plate. We found individuals from the Flathead River in British Columbia (with the highest natural flow) failed at significantly higher Uburstvelocities than fish from the southern Albertan populations. However, there was no relationship between peak hydrologic flow from the natal river and Uburst or Uslip. Further, Uburst velocities decreased from 51.8 cm s−1 (7.2 BL s−1) to 45.6 cm s−1 (6.3 BL s−1) by the third consecutive test suggesting the use of anaerobic metabolism. Uslip was not different between trials suggesting the use of aerobic metabolism in station-holding behaviours (Uslip). Moreover, we found no significant differences in individuals from the altered North Milk River system. Finally, individual caudal morphological characteristics were related to both slip and failure velocities. Our study contributes to the conservation of Rocky Mountain Sculpin by providing the first documentation of swimming and station-holding abilities of this benthic fish.

CitationVeillard, M.F.*, Ruppert, J.L.W.*, Tierney, K., Watkinson, D., and Poesch, M.S. 2017. Comparative swimming and station-holding ability of the threatened Rocky Mountain Sculpin (Cottus sp.) from four hydrologically distinct rivers. Conservation Physiology 5: 1-12.

Difference in Swim Performance Across Populations of Rocky Mountain Sculpin. Shown are Tukey contrasts (estimate +/- 95% confidence intervals) between rivers (top row) and constant acceleration trial (CAT) numbers (bottom row) for failure (Uburst) and slip (Uslip) velocities from linear effects model. Significant differences are noted in yellow; Rivers are abbreviated as: Flathead River (FH), St. Mary River (SM), Lee Creek (LC) and North Milk River (NM).

Also Read:

Rudolfsen, T.*, Watkinson, D. and Poesch, M.S. (2018) Morphological divergence of the Threatened Rocky Mountain sculpin (Cottus sp.) is driven by biogeography and flow regime. Aquatic Conservation: Marine and Freshwater Ecosystems 28: 78-86.

*Lab members: Marie VeillardJonathan RuppertMark Poesch. Check out opportunities in the lab!

Ruppert, J.L.W.*, James, P.M.A., Taylor, R., Rudolfsen, T.*, Veillard, M.*, Davis, C., Watkinson, D. and Poesch, M.S. (2017) Riverscape genetic structure of a threatened and dispersal limited freshwater species, the Rocky Mountain Sculpin (Cottus sp.). Conservation Genetics 18: 925-937.

Abstract:

Understanding the movement ability and the spatial scale(s) of population genetic structure of species can together better ‘tune’ management objectives to prevent potential range contraction and population declines. We studied the Rocky Mountain Sculpin (Cottus sp.), a threatened species in Canada, to demonstrate the utility of using two complementary approaches to assess connectivity of a species. To do so, we used Passive Integrated Transponder (PIT) tags with a stationary tracking array (n = 223) to track movement and genetic data (n = 1,015) from nine microsatellite loci to assess genetic population structure. The PIT tag results indicated that Rocky Mountain Sculpin are sedentary; approximately 50% of individuals only moved a maximum distance of 10 meters (upstream or downstream) over a 5-month period. Genetic analyses indicated that at the spatial scale of our study area (5500 km2), watershed structure (river basins) is the main geographic feature influencing population genetic structure. We used the Bayesian clustering tool STRUCTURE, which suggested four distinct sub-populations of Rocky Mountain Sculpin in Canada. Genetic structure at finer spatial scales (within basins and sub-basins) appears to be influenced by fluvial distance (i.e., geographic distance along a river) and elevation change between sample locations (i.e., isolation-by-distance and isolation-by-environment). Combining movement and genetic analyses provides complimentary evidence of limited dispersal in Rocky Mountain Sculpin and highlights that both approaches together can provide broader insight into connectivity between populations that may ultimately help to aid future management decisions.

Citation: Ruppert, J.L.W.*, James, P.M.A., Taylor, R., Rudolfsen, T.*, Veillard, M.*, Davis, C., Watkinson, D. and Poesch, M.S. 2017. Riverscape genetic structure of a threatened and dispersal limited freshwater species, the Rocky Mountain Sculpin (Cottus sp.). Conservation Genetics 18: 925-937.

STRUCTURE results showing mean assignment of individuals into four clusters and sorted by geographic locatoins. Geographic locations are abbreviated as FH: Flathead River, LC: Lee Creek, STM: St Mary River and NM: North Milk River. 

Also Read:

Nelson-Chorney, H.*, Carli, C.M., Davis, C.S., Vinebrooke, R.D., Poesch, M.S., and M.K. Taylor (2019) Environmental DNA in lake sediment reveals biogeography of native genetic diversity. Frontiers in Ecology and Evolution 17: 313-318.

*Lab members: Jonathan RuppertTyana RudolfsenMarie VeillardMark Poesch. Check out opportunities in the lab!