Tag Archives: Jono

Thayer, D.*, Ruppert, J.L.W., Watkinson, D., Clayton, T. and M.S. Poesch. (2017) Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fluvescens) show highly restricted movement and habitat-use overwinter. Global Ecology and Conservation 10: 194-205.

Abstract:

The relationship between species’ size and home range size has been well studied. In practice, home range may provide a good surrogate of broad spatial coverage needed for species conservation, however, many species can show restricted movement during critical life stages, such as breeding and over-wintering. This suggests the existence of either a behavioral or habitat mediated ‘temporal bottleneck,’ where restricted or sedentary movement can make populations more susceptible to harm during specific life stages. Here, we study over-winter movement and habitat use of Lake Sturgeon (Acipenser fulvescens), the largest freshwater fish in North America. We monitored over-winter movement of 86 fish using a hydro-acoustic receiver array in the South Saskatchewan River, Canada. Overall, 20 fish remained within our study system throughout the winter. Lake Sturgeon showed strong aggregation and sedentary movement over-winter, demonstrating a temporal bottleneck. Movement was highly restricted during ice-on periods (ranging from 0.9 km/day in November and April to 0.2 km/day in mid-November to mid-March), with Lake Sturgeon seeking deeper, slower pools. We also show that Lake Sturgeon have strong aggregation behavior, where distance to conspecifics decreased (from 575 to 313 m) in preparation for and during ice-on periods. Although the Lake Sturgeon we studied had access to 1100 kilometers of unfragmented riverine habitat, we show that during the over-winter period Lake Sturgeon utilized a single, deep pool (<0.1% of available habitat). The temporal discrepancy between mobile and sedentary behaviors in Lake Sturgeon suggest adaptive management is needed with more localized focus during periods of temporal bottlenecks, even for large-bodied species.

Citation: Thayer, D.*, Ruppert, J.L.W., Watkinson, D., Clayton, T. and M.S. Poesch. (2017) Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fluvescens) show highly restricted movement and habitat-use overwinter. Global Ecology and Conservation 10: 194-205.

Monthly core (C) and range (R) extent kernel density maps for: A) November, B) December, C) January, D) February, E) March, and F) April. Black lines are core range (50% percentile), broken lines range (90th percentile) extent.

Also Read:

Miller, M., Stevens, C. and M. S. Poesch. (In Press). Effectiveness of Spawning Substrate Enhancement for Adfluvial Fish in a Regulated Sub-Arctic River. River Research and Applications.

*Lab members: Donnette Thayer, Jonathan Ruppert, Mark 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 Ruppert, Tyana Rudolfsen, Marie Veillard, Mark Poesch. Check out opportunities in the lab!