Impacts of nonpoint inputs from potato farming on populations of slimy sculpin (Cottus cognatus)

Abstract

The potential influence of agricultural activity, particularly potato cultivation, on slimy sculpin populations (Cottus cognatus) was examined at 19 rivers of New Brunswick, Canada. Comparisons with forested streams resulted in differences in fish density, size, and reproductive performance. Young-of-the-year (YOY) sculpin were present only at two of 11 agricultural sites, though they were present at all nine forested sites. Sediment deposition was greatest at agricultural sites, with increased fine sediments deposited. Larger, coarse sands were deposited at two sites with active forest operations. Temperature had a stronger correlation than sedimentation with sculpin size and density in the agricultural region. Agricultural catchments were warmer than in forested catchments (median = 16.0 and 13.3 degrees C, respectively). Body size of slimy sculpin was correlated positively and YOY densities correlated negatively with temperature, and sites with temperatures > or = 25 degrees C were devoid of YOY sculpin. Our data indicate there is a significant effect of temperature on slimy sculpin populations in rivers of potato farming areas, highlighting the importance of examining indirect factors when investigating possible impacts of nonpoint source agricultural inputs. Indirect factors such as sediment deposition and temperature need to be considered in order to discriminate accurately the chronic impacts of agricultural chemicals on fish populations.

The biology and ecology of slimy sculpin: A recipe for effective environmental monitoring

“…3B). For example, in agricultural regions of northwestern New Brunswick, YOY proportions ranged from 0% to 30% at impacted sites Gray et al 2005a).…”

“…a Migration is less of a concern for non-point sources of contamination. In the past 15 years in Canada, much work has been done following the sentinel species approach using small-bodied species (Gibbons et al 1998;Gray et al 2005aGray et al , 2005bBarrett et al 2015). This is in contrast to much of the initial monitoring under EEM, which focused on large-bodied species .…”

“…The slimy sculpin is a small coolwater fish, with an average length of 76 mm (Scott and Crossman 1973), exhibiting limited home ranges within stream systems (e.g., Brown and Downhower 1982;Hill and Grossman 1987;Gray et al 2004), and has easy to measure life history characters (e.g., length, weight, and somatic indices). Studies have ranged from impacts of timber harvest (Edwards 2001), potato farming (Gray et al 2002;Gray and Munkittrick 2005;Gray et al 2005a;Brasfield et al 2015), diamond mining (Gray et al 2005b), oil sands (Tetreault et al 2003), metal mining (Dubé et al 2005;Allert et al 2009) and coal mining (Miller et al 2015), pulp and paper mills (Galloway et al 2003), and sewage (Arciszewski et al 2011). Due to the lack of general background information available for slimy sculpin, it has been necessary to compile unique basic reference data, or baseline data, for almost each study project conducted.…”

“…Furthermore, sculpins tend to prefer cold water, but like other stream fishes would also be affected by interactions of chemical and physical environment (e.g., pH and habitat; Warren et al 2010). They have an upper lethal water temperature estimated between 23 and 25°C (Symons et al 1976;Otto and Rice 1977), and slimy sculpin are rarely found in habitats with sustained water temperatures >19°C (Gray et al 2005a;Edwards and Cunjak 2007).…”

Freshwater Sculpins: Phylogenetics to Ecology

“…Endangered Species Act (the threatened pygmy sculpin C. paulus; USFWS 2006), are restricted to a single spring, lake, or cave (Burr et al 2001;Espinasa and Jeffery 2003). Species introductions have adversely affected a number of sculpin populations via predation (White and Harvey 2001), resource shifts (Owens and Dittman 2003), and competitive or behavioral interactions (Lauer et al 2004), and habitat modifications have influenced sculpins in numerous ways (e.g., see Fischer and Kummer 2000;Maret and MacCoy 2002;Lessard and Hayes 2003;Gray et al 2005).…”