The influence of groundwater withdrawal and land use changes on brook charr (Salvelinus fontinalis) thermal habitat in two coldwater tributaries in Michigan, U.S.A.

Abstract

Brook charr (Salvelinus fontinalis) is a sentinel fish species which requires clean, cold water habitats. As such, many jurisdictions in the United States where brook charr are present use this species as an indicator of ecosystem health. In Michigan, groundwater-dominated streams are currently being impacted by increased groundwater withdrawal and land use/land cover changes which alter stream temperatures and their flow, and thus have the potential to significantly influence brook charr production and behavior. We quantified the influence of groundwater withdrawal and land use alteration on thermal habitat availability for brook charr using a groundwater modeling tool that estimated changes in baseflow to a stream segment based on changes to the groundwater system due to groundwater withdrawal and changes in rates of recharge related to landscape changes within a watershed. Projected stream temperature changes were calculated using a stream temperature modeling tool and compared to the range of temperature preferenda for brook charr in order to evaluate the potential impact of policy decisions regarding water extraction and land use/cover changes. The models predicted relatively small changes in both stream baseflow and consequently, stream temperature, with increased groundwater withdrawal rates. Land use/land cover alterations which we analyzed were shown to either mitigate or enhance the loss of brook charr thermal habitat as a result of groundwater withdrawal, depending on its relationship to recharge dynamics. This study emphasizes the importance of collaboration between water, land, and fisheries managers to ensure brook charr population viability, productivity, and sustainability in the face of environmental change, increasing water use and development in the watershed.Keywords Brook charr Á Groundwater withdrawal Á Thermal habitat Á Land use/land cover alteration Á Groundwater and stream temperature modeling

The influence of land cover composition and groundwater on thermal habitat availability for brook charr (Salvelinus fontinalis) populations in the United States of America

“…Our conclusions are consistent with other studies in Upper Midwest watersheds such as those by Waco & Taylor (2010) who found that conversion of forest to pasture would result in very minor shifts in stream temperature. However, based on the relatively high amount of baseflow in this stream (65%), the groundwater aquifer supplied this stream with water temperatures that can support brook charr populations throughout the year.…”

“…In groundwater-dominated brook charr streams, it is imperative to evaluate the effects of aquifer withdrawal for human use in the light of brook charr production (Waco & Taylor 2010). Identification of the key mechanisms controlling cold water delivery and maintenance in brook charr streams is a fundamental step in the effective management of this cold water-reliant species.…”

Microsatellite variation and genetic structure of brook trout (Salvelinus fontinalis) populations in Labrador and neighboring Atlantic Canada: evidence for ongoing gene flow and dual routes of post‐Wisconsinan colonization

“…2008; Kanno et al. 2010; Waco and Taylor 2010). The populations surveyed in this study are under the same anthropogenic threats due to the proximity of the TLH which crossed 20 watersheds in its Phase II section (Red Bay to Cartwright) alone (Jacques Whitford Environment Limited 1998).…”

“…2008; Kanno et al. 2010; Waco and Taylor 2010). Second, fishing pressure may increase as lakes become more easily accessible; previously, the majority of the lakes in Labrador were accessible by float plane only.…”

Sibship reconstruction for inferring mating systems, dispersal and effective population size in headwater brook trout (Salvelinus fontinalis) populations

“…Brook trout have been lost from over 50% of the historical habitat in Connecticut, USA, (Hudy et al 2008), and lotic populations are primarily located in small, cold headwater streams (Kanno and Vokoun 2008). Land development and resulting habitat alteration has often been associated with population declines (Kanno et al 2010;Stranko et al 2008;Waco and Taylor 2010), and climate change raises concern for the persistence of this steno-thermal species (Chu et al 2008;Flebbe et al 2006).…”