A weight‐of‐evidence approach for defining thermal sensitivity in a federally endangered species

Abstract

Managing for threatened and endangered species under changing environmental conditions is a challenge faced by resource managers worldwide. Lack of basic knowledge of the biology and habitat requirements of these species can contribute to this difficulty but is exacerbated by the limitations of working with rare species (i.e. few individuals) or unrefined and non‐lethal methods for evaluating stress. A weight‐of‐evidence approach was used to evaluate the thermal biology of the federally endangered dwarf wedgemussel (Alasmidonta heterodon), using cumulative results from multiple experimental assessments, co‐occurring species, and their host fish to begin defining the thermal limits and optimal conditions for the species. Results suggest that dwarf wedgemussel and its host fish are thermally sensitive species compared with other Atlantic‐slope mussels, with a lower critical thermal maximum (CTM) and the selection of reduced temperatures during choice experiments. Physiological studies resulted in a lack of statistical significance, primarily owing to low power, which was a function of sample size – an unavoidable problem when studying rare species. Given these limitations, thermal choice and CTM may be more useful end points than physiological processes such as clearance and respiration rates when dealing with sample‐size limitations. These results suggest that management strategies that avoid exposing dwarf wedgemussel and its thermally sensitive host fish to extreme temperatures could be important for species conservation.

Train, Inform, Borrow, or Combine? Approaches to Process‐Guided Deep Learning for Groundwater‐Influenced Stream Temperature Prediction

“…Stream temperature is a driving variable in aquatic ecosystems, influencing the life cycle of temperature sensitive species such as salmonids (Jonsson & Jonsson, 2009; Sloat & Osterback, 2013; Xu et al., 2010a, 2010b) and mussels (Briggs et al., 2013; Elena et al., 2012; Galbraith et al., 2020), controlling the spatial patterns of climate refugia (Ebersole et al., 2020; Isaak et al., 2015), and influencing biogeochemical rates (Ouellet et al., 2020). Throughout a river network, temperature is controlled by a combination of meteorological, anthropogenic, and landscape characteristics.…”

Long‐term monitoring shows that drought sensitivity and riparian land use change coincide with freshwater mussel declines

“…Physiological stress results in disruptions and alterations to metabolic pathways such as respiration, protein synthesis and gene expression (Roznere et al, 2017; Ferreira‐Rodríguez et al, 2018; Curley et al, 2021), which in turn affect mussel body condition and growth. Thermal sensitivity is a functional trait that integrates a mussel species’ behavioural and metabolic responses to increasing temperatures (Galbraith, Blakeslee & Lellis, 2012; Khan et al, 2019; Galbraith et al, 2020). Southern North American mussel species can generally be placed in two guilds based on their physiological tolerance to high water temperatures: thermally sensitive species that suffer decreased body condition and thermally tolerant species that continue to grow (Spooner & Vaughn, 2008).…”

“…Thermal sensitivity is a functional trait that integrates a mussel species' behavioural and metabolic responses to increasing temperatures (Galbraith, Blakeslee & Lellis, 2012;Khan et al, 2019;Galbraith et al, 2020). Southern North American mussel species can generally be placed in two guilds based on their physiological tolerance to high water temperatures: thermally sensitive species that suffer decreased body condition and thermally tolerant species that continue to grow (Spooner & Vaughn, 2008).…”