Linking Hydroclimate to Fish Phenology and Habitat Use with Ichthyographs

Abstract

Streamflow and water temperature (hydroclimate) influence the life histories of aquatic biota. The relationship between streamflow and temperature varies with climate, hydrogeomorphic setting, and season. Life histories of native fishes reflect, in part, their adaptation to regional hydroclimate (flow and water temperature), local habitats, and natural disturbance regimes, all of which may be affected by water management. Alterations to natural hydroclimates, such as those caused by river regulation or climate change, can modify the suitability and variety of in-stream habitat for fishes throughout the year. Here, we present the ichthyograph, a new empirically-based graphical tool to help visualize relationships between hydroclimate and fish phenology. Generally, this graphical tool can be used to display a variety of phenotypic traits. We used long-term data sets of daily fish passage to examine linkages between hydroclimate and the expression of life-history phenology by native fishes. The ichthyograph may be used to characterize the environmental phenology for fishes across multiple spatio-temporal domains. We illustrate the ichthyograph in two applications to visualize: 1) river use for the community of fishes at a specific location; and 2) stream conditions at multiple locations within the river network for one species at different life-history stages. The novel, yet simple, ichthyograph offers a flexible framework to enable transformations in thinking regarding relationships between hydroclimate and aquatic species across space and time. The potential broad application of this innovative tool promotes synergism between assessments of physical characteristics and the biological needs of aquatic species.

Deep‐Seated Landslides Drive Variability in Valley Width and Increase Connectivity of Salmon Habitat in the Oregon Coast Range

“…; Flitcroft et al. ). Coho Salmon are known to need gravel for spawning (Groot and Margolis ; Bilby and Bisson ).…”

“…Based on these life cycle needs (Groot and Margolis 1991), adequate potential habitat for Coho Salmon for spawning, summer-rearing, and winter-refuge can be identified by querying the stream survey data for specific criteria. We identified habitat variables known to be biologically relevant for different life stages (sensu Flitcroft et al 2014;Flitcroft et al 2016). Coho Salmon are known to need gravel for spawning (Groot and Margolis 1991;Bilby and Bisson 1998).…”

Identifying potential causes of fish declines through local ecological knowledge of fishers in the Ganga River, eastern Bihar, India

“…Different species were placed under the causes of decline attributed to them by fishers. Fish species were mapped on an ichthyograph (Flitcroft et al, ) based on their spawning seasonality. The graph was compared with a seasonal fish catch calendar prepared from fishers’ inputs.…”

Using expressed behaviour of coho salmon (Oncorhynchus kisutch) to evaluate the vulnerability of upriver migrants under future hydrological regimes: Management implications and conservation planning

“…Coho salmon were chosen for this analysis owing to their status under the US Endangered Species Act as an endangered, threatened, or species of concern in portions of their southern distribution in the states of Washington, Oregon, and California (Federal Register, , , ). Coho salmon also exhibit narrow migration timing compared with other native fishes (Flitcroft et al, ). This imperilled anadromous salmonid is iconic of the region, with strong economic and cultural significance.…”

“…temperature and discharge) are fundamental drivers of adaptation in native fishes (Beechie, Buhle, Ruckelshaus, Fullerson, & Holsinger, 2006;Lytle & Poff, 2004). In particular, phenological events may be linked to predictable patterns of stream temperature and discharge (Flitcroft et al, 2016;Lisi, Schindler, Bentley, & Pess, 2013). Adaptive evolutionary relationships among life history, behaviour, and the hydroregime are relevant in conservation planning for native aquatic species owing to predicted changes both in climate and water management (Reed et al, 2011;Waples, Zabel, Scheuerell, & Sanderson, 2008).…”