Estimating behavior in a black box: how coastal oceanographic dynamics influence yearling Chinook salmon marine growth and migration behaviors

Abstract

0508-7This version is available at https://strathprints.strath.ac.uk/58466/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. AbstractOcean currents or temperature may substantially influence migration behavior in many marine species. However, high-resolution data on animal movement in the marine environment are scarce; therefore, analysts and managers must typically rely on unvalidated assumptions regarding movement, behavior, and habitat use. We used a spatially explicit, individual-based model of early marine migration with two stocks of yearling Chinook salmon to quantify the influence of external forces on estimates of swim speed, consumption, and growth. Model results suggest that salmon behaviorally compensate for changes in the strength and direction of ocean currents. These compensations can result in salmon swimming several times farther than their net movement (straight-line distance) would indicate. However, the magnitude of discrepancy between compensated and straight-line distances varied between oceanographic models. Nevertheless, estimates of relative swim speed among fish groups were less sensitive to the choice of model than estimates of absolute individual swim speed. By comparing groups of fish, this tool can be applied to management questions, such as how experiences and behavior may differ between groups of hatchery fish released early vs. later in the season. By taking into account the experiences and behavior of individual fish, as well as the influence of physical ocean processes, our approach helps illuminate the "black box" of juvenile salmon behavior in the early marine phase of the life cycle.

Role of carryover effects in conservation of wild Pacific salmon migrating regulated rivers

“…Determining population-specific marginal effect sizes would require more research, but is an important step toward examining relationships between survival and fish length and better understanding underlying mechanisms. Hypothesized mechanistic processes that are important to consider include size-selective predation (Muir et al 2006) and other interacting factors: size-selectivity through dam passage routes (Hostetter et al 2015) and increased stress with passage through the powerhouses (Budy et al 2002); size-and body-conditiondependent predation (Tucker et al 2016); stockspecific size and migration timing downstream and at ocean entry (Weitkamp et al 2015); and size-dependent migratory behavior and ocean conditions (Burke et al 2016). Given the uncertainty and complexity of multiple factors, maintaining heterogeneity in mass within a population (Gosselin and Anderson 2013) or size at the metapopulation level (Moore et al 2010) may contribute to persistence via portfolio effects and selective mortality.…”

“…2015); and size‐dependent migratory behavior and ocean conditions (Burke et al. 2016). Given the uncertainty and complexity of multiple factors, maintaining heterogeneity in mass within a population (Gosselin and Anderson 2013) or size at the metapopulation level (Moore et al.…”

A sense of place: Pink salmon use a magnetic map for orientation

“…2) lends support to the view that magnetic map cues play an important role in the ontogenetic migrations of diverse marine species (Secor, 2015;Putman, 2018). Magnetic displacement experiments paired with simulation of the observed behavior in realistic environmental models could be a powerful and relatively inexpensive way to investigate the many open questions in migration ecology (Putman, 2015;Burke et al, 2016). Such work could provide an important component of the information needed to improve predictions of shifting distributions and abundances of marine species in response to changing environmental conditions (Secor, 2015;Hays et al, 2016).…”

Energy dynamics of subyearling Chinook salmon reveal the importance of piscivory to short‐term growth during early marine residence

“…Inappropriate biological assumptions leading to error in bioenergetics models have been recognized for some time (Canale & Breck, ; Madenjian, David, & Pothaven, ; Trudel, Geist, & Welch, ), especially for juvenile Chinook salmon, whose oxygen consumption rates likely differ from adults (Trudel & Welch, ). Differences in activity may also result from differences in oceanographic currents among years, which could influence ocean growth and migration rates (Burke et al., ). Laboratory studies can help identify systematic error in bioenergetics models, even though consumption rates and activity may differ considerably between the laboratory and the field (Madenjian, O'Connor, Cheryak, Rediske, & O'Keefe, ).…”

“…Alternatively, if overwinter survival of subyearlings depends on a critical (Canale & Breck, 2013;Madenjian, David, & Pothaven, 2012;Trudel, Geist, & Welch, 2004), especially for juvenile Chinook salmon, whose oxygen consumption rates likely differ from adults . Differences in activity may also result from differences in oceanographic currents among years, which could influence ocean growth and migration rates (Burke et al, 2016). Laboratory studies can help identify systematic F I G U R E 6 Average (±SD) specific growth rates (SGR; g, % body weight/day) of subyearling Chinook salmon (Oncorhynchus tshawytscha) ranging from 5 to 25 g (a-c) feeding at the minimum, average, and maximum observed feeding rates (% of maximum consumption C max ), diet energy densities (J/g), and temperatures (°C) measured during the field study.…”