Using Hard‐Part Microchemistry to Advance Conservation and Management of North American Freshwater Fishes

Abstract

Hard‐part microchemistry offers a powerful tool for inferring the environmental history and stock assignment of individual fishes. However, despite the applicability of this technique to a wide range of fisheries conservation and management issues, its use has been restricted to only a small fraction of North American species and inland waters. In this article, we provide freshwater fisheries professionals with an accessible review of methods and applications of hard‐part microchemistry techniques. Our objectives are to (1) summarize the science of hard‐part microchemistry; (2) provide guidelines for designing hard‐part microchemistry studies, including sample sizes, laboratory analyses, statistical techniques, and inferential limitations; and (3) identify conservation and management applications where these techniques may be particularly useful. We argue that strategic use of hard‐part microchemistry methods (specifically when they are used in concert with other indirect tracer techniques such as stable isotope chemistry and genetics) can advance fish management and conservation across all stages of fish life history.

Spatial and temporal variation in otolith chemistry and its relationship with water chemistry: Stock discrimination of Sperata aor

“…Traditional environmental history studies are based mainly on the physical tagging of fish and telemetry, but these methods are time-consuming and costly. Several studies have confirmed that otolith chemistry is an important tool to determine natal origin of fish stocks, population structure, migration patterns and to address a wide range of ecological issues such as the difference in habitat use and degree of stock mixing (Campana, 1999;Elsdon et al, 2008;Pracheil et al, 2014;Ruttenberg et al, 2005). Several studies have confirmed that otolith chemistry is an important tool to determine natal origin of fish stocks, population structure, migration patterns and to address a wide range of ecological issues such as the difference in habitat use and degree of stock mixing (Campana, 1999;Elsdon et al, 2008;Pracheil et al, 2014;Ruttenberg et al, 2005).…”

Assessing the Utility of Otolith Chemistry for Management of Six Freshwater Fishes from a River–Reservoir System

“…Researchers should also ensure that water chemistry is distinct among habitats at the scales of interest and integrate otolith chemistry with effective techniques at larger scales (e.g., genetics, mark–recapture) and smaller scales (e.g., telemetry, muscle isotopes) to improve inferential power (Pracheil et al. ). Moreover, we encourage researchers to use otolith chemistry to evaluate temporal patterns in fish habitat use, making sure to consider the spacing of otolith annuli and circuli relative to the sizes of laser ablation spots and transects.…”

Spatial and Temporal Distinction of Microelemental Signatures of Missouri River Tributaries

“…The relative concentrations of these elements within the water column are influenced by several factors such as bedrock and surficial geology, groundwater sources and runoff, habitat (e.g. floodplains, channels, estuaries), and water residence time (Pracheil et al ., ). Thus, elemental signatures at each annulus may reflect the trace elemental composition of the water environment at the location in which the fish lived in that particular year (Rose, ).…”

“…Typically, a suite of trace element measures are considered in concert as a distinct microelemental signature to assign fish accurately to a specific area at a given time (Campana, ). However, the signatures of the habitats of interest must differ markedly from one another and be temporally stable (Ludsin et al ., ; Pracheil et al ., ; Schaffler and Winkelman, ). Fortunately, validation of the spatial differences in and temporal stability of water signatures is much less expensive in comparison to hard‐part microchemistry analysis ( personal observation ) and should be completed prior or simultaneous to fish sampling (Pracheil et al ., ).…”