Atlantic sturgeon ( Acipenser oxyrinchus oxyrinchus Mitchill, 1815) early life stage consumption evidenced by high‐throughput DNA sequencing

Abstract

Predation on early life stages of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus (ATS) may be a constraint to species recovery. Due to the difficulty in assessing consumption of early life stages with traditional diet analysis methods, we pursued an alternative DNA‐based approach. We extracted total gut content from gastrointestinal tracts of 23 fish species (593 samples) within the tidal‐fresh Pamunkey River fish assemblage collected from known ATS spawning grounds during prime spawning periods (September‐October) in 2016. High‐throughput DNA sequencing was used to amplify two markers for each sample: mitochondrial cytochrome c oxidase I (COI) and nuclear 18S ribosomal RNA gene. DNA sequences were compared to custom, SILVA 132, and NCBI databases. Results showed presence of ATS DNA in 22 samples (4%) across multiple native and nonnative tidal‐fresh fishes. The highest percentage of consumption occurred in samples from Common Carp Cyprinus carpio (11.5) and Striped Bass Morone saxatilis (12.5). Six percent of Blue Catfish Ictalurus furcatus samples had target DNA. Considering there were no bony structures or tissue resembling ATS during morphological evaluation, DNA detections were likely from partially‐fully digested eggs or early developing days‐old larvae. High‐throughput sequencing is capable of detecting consumption of ATS.

Development and testing of an environmental DNA (eDNA) assay for endangered Atlantic sturgeon to assess its potential as a monitoring and management tool

“…eDNA is a viable approach for monitoring this important endangered species and can inform DNA‐based trophic dynamics studies (Bunch et al. 2021). Given the relatively low eDNA abundances in river samples, increasing the water volume sampled, the sampling frequency, and varying the depths sampled may improve detection probability.…”

“…Overall, these results indicate that qPCR-based eDNA analysis of Atlantic sturgeon has broad potential application. eDNA is a viable approach for monitoring this important endangered species and can inform DNA-based trophic dynamics studies (Bunch et al 2021).…”

A size‐based stock assessment model for invasive blue catfish in a Chesapeake Bay sub‐estuary during 2001–2016

“…The species was introduced into the Chesapeake Bay basin in 1974 to provide new fishing opportunities and has since expanded its range to include most tributaries of Chesapeake Bay (Jenkins & Burkhead, 1994;Nepal & Fabrizio, 2019). Blue catfish are omnivores (Eggleton & Schramm, 2004;Jennings et al, 2018) and may consume species of conservation need (e.g., American shad Alosa sapidissima and American eel Angullia rostrata) or economic importance (e.g., blue crab Caliinectes sapidus) that are locally or seasonally abundant (Bunch et al, 2021;Evans et al, 2021;Schmitt et al, 2017Schmitt et al, , 2019aSchmitt et al, , 2019b. Blue catfish also support valuable recreational and commercial fisheries in the Chesapeake Bay region (Fabrizio et al, 2021;Orth et al, 2020).…”