Simulated effects of imperfect sterile sport fish stocking on persistence of fertile fish in new exploited populations DOI Creative Commons
Adam G. Hansen, Collin J. Farrell, Brett M. Johnson

et al.

North American Journal of Fisheries Management, Journal Year: 2023, Volume and Issue: 43(4), P. 908 - 934

Published: June 17, 2023

Abstract Objective Sterile fish are used for multiple purposes, including enhancing sport fisheries where reproduction is not wanted. In some regions with few native fish, but strong angler desire nonnative piscivorous species, establishing new using sterile predators being explored as a management option. this context, objective information needed to guide discussions stakeholders and inform policy. Methods Artificial induction of triploidy commonly produce predators, the process rarely 100% effective. Thus, starting triploid fishery would require stocking imperfect induction, which carries risk jump‐starting feral population if stocked diploids survive maturity become self‐sustaining. We developed joint stochastic age‐structured model explore potential consequences Walleye Sander vitreus into locations devoid decisions. Result Model simulations demonstrated that high rate (≥95%) fingerling combined simultaneous constraints on natural were required minimize probability diploid persistence or maintain abundance natural‐origin near below expectations from alone. Reproductive interference males could suppress expansion under circumstances. Above patterns also contingent maintaining relatively annual mortality (>50%)—reflective exploited populations—on age‐classes particularly vulnerable catch harvest. Conclusion Our modeling framework provides decision makers weigh options discussions. A better understanding recruitment exploitation dynamics populations poststocking performance behavior help refine models expectations.

Language: Английский

Lagging spawning and increasing phenological extremes jeopardize walleye (Sander vitreus) in north‐temperate lakes DOI Creative Commons

Martha E. Barta,

Greg G. Sass,

Jeffrey R. Reed

et al.

Limnology and Oceanography Letters, Journal Year: 2024, Volume and Issue: 9(3), P. 229 - 236

Published: Feb. 26, 2024

Abstract The phenology of critical biological events in aquatic ecosystems is rapidly shifting due to climate change. Growing variability phenological cues can increase the likelihood trophic mismatches (i.e., timing peak prey and predator abundances), causing recruitment failures important fisheries. We assessed changes spawning walleye ( Sander vitreus ) 194 Midwest US lakes investigate factors influencing responses change associated variability, including ice‐off timing, lake physical characteristics, population stocking history. Ice‐off shifted earlier, about three times faster than over time. Spawning deviations from historic averages increased magnitude time, large were with poor offspring survival. Our results foreshadow risks increasingly frequent natural between historically tightly coupled phenology.

Language: Английский

Citations

8
The decline of walleye populations: an ecological tipping point? DOI Creative Commons
Greg G. Sass

FACETS, Journal Year: 2025, Volume and Issue: 10, P. 1 - 17

Published: Jan. 1, 2025

Walleye/ogaa ( Sander vitreus (Mitchill)) (hereafter, walleye; ogaa = Ojibwe translation) populations have historically supported important multi-use, harvest-oriented fisheries. Despite intensive management, walleye declined in the midwestern United States raising concerns about sustainability of species. Numerous factors been implicated population declines, including climate change, habitat loss, invasive species, species-interactions, production overharvest (i.e., harvest consistently exceeding annual production), and changing angler behaviors. These negatively influenced natural recruitment contributed to depensatory dynamics. I provide a review perspective suggesting that current trajectory is at or nearing an ecological tipping point. Although fish are often considered compensatory density-dependent), appear prone depensation positive density dependence). My suggest management for misaligned. A change towards resource focus using ecosystem-based fisheries recognition as social–ecological systems needed conservation. If ensues, persistence will likely be further threatened because many drivers outside managerial control, those commonly used within control seemingly ineffective sustaining rehabilitating naturally reproducing populations.

Language: Английский

Citations

0
Healing Ogaa (Walleye Sander vitreus ) Waters: Lessons and Future Directions for Inland Fisheries Rehabilitation DOI
Holly S. Embke, Zachary S. Feiner, Gretchen J. A. Hansen

et al.

Reviews in Fisheries Science & Aquaculture, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 19

Published: April 9, 2025

Language: Английский

Citations

0
Diminishing productivity and hyperstable harvest in northern Wisconsin walleye fisheries DOI
Joseph T. Mrnak, Holly S. Embke,

Martin Wilkinson

et al.

Canadian Journal of Fisheries and Aquatic Sciences, Journal Year: 2024, Volume and Issue: 81(12), P. 1650 - 1665

Published: Aug. 1, 2024

Managing fisheries in a changing socio-ecological environment may require holistic approaches for identifying and adapting to novel ecosystem dynamics. Using 32 years of Ceded Territory Wisconsin (CTWI) walleye ( Sander vitreus) data, we estimated production P), biomass B), turnover P/B), yield Y), over Y/P) tested hyperstability yield. Most CTWI populations showed low P B, Y/P < 1 . Yet, overharvest > 1) was prevalent among recruitment-based management (natural recruitment (NR), sustained only by stocking, combination). Production, P/B have declined NR populations, while Y remained constant. Walleye hyperstable along gradient all fishery types (i.e., angling only, angling/tribal harvest combined). Diminishing productivity be jointly contributing observed declines. We classified lakes into groups low, moderate, or high vulnerability based on dynamics identify that benefit from declines maintain increase the adaptive capacity walleye.

Language: Английский

Citations

2
Simulated effects of imperfect sterile sport fish stocking on persistence of fertile fish in new exploited populations DOI Creative Commons
Adam G. Hansen, Collin J. Farrell, Brett M. Johnson

et al.

North American Journal of Fisheries Management, Journal Year: 2023, Volume and Issue: 43(4), P. 908 - 934

Published: June 17, 2023

Abstract Objective Sterile fish are used for multiple purposes, including enhancing sport fisheries where reproduction is not wanted. In some regions with few native fish, but strong angler desire nonnative piscivorous species, establishing new using sterile predators being explored as a management option. this context, objective information needed to guide discussions stakeholders and inform policy. Methods Artificial induction of triploidy commonly produce predators, the process rarely 100% effective. Thus, starting triploid fishery would require stocking imperfect induction, which carries risk jump‐starting feral population if stocked diploids survive maturity become self‐sustaining. We developed joint stochastic age‐structured model explore potential consequences Walleye Sander vitreus into locations devoid decisions. Result Model simulations demonstrated that high rate (≥95%) fingerling combined simultaneous constraints on natural were required minimize probability diploid persistence or maintain abundance natural‐origin near below expectations from alone. Reproductive interference males could suppress expansion under circumstances. Above patterns also contingent maintaining relatively annual mortality (>50%)—reflective exploited populations—on age‐classes particularly vulnerable catch harvest. Conclusion Our modeling framework provides decision makers weigh options discussions. A better understanding recruitment exploitation dynamics populations poststocking performance behavior help refine models expectations.

Language: Английский

Citations

4