The University of Southampton
University of Southampton Institutional Repository

Corroborating otolith age using oxygen isotopes and comparing outcomes to scale age: Consequences for estimation of growth and reference points in northern pike (Esox lucius)

Corroborating otolith age using oxygen isotopes and comparing outcomes to scale age: Consequences for estimation of growth and reference points in northern pike (Esox lucius)
Corroborating otolith age using oxygen isotopes and comparing outcomes to scale age: Consequences for estimation of growth and reference points in northern pike (Esox lucius)

Accurate age estimates are crucial for assessing the life-histories of fish and providing management advice, but validation studies are rare for many species. We corroborated age estimates with annual cycles of oxygen isotopes (δ 18O) in otoliths of 86 northern pike (Esox lucius) from the southern Baltic Sea, compared results with visual age estimates from scales and otoliths, and assessed bias introduced by different age-estimation structures on von Bertalanffy growth models and age-structured population models. Age estimates from otoliths were accurate, while age estimates from scales significantly underestimated the age of pike older than 6 years compared to the corroborated reference age. Asymptotic length ((Formula presented.)) was larger, and the growth coefficient (Formula presented.) was lower for scale ages than for corroborated age and otolith age estimates. Consequentially, scale-informed population models overestimated maximum sustainable yield ((Formula presented.)), biomass at (Formula presented.) ((Formula presented.)), relative frequency of trophy fish ((Formula presented.)), and optimal minimum length limit but underestimated fishing mortality at (Formula presented.) ((Formula presented.)). Using scale-based ages to inform management regulations for pike may therefore result in conservative management and lost yield. The overestimated asymptotic length may instill unrealistic expectations of trophy potential in recreational anglers targeting large pike, while the overestimation in MSY would cause unrealistic expectations of yield potential in commercial fishers.

age estimation, secondary ion mass spectrometry, stable oxygen isotopes, yield, δO
0969-997X
Rittweg, Timo D.
9a41eebc-0563-4575-abf6-7c9002cb1c7f
Trueman, Clive
d00d3bd6-a47b-4d47-89ae-841c3d506205
Ehrlich, Elias
bfeaff4d-b0c0-4e44-820c-193aaa7b2657
Wiedenbeck, Michael
c02574b6-defc-46d3-b187-b45fdf08decc
Arlinghaus, Robert
8678b969-6a70-480a-8be0-9794c99048c9
Rittweg, Timo D.
9a41eebc-0563-4575-abf6-7c9002cb1c7f
Trueman, Clive
d00d3bd6-a47b-4d47-89ae-841c3d506205
Ehrlich, Elias
bfeaff4d-b0c0-4e44-820c-193aaa7b2657
Wiedenbeck, Michael
c02574b6-defc-46d3-b187-b45fdf08decc
Arlinghaus, Robert
8678b969-6a70-480a-8be0-9794c99048c9

Rittweg, Timo D., Trueman, Clive, Ehrlich, Elias, Wiedenbeck, Michael and Arlinghaus, Robert (2024) Corroborating otolith age using oxygen isotopes and comparing outcomes to scale age: Consequences for estimation of growth and reference points in northern pike (Esox lucius). Fisheries Management and Ecology, 31 (1), [e12646]. (doi:10.1111/fme.12646).

Record type: Article

Abstract

Accurate age estimates are crucial for assessing the life-histories of fish and providing management advice, but validation studies are rare for many species. We corroborated age estimates with annual cycles of oxygen isotopes (δ 18O) in otoliths of 86 northern pike (Esox lucius) from the southern Baltic Sea, compared results with visual age estimates from scales and otoliths, and assessed bias introduced by different age-estimation structures on von Bertalanffy growth models and age-structured population models. Age estimates from otoliths were accurate, while age estimates from scales significantly underestimated the age of pike older than 6 years compared to the corroborated reference age. Asymptotic length ((Formula presented.)) was larger, and the growth coefficient (Formula presented.) was lower for scale ages than for corroborated age and otolith age estimates. Consequentially, scale-informed population models overestimated maximum sustainable yield ((Formula presented.)), biomass at (Formula presented.) ((Formula presented.)), relative frequency of trophy fish ((Formula presented.)), and optimal minimum length limit but underestimated fishing mortality at (Formula presented.) ((Formula presented.)). Using scale-based ages to inform management regulations for pike may therefore result in conservative management and lost yield. The overestimated asymptotic length may instill unrealistic expectations of trophy potential in recreational anglers targeting large pike, while the overestimation in MSY would cause unrealistic expectations of yield potential in commercial fishers.

Text
Fisheries Management Eco - 2023 - Rittweg - Corroborating otolith age using oxygen isotopes and comparing outcomes to scale - Version of Record
Download (8MB)

More information

e-pub ahead of print date: 3 August 2023
Published date: February 2024
Keywords: age estimation, secondary ion mass spectrometry, stable oxygen isotopes, yield, δO

Identifiers

Local EPrints ID: 491039
URI: http://eprints.soton.ac.uk/id/eprint/491039
ISSN: 0969-997X
PURE UUID: 5490092f-44f6-407a-8193-d3f79999a8c3
ORCID for Clive Trueman: ORCID iD orcid.org/0000-0002-4995-736X

Catalogue record

Date deposited: 11 Jun 2024 16:43
Last modified: 15 Jun 2024 01:39

Export record

Altmetrics

Contributors

Author: Timo D. Rittweg
Author: Clive Trueman ORCID iD
Author: Elias Ehrlich
Author: Michael Wiedenbeck
Author: Robert Arlinghaus

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×