Loading...
Sweepstakes reproductive success is absent in a New Zealand snapper (Chrysophrus auratus) population protected from fishing despite “tiny” Ne/N ratios elsewhere
Jones, Andy Lavery, Shane D. Le Port, Agnès Wang, You-Gan Blower, Dean Ovenden, Jennifer
Jones, Andy
Lavery, Shane D.
Le Port, Agnès
Wang, You-Gan
Blower, Dean
Ovenden, Jennifer
Abstract
A landmark study published in 2002 estimated a very small Ne/N ratio (around 10–5) in a population of pink snapper (Chrysophrys auratus, Forster, 1801) in the Hauraki Gulf in New Zealand. It epitomized the tiny Ne/N ratios (<10–3) reported in marine species due to the hypothesized operation of sweepstakes reproductive success (SRS). Here we re-evaluate the occurrence of SRS in marine species and the potential effect of fishing on the Ne/N ratio by studying the same species in the same region, but in a population that has been protected from fishing since 1975. We combine empirical, simulation and model-based approaches to estimate Ne (and Nb) from genotypes of 1,044 adult fish and estimate N using recapture-probabilities. The estimated Ne/N ratio was much larger (0.33, SE: 0.14) than expected. The magnitude of estimates of population-wide variance in individual lifetime reproductive success (10–18) suggested that the sweepstakes effect was negligible in the study population. After evaluating factors that could explain the contrast between studies – experimental design, life history differences, environmental effects and the influence of exploitation on the Ne/N ratio – we conclude that the low Ne of the Hauraki Gulf population is associated with demographic instability in the harvested compared to the protected population despite circumstantial evidence that the 2002 study may have underestimated Ne. This study has broad implications for the prevailing view that reproductive success in the sea is largely driven by chance, and for genetic monitoring of populations using the Ne/N ratio and Nb.
Keywords
deterministic modelling, fishing pressure, genetic effective population size, life history, reproductive success, simulation
Date
2019
Type
Journal article
Journal
Book
Volume
28
Issue
12
Page Range
2986-2995
Article Number
ACU Department
Institute for Learning Sciences and Teacher Education (ILSTE)
Faculty of Education and Arts
Faculty of Education and Arts
Relation URI
Source URL
Event URL
Open Access Status
License
All rights reserved
File Access
Controlled