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Fewer eggs from larger size limits: counterintuitive outcomes in a spatially heterogeneous fishery
journal contribution
posted on 2023-05-18, 03:42 authored by Caleb GardnerCaleb Gardner, Klaas HartmannKlaas Hartmann, Punt, AE, Eriko HoshinoThe legal minimum length (LML) of female Southern Rock Lobster (Jasus edwardsii) was reduced in the Tasmanian fishery in 1966 for higher sustainable catches. Originally, the LML was to be reduced in slow growth southern areas only; however, the change was implemented across the entire fishery due to lobbying by commercial fishers. The lower LML has been controversial ever since, including during recent years when low recruitment resulted in a lower total allowable catch (TAC). Fishers argued that this could have been prevented with a higher female LML across the jurisdiction. A length- and sex-based bioeconomic model was used to examine probable outcomes of the larger statewide LML. This model showed that management of egg production would be poorly served by raising the statewide LML because of spatial patterns in the stock and fishery. Catch would be displaced from areas where egg production was already high and into the most depleted areas thus reducing production in areas of greatest concern. Spatial variation in biological parameters can have a profound effect on outcomes of management perceived to be conservative, possibly leading to negative impacts. This risk exists wherever catch is displaced, such as with Marine Protected Areas, spatial TACs and gear restrictions.
Funding
Australian Seafood Cooperative Research Centre
History
Publication title
ICES Journal of Marine ScienceVolume
72Pagination
i252-i259ISSN
1054-3139Department/School
Institute for Marine and Antarctic StudiesPublisher
Academic Press Ltd Elsevier Science LtdPlace of publication
24-28 Oval Rd, London, England, Nw1 7DxRights statement
Copyright 2014 International Council for the Exploration of the SeaRepository Status
- Restricted