University of Tasmania
Browse

File(s) under permanent embargo

Implications of a climate-induced recruitment shift in the stock assessment of Patagonian grenadier (Macruronus magellanicus) in Chile

journal contribution
posted on 2023-05-20, 02:24 authored by Castillo-Jordan, C, Wayte, SE, Tuck, GN, Sean TraceySean Tracey, Stewart FrusherStewart Frusher, Punt, AE
Patagonian grenadier (Macruronus magellanicus) is the most abundant demersal fisheries resource off Chilean Patagonia, and also is a key fisheries species off the south of Argentina and off the Falkland Islands. A Stock Synthesis assessment shows that this stock has declined in abundance off Chile, which has been attributed to a major change in recruitment strength, and subsequent production, after 1999. An assessment is conducted in which the change in recruitment is modelled as a shift in the stock-recruitment relationship. Management Strategy Evaluation is then used to examine the consequences of a mismatch between the assumptions related to recruitment in the assessment used to set the annual total allowable catch (TAC), and those in the operating model that represents the actual situation being managed. A management strategy that does not consider a shift in recruitment resulted in average TAC values of approximately 125,000 t, substantially larger than the sustainable yield of 45,000 t when there is a recruitment shift. A management strategy based on ignoring the shift in recruitment would thus lead to unsustainable catches, with major impacts on the ecosystem as well as the industry and coastal communities reliant on the fishery, if there was an actual shift in recruitment. Management of the fishery has not accounted for a recruitment shift, and annual landings have been consistently lower than the estimated annual TACs. The 2014 landings are similar to the long term TAC estimated by the assessment models under the Shift operating model. The history of the Patagonian grenadier fishery demonstrates the benefits of taking a precautionary approach that accounts for changes in fish productivity (whether climate-driven or otherwise). However, there can be considerable delays before a shift is observed in recruitment estimates or assessment model mis-specification is detected. The need for alternative approaches for providing more timely recruitment information is discussed.

History

Publication title

Fisheries Research

Volume

212

Pagination

114-122

ISSN

0165-7836

Department/School

Institute for Marine and Antarctic Studies

Publisher

Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Rights statement

Crown Copyright 2018

Repository Status

  • Restricted

Socio-economic Objectives

Wild caught fin fish (excl. tuna)

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC