IDEAS home Printed from https://ideas.repec.org/a/eee/ecomod/v331y2016icp31-43.html
   My bibliography  Save this article

Assessing the effects of demersal fishing and conservation strategies of marine mammals over a Patagonian food web

Author

Listed:
  • Ocampo Reinaldo, Matías
  • Milessi, Andrés C.
  • Romero, María Alejandra
  • Crespo, Enrique
  • Wolff, Matthias
  • González, Raúl A.

Abstract

The San Matías Gulf (SMG) is a semi-enclosed ecosystem where the Argentine hake Merluccius hubbsi (AH) has been the main fishery resource since 1971. During the 20th century the South American sea lion Otaria flavescens (SASL) population was severely reduced in this ecosystem due an intense hunting, but in the 1970's conservation was promoted and hunting was banned. As a consequence SASL have been slowly recovering, until the 1990's when rapidly rebuilt their populations. Recent studies indicate that they feed mostly over commercially profitable medium-sized AH. Also, medium-sized and large hake are well-known cannibals that feed heavily over smaller AH. Fishing trawlers affect juvenile and medium-sized AH and artisanal long-liners capture exclusively large AH. The objective of this study was to evaluate the effect of a growing SASL population over the AH in the SMG, considering the changes in the fishing activity as well as the size-structured cannibalism within the AH population. The evaluations were based on time series of hake and SASL biomass using the “Ecopath with Ecosim” dynamic modelling approach. The analyses show that over 4 decades the increase in Sea Lions biomass has not generated a significant increase in the predation mortality over AH. On the other hand, an increase and subsequent variations in the fishing mortality seems to be related with long-term variations in large AH abundance, and a decrease in medium-sized AH abundance, constraining the cannibalism mortality. This led to a positive effect over juvenile AH abundance due to a released cannibalism pressure, even considering that the less abundant larger AH are also the main spawners of the population. In this scenario, where it seems that trawlers and long-liners have replaced several predators over the SMG food web, SLAS population is still growing but they may not reach the pristine abundance levels of the time before hunting.

Suggested Citation

  • Ocampo Reinaldo, Matías & Milessi, Andrés C. & Romero, María Alejandra & Crespo, Enrique & Wolff, Matthias & González, Raúl A., 2016. "Assessing the effects of demersal fishing and conservation strategies of marine mammals over a Patagonian food web," Ecological Modelling, Elsevier, vol. 331(C), pages 31-43.
  • Handle: RePEc:eee:ecomod:v:331:y:2016:i:c:p:31-43
    DOI: 10.1016/j.ecolmodel.2015.10.025
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/S0304380015005104
    Download Restriction: Full text for ScienceDirect subscribers only

    File URL: https://libkey.io/10.1016/j.ecolmodel.2015.10.025?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    References listed on IDEAS

    as
    1. Gurney, Leigh J. & Pakhomov, Evgeny A. & Christensen, Villy, 2014. "An ecosystem model of the Prince Edward Island archipelago," Ecological Modelling, Elsevier, vol. 294(C), pages 117-136.
    2. Zhang, Yuying & Chen, Yong, 2007. "Modeling and evaluating ecosystem in 1980s and 1990s for American lobster (Homarus americanus) in the Gulf of Maine," Ecological Modelling, Elsevier, vol. 203(3), pages 475-489.
    3. Cronin, M. & Jessopp, M. & Houle, J. & Reid, D., 2014. "Fishery-seal interactions in Irish waters: Current perspectives and future research priorities," Marine Policy, Elsevier, vol. 44(C), pages 120-130.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Guan, Lisha & Shan, Xiujuan & Jin, Xianshi & Gorfine, Harry & Yang, Tao & Li, Zhongyi, 2020. "Evaluating spatio-temporal dynamics of multiple fisheries-targeted populations simultaneously: A case study of the Bohai Sea ecosystem in China," Ecological Modelling, Elsevier, vol. 422(C).
    2. Nuttall, M.A. & Jordaan, A. & Cerrato, R.M. & Frisk, M.G., 2011. "Identifying 120 years of decline in ecosystem structure and maturity of Great South Bay, New York using the Ecopath modelling approach," Ecological Modelling, Elsevier, vol. 222(18), pages 3335-3345.
    3. Torbjörn Jansson & Staffan Waldo, 2022. "Managing Marine Mammals and Fisheries: A Calibrated Programming Model for the Seal-Fishery Interaction in Sweden," Environmental & Resource Economics, Springer;European Association of Environmental and Resource Economists, vol. 81(3), pages 501-530, March.
    4. Goedegebuure, Merel & Melbourne-Thomas, Jessica & Corney, Stuart P. & Hindell, Mark A. & Constable, Andrew J., 2017. "Beyond big fish: The case for more detailed representations of top predators in marine ecosystem models," Ecological Modelling, Elsevier, vol. 359(C), pages 182-192.
    5. Morales-Zárate, M.V. & Lluch-Cota, S.E. & Serviere-Zaragoza, E. & del Próo, S. Guzmán, 2011. "Modeling an exploited rocky coastal ecosystem: Bahia Tortugas, Mexico," Ecological Modelling, Elsevier, vol. 222(5), pages 1185-1191.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:ecomod:v:331:y:2016:i:c:p:31-43. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: http://www.journals.elsevier.com/ecological-modelling .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.