Context-dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species
|Author(s)||Hidalgo Manuel1, Rouyer Tristan1, Bartolino Valerio2, 4, Cervino Santiago3, Ciannelli Lorenzo5, Massuti Enric6, Jadaud Angelique7, Saborido-Rey Fran8, Durant Joel M.1, Santurtun Marina9, Pineiro Carmen3, Stenseth Nils C.1|
|Affiliation(s)||1 : Univ Oslo, CEES, Dept Biol, NO-0316 Oslo, Norway.
2 : Swedish Univ Agr Sci, Dept Aquat Resources, SE-45321 Lysekil, Sweden.
3 : Spanish Inst Oceanog, Vigo Oceanog Ctr, ES-36200 Vigo, Spain.
4 : Univ Gothenburg, Dept Earth Sci, SE-40530 Gothenburg, Sweden.
5 : Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA.
6 : Spanish Inst Oceanog, Balearic Oceanog Ctr, ES-07015 Palma de Mallorca, Spain.
7 : IFREMER, Ctr Halieut Mediterraneen & Trop, Lab Ressources Halieut, FR-34203 Sete, France.
8 : Inst Marine Res, ES-36208 Vigo, Spain.
9 : AZTI Tecnalia, Resource Dept, Txatxarramendi Ugartea ZG, ES-48395 Sukarieta, Bizkaia, Spain.
|Source||Ecography (0906-7590) (Wiley-blackwell), 2012-07 , Vol. 35 , N. 7 , P. 637-649|
|WOS© Times Cited||9|
|Note||Subject Editor: Thierry Oberdorff. Accepted 8 July 2011|
|Abstract||Fisheries ecologists traditionally aimed at disentangling climate and fishing effects from the population dynamics of exploited marine fish stocks. However, recent studies have shown that internal characteristics and external forcing (climate and exploitation) have interactive rather than additive effects. Thought most of these studies explored how demographic truncation induced by exploitation affected the response of recruitment to climate, identifying a general pattern revealed to be difficult as interactions are often case-specific. Here we compared five exploited stocks of European hake Merluccius merluccius from the Atlantic Ocean and Mediterranean Sea to investigate how the interaction between internal characteristics and external forces affect the variability of the population growth rate and their consequences on recruitment. Our results show that demographic truncation induces a novel population scenario in which the growth rate is maximized when the reproductive stock is younger and less diverse. This scenario is shaped by the climate variability and the fishing pattern. The population growth rate becomes more dependent on the maturation schedule and less on the survival rates. The consequences for the recruitment dynamics are twofold; the effect of density-dependent regulatory processes decreases while the effect of the density-independent drivers increases. Our study shows that the interaction between internal characteristics and external forces changes across geographic locations according to 1) the importance of demographic truncation, 2) the influence of the climate on the regional hydrography and 3) the spatiotemporal heterogeneity of the physical environment to which fish life history is adapted.|