title: Implications of a warming North Sea for the growth of haddock Melanogrammus aeglefinus.
abstract: The present study aimed firstly, to test for a temperature effect on North Sea haddock Melanogrammus aeglefinus growth and secondly, to develop a model that could be used to assess total length (L(T)) and mass (M)-at-age response to different temperature scenarios. The von Bertalanffy growth model was fitted on a cohort-by-cohort basis from 1970 to 2006. The asymptotic L(T) (L(∞)) was negatively correlated with temperature while the rate at which L(∞) is reached (K) was positively correlated with temperature. K was negatively correlated with density, whereas no effect on L(∞) was observed. These effects were incorporated into a von Bertalanffy model which was extended to include temperature and density as explanatory variables. Only the temperature variable was significant. Fitting the extended von Bertalanffy model revealed that L(∞) decreased while K increased with increasing temperature, resulting in up to a 40% loss of individual yield at older ages. The dramatic decline observed in the mean age at which 50% of the population becomes mature suggests that higher temperatures resulted in larger young M. aeglefinus that matured earlier and therefore reached a smaller maximum size. In a global warming context, the loss of individual yield observed at old ages is likely to reduce the fisheries yield for M. aeglefinus in the North Sea.
authors.affiliation: Zoology Building, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ Scotland, U.K.
authors.forename: A R
authors.initials: AR
authors.lastname: Baudron
authors.forename: C L
authors.initials: CL
authors.lastname: Needle
authors.forename: C T
authors.initials: CT
authors.lastname: Marshall
mesh_terms: D000818:Animals; D049628:Body Size; D048388:Gadiformes / Q000033:anatomy & histology / Q000254:growth & development*; D057232:Global Warming; D009659:North Sea; D011156:Population Density; D011157:Population Dynamics; D012623:Seawater / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors