David Carmen L.

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Last Name
David
First Name
Carmen L.
ORCID
0000-0002-4241-1284

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  • Article
    The interactive effects of temperature and food consumption on growth of larval Arctic cod (Boreogadus saida): a bioenergetic model
    (University of California Press, 2022-02-10) David, Carmen L. ; Ji, Rubao ; Bouchard, Caroline ; Hop, Haakon ; Hutchings, Jeffrey A.
    Understanding larval growth, mediated by the interaction of early life traits and environmental conditions, is crucial to elucidate population dynamics. We used a bioenergetic model as an integrative tool to simulate the growth of Arctic cod (Boreogadus saida) larvae and to test the sensitivity of modeled growth to temperature and food quantity and quality. The growth was computed as the energy gained through food consumption minus the energy lost through respiration and other metabolic processes. We extended a previously published bioenergetic model to cover the full range of larval length and used a simplified feeding module. This simplification allowed us to build a predictive tool that can be applied to larval Arctic cod at a large spatial scale. Our model suggested that with subzero temperatures in the High Arctic, larvae need to increase food consumption in order to reach the observed length-at-age in late summer. The modeled growth agreed well with the field observations in the High Arctic but was 2–3 times higher than the laboratory-derived growth rate, probably due to differences in food type and selective mortality. Our study reveals important knowledge gaps in our understanding of larval cod growth in the High Arctic, including the lack of empirical estimations of daily ration and respiration for larvae under the natural habitat temperatures.
  • Article
    Allometric relationships of ecologically important Antarctic and Arctic zooplankton and fish species
    (Springer, 2022-01-08) Schaafsma, Fokje L. ; David, Carmen L. ; Kohlbach, Doreen ; Ehrlich, Julia ; Castellani, Giulia ; Lange, Benjamin A. ; Vortkamp, Martina ; Meijboom, André ; Fortuna-Wünsch, Anna ; Immerz, Antonia ; Cantzler, Hannelore ; Klasmeier, Apasiri ; Zakharova, Nadezhda ; Schmidt, Katrin ; Van de Putte, Anton ; van Franeker, Jan A. ; Flores, Hauke
    Allometric relationships between body properties of animals are useful for a wide variety of purposes, such as estimation of biomass, growth, population structure, bioenergetic modelling and carbon flux studies. This study summarizes allometric relationships of zooplankton and nekton species that play major roles in polar marine food webs. Measurements were performed on 639 individuals of 15 species sampled during three expeditions in the Southern Ocean (winter and summer) and 2374 individuals of 14 species sampled during three expeditions in the Arctic Ocean (spring and summer). The information provided by this study fills current knowledge gaps on relationships between length and wet/dry mass of understudied animals, such as various gelatinous zooplankton, and of animals from understudied seasons and maturity stages, for example, for the krill Thysanoessa macrura and larval Euphausia superba caught in winter. Comparisons show that there is intra-specific variation in length–mass relationships of several species depending on season, e.g. for the amphipod Themisto libellula. To investigate the potential use of generalized regression models, comparisons between sexes, maturity stages or age classes were performed and are discussed, such as for the several krill species and T. libellula. Regression model comparisons on age classes of the fish E. antarctica were inconclusive about their general use. Other allometric measurements performed on carapaces, eyes, heads, telsons, tails and otoliths provided models that proved to be useful for estimating length or mass in, e.g. diet studies. In some cases, the suitability of these models may depend on species or developmental stages.