Field data and growth model for mussels Mytilus edulis in Danish waters

Abstract

Growth rates of blue mussels, Mytilus edulis, in suspended net-bags were measured in field experiments conducted in Limfjorden and Great Belt, Denmark, for extended periods of time (22–69 days) with up to 8 intermediate data samplings during the period. The resulting time series of growth of different overlapping size-classes of M. edulis were analysed individually and after being assembled to cover the full range of sizes, as full time series in terms of weight specific growth rate (µ=(1/W) dW/dt,% day⁻¹) as a function of dry weight of soft parts (W, g). The results were compared to a simple bioenergetic growth model for mussels (µ=aW ^b , a=0.871×C−0.986, b=− 0.34), and observed power-law relations of growth data were in good agreement with the model, which takes into account the prevailing average chlorophyll a (chl a) concentration (C, µg chl a l⁻¹) at field sites. Thus, the b-values of data were close to the predicted −0.34 while the a-value was in one case lower than estimated due to suboptimal conditions during part of the growth period. As a supplementary interpretation the growth data have been expressed in terms of the time to double the dry weight of soft parts for a given size of mussel and at a given experimental site.

Keywords:

• Energy budget
• bioenergetics
• doubling time
• condition index
• chl a
• suspension-feeding

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

This work formed part of the MarBioShell project supported by the Danish Agency for Science, Technology and Innovation for the period January 2008 to December 2012. Thanks are due to Mads Anker van Deurs and Isabel B. Saavedra for technical assistance. Thanks are due to Dr Franz Uiblein and two anonymous referees for constructive criticism of the manuscript.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark