Growth and reproductive simulation of candidate shellfish species at fish cages in the Southern Mediterranean: Dynamic Energy Budget (DEB) modelling for integrated multi-trophic aquaculture G. Sarà a, ⁎, G.K. Reid b , A. Rinaldi a, c , V. Palmeri a , M. Troell d, e , S.A.L.M. Kooijman f a Dipartimento di Scienze della Terra e del Mare, Università di Palermo, Italy b Canadian Integrated Multi-Trophic Aquaculture Network, University of New Brunswick/Fisheries and Oceans Canada, Canada c Dipartimento di Ecologia Marina, Università di Messina, Italy d The Beijer Institute, Swedish Royal Academy of Sciences, Stockholm, Sweden e Stockholm Resilience Centre, Stockholm University, Sweden f Department of Theoretical Biology, Vrije Universiteit, Amsterdam, the Netherlands abstract article info Article history: Received 8 June 2011 Received in revised form 26 October 2011 Accepted 27 October 2011 Available online 7 November 2011 Keywords: IMTA DEB model Chlorophyll-a Mytilus galloprovincialis Crassostrea gigas Mediterranean Sea A Dynamic Energy Budget (DEB) model is used to simulate growth and reproduction of the shellfish Mytilus galloprovincialis and Crassostrea gigas in an integrated multi-trophic aquaculture (IMTA) farm scenario situ- ated in the Southern Mediterranean (the Gulf of Castellammare, Sicily). We modelled the effect of primary production enrichment at fish cages on shellfish growth and life history traits using 4 years-hourly temper- ature data (01 January 2006–31 December 2009) at a depth of 1 m. Outputs of the DEB simulations were: the maximum theoretical total shell length of shellfish, the potential reproductive outputs and the mean an- nual von Bertalanffy growth rate. There was a mean increase in empirically measured suspended chlorophyll- a of approximately 45% close (within about 100 m) to fish cages (2.3 ± 1.1 μgl -1 ) compared to sites away (about 1.5 km) from the cages (1.3 ± 0.6 μgl -1 ). DEB simulations using localised CHL-a measures showed that mussels close to cages could reach greater maximum length at the end of 4th year than those far from cages and in open-sea. Simulations of oyster growth close to cage sites resulted in double growth rate (12 cm in 4 years) compared to oysters at far sites (6.5 cm in 4 years). The present study improves knowl- edge of the application of DEB models to predict the potential fitness of shellfish starting from First Principles. This is an innovative approach with potential for application at larger scales than those of local facilities. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Integrated multi-trophic aquaculture (IMTA) is a practice that cou- ples low trophic (e.g., suspension feeders) to higher trophic fed (e.g., fish) organisms so that the nutrient waste of one species can become nutritional inputs for another (e.g., shellfish; Reid et al., 2010; Troell et al., 2003, 2009). IMTA effectiveness has been demonstrated in both fresh and marine waters by coupling many different types of organisms (FAO, 2009). Shellfish growth is highly adaptable to a wide range of temperatures and diet varieties making them a highly successful global aquaculture species (Barrington et al., 2009) well suited for IMTA (Sarà et al., 2009; Troell et al., 2009). Shellfish acquire energy filtering sus- pended particles such as phytoplankton and detritus (Reid et al., 2010; Sarà, 2006, 2007a; Sarà et al., 2000, 2003). Gradients of organic particulates as indicated by shellfish uptake (Gao et al., 2006; Jones and Iwama, 1991), inorganic soluble nutrients (Reid et al., 2006; Sanderson et al., 2008; Yokoyama and Ishihi, 2010) and phytoplankton (Sarà et al., 2007), have been reported close to fish cages, although often with extensive spatial and temporal variation (Dalsgaard and Krause- Jensen, 2006; Pitta et al., 2009; Sarà, 2007a, 2007b, 2007c; Sarà et al., 2009, 2011b). In open-water, IMTA systems, proximate shellfish can po- tentially benefit from solid organic particulates (faeces and waste feed) directly from the fed trophic level (i.e. fish); or through a step wise pro- cess of soluble nutrient loading (ammonium phosphate) driving an in- crease in primary production (PP). These two possible routes of augmented diet production for IMTA shellfish will be a function of sev- eral mechanisms, such as fish farm scale, temporal scales (time of PP re- sponse to a nutrient load, which can range from hours to days respectively), ambient nutrient concentrations, temperature and hy- drodynamics (Aure et al., 2007; Troell et al., 1999, 2011). To date most studies on IMTA effectiveness have been derived from empirical field research (e.g., Cheshuk et al., 2003; MacDonald et al., 2011; Sarà et al., 2009). However, IMTA site design and feasibility studies could benefit significantly from a modelling approach capable of mecha- nistic predictions for the growth of shellfish under a variety of tempera- tures in conjunction with varying diet concentrations. Specifically, this would address important planning criteria for IMTA development by Aquaculture 324-325 (2012) 259–266 ⁎ Corresponding author. Tel./fax: + 39 09123862853. E-mail address: gianluca.sara@unipa.it (G. Sarà). 0044-8486/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.aquaculture.2011.10.042 Contents lists available at SciVerse ScienceDirect Aquaculture journal homepage: www.elsevier.com/locate/aqua-online