A box model for ecosystem-level management of mussel culture carrying capacity in a coastal bay

12 páginas, 2 tablas, 5 figuras.-- The final publication is available at www.springerlink.com
Shellfish carrying capacity is determined by the interaction of cultured species with the ecosystem principally constrained by environmental characteristics, and particularly food availability. A multiple box ecosystem model was constructed to examine the carrying capacity for mussel aquaculture in Tracadie Bay, Prince of Edward Island, Canada. The model was run in two different years, 1998 and 1999, in which time series in the far field and three points inside the bay were available. This dataset constitutes an ideal situation for groundtruthing, allowing a spatial validation of the ecosystem model and checking its robustness when the boundary conditions are changed. The groundtruthing process suggested that the differential equations and parameters used on the model could provide a good prediction of the ecological dynamics within the bay. Results indicated that the mussel biomass exerts a top-down control of phytoplankton populations. Given that phytoplankton constitute the first step in marine food webs and that mussels exert a control of primary producers, carrying capacity has been studied in terms of chlorophyll depletion. The analysis of the chlorophyll depletion highlighted the importance of inter-annual variability in carrying capacity of the bay. In this way, results of the model suggest that the conditions observed during 1999 are more sensitive to aquaculture activity than observed during 1998. This result is very important from an ecosystem-level point of view because it reveals the importance of applying a precautionary policy in the management of aquaculture activity
This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) and a Fundación Juana de Vega fellowship to R.F