Assessing the carrying capacity of ecosystems is crucial to the selection of suitable and sustainable locations for aquaculture farms. In Malpeque Bay (PEI, Canada), the potential expansion of mussel farms has driven a series of numerical modelling studies. We coupled sub-models for sea lettuce, wild and cultured oysters and wild softshell clams to an existing ecosystem model to better understand nutrient dynamics and the carrying capacity of Malpeque Bay. Simulations suggested that competition for nutrients between phytoplankton and sea lettuce and filtration by cultured bivalves predominantly mitigate eutrophication effects. The addition of sea lettuce reduced mussel growth by 2% on average and up to 9% near eutrophic estuaries favouring macroalgae growth. Projected new mussel farms reduced current mussel growth by 2% also, suggesting that the carrying capacity of the bay may not be reached yet. Both current and projected aquaculture activities seemed to have limited effects on natural bivalve growth.

评估生态系统的承载能力对于选择适合的和可持续的水产养殖场地点至关重要。在Malpeque湾（加拿大PEI），贻贝养殖场的潜在扩展推动了一系列数值模拟研究。我们将生菜，野生牡蛎和养殖牡蛎以及野生软壳蛤的子模型与现有的生态系统模型相结合，以更好地了解营养动态和马尔佩克湾的承载能力。模拟表明，浮游植物与海生菜之间的养分竞争和养殖双壳类动物的过滤主要减轻了富营养化的影响。添加海生菜使贻贝平均减少2％，在接近富营养化河口的地区最多减少9％，有利于大型藻类的生长。预计的新贻贝养殖场也会使目前的贻贝生长量减少2％，提示可能尚未达到托架的承载能力。目前和预计的水产养殖活动似乎对自然双壳类动物的生长影响有限。