The role of filter-feeders in coastal ecosystem functioning

人类与海洋沿海区的互动可能损害海洋生态系统的健康。例如，贻贝和牡蛎的养殖可以改变其他物种的食物供应。此外，为此目的在海洋中部署的人造结构构成了新的栖息地，可以被其他物种如海鞘（被囊动物）殖民。一些海蜇是入侵者，可以迅速繁殖并与贻贝和牡蛎竞争，主导生态系统，并对水产养殖部门的经济可行性产生负面影响。评估这种人类活动对生态系统的总体影响取决于我们对贻贝、牡蛎和海蜇摄食行为的了解。这些所谓的滤食性动物通过过滤水中的小食物颗粒来进食，通常是通过专门的过滤结构来过滤水。尽管滤食性动物在沿海生态系统中的重要性，但其摄食行为的一些关键方面仍然不清楚。这项拟议的研究计划将提高我们对贻贝、牡蛎和两种入侵海虾蛄的摄食行为的理解。这项研究将确定（1）这些物种可以有效地保留在其过滤结构中的颗粒的大小和类型，（2）它们在不同环境条件下的摄食率和行为，以及最终（3）它们对生态系统的潜在影响。我们将通过在野外和实验室受控条件下进行实验来实现这些目标，例如，探索未来海洋温度升高对滤食性动物摄食率的影响。我们还将把这些新的信息整合到数学模型中，这些模型可用于预测这些物种在当前和未来生态系统情景下的行为，如气候变化或人类对沿海地区的改造。从这项研究中获得的知识将提高我们为加拿大沿海地区做出明智的管理决策的能力。例如，我们将能够（1）探索贻贝和牡蛎养殖对环境的影响，并因此提供建议，以保证这一重要经济活动的可持续性;（2）在实验室中模拟预测的气候变化，以探索预期的未来入侵模式。总之，该计划将产生可直接应用于改善加拿大沿海地区管理的基础科学知识，并将有助于促进全球可持续水产养殖实践。

Human interactions with the coastal zones of our oceans can compromise marine ecosystem health. For example, the cultivation of mussels and oysters can alter the food supplies available for other species. In addition, the man-made structures that are deployed in the ocean for this purpose constitute new habitat that can be colonized by other species such as sea squirts (tunicates). Some sea squirts are invaders that can rapidly proliferate and out-compete mussels and oysters, dominating the ecosystem, and negatively impacting the economic viability of the aquaculture sector. Assessing the overall impact of this human activity on the ecosystem relies on our understanding of the feeding behaviour of mussels, oysters and sea squirts. These so-called filter-feeders feed by straining small food particles from water, typically by passing the water over a specialized filtering structure. Despite the importance of filter-feeders in coastal ecosystems, some critical aspects of their feeding behaviour are still not clear. This proposed research program will improve our understanding of the feeding behaviour of mussels, oysters and two species of invasive sea squirts. This research will determine (1) the size and type of particles that these species can effectively retain in their filtering structures, (2) their feeding rates and behaviour under different environmental conditions, and ultimately (3) their potential impact on the ecosystem. We will achieve these goals by performing experiments in the field and under controlled conditions in the laboratory, for example, to explore the effect of a higher future ocean temperature on filter-feeder feeding rates. We will also integrate this novel information into mathematical models that could be used to predict the behaviour of these species under current and future ecosystem scenarios such as climate change or human modifications to the coastal zone. The knowledge to be gained from this research will improve our ability to make informed management decisions for Canadian coastal zones. For example, we will be able to (1) explore the impact of mussel and oyster aquaculture on the environment and consequently provide recommendations to guarantee the sustainability of this important economic activity; (2) simulate predicted climate change in the laboratory to explore the anticipated future invasive pattern of sea squirts. In summary, this program will generate fundamental scientific knowledge that can be directly applied to improving coastal zone management in Canada, and will help to promote sustainable aquaculture practices worldwide.