Effects of variability in food quantity and quality on the feeding, growth, and condition of larval fish under natural field conditions.

长期以来，人们一直认为，幼鱼所遇到的食物量决定了它们在海洋中的生存，而每年可获得的食物量的变化也因此导致了鱼类种群年强度的年变化。尽管有实验室实验的支持，但在野外条件下证明这种关系的令人信服的证据却少得惊人。最近，研究表明，食物质量（而不是数量）的变化也可能在浮游生物的生长和生存中发挥重要作用。然而，目前对食物质量的自然变化是否也会影响幼鱼的生长和存活知之甚少。本项目旨在通过开展实地工作来检验这种可能性，这些工作将比较食物供应和食物质量对幼鱼生长速度的影响，以及对它们在自然条件下的“状况”或健康状况的各种衡量标准的影响。我们还将探索幼鱼以原生动物为食的程度——原生动物是一组微小的软体浮游生物，通常在研究幼鱼的摄食中不被考虑（因为它们消化迅速，难以识别），但它们可能是重要的猎物来源。研究将在沿海的纽芬兰和乔治亚海峡进行。

It has long been believed that the amount of food encountered by larval fish determines their survival in the ocean, and that year-to-year variations in the amount of food available thus lead to year-to-year variations in year-class strength in fish populations. Although supported by lab experiments, convincing evidence for this relationship under field conditions is surprisingly rare. Recently, research has shown that variations in food quality (as opposed to quantity) may also play a significant role in the growth and survival of plankton. However, very little is currently known about whether natural variations in food quality also affect the growth and survival of larval fish. This project aims to test this possibility by conducting field work that will compare the effects of food availability and food quality on the growth rates of larval fish and on various measures of their "condition", or health, under natural conditions. We will also explore the extent to which larval fish may feed upon protozoans - a group of tiny soft-bodied plankton that are not usually considered in studies of larval fish feeding (as they are rapidly digested and hard to identify), but which may be an important prey source nonetheless. Research will be conducted in coastal Newfoundland and in the Strait of Georgia.