Population and habitat restoration - Preamble to section 5

Diadromous fish populations are particularly difficult to understand, model and manage because they traverse multiple habitats that present not only environmental, ecological, reproductive, and physiological challenges, but also frequently convey them across multiple management jurisdictions. Our knowledge of population-level effects is also dependent on the quality and extent of biological, population, and demographic data. For some species, such as Pacific salmon, populations are routinely monitored, life cycles are fairly well understood, and population trends are, in general, well documented. However, for other species such as anguillid eels, our understanding of life history is incomplete, population-level data are meager, and the trends in abundance are less clear.