How do river ecosystems support fish? How do environmental changes influence the system’s capacity to support fish? And how might different restoration strategies influence fish? These are questions J. Ryan Bellmore, a research fish biologist who works in Juneau, Alaska, for the USDA Forest Service’sPacific Northwest Research Station, and his partners set out to answer.
River restoration is typically aimed at recovering or conserving one or two target species like salmon or trout. It also influences all the other river species and the larger food web—the natural interconnection of many food chains made up of animals and plants that connect in many ways.
“To successfully conserve and restore one species, we need to know how the larger food web responds to our efforts,” said Bellmore. Bellmore and his partners recently published a report describing a model that can help address specific river research and management questions.
This model—the Aquatic Trophic Productivity (ATP) computer simulation—is an interactive tool that links the success of fish populations to the food webs and the conditions that influence them. The model separates aquatic organisms into “trophic groups” that share similar predators and prey. These relationships are then linked to the physical and chemical conditions of the river, including the movement of the water and the structure and composition of vegetation along the river’s edge.