Animal migrations can affect disease dynamics. One consequence of migration common to marine fish and invertebrates is migratory allopatry-a period of spatial separation between adult and juvenile hosts, which is caused by host migration and which prevents parasite transmission from adult to juvenile hosts. We studied this characteristic for sea lice (Lepeophtheirus salmonis and Caligus clemens...

Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce...

Cultured Atlantic salmon (Salmo salar L.) may be introduced into natural systems intentionally or accidentally. As smolts or post-smolts, they move to the feeding areas of wild salmon in the North Atlantic Ocean. As maturing fish, they return to the area of release and enter rivers to spawn. Lack of juvenile river experience is the prime reason why cultured salmon often enter fresh water later ...

Three independent modeling methods—a nutrient-phytoplankton–zooplankton (NPZ) model (NEMURO), a food web model (Ecopath/Ecosim), and a bioenergetics model for pink salmon (Oncorhynchus gorbuscha)—were linked to examine the relationship between seasonal zooplankton dynamics and annual food web productive potential for Pacific salmon feeding and growing in the Alaskan subarctic gyre ecosystem. Th...

Recovery of depleted species is difficult, but it can be especially complex when the target species interacts strongly with other depleted species. Such is the case for northern and southern resident killer whales Orcinus orca which are listed as ‘endangered’ under the US Endangered Species Act (ESA) and Canada’s Species at Risk Act. These resident killer whales prey heavily on Pacific salmon O...

The amount of time and money spent on restoring rivers for declining populations of salmon has grown substantially in recent decades. But despite the infusion of resources, many studies suggest that salmon populations are continuing to decline, leading some to question the effectiveness of restoration efforts. Here we examine whether a particular form of salmon restoration—channel reconfigurati...

Salmon farming has become a prosperous international industry over the last decades. Along with growth in the production farmed salmon, however, an increasing threat by pathogens has emerged. Of special concern is the propagation and spread of the salmon louse, Lepeophtheirus salmonis. In order to gain insight into this parasites population dynamics in large scale salmon farming system, we pres...

In aquarium experiments using coho salmon as a model species, prior residents dominated intruders of the same size but intruders with a 6% length advantage were equally matched against prior residents. Prior winning experience (distinct from individual recognition) also strongly influenced competitive success and overcame a prior residence effect. Coho salmon reared in a hatchery dominated size...

—We report on a 3-year study of the infestation rates of the sea louse, Lepeophtheirus salmonis, on wild juvenile pink salmon Oncorhynchus gorbuscha and chum salmon O. keta in the Broughton Archipelago, British Columbia. In 2002, the British Columbia Ministry of Agriculture, Fisheries, and Food ordered farm fallowing (i.e., the removal of farmed Atlantic salmon Salmo salar from net-cages) along...

In British Columbia, Canada (BC), aquaculture of finfish in ocean netpens has the potential for pathogen transmission between wild and farmed species due to the sharing of an aquatic environment. Viral hemorrhagic septicemia virus (VHSV) is enzootic in BC and causes serious disease in wild Pacific herring, Clupea pallasii, which often enter and remain in Atlantic salmon, Salmo salar, netpens. I...