Fish migration represents one of the most complex and intriguing biological phenomena in the animal kingdom. How do fish migrate such vast distances? What are the costs and benefits of migration? Some of these fundamental questions have been addressed through the use of telemetry. However, telemetry alone has not and will not yield a complete understanding of the migration biology of fish a or provide solutions to problems such as identifying physical barriers to migration or understanding potential impacts of climate change. Telemetry can be coupled with other tools and techniques to yield new insights into animal biology. Using Fraser River sockeye salmon (Oncorhynchus nerka) as a model, we summarize the advances that we have made in understanding salmonid migration biology through the integration of disciplines (i.e., interdisciplinary research) including physiology, behavior, functional genomics, and experimental biology. We also discuss opportunities for using large‐scale telemetry arrays and taking a more experimental approach to studies of fish migration that use telemetry (i.e., intervention studies involving endocrine implants, simulated migration studies) rather than simply focusing on descriptive or correlational techniques. Only through integrative and interdisciplinary research will it be possible to understand the mechanistic basis of fish migrations and to predict and possibly mitigate the consequences of anthropogenic impacts. Telemetry is a tool that has the potential to integrate research across disciplines and between the lab and the field to advance the science of fish migration biology. The techniques that we have applied to the study of Pacific salmon are equally relevant to other fish taxa in both marine and freshwater systems as well as migratory animals beyond ichthyofauna. The interdisciplinary approach used here was essential to address a pressing and complex conservation problem association with sockeye salmon migration.

Record low returns of sockeye salmonOncorhynchus nerka to the Fraser River in 2009 were followed by record high returns to the river in 2010, providing an unprecedented opportunity to examine links between oceanic factors and the survival of Pacific salmon stocks. The low returns in 2009 indicated poor early marine survival of juvenile sockeye salmon in 2007. The poor survival was likely due to low food levels arising from unfavorable wind and runoff conditions in the Strait of Georgia and the Queen Charlotte Sound-Hecate Strait region in the spring of 2007. Conversely, the high returns in 2010 were associated with a large smolt output from the Fraser River and good early marine survival in 2008. This enhanced survival was likely associated with adequate food levels arising from favorable oceanic conditions in the Strait of Georgia and the Queen Charlotte Sound-Hecate Strait region in the spring of 2008. We speculate that ocean factors during the subsequent marine years also affected brood year strength. Specifically, the back-to-back La Niña winters of 2007-2008 and 2008-2009 would have negatively influenced the survivability of the 2007 entry stocks, while the El Niño winter of 2009-2010 would have positively affected the survivability of the 2008 entry stocks. We conclude that poor early marine survival leads to low production. However, if large numbers of healthy fish survive the early marine entry, and if conditions during at least one of the two ocean winters in the Gulf of Alaska are favorable to stock survivability, then returns to the river can be high. Sockeye salmon Oncorhynchus nerka originating from the Fraser River in British Columbia (Figure 1) support one of the most important fisheries on the Pacific coast of Canada.

Simulation results from the Canadian Climate Centre's atmospheric general circulation model (CCC GCM) coupled to a simplified mixed-layer ocean model predict that doubled atmospheric C8, concentrations would increase northeast Pacific Ocean sea surface temperatures and weaken existing north-south air pressure gradients. On the basis of predicted changes to air pressure and an empirical relationship between wind-driven upwelling and zooplankton biomass, we calculate that production of food for sockeye salmon (Bncorhynckus nerkca) may decrease by 5-9%. We developed empirical relationships between sea surface temperature, zooplankton biomass, adult recruitment, and terminal ocean weight for the early Stuart stock of Fraser River sockeye salmon. Our analyses show that warmer sea surface temperatures, larger adult recruitment, and lower zooplankton biomass are correlated with smaller adult sockeye. Bioenergetics modeling suggests that higher metabolic costs in warmer water coupled with lower food availability could cause the observed reductions in size. Warmer sea surface temperatures during coastal migration by juveniles were correlated with lower recruitment 2 yr later. Warmer sea surface temperatures may be a surrogate for increased levels of predation or decreased food during the juvenile stage. We speculate that Hraser sockeye will be less abundant and smaller if the climate changes as suggested by the Canadian Climate Centre's general circulation model.RCsnmC : Les resultats obtenus par des simulations faites avec le modkle de circulation atmosphkrique general du Centre climatologique canadien, et combines ?i ceux d'un modkle simplifik ?i couche ockanique mixte, nous amknent ?i prkvoir que le doublement de la concentration atmospherique du CO, conduirait A une hausse de la temperature en surface de l'eau dans le nord-est du Pacifique ainsi qu'h un affaiblissement des gradients de pression atmosphkrique nord-sud. En nous appuyant sur Ies changements prevus de la pression atmospherique et sur un rapport einpirique entre les remontees des eaux sous l'effet du vent et la biomasse zooplanctonique, nous pouvons caleuler que la production des ressources alimentaires exploitkes par le saumon rouge (Oncorhynchus nerka) pourrait &re rkduite de 5 8 9%. Nous avons dktermink des rapports empiriques entre la tempkrature en surface de l'eau, la biomasse zooplanctonique, le recrutement chez les adultes et le poids au retour de la migration en mer des sujets qui constituent le stock hitif de saumon rouge de la Stuart dans le Fraser. Nos analyses montrent que 1'Clkvation de la temperature en surface de l'eau, le recrutement plus important chez les adultes et la baisse de la biomasse zooplanctonique sont en corrklation avec une taille infkrieure des adultes du saumon rouge. Les modkles de bioenergktique paraissent montrer que le coQt metabolique accru de la vie en eaux plus chaudes, lorsqu'il est combink B une baisse des ressources alimentaires, pourrait expliquer la rCduction observee de la taille. Une hausse de la temperature en...

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The biological productivity of coastal upwelling regions undergoes marked interannual variability as marine ecosystems respond to changes in the prevailing winds. Determination of the principal metrics that define the upwelling cycle-the spring transition, when ocean conditions switch from downwelling-to upwelling-favorable, and the Fall Transition, when conditions return to downwelling-favorable-is essential for understanding changes in coastal productivity. Here we demonstrate that upwelling in the northern California Current System may be delineated by changes in microseismic activity recorded at a broadband seismological station in southwestern British Columbia. Observed high correlation between microseismic intensity and offshore bottom pressure fluctuations at~0.2 Hz confirms a direct link to regional wind-wave generation. Comparison of transition times derived from coincident 20 year records of microseismic intensity and alongshore wind stress for the British Columbia-Oregon coast suggests that seismically derived times may be more representative of coastal upwelling than times derived using traditional methods.