PFRCC calls for more study of pre-spawning mortality of the late run sockeye

Vancouver, October 19, 2006 - In recent years there has been an increase in mortality of salmon between the time they leave the ocean and the time they spawn. The Adams River sockeye run is a key indicator of this problem. Many Adams River sockeye are dying now before they have an opportunity to spawn.

This phenomenon, known as pre-spawning mortality, has historically been at very low levels – usually less than 5 per cent. But in recent years the pattern has changed and mortality rates prior to spawning have been very high, sometimes approaching 90 percent. Scientists predict mortalities of 30 to 50 per cent for the 2006 Adams run.

The factors contributing to pre-spawning mortality of not only the Adams sockeye, but other late-run stocks such as the Cultus Lake populations, comprise one of the primary conservation problems in BC. This is making the task of determining safe harvest levels exceedingly difficult for the Pacific Salmon Commission and the Department of Fisheries and Oceans (DFO). If recent pre-spawning mortality rates become a regular occurrence, the future of the late-run sockeye runs, without question, will be in jeopardy.

Four years ago PFRCC first expressed concern about pre-spawning mortality and recommended DFO direct a greater effort into research to determine its causes. While DFO and the Pacific Salmon Commission have begun scientific investigation into the relation between migration timing and mortality, insufficient resources have been devoted to studying the causes of the problem.

Council is calling for a focused ecosystem approach to the issue of pre-spawning mortality to better understand its cause. In particular, there must be better understanding of the new dynamics of the Georgia Strait from which sockeye enter the Fraser River. Warming water temperatures, changes in abundance of fish species and their predators and other factors have to be better understood.

In the shorter term, there also needs to be a basis by which to establish better estimates of likely mortalities to ensure that the resource is not put at risk and that viable fishing opportunities are not lost.

For more information, contact:

Carla Shore
Media Liaison C-Shore Communications
604-731-0975
carla@shore.ca

Gordon Ennis
Managing Director PFRCC
604 775-6070
ennis@fish.bc.c