Tissue toxicants and prespawn mortality in Willamette River Chinook salmon

Laboratory infection rates and associated mortality of juvenile Chinook Salmon (Oncorhynchus tshawytscha) from parasitic copepod (Salmincola californiensis)

“…Additional threats to salmon populations come in the form of infections by pathogens (Ferguson et al 2011(Ferguson et al , 2012, with estimates of juvenile Coho Salmon (Oncorhynchus kisutch) mortality as high as 68% from Ceratonova shasta (Som et al, 2019). Furthermore, the high prespawn mortality rates (up to 83.3%) of spring Chinook Salmon observed on the spawning grounds (O. tshawytscha) (Keefer et al, 2020) are associated with multiple pathogens (Benda et al, 2015;Kent et al, 2013).Pathogens have the potential to complicate recovery efforts for Pacific salmon. For example, Monzyk et al, (2015) reported juvenile Chinook Salmon infection rates in most Willamette basin, US reservoirs above dams by a parasitic copepod, Salmincola californiensis, averaged 78%-97% with an infection intensity (the…”

“…Additional threats to salmon populations come in the form of infections by pathogens (Ferguson et al 2011(Ferguson et al , 2012, with estimates of juvenile Coho Salmon (Oncorhynchus kisutch) mortality as high as 68% from Ceratonova shasta (Som et al, 2019). Furthermore, the high prespawn mortality rates (up to 83.3%) of spring Chinook Salmon observed on the spawning grounds (O. tshawytscha) (Keefer et al, 2020) are associated with multiple pathogens (Benda et al, 2015;Kent et al, 2013).…”