Predation Challenges Faced By Columbia River Salmon 1 October 4, - PowerPoint PPT Presentation

Predation Challenges Faced By Columbia River Salmon 1 October 4, 2013 Columbia River Inter-Tribal Fish Commission

The Big Four Caspian Tern Double-crested Cormorant Northen Pikeminnow California Sea Lion Columbia River Inter-Tribal Fish Commission

Avian Predation Caspian Tern Double-crested Cormorant Birds consumed an estimated 24.3 million migrating juvenile chinook and steelhead in 2010, which represents 228,000 returning adults Columbia River Inter-Tribal Fish Commission

Aquatic Predation Northen Pikeminnow Predator fish consume an estimated 12 million migrating juvenile chinook and steelhead, which represents 38,000 returning adults Columbia River Inter-Tribal Fish Commission

Pinniped Predation California Sea Lion Pinnipeds consume an estimated 18,000 returning adult chinook and steelhead Columbia River Inter-Tribal Fish Commission

Sea Lion Impact 4.2% predation rate is only from observations within 400 yards of Bonneville Dam Sea lions roam throughout the 146 miles of the lower Columbia River, where they have an estimated 18% Columbia River Inter-Tribal Fish Commission predation rate

Pinniped Impacts Columbia River Inter-Tribal Fish Commission

California Sea Lions in Bonneville Pool  At least 4 California sea lions currently reside in the Bonneville pool.  At least one animal has been there for more than 3 years.  These animals impact all stocks that originate upstream of Bonneville Dam including some of the weakest stocks like winter steelhead. 8 Columbia River Inter-Tribal Fish Commission

California Sea Lions in Bonneville Pool  Sea lions below the Bonneville Dam tailrace generally leave within two months.  Sea lions residing in the Bonneville pool impacting stocks year-round, making their individual impacts about 6 times greater than sea lions that can leave the system.  The impacts from the 4 sea lions in the Bonneville pool may be similar to 25 animals in the tailrace. Removing these animals needs to be a priority. 9 Columbia River Inter-Tribal Fish Commission

California Sea Lions in Bonneville Pool  These animals impact tribal fishers by damaging gear and catch.  This is a particular problem at the beginning of the season during ceremonial fishing, when total fish numbers are very low. 10 Columbia River Inter-Tribal Fish Commission

Other Predator Species on the Rise Smallmouth Bass Smallmouth Bass consume about 7,000 juvenile salmon a day in the Yakima River. 98% are subyearling chinook; 70% are natural-origin Steller Sea Lion abundance at Bonneville Dam 2008: 17 2009: 26 2010: 53 Steller 2011-2013: >70 Sea Lions Columbia River Inter-Tribal Fish Commission Listed under MMPA and ESA

Non-native Fish a Growing Problem Largemouth Bass Walleye Catfish Columbia River Inter-Tribal Fish Commission

Columbia River Inter-Tribal Fish Commission