Abundance and Run Timing of Adult Pacific Salmon in Big Creek, Becharof National Wildlife Refuge, Alaska, 2000-2002
Whitton KS. 2003. Abundance and Run Timing of Adult Pacific Salmon in Big Creek, Becharof National Wildlife Refuge, Alaska, 2000-2002. Alaska Fisheries Technical Report. 65. US Fish and Wildlife Service. King Salmon, AK
Beginning in 2000, the King Salmon Fish and Wildlife Office installed a weir on Big Creek, Becharof National Wildlife Refuge to estimate salmon escapement. Salmon are an important Refuge resource and accurate escapement estimates are needed to conserve these resources. Prior to the weir, only aerial survey data, focused on chinook salmon, were available. From 2000 to 2002, five species of Pacific salmon and six resident fish species were passed through the weir. The annual salmon escapement was highly variable for the main spawning populations with an average escapement of 14,450 for Chum salmon Oncorhynchus keta, the most abundant species, followed by chinook O. tshawytscha (2,246) and coho salmon O. kisutch (2,099). Less than 100 sockeye O. nerka and pink salmon O. gorbuscha migrated through the weir each year. In 2000 and 2001, the seasonal female chum salmon sex ratios were less than 33%, and increased to 43% in 2002. Chum salmon age composition varied between years, with ageclasses 0.3 and 0.4 being the most abundant. The seasonal female chinook salmon sex ratios varied from 61% in 2000 to 34% in 2002. Age-class 1.3 and 1.4 chinook salmon were more abundant in 2000 and 2001, while in 2002, age-class 1.2 chinook were more abundant. Female coho salmon sex composition varied from 30% in 2000 to 50% in 2001. Age 2.1 was the most abundant coho salmon age-class (70%) sampled during all three years.
- Type
- Published Report
- Authors
- Whitton, Kellie
- Date of Issue
- 2003
- Publisher
- US Fish and Wildlife Service
- Units
- SWAN , WRST
- Keywords
- Alaska, Anadromous, Becharof National Wildlife Refuge, Becharof NWR, Big Creek, Chinook Salmon, Chum Salmon, Coho Salmon, Fish, Pacific Salmon, resistence-board weir, Riverine, weir