Somass River Escapement Bulletin
Observations to September 8, 2013
OBSERVATIONS:
Through September 8, a total of 22,434 adult coho, 1140 coho jacks, 5099 adult Chinook, 195 Chinook jacks, 88,890 adult sockeye, and 93,470 sockeye jacks are estimated to have passed through the Stamp falls fishway. A total of 6032 adult coho, 6 adult Chinook, 121,363 adult sockeye, and 331,895 sockeye jacks are estimated to have passed through the Sproat falls fishway.
Since September 2, daily escapement counts through the Stamp Falls fishway ranged between 255 and 510 adult Chinook, and 1023 and 2058 adult coho. Adult sockeye daily escapement since September 2 ranged between 0 and 3 at the Stamp falls fishway and between 21 and 249 at the Sproat fishway.
River temperatures over the past week have ranged between 18.9 and 21.0oC at the Stamp Falls fishway (Figure 4). The discharge rate is moderate.
Note: Salmon escapement estimates in this bulletin are preliminary, based on an initial digital video review.
2013 PRE-SEASON EXPECTATIONS:
Sockeye: The 2013 management forecast for Somass sockeye was 350,000, which corresponds to the low level management zone defined through Area 23 Wild Salmon Policy implementation (range 350,000 to 500,000). Expected stock composition is about 45% Great Central and 55% Sproat sockeye. Expected age composition is about 75%, 10%, 10%, and 5% for age 42, 52, 53, and 63 adults, respectively. Based on current catch, escapement, and abundance estimates in the Alberni Inlet and Somass River, the forecast was downgraded on July 11 to 300,000 adult sockeye. The escapement target for this run size is 231,250.
Chinook: Approximately 16,000 Somass Chinook are forecast to return to Barkley Sound and Alberni Inlet in 2013. The predicted adult age composition is 43%, 22% and 34% of 3, 4 and 5-year olds, respectively. At a forecast terminal return of less than 20,000 adults, no directed Chinook fisheries are anticipated in the terminal Alberni Inlet area.
Chum: Approximately 563,000 chum are forecast to return to South West Vancouver Island in 2013 (54,000 to Area 23). This forecast is well below the long term average for the CU but higher than the recent 5-year average. Only limited directed fisheries are anticipated.
Coho: For 2013, the total expected return to the Somass system is about 20,000 to 40,000 coho. The forecast survival rate for the 2010 brood year (2012 sea entry) year is above the long-term average for West coast Vancouver Island coho.