The Fraser River Panel met Tuesday, July 14, to receive an update on the migration of the Fraser Sockeye runs to date and review the status of migration conditions in the Fraser River watershed.
Fisheries and Oceans Canada (DFO) provided a forecast of the 2020 Fraser River Sockeye salmon abundance, timing and diversion rate to the Fraser Panel for pre-season planning. The majority of Sockeye returning in 2020 will be recruits from adult spawners in 2015 (age 5) and 2016 (age 4) both of which had below average spawners for the respective cycle lines. DFO has advised that Fraser River Sockeye salmon forecasts for 2020 continue to be highly uncertain due to variability in annual survival rates and uncertainty about changes in their productivity as a result of changing ocean conditions from 2013 to 2019 that included the warm blob and an El Nino event.
In addition the November 2018 landslide at Big Bar in the Fraser River upstream of Lillooet will continue to be an impediment to upstream migration for Sockeye, Chinook, Coho and Steelhead destined for spawning habitats upstream of the slide. Significant work has occurred over the past several months to improve passage for fish combined with assessment programs to evaluate passage success as well as brood stock collection for enhancement purposes. Additional information and regular updates on passage can be found at the following link. http://www.pac.dfo-mpo.gc.ca/pacific-smon-pacifique/big-bar-landslide-eboulement/index-eng.html.
To put the Sockeye run size forecast uncertainty into context, there is a one in four chance that the actual number of returning Sockeye will be at or below 488,000 fish (the 25% probability level forecast) and there is a one in four chance that the actual number of returning Sockeye will be at or above 1,913,000 fish (the 75% probability level forecast). For pre-season planning purposes, the Fraser Panel used the 50% probability level forecast (equal chance of a higher or lower return) of 941,000 fish for all management groups. This return is well below the cycle average. The largest contributing stocks for the 2020 return are expected to be the Chilko, Harrison, Stellako, Nadina and Birkenhead.
For 2020 pre-season planning purposes the Early Stuart and Chilko forecast Area 20 median timing of July 4 and August 4 respectively, were adopted by the Fraser Panel during the June meeting. For Early Stuart Sockeye this timing is consistent with the historical median timing since 1982 while the Chilko timing was 5 days earlier than the historical median. Timing for all other Summer and Late run stocks as well as the Early Summer Thompson stocks was based on the 2016 Cycle line median dates since 1982 while the other Early Summer stocks was based on the all years median dates since 1982. The pre-season forecast of the proportion of Fraser River Sockeye salmon diverting their migration through Johnstone Strait is 35% which the Panel also adopted for planning purposes.
The snow pack volume in most of the Fraser River watershed has been above average from March through June of this year with recent warmer weather and rain storms resulting in a significant increase in water discharge levels and flooding conditions. Recent years where similar discharge levels were experienced at this time (e.g. 1999 and 2011) had above average discharge levels for the remainder of the season which may be what will be observed this year as well. Water temperatures have been well below average to date and will likely continue to be that way unless air temperatures increase substantially in the weeks ahead.
The observed water temperature at Qualark on July 13 was 14.2° Celsius which is 1.9° Celsius below average for this date. Water temperatures are forecast to increase to 15.8° Celsius by July 19. The Fraser River discharge at Hope on July 13 was 8,288 cubic meters per second which is 52% above the average discharge for this date.
Discharge levels are forecast to drop to 7,787 cubic meters per second by July 19.
For pre-season planning purposes the Fraser Panel has adopted management adjustments for Early Stuart based on the historical median for all years, Early Summer based on the historical weighted all years median excluding Pitt and Chilliwack, and Summer run Sockeye based on the historical median for all years excluding Harrison. The Late run management adjustment is based on the weighted 2020 cycle line median excluding Birkenhead.
Model predicted management adjustments based on the water discharge and temperature predictions were not adopted largely due to the high degree of uncertainty in the forecasts. Management adjustments are additional fish that are removed from identified harvest levels and allowed to escape upstream in an attempt to assist in achievement of identified escapement objectives for the different run timing groups. Returns at the p50 forecast level for all management groups in 2020 are below levels that generate allowable harvest and as such will be managed based on the respective Low Abundance Exploitation Rate (LAER) of 10% which will not require modifications to the management adjustments. If in-season run sizes increase to p75 levels or higher, modifications to the Late Run LAER and management adjustment may occur as required.
Gill net test fishing began in the Fraser River on June 23 at Whonnock, July 8 at Cottonwood and July 11 at Qualark. The Round Island gill net test fishery began operations on July 9 while the Area 20 gill net test fishery began on July 11. To date Sockeye catches have been low in all test fisheries but are increasing in Area 20 and Whonnock. Recent DNA samples from the Whonnock test fishery indicate that 57% of the escapement to date is comprised of Early Stuart Sockeye and the rest are
Early Summer stocks. The total escapement estimate to July 14 is estimated to be 15,100. In-season assessment of Early Stuart Sockeye will be provided later in July once more information becomes available. In-season assessment of all run timing groups generally occurs shortly after identification of their peak migration through marine areas.
Currently, First Nations food, social and ceremonial (FSC) Sockeye fisheries are closed due a 4 week window closure to protect Early Stuart and the earlier timed Early Summer run stocks. Very limited fishing opportunities directed at Chinook salmon for ceremonial purposes have occurred to date. The start-up of Sockeye directed FSC fisheries is not anticipated in 2020 unless run sizes increase to the p75 level or higher. FSC fishers in marine approach areas as well as the Fraser River are requested to check for the opening times and any restrictions in their local area. Commercial and recreational fisheries are not anticipated on Fraser River Sockeye in 2020.
The next in-season meeting of the Fraser River Panel is scheduled to occur on Friday, July 17, 2020.
FOR MORE INFORMATION:
Regional Salmon Team – DFO Pacific
Visit us on the Web at http://www.pac.dfo-mpo.gc.ca