I guess I should have known better but my timing is a little off as I get back into the swing of writing what I hope to be a weekly piece. Sure enough, no sooner had my previous column been posted when DFO released its first in-season abundance update for the age-5 Fraser stream-type chinook return as measured by the gillnet test fishery at Albion, in the lower river.
Given the connotations for the word in most peoples mind “abundance” may not be quite the right word this year, for the total catch of chinooks in the test fishery for the first two weeks of May was exactly zero, as in no fish whatsoever. Based on this first assessment DFO is estimating the aggregate run-size for both the spring and summer-run timing components will be less than 25,000 fish and as such is planning on the continuation of Zone 1 restrictions for all fisheries that may impact this stock of concern in 2016.
This said it is early days and too soon to assume the run will be very low. The first update in 2014 showed the same result – zero – and yet the return as measured on the spawning grounds showed an aggregate return of about 55,000 spring and summer age-5 chinooks in the Fraser watershed later in the year. The spring fish slightly exceeded their base period doubling goal, a measure developed back when the first Pacific Salmon Treaty with the US was signed in 1985, and the summer-run chinooks were fairly close.
However zero is still zero and not a lot to take assurance from. The 2009 broodyear for the 2014 return was about 50% bigger than the 2011 broodyear for this years return and marine conditions for the past several years out in the open Pacific Ocean where these fish live while at sea have been unfavourable for salmon – record heat because of the so-called “warm blob”, followed closely by a strong El Nino event. The next update will likely be indicative of the real story for this year.
The test fishery at Albion, approximately 50 kilometers upstream from the mouth of the Fraser River, is perhaps the longest running test fishery of any kind in the Pacific region. Commencing in 1980, it has been conducted by the same individual using the same boat ever since. It starts in late April, fishing daily on the high slack tide using an 8-inch mesh or multi-panel (different sized) net on alternate days for chinooks until September 1st when a slightly smaller mesh net is used to assess the chum return. It represents an invaluable record of catch data, a time-series unmatched anywhere else – perhaps the big surprise is that it has been able to continue through the years when so many other assessment programs have been curtailed or eliminated because of persistent government cutbacks to DFO’s budget, regardless of which party is in power.
Because of this consistent data set not so long ago DFO staff reviewed the estimated returns of age-5 Fraser stream-type chinook and found there was a reasonably strong correlation between the spawning ground counts and the catch several months earlier at Albion and it is from this historical relationship that the final mid-June prediction of run-size, within the Zone 1, 2 or 3 ranges, is made.
Stay tuned ….