The following narrative is by former President John Barker who led the 2023 student spawner survey programme and Anthea Cameron streamkeeper member survey co-ordinator.. Many thanks John & Anthea!
Report on the 2023 Spawner Salmon Surveys
The 14 creeks we survey for returning spawning salmon are, east to west: Brothers, Hadden, Macbeth, West Brothers, Lawson, McDonald, Rogers, Claymore, Willow, Cypress, Wood, Eagle, Nelson and Larson.
Our creeks volunteer surveyors started in late summer and continued until the middle of December.
The four species of salmon surveyed this year are: Chum, Coho, Pink and Chinook.
On our most productive creeks, Brothers and Hadden, volunteer surveyors were augmented by teams of secondary school students, assisted by experienced Streamkeeper Sponsors with many years of survey experience. The student teams began just after Thanksgiving, in the second week of October, and finished at the end of November.
The first week of surveys (October 16-22), the students encountered heavy rainfall which followed a very dry September into early October.
The second week (Oct 21-27), with continuing rain, the students saw many dead Coho, and initially there was a lot of excitement. Then when they cut them open, they discovered these salmon had not spawned.
It was most likely that the Coho died from 6PPD-quinone which is a by product from car tire wear. The tire wear material accumulates along the roadside over a long dry summer. Then when the rain starts, runoff from the roads, containing this toxic substance, is transported into the streams through the storm sewer system. The first big rainfall occurred just as Coho were starting to enter our streams. There were 44 dead Coho reported during the surveys this period. The effect is known as URMS - Urban Runoff Mortality Syndrome.
This was an unprecedented event that had not been previously observed in West Vancouver streams. It could account for the decline in Coho runs in other parts of the community.
After this toxic plume passed through the creeks, the rest of the weeks went better with a mix of Coho, Chum and Chinook showing up to spawn. It was predicted by DFO to be a good Coho year and as such we had larger numbers observed. Ironically, after the tragic mortality of the early Coho, this turned out to be the second largest return of Coho into the Brothers Creek watershed in the last 16 years. These fish were well dispersed with some observed well above the Upper Levels Highway.
While our other creeks to the west are not as productive as Hadden and Brothers, they are important to monitor, not only for returning fish, but to check on anything that might impede the return of spawning salmon.
2023 was a dominant Pink Salmon year, so several volunteers were recruited to observe the streams starting in late August. However, this fall started out with very little rain, and not much opportunity for the fish to enter our local streams and the Pinks did not show until later in September.
Pinks were found only on Brothers Creek and there were quite a few arrivals after the first rainfall.
Every fall there is a call out for volunteers to do the creek surveys. There is usually an enthusiastic initial response. However, reports from some creeks became sparse and sporadic. There were a number of intrepid surveyors, who did get to the streams on a weekly basis and file their reports which is very much appreciated. Near the mouth of Lawson Creek, signs are posted each year with a phone number for members of the public to let us know of any fish sightings. This all helps in gathering data on returning adult salmon.
Some of these creeks may not have returning fish but to know, we need to have volunteers out there conducting regular checks. The reports we receive are shared publicly and if we do not have reports then the assumption is that there are no fish. This could, in turn, affect support and funding for salmon enhancement initiatives on our creeks.