Other Updates and Dates to RememberStonefly HatchFirst evidence of the 2017 stonefly hatch was on July 2nd, 2017. The area this was observed was right underneath the HWY 1 bridge. Dozens of empty casings where spotted on larger boulders. Perhaps the stoneflies chose this area due to the fact that it is so dry. Fry SizeAlso on July 2nd I came across a large pool that was left stranded by receding water levels, with no help in sight from the weather forecast I took action with a small fish tank net to save the stranded Coho. Below find a variety of sizes of Coho fry that I was able to save and safely release. They weren't photo shy after I released them! Sizes were roughly 2.5" (see the fish on the top left) to the very large outlier on the bottom right who was 3.5". Cutthroat FryCutthroat fry were first sighted in the Fell Channel July 3rd, they were absolutely tiny! Around 1/3 the size of an emerged Coho Fry. I was unable to get a clear photo of them as they were smaller than most pieces of gravel. Thain Coho Fry & Garbage Clean UpIn late October of last year I cleaned out the Queens fish ladder on Thain Creek. It was entirely necessary as all the steps were completely encased in rock and sand, and the fact that there was no flow coming down the ladder. Following this I worked my way down Thain Creek to the "daylighted" section. At the beginning of the daylighted section (looking upstream), there is a very steep section of boulders. I was able to recreate this area by moving several large 50-150lb boulders around to create step pools to make this obstacle fish passable, as well as removing all sorts of sticks and debris that were clogging up the easiest to pass sections. Following my trappings on Thain with Sandie we believed my attempts were done too late in the year and that no Coho had spawned aboved the steep obstacle section. We believed this as our traps came back with only Cutthroat and no Coho. However, after working my way from the bottom of this obstacle to Westview Drive I was completely surprised. There were Coho fry holding in pretty much every little pool, and as I worked my way up to the man made spawning/rearing pools in the section that had been daylighted the numbers I was seeing grew immensly. The 3-4 large man made rearing pools were holding hundreds of Coho fry. Each had shoals of 30-50, and those were just the numbers I could see. Who knows how many hid under the rocks. It was amazing to see so many fish that nobody knew were there, especially in an area of creek I didn't think adults were able to make it to for spawning last year. Surely if the Coho had made it this far, then they could have surpassed the Queens ladder and worked their way up to the Evergreen Place culvert. This means an extra KM had been opened up for spawning, but even more importantly for rearing. By having an extra 1,000 meters of creek for fish rearing this will hopefully mean more fry will survive to smolts as the density will be less harsh and should provide for more area/food for development. Thain Cont'dContinuing the day of my pure joy and excitement in seeing the unexpected Coho fry in Thain, I came across some not so good news.
A garbage bag from the Westview McDonalds had somehow ended up alongside/in the creek. Several hundred pairs of plastic gloves along with all sorts of other garbage was everywhere. Right by the little Salmon Hut on the west side of Westview where Thain goes underneath the road. I couldn't stand to see it and I knew if I had gone to the district for clean up it would probably take days. So I took it upon myself to clean it all up. What I thought would be one garbage bag full was actually 4! I filled 4 big garbage bags with McDonalds trash and all sorts of bottles that had accumulated over the years. Needless to say it looks much better now, hopefully the fish appreciate it!
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Protecting the East AlcoveAlcove EntranceOn my previous post I discussed the importance of the Alcoves on Mosquito Creek and the abuse the East Alcove has been receiving from consistent dog pressure and the direct effect it is having on the Coho fry population. Here is what I have done in an attempt to protect the alcove from dogs. Firstly, I built a 3 tiered wall of natural debris along the south side of the entrance to the alcove.
Areas of Erosion / Dog Paths into AlcoveAlthough the entrance to the alcove is doing extremely well for preventing dog access, the areas along the "decommisioned trail" which is strictly "dog on lease only" seems to be the #1 area for dogs entering the alcove.
Since my DFO "salmon at work sign" seemed to have little effect, it was necessary I take measures into my own hands for beefing up protection. Especially since had I gone to City for help it would take them months or years to complete the construction of a proper fence. Week after week I steadily added debris to the three main entrances that dogs had been using the access the alcove. Every other week it seemed a die-hard dog owner would remove pieces of the dog fences I had created. And so began my battle of adding more and more debris faster and faster than those owners could remove it. Now it seems like I am at the point where it is about as good as it can get, I can clearly see evidence that some dogs are still making their way down as wet marks are left in the sand/dirt. I am confident that my efforst have reduced the dogs entering the alcove by about 50%, but my ultimate goal is to have a 99% reduction by way of a real fence. I have gone to the City asking for help but have not yet heard back as to if they can provide assistance. I will be sure to post here first when I hear back from them. East AlcoveI have been doing a lot of work on the East Alcove since putting lots of woody debris into the Alcove in January. After the Coho fry emerged from the gravel in March they were quickly swept downstream into the man made alcoves. This is by design, to give the fry refuge from the violent water flows to do the large storm drain catchment area. I have spotted many fry in both alcoves, the West one is particularly dense. I would esitmate anywhere from 1,000 - 2,000 fry take refuge in this alcove. The East, an area just as large, on the other hand has only 100 - 250 by my estimates - Here's why. Unlike the largely fence protected West Alcove, the East Alcove has no fencing and so it is an all access dog swimming pool. There are many issues heavy dog traffic contributes to:
During the spring months there was little evidence of the dog traffic being a major issue. Largely due to the fact that it was so cold that not many dogs took the opportunity to take a swim, and that rains filled & flushed the alcoves on a consistent basis. However, as the weather became warmer the dog pressure became a significant issue as the stirred silt stays suspended for long periods of time - several hours on end. Upon close viewing one can see the Coho fry going through a process in which they flare their gills in an attempt to clear them of the silt. A process called gill extrication, or when the fry are forced to clean their gills in an attempt to breathe. My fear is many fry are simply suffocating to death, and if holding on are under major stress likely causing stunted growth. As the water recedes further and the temperature rises it is likely more fish will succumb to stress & suffocation. Here is a photo from mid Spring when the water was actually somewhat translucent. Was even able to get a half decent photo with a Coho fry at the top of the water.
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AuthorKeegan Casidy Archives
January 2020
CategoriesMosquito Creek,
North Vancouver, British Columbia |