Wintering Coho Fry (Yearlings)
For Christmas I purchased a GoPro Hero 5 to assist with my stream keeping, and to bring along for snorkeling during my Mexico trip for mid January.
I had taken it out a few times for practice runs on the Fell and Griffin Channels, but as happens during the Winter months the fish seemingly all but disappear.
On a whim before going to the gym at Delbrook Recentre I decided to take the camera to my absolute favorite spot on the Mosquito Watershed. Where I have spotted many winter Coho fry and Cutthroat in the past. As well as spawning adults in the fall.
This pool is literally the only refuge pool on the entire watershed. It is about 3ft deep during normal flows and can be in excess of 6ft deep during peak flows. Which is totally unheard of on this system. It is also very large about 15ft x 15ft, filled with both woody debris and leaf litter. Again, something no other pools on Mosquito Creek has.
It is seemingly the holy grail of pools and the most critically important piece of water for Mosquito Creek. It is actually part of the tributary known as Thain (or Mission) Creek.
The Refuge Pool
I was super excited the second I laid eyes on the pool. I was a bit worried as to if it held up during the heavy periods of rain we experienced this year. To my delight it was still in place, looking as strong as ever. There were two times this Fall during the rains, where I had been down and actually removed some logs from the jam to relieve pressure as it had, by my estimate, multiplied its volume by 400%.
Sure enough as I walked closer I was able to immediately see fry holding, it was great to see! I couldn't believe how many there were. Last year there were approximately 100-150 fish holding. This year there was at least 400, maybe more.
I think I only spotted 2 or 3 adult Cutthroats, but that was ok. The shear amount of Coho fry in the shoal was astonishing. This is literally the future of the Coho on this creek and the numbers were great to see.
I reall hope the District/DFO/Squamish Nation does something to protect this section of creek. Without it I don't think there would be any Coho left.
Below find the Video - *Also* be sure to read the bio beneath the video on this page.
The Importance of Winter Habitat
Did you know that Coho fry spend a year in their Creek/Stream before leaving to the Ocean?
This extended rearing phase is often the limiting factor for the species success. In the Summer months the fry have to deal with hot temperatures and low flows, and during the Winter they rely on deep slow moving pools for refuge.
Mosquito Creek like many urban streams have their challenges.
One of which is they generally have large storm drain networks that are fed by our roads. Mosquito has seen mass fish kill offs in the past from neglegent residents. Low flows during Summer and Winter months make this a very challenging time for the life under the water.
Also, many urban streams have lost complexity created by large fallen trees and the deeper pools that come with it. These deeper pools are few and far between. It is likely almost every fish within several hundred meters has come to seek refuge in this one pool, making it critical to the species success on this watershed. The challenge here is there is literally so few of these refuges that you can count them on 1 hand.
Another challenge is that Mosquito Creek has a large off leash dog area and with it these refuge pools have become dog swimming pools. There are 4 areas on Mosquito that were created specifically to help the Salmon. 1) The channel south of the skateboard bowl (Griffin Channel) 2) The channel below HWY 1 which runs parallel to Fell Ave (Fell Channel) 3) The two Alcoves that hold deep still water, there's one just south east of the trailhead coming down off Fell Ave hill (West Alcove) 4) The other just a few steps up from the closed trail sign from the access on 19th to the East trail (East Alcove). Although Fell Channel is highlighted at every entrance as a "No Dog" zone, many trail users ignore these signs. There is very little water that enters this channel regardless of the time of year, and very little summer and wintering refuge, so dog pressure is magnified.
East Alcove has significant dog pressure, especially during Summer months when dog activity kicks up silt and sediment to suffocate the fry.
Fell Channel Spawners
It was nearly mid November and I was walking Mosquito with no expectations. I had only seen 1 dead Coho jack in the lower reaches and 1 dead Chum up to this point.
This had been a tough year to this point as we had seen 0 Pinks and nearly 0 Chum as well. There had only been a few days of heavy rain in October, but with no signs of Coho.
Today I was walking the main path of the Trail along the Fell Channel. I had never spotted an adult in this channel, but figured it must receive some utilization as many fry use it as rearing habitat.
I was actually really curious to see how the head pool was holding up after being suctioned out by Sandie and Al late this summer. It looked good, but with noticeable sediment accumulating from the heavy rains we had been receiving.
To my surprise, not more than 30 yards down the channel I saw an adult Coho. She was paired up with a noticeably smaller male, a jack, about 1/4 of her size.
I was able to visit the pair many times in the following two weeks. I noticed the female utilized more than 1 redd, perhaps her first was too exposed to the walkers on the trail.
Unfortunately on Nov 23rd there had been an issue with the intake to the channel. Nearly no water was flowing. I immediately called Sandie and let her know we had an issue.
A day or so later Sandie and Tyler were able to restore the flow. I hope the eggs survived as they were most and buried during the approx 2 days without water flowing.
I was not able to locate either of the adults the day the channel dried up, or anytime after it was restored.
Here is the video of them spawning.
Cedar Tree Planting & Updates
I am a little late posting this update, but in mid July, Ken had arranged some cedar trees for me to pick up and plant on Mosquito.
A few days later, July 24th or so, I started getting to work planting all the trees.
I was able to do about 15-20 a day, it was tough going in the hot 30+ weather and I wanted to make sure the trees got put in an area that gave them the best chance to grow into big strong trees. Needless to say it was much more time consuming than expected, in hindsight I should have definitely arranged another couple people to help out.
Over the period of 4 days I was able to plant about 80 cedars and 10 Douglas Fir saplings. I had a couple run in with ground wasp nests, which was not fun at all. Lots of stings!
I was quite pleased with the level of interest the trail walkers had in my doing. Many people stopped and asked what I was doing, many concerned I was doing something negative. To their surprise I was actually helping the creek, nobody had guessed that haha!
Here are some pics of the guys I planted!
Here are pics of their progress on Sept 7th
I only went back twice since planting the trees to water them, I had forgotten where I planted most. To my surprise nearly all of them were doing extremely well given the dry summer we experienced. As of Sept 7th I was seeing about 5% which had not made it, which is surprisingly really good numbers for Cedar transplanting (so I have heard).
Hydro-Vac-ing Fell Channel Pool
On the morning of Aug 24th, Al & Sandie had organized a hydrovac to pull sand and silt out of the pool at the outfall of the pipe that takes water from the main-stem into the Fell Channel.
In my previous post, I had mentioned there was around 50 Cutties and Coho fry holding in this particular pool in tight quarters. They ended up getting a whole bunch more space to move around.
After it's installment 20 years ago, the Fell Channel has not had too much upkeep, as it hasn't been required. However, Al & Sandie figured it was time to do something to the first pool as it had seen the most sediment fill in over the 20 year period.
The morning did not start off to well, the company dispatched the wrong size of truck. It was much larger than requested. It was actually so large it could barely fit width-wise along the trail. To make matters worse it was too tall, and some of the truck's hose ended up breaking when it got tangled in the branches of a maple tree.
This caused the truck to lose air pressure in some areas. The driver was a little bit nervous and asked dispatch to send out the mechanic. After about 2hrs of working it's way up the trail, the truck was finally in place.
Fortunately we were able to get started without the mechanic. One of the issues was the crew was stuck using the smaller Vac as the larger one required repair. They made good work for the first 30 mins or so, then we seemed to get plauged by large stones getting stuck in the hose every 10-15 minutes for quite some time. Everytime there was a clog, the hose had to be shut down manually and hammered until we found and broke the clog free.
After about an hour or two of vacuuming the truck lost power, good news was the mechanic was driving up the trail road. He showed up in under 2 minutes and got the truck back up and running in no time.
We got back to the Vacuuming for another 2 hours, ran into a bunch more clogs, and then the tank ended up at about 70% capacity or so when we decided to call it a day.
When hydro-vac-ing the truck ends up filling up largely with water instead of the intended rock and gravel. We did pretty good given all the hiccups along the way. However we would have done much better had we a smaller truck with it's large hose working.
Here are some pics!
Pool After Hydro-Vac was complete
Fell Channel Updates
Do you ever take a second to stop and look at the water in a creek when you're hiking or walking?
I can't say I do unless I am doing something volunteer related.
Recently I was walking Fell Channel on Mosquito and came across a pool that is a favorite for dogs, even though no dogs are allowed on this trail on or off the leash.
I was actually taking a few pictures to send to the City in an ask for them to fence off this area of creek entirely to protect it from dogs when I witnessed something.
A Coho fry had breached the water to feed.
It happened so fast I didn't get a good look, then not 10 seconds later it happened again and again. And so I got my phone out to record.
Sure enough I was able to get a couple shots of these guys breaching the water. I couldn't see what it was they were feeding on but it was something I had never witnessed before.
I wonder if dog owners took a second to see this beautiful display would they stop allowing their dogs to enter the channel to continually destroy it?
Coho Fry and Cutthroat Holding in Numbers
Further up the channel there is a sight that occurs every summer.
Large numbers of Coho fry and Cutthroat hold in the first pool where the flow enters the channel from the main-stem.
It is hard to understand why they choose this area over the rest of the creek, but I have a few guesses:
Sad to see a recurring theme here, DOGS being a large issue.
My question is why are all the largest & deepest pools on Mosquito treated as dog swimming pools? It seems it's a given, "Oh this trail is off leash so the whole creek is game. Oh a nice large pool, yup that must mean its a dog swimming pool, right?"
Why is everything North of Marine Drive seemingly overly inviting for dogs to come have a swim?
I think it's time only some sections of the creek be welcoming to dogs and the rest become fenced off.
The equation is very simple:
Constant Dog Pressure = Far Less Fish
Don't believe me?
Check out the spawning beds on Thain Creek.
There is not a whole lot special about that area of creek.
The pools are not especially deep, as they run straight up and down being that they are man-made, and they are bound by ivy & blackberry bush on either side.
...Yet they yield the highest density of fish on the ENTIRE watershed.
Hmmm wonder why that is?
Your answer, no dog pressure.
Here's a vid of the fish in tight quarters on Fell Channel.
Other Updates and Dates to Remember
First 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.
Also 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 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 Up
In 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.
Continuing 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!
Protecting the East Alcove
On 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 Alcove
Although 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.
I 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.
Thain/Upper Mission Creek Trapping
On May 9th, 2017 Sandie, myself and a friend headed out to retrieve traps we had set the evening previous.
The goal of this trapping was to see if we could trap some Coho juveniles in this reach of Thain Creek. The concern was no adult Coho were making it up a very steep section of creek to the west of Westview Drive. The second concern was if fish were making it up this steep section of creek, were they able to get up the Queens fish ladder prior to me cleaning it out.
We only placed two traps, one below the fish ladder at Queens and one above it. There were plenty of Cutthroat spotted during the placement of the traps. Some of which were very large, a few that looked to be 8" or larger.
Since there were so many Cutthroat spotted, we didn't want to entice too many into the traps incase Coho fry of the year were captured. In which case, the Cutthroat may eat the Coho. The traps were placed in very shallow sections of the creek for this reason.
Both traps yielded 3 Cutthroat for a total of 6 fish.
So few fish with large chunks of roe had them looking very chubby! They looked as if they were ready to explode, well at least they won't have to eat anytime soon now!
Unfortunately there were no Coho fry of the year or 1 year olds. Which leads us to believe that the spawning Coho in the previous two years were not able to pass a very steep section of Thain Creek.
I remediated the steep section of Thain creek by hand, creating large step pools with boulders to allow for salmon passage for the coming year - only time will tell if it works!
The Cutthroat in Trap 1 - Below the fish ladder were:
14.2CM, 12.6CM & 10.1CM
Trap 2 - Above the fish ladder were:
12.8CM, 12.0CM & 11.2CM
Coho Fry of the Year
The colder than usual winter we experienced on the Lower Mainland meant that I would have to wait extra-long for the Coho fry to emerge from the gravel this year.
After visiting MacKay Creek in late March and seeing dozens of tiny fry, I couldn't help myself but visit Mosquito Creek every 2nd or 3rd day until I was finally able to spot some fry.
The fry were spotted in the Fell Channel a day or two before the juvenile trapping with Scott & Sandie on April 4th/5th. I was quick to point out the exact spot I had seen them with Scott & Sandie on the day of the trapping, April 4th. As a group we were lucky enough to see a couple in that very same pool, but nothing like the numbers I was seeing throughout MacKay Creek.
I was surprised to see any year of the year in the Fell Channel, as I had not seen a spawning pair in there during the fall. I suppose it is quite possible they evaded my eyes, but another strong possibility is these fry had been swept into the intake of the fell channel. This would mean they were actually from the main stem of Mosquito, or had been pushed down all the way from Thain Creek.
Either way it was a great find and they sure looked happy to be in the slower-moving channel environment.
Thain Creek & Mosquito Main-Stem
The channel where I had seen four adults was the Griffin Channel, and the possible redd (nest) Sandie had helped identify still showed no signs of successful yield all the way through to around April 14th.
I decided to go to check out an area of Thain Creek where I had seen plenty of Coho spawning in the fall. First stop was the jimmy-rigged bridge over the creek that trail go-ers maintain. Sure enough in the back-eddys in the nearby area of the bridge I spotted some Coho fry of the year.
This was a good sign, but I knew there would be plenty more where I was headed. Sure enough the holy grail of spawning pools had produced a great number of fry. In this particular area of creek I was able to see around 20 fry of the year, which was about the number I had expected to see. I am hopeful a large majority were able to avoid my eyes though. I had seen 6 spawners in this area, so only 20 fry would be a huge dissapointment if that was all that had survived.
As I made my way down the trail, I decided to check out the West Alcove on Mosquito Creek, on my way to the alcove opening there was a large deep pool of slow moving water, protected by a large boulder. I didn't think I was going to be so lucky as to see any fry in the mainstem as the water was still fairly high, but protected from the torrent there were 3 fry of the year hanging out in plain sight! I continued down only a couple feet further to survey the alcove itself, but was unable to spot any fry in the alcove itself.
On the morning of Saturday April 15th I decided to check out the Griffin Channel. Sure enough, just above the top habitat pool I spotted my first pair of fry in the Griffin Channel. This was a hugely positive sign as that now meant I had seen Coho fry of the year in both channels, Thain Creek, & the main-stem of Mosquito Creek.
I continued down the channel to see if there were more fry around the redd, but yet again not a fry in sight. I walked a bit further down the channel and was able to find two more areas with a few fry. This area of the channel is mostly fast flowing, but where the fry were spotted was in protected still water. The substrate was a dark muddy color and the fry blended in very well. By my estimate I had seen approximately 8 fry all together in the Griffin Channel.
It was hugely positive to see fry in the Griffin Channel, but even in these wonderful channel habitats it seems the survival rates from egg to fry are extremely small.
MacKay Creek Comparison
Firstly, I would like to thank everyone involved with the restoration and enhancement of MacKay Creek, including the recent estuary revamp. It is truely a gem in the urban world in which we live and all the hard work is definitely starting to show.
After walking MacKay a couple times in April, I really wish we were so lucky as to have every creek in North Vancouver as healthy as MacKay... - Maybe one day.
One of the first things you might notice when walking the trails of MacKay Creek, is the amount of woody debris in the creek itself. If you were to compare MacKay to pretty much any other creek on the North Shore, especially Mosquito, you will find there is really no comparison. Most creek beds now run debris-free, but MacKay Creek is an outlier.
I am beginning to think this woody debris has a deeper impact on creeks than we currently understand.
You can probably tell I am hinting at something, if so you are right.
In just a few trips I was able to see, without a doubt, literally thousands of Coho fry on MacKay Creek. The results in 2017 have been phenomenal! I have been able to identify two particular areas of the creek where shoals, yes shoals, of fry hold up.
The number of fry in these shoals come close to breaking the 50 mark. As one walks past one of these areas in particular, a 6-ft long section of streambed seems to move in synchronization!
Fry of the year in these numbers are so rare, which leads to another comparison in which there really is no comparison. No other small creek on the North Shore has the number of fry as does MacKay.
Don't get me wrong, I am extremely excited to see fry on Mosquito in the numbers I have seen. I do however think MacKay Creek should be used as a model, an example of sorts, which all the creeks on the North Shore should strive to become.
I would recommend maximizing this video to full screen and keeping an eye on the bottom left area of the screen as that is where the most action happens.
I am definitely not doing Apple any favors by selling their iPhone 6 camera, but as I am sure you can understand these little guys are super camera shy. If you get too close they'll disapear. This was the best footage I was able to get.