Salvaging coho fry on the Little Campbell (Tatalu) River
With the rain and cooler temps during the month of June, the Little Campbell (Tatalu) River was running strong during early summer. But we knew it was only a matter of time before the river eventually de-watered in a 1-2 km reach centred around 200 Street, in the Brookswood-Fernridge area of South Langley, and salmon fry stranded in disconnected pools would require salvaging.
The first extended heat wave of summer, beginning the first week of July, really kicked the de-watering into high gear. On Friday, July 12 the river was still connected and flowing. Two days later, a section of it was dry and there was already salmon fry mortality in one of the disconnected pools.
The organization that I volunteer with, A Rocha Canada, quickly mobilized a salvage response with DFO and on Monday morning July 15 we were on the river with nets and DFO's water tank trailer. Fish were seined and dip netted from pools, placed in buckets with battery powered aerators, and the buckets carried to the trailer.
The fry were thick in the pools, and on the this first day we netted thousands of fish from four pools. Our guess is in excess of 5,000 but it's really hard to count a black cloud of 5 cm fish in a tank!
A pleasant surprise was the two coastal cutthroat that we netted; one a mature 25 cm fish!
At the same time, it was also disappointing to come across the remains of other juvenile cutthroat that had already been killed by predators. I super dig cutthroat, so it was really rewarding to rescue these two and give them a new lease on life, considering that they would almost certainly be dead in a couple days time.
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| We netted several cutthroat from this rapidly drying pool |
We also netted a number of pumpkinseed sunfish and a couple of American bullfrog tadpoles. These invasive species were not re-located... if you get my drift 😉
As we netted pools, we muddied the waters so it was difficult to see if more fry were remaining. In several pools we left minnow traps baited with coho roe, hoping to trap some remaining fry overnight.
The following day (Tuesday) we were back at it, this time with participation from other stakeholders, including Salish Sea Indigenous Guardians Association (SSIGA) and Kwantlen Guardians. The plan was to return to the pools that we netted yesterday to round up any stagglers, and to walk further up and downstream to find other pools needing salvaging.
We were surprised to find good numbers of fry remaining in pools that we netted yesterday. These were quickly rounded up, including two more cutthroat!
The minnow traps left overnight yielded additional fish, except sadly for one trap that was completely exposed and the fish inside dead: coho, stickleback, pumpkinseed and sculpin. The water in this particular pool dropped almost 40 cm overnight! That was unexpected, and surprising...
The Little Campbell is closely connected to groundwater and it's the Brookswood aquifer that sustains flows in the river over summer months.The water in this pool didn't evaporate overnight; it must have drained into the groundwater. I'm not a hydrologist, but I suspect that the recent spell of hot weather increased water consumption from the aquifer, which in turn lowered the water table, which in turn led to this particular pool, and perhaps the rest of the river, draining into the aquifer. I could be wrong, but it was alarming to see how fast the water in this shaded pool dropped from 1PM on Monday to 10AM the following morning.
At this point in the summer the dry reach of the river is only half of its normal length. Much more de-watering is anticipated and there are several large pools that we will be monitoring. As the dry reach lengthens, the bucket carries get longer and longer. Thankfully, A Rocha has established relationships with local landowners who are receptive to us using their property to access the river.
So, all in all, a two good days of effort. It's hard work carrying full 5 gallon buckets down a dry stream bed, over and under obstacles, but rewarding. And who knows, maybe the some of the fry that we rescued will take my fly when they return as adults in a couple years time.
Thank you Scott. Nice work.
ReplyDeleteAre you sure that's not the Anderson Creek rather than the Little Campbell River? I have helped remove stranded Coho fry from the Anderson Creek above 36th Ave (Noel Booth Park) for many years--the creek began drying out after they removed gravel creating what is now called Sunrise Lake in the late 1950's and 60's -it lowered the water table so much the creek dries up every year--stranding fry above 36th Ave through Noel Booth Park.
DeleteI have lived in Langley for over 80 years and have seen what were once great spawning creeks -Murray Creek and Anderson Creek become a shadow of what they once were--I also have seen several smaller creeks in the vicinity of the City of Langley become culverted since 1950's killing off the runs of salmon they once supported.
Bob Norman
Thanks for the comment, Bob. Yes, this was definitely the mainstem of the Little Campbell River. We were in the 2600 block of 200th Street in Langley; but not that far away from Anderson Creek. Thanks for your work on Anderson Creek! It used to be a very productive spawning trib of the Nicomekl. Yes, development and ground water use has really affected the flow in the these small upland streams. Cheers, Scott
DeleteAwesome use of your time. Just making sure you have fish to catch. Wise man!!
ReplyDelete