March 03, 2006
Minimal Life Signs in Post-Kill Byrne Creek
We're finding a few signs of life in Burnaby's Byrne Creek, five days after a toxic substance entered a storm drain in the upper watershed, killing hundreds of trout and some young coho salmon. It appears a few fish are beginning to gradually repopulate the creek from some of its tributaries.
A biologist from the BC Environment Ministry who was collecting dead fish from the creek for further studies called me last night to say that he had placed 16 baited traps in the creek yesterday, and invited me to join him this morning to check them out.
There were a few signs of life in the lower reaches that were the farthest away from the toxin's point of entry. We found 3 cutthroat trout, 1 coho smolt, several dozen stickleback, and 1 sculpin spread out among 10 traps between the Fraser River and the golf course. They could have come from the tributaries, or found refuge in them, or perhaps whatever hit the system was diluted by the time it got down there. The 1 coho smolt was in a trap at the outflow where Gray Creek joins Byrne Creek on the u/s (Gray) side of a flood gate, so perhaps it wasn't in the main stem when the event occurred.
We also found a couple of stickleback in three traps around Meadow Bridge and the lower end of the spawning channel in the artificial habitat. The stickleback may have survived by being in the upper reaches of the overflow pond where they might have avoided the flow of deadly stuff. We often see stickleback at the upper end of the overflow pond where there is stagnant water unless rain pushes water down the spillway.
There were no fish in three traps placed near Ron McLean park upstream and downstream of a storm drain outfall we call the "Hell Hole."
So it looks deathly quiet all through the ravine and the habitat, with some signs of life starting around Meadow Bridge, and building up a bit moving further downstream below Marine Way. We've seen lots of cutthroat in Froggers Creek in the past, and there are likely more in the other tributaries, so the cutthroat will gradually repopulate.
We also spotted one free-swimming salmonid fry at the lower end of the Southridge Dr. culvert yesterday, so perhaps it popped out of the gravel after the event and the toxin didn't penetrate the redds (nests of eggs laid by spawning salmon and trout). We're keeping our fingers crossed and our eyes open! With luck there may be a few redds, both salmon and trout, yet to produce....
While the above numbers are minimal, and in no way mitigate the extent of the tragedy, some life is better than no life!
Here's a dragonfly nymph found in one of the traps. Its labium, or mouth, is extended. Cool! I'd never seen one before...