April 14, 2006
Trout Fry Found in Byrne Creek, pH Fears
More good news mixed with bad from Byrne Creek, which was devasted by a toxin that killed hundreds of fish about six weeks ago. In addition to the chum fry (salmon babies) that streamkeepers began seeing a few weeks ago, we're starting to see cutthroat fry.
Yumi and I saw several very small fry in the ravine portion of the creek around noon today, extending from just below the footbridge (T516) to the area near the monument (T519-520). We netted one from a pool about 3 - 4m downstream of the footbridge and it was a cutthroat. It was tiny, two-three centimeters long.
We released this tiny trout unharmed after getting some photos.
Assuming the normal time of around seven weeks for cutthroat to hatch and another week to emerge from the gravel (these figures taken from the BC provincial "Fish Facts" coastal cutthroat pamphlet), the eggs that these fry came from were perhaps laid about 8 - 9 weeks ago, or a week or two before the toxin killed fish in the creek. Nice to know cutthroat are being born!
A negative recording to offset the good news is that we got a low pH reading at T521 (the bottom of the Brynlor stairs) of around 5.5 - 6, which is definitely on the edge for fish and other aquatic life. We got 6.0 on our old pH paper and around 5.5 on new paper streamkeepers bought a few weeks ago. Water temp was 8.5C and air temp was 6.0C.
We're going to monitor the pH closely. Apparently fish need at least 6.5 to do well, and thrive at around 7.5. Try Googling "salmon optimum pH" and you'll find lots of good information.
Posted by Paul at April 14, 2006 05:46 PM