Fish counter pictures Jan/Feb 2017

During January, six fish  were detected ascending the ladder by the counter as well as an otter. A few kelts descended, also about 20 kayaks.

In the first week of February seven fish ascended, including a couple of salmon around the 15lb mark. Although it is difficult to distinguish salmon from sea trout in overhead pictures, it looks like some of the fish were sea trout, earlier perhaps than we might have expected.

Below is a selection of grabs from the overhead camera. To remind readers, the horizontal strips, which are the counter’s electrodes are 45cm apart.

Salmon kelt descending ‘in reverse’
Salmon of about 15lbs ascending
Salmon kelt descending? Suggestions for the strange shape gratefully received!
Another good salmon
Sea trout?
Another sea trout? (left)

After more analysis of last years counter data and video, Fishtek (the counter’s operator) have estimated that, although about 700 fish were counted electronically, approx 3500 fish migrated up-river. The counter was undergoing much testing and modification during the year and it has been determined that for most of this time only the larger fish were being counted. A large majority of smaller fish, school peal in particular, were missed by the counter, but their number was able to be estimated by laborious analysis of video footage.  More detail on the method of estimation and assumptions made to follow. The modifications to the counter should now make it possible to detect the smaller fish in future.