It has been another week of high catches in the River Ayr smolt trap, with almost 2000 fish, despite the low water which is now just 2″ above summer level. However, there was a small rise of 2″ during the week which had an impact on water quality. The daily catch totals for the last seven days (includes all fish) are as follows:
The vast majority of these fish are salmon smolts with only about 1% sea trout. The low catch on Thursday was interesting. The river had actually risen by an inch or two but the oxygen level was only 88%, whereas it has been above 100% every other days, sometimes as high as 117%. We got the impression that the low oxygen levels had slowed down the movement of smolts. The reasons for the low oxygen levels are not clear but it could be due to a number of factors including flush of dirty water from ditches, urban run-off or sewage inputs.
We had a perch in the trap midweek, the first so far and an unusual occurance in the River Ayr, although we were aware of their presence in the catchment.
We are recording evidence of bird damge and the incidence appears to be higher now, no surprise given the low, clear water conditions. The smolt below will do well to survive the severe bird damage. There were several parallel beak marks along the flanks, probably caused by a heron.
The largest salmon smolt caught so far was found in the trap on Saturday. It was 189mm and the scales showed it to be 2 years old, a fast growing fish!
Thanks to Aleta, Katie and Mandy for the assistance with the trap this weekend!