Monday 13th July: An office day, organising samplings over the summer
Tuesday 14th July: Out with Shaun to take genetics tissue samples from the lower Tweed, around Coldstream. Some electric-fishing machine problems - just after servicing, as usual, but got the samples. The key to finding the fry in the large, main, river, where there's acres of water is find the shallow, faster-flowing, "riffle" bits. The size difference in today's fry was very marked - some were 70mm in length, some not much more than half that. The larger ones were noticeably further out in the water than the smaller, which were closer to the bank. Already, therefore, the "winners" and "losers" of the competition for survival are obvious, just three months or so after emergence from the gravel. That's the "Way of the Salmon", a vast production of eggs (200 average sized female salmon = 1,000,000 eggs) , then a battle for survival between the fry, with only the very best being able to get a share of the available food and space to live. Typically, 95% of Salmon fry die in the first three months of life, as the numbers are brought down to the carrying capacity of the water.
Wednesday 15th July: Up to the Freshwater Fisheries Laboratory, Pitlochy, for a Beavers' meeting
Thursday 16th July: Netting the Teviot at two points near Nisbet Bridge. A couple of inches of extra water but conditions still good. Got 400 or so fish at the first site, including a Sea-trout of about 5lbs. A mass of Salmon parr, all big and chunky, almost all over 120mm and many in the 130s - the average size of Salmon smolt on the Tweed is 120mm, so they have made smolt size already. Rather on the fat side for swimming long distances, but the smoltification process includes the thinning and slimming of the body shape, so they will turn into long-distance swimmers at the right time. Lots of Grayling fry as well, all around 100mm in length. At the second site, got a good number of 1yr old Grayling, all around 220mm and a dozen or so takeable trout (over 8") and one Brown-trout of several lbs (the catches still have to be totted up and finalised).
Friday 17th July: Weekly staff meeting in the morning, then out to clean the Peebles trap. Admin in the afternoon. Netting tomorrow cancelled.