0/ the Fishery Board for Scotland. 



73 



recent writers on the subject, determine the ascent of salmon from sea to 

 river — viz., tlie approximation (we might in this case say the identity) of 

 the temperatures of river and sea. Two temperature curves could 

 scarcely be more exactly approximated than those of January and 

 February, yet in those two months no fish were or are ever taken. I 

 have been favoured with a complete record of all the net-caught salmon 

 and sea-trout taken in 1902, through the kindness of Mr. Charles Turner, 

 Dumfries, who controls all the commercial fishings of the river. From 

 this it appears that the first sea-trout was taken on 21st March, then a 

 few trout on 25th March, and at intervals upwards till 8th April. On 

 15th April the steady run began, and lasted till the height of summer, 

 when it again became intermittent, and finally ceased at the end of July. 

 With regard to salmon, it appears that only a few individual fish entered 

 the tidal portion of the river between 2nd and llth April and between 

 20th and 30th April, and that the occurrence of salmon did not become 

 at all regular till the beginning of May. It is right to state in connection 

 with the runs of fish in the Nith that the river suffers most materially at 

 the hands of many in the district, that the spawning tributaries are to a 

 great extent rendered impassable to fish by reason of high weirs, and that 

 pollutions of a gross nature enter the river at Dumfries. On account of 

 those injurious influences the river is not as well stocked with fish as it 

 might be, and the early runs are perhaps most of all reduced. Glancing 

 at the readings of water level, we see also that when the first sea- trout 

 and salmon appeared — March and the first half of April — the river was by 

 no means high, nor did it fluctuate more than about a foot. Immediately 

 after the flood which occurred in the third week of April, when the 

 temperature was evidently steadily rising, the first really marked run of 

 sea-trout for the season occurred. But in noting the absence of an 

 early run in January and February, we have to remark that in the third 

 week of January a flood occurred, with a rise of temperature from 37° 

 to 43°, thus bearing out wliat has already been said, that in a late river a 

 rise of temperature during the blank months, or Ashless months, will not 

 produce a run of fish, and this even when accompanied by a rise in water 

 level. The flood shown in February was accompanied by a very low 

 temperature — one to two degrees above freezing — and therefore would not, 

 even in an early river, have produced a run of fish, although a run would 

 in all probability have occurred immediately afterwards. 



There are two early rivers which are somewhat peculiar in this, that 

 spring fishing (angling) is prosecuted only in their upper tributaries. The 

 conditions in these rivers therefore demand our attention. I refer to the 

 Garry (Inverness-shire) and the Orchy. It is important to observe, how- 

 ever, that although called tributaries the rivers in question are in reality 

 the upper portions of the main waterways, and are rivers of good size. 

 In each case the early fish ascend the lower river rapidly, and passing 

 through the large deep loch from which in each case the lower river 

 flows, viz. Loch ^^ess and Loch Awe, enter the head waters. Garry fish, 

 indeed, not only pass through Loch Ness, but have to pass also through 

 the river Oich and part of Loch Oich. Is there any peculiarity in the 

 temperature of the Garry which draws fish from Loch Ness through the 

 Oich ? This question seemed to me to require a definite answer. Tay 

 fish ascend to Loch Tay and remain in the loch till May. Why do fish 

 not enter the Dochart at once as they do the Garry, and why do they 

 move into the Dochart in May 



To test the question of temperature in the case of the Garry and of the 

 Orchy, I arranged that a max. and min. thermometer be constantly 

 floated in a wooden box in each river, and that similar instruments 

 similarly used be also immersed in the lower main rivers, Ness and Awe. 



