of the Fishery Hoard jor Scotland. 



7:; 



The average interval between marking and recapture is, for the short- 

 time migration 162 days, or say 5| months; for the long-time migration 

 519 days, or 17 months. There are eight short-time recaptures and 

 seventeen long-time recaptures. The shortest interval is 102 days, the 

 longest 655 days. 



With regard to increase of weight, it is noticeable that, although three 

 different river systems are represented in the above returns, viz., the 

 Helmsdale, Naver, and Tay, the average increase of the long-time 

 series is just double the average increase of the short-time series, a 

 result exactly similar to that noted in last year's report when dealing 

 with Tay returns alone. The same great extremes are again 

 noticeable in the long-period fish. The greatest increase is 19 lbs., in 

 a Tay fish, in 535 days. The least increase is 3f lbs. in a Helmsdale 

 fish, which, curiously enough, has the longest interval of time, viz., 664. 

 The explanation may be this, that the latter fish has been up a river 

 and spawned in the interval, and is not therefore a proper long 

 migration at all, while the former has continued to put on weight in 

 the sea. 



Three of the recaptures have been made on the coast, and are exactly 

 similar to certain recaptures noted on the chart of coastal movements 

 published last year — Helmsdale to Portmahomack, south of Tarbat Ness. 



Ascending Clean Fish. 



Four clean fish marked in the Dee were recaptured. In each case 

 loss of weight is noticeable. 



No. 



Lbs. 



Inched. 



Condition. 



Date. 



District. 



1884 | 



f 



27 



Clean. 

 Clean. 



16th February 1906. 

 16th May 1906. 



Durris. 

 Banchory. 



1851 1 



n 

 7 



262 



Clean. 

 Clean. 



15th December 1905. 

 21st May 1906. 



Crathes. 



Crathes, in a lower pool. 



1886 | 



n 



64 



272 



Clean. 

 Clean. 



16th December 1905. 

 16th August 1906. 



Floating Bank. 

 Invercauld. 



1902 1 



8 



64 



26 

 26i 



Clean. 

 Clean. 



18th December 1905. 

 4th September 1906. 



Donald's Garth. 

 700 yards up Cluny. 



Two similar returns respecting fish of the same series, which had been 

 recaptured after shorter intervals, were included in last year's report. 

 One fish from Culter had ascended 28 miles to Glentana. The other 

 had remained in the lower water and was recaptured at Culter. 



An ascending Beauly fish, No. 3008, has also been recaptured after a 

 short interval. 



[Table. 



