216 Part III.— Seventeenth Annual Report 



outward movement is indicated by the high averages for October and 

 November — the average for October being the highest for any of the 

 months and double the average for June. At Smith Bank gurnards 

 appear to be numerous in May and June, much less abundant in July 

 and August, and very abundant in October and November, when the 

 averages are 40 and 37 respectively. Only 20 hauls, however, were made 

 at Smith Bank in these months. 



In the Firth of Clyde, in which over 3000 gurnards were caught by 

 the " Garland," the abundance of this fish in the various months is much 

 the same as in the Moray Firth. Excluding those caught in Loch Fyne, 

 which fall into a different category, the averages for the different months 

 are as follows : — 



January. February. March. April. May. June. 



13-6 0 0 26-5 22-2 18-6 



July. August. September. October. November. December. 



10-6 63-6 11-8 27*0 19*0 31*1 



No hauls were made in June, and only two in February. The most 

 striking feature of difference between these figures for the Clyde and 

 those for the Firth of Forth area and St. Andrews Bay is the compara- 

 tively high averages for January, March, October, November, and December. 

 It is clear that the gurnards do not leave the Clyde area in the winter as 

 they do in the other inshore areas mentioned. With the exception of 

 two or three stations, near shore and in comparatively shallow water, 

 gurnards were present in all the hauls in January and December. They 

 were present at all stations except one in November, and at all except 

 one in October. But in these months and in March by far the greatest 

 numbers were got at the outer stations, in deep water, to the west of 

 Ailsa Craig (VIII.-IX.), and off Rhuad Point, Cantire (VI.). The 

 temperature of the bottom water at these stations in December and Janu- 

 ary is nearly the same as it is in the Firth of Forth in June and July. 



In the upper parts of Loch Fyne gurnards are not present in abundance, 

 but they were found there in all the months when hauls were made — viz., 

 March, April, May, August, October, November, and December. The 

 numbers caught in the 39 hauls were small, but the averages may be 

 given, as follows : — 



March. April. Mav. August. October. November. December. 

 0-6 37 2-2 8-4 14-0 3-6 3-5 



The remark regarding temperature applies also here, viz., that the 

 bottom water in Loch Fyne at the stations where the gurnards were caught 

 is as warm in December as the bottom water in the Forth is in July. 



The Relation between the Temperature of the Water and the 

 Migratory Movements. 



Turning now to the question of the temperature of the water in the 

 Firth of Forth area in the various months of the year, it will be found 

 that a very definite relationship exists between the changes in the tem- 

 perature and the migratory movements of the gurnards. The mean 

 temperature of the surface and bottom water in each month of the ten 

 years, at all the stations where the gurnards were captured, has been 

 calculated in the Fahrenheit scale as follows, from over 1200 observa- 

 tions : — 



