48 Fishery Board for Scotland. 



Experiments with drift bottles have proved that the general 

 south-going current is profoundly modified in the Moray Firth, for 

 while the bulk of the water after impinging on the coast of Banff and 

 Aberdeen continues its southward course a portion is deflected west- 

 wards to the inner reaches of the Firth. The third western meridian 

 is roughly the line of division of the directions of the flow of these 

 bodies of water, the westerly deflected portion of the current forming 

 a series of eddies within the Firth. Captain Brown shows that not 

 only is there a south-westerly set towards the Cromarty Firth, but 

 that these currents are continued along the shores of Sutherlandshire. 



Now our most important plaice spawning grounds lie within this 

 region of the Firth, and their position is such that the drift of the 

 pelagic eggs is affected by the currents mentioned. The important 

 spawning ground off Lossiemouth lies just at the point where the final 

 separation takes place between the east and west-going currents. 

 It has already been shown that there is a gradual increase in the 

 percentage of eggs in the later stages of development eastwards 

 along the coast from Lossiemouth. In addition, the region off Tarbet 

 Ness is known to be not only an early spawning area but one of high 

 density. This area of high density is of considerable extent, for 

 in the statistics already given there is a great similarity at any 

 particular time in the percentages of eggs at the same stages of 

 development. This similarity is easily explained by the existence 

 of a circular movement of the water in the locality. At a given 

 moment the stages of development of eggs at Helmsdale agree rather 

 with the conditions at Tarbet Ness than those at Noss Head. The 

 circular motion of the waters would also fully account for the appear- 

 ance of eggs with well developed embryos on the off-shore grounds 

 before spawning had begun there. These eggs must have been 

 derived from the early spawning gTounds of the Dornoch Firth or 

 Tarbet Ness since spawning had not begun within the areas to the 

 north. It might be suggested that eggs in an advanced stage of 

 development, which appear early on the south edge of Smith Bank, 

 had been carried from spawning grounds on the North of Scotland 

 or to the east of Orkney. A reference to the remarks already made, 

 when the separate stations were being considered, will show how 

 unlikely it is that, thus early in the season, these eggs could have 

 been carried from the northern areas. Neither can they be derived 

 from Noss Head since that has been shown to be a later spawning area. 



The influence of the south-flowing current is well seen in the 

 non-appearance of eggs in the later stages of development to the east 

 of Orkney even in the month of March, although spawning begins there 

 in February. 



In the present communication little can be said with certainty 

 concerning the conditions on the more northerly areas around 

 Shetland since it has been found that spawning is late in that locality. 

 This much, however, may be said that spawning is not general in the 

 shallow coastal zone round the Islands. 



Dr. Fulton has traced out the general southerly movement of the 

 sm-face waters on the East Coast of Scotland, and has shown how the 

 current impinges on those portions of the coast which lie at right angles 

 to its general flow, and that on the Yorkshire coast it is finally deflected 

 eastwards towards the continental coast. Captain Brown describes 



