of the Fishery Board for Scotland. 



331 



It is found that the time required for the ' seed ' to mature and reach 

 the bait size varies from three to eight years. If it is immediately planted 

 on one of the best banks it may grow to two inches in length in three 

 years or so, but on most of the banks, unless the mussels are shifted once 

 or twice to lower banks, a much longer time than three years is requisite. 

 Besides, if there is a succession of mild winters the mussels are found to 

 mature more rapidly than when the winters are severe. Cold winters 

 generally retard the growth of the mussel. Exposure too long to the air 

 also tends to hinder rapid growth. This is remarkably well-illustrated in 

 the experimental bouchots erected by Messrs Johnston. Mussels were 

 fixed to the wattling of the hurdles by netting, and mussels of the same 

 kind and size were planted alongside in beds. The bouchot mussels 

 gradually died off, while those of the bed alongside continued to thrive. 

 Of course the temperature of the air would tend to lower the temperature 

 of the bouchot mussels more than the temperature of the bank would that 

 of the bed mussels. If, however, the bouchot system is to be tried again, 

 the trial ought to be made where the conditions of temperature are more 

 favourable than on the east coast, and it might also be preferable to try 

 it where the difference of tide is greater. If the latter were the case, then 

 the bouchot mussels might be high out of the water at low-tide, and yet 

 not be long altogether out of the water between tides. 



Moreover, if the bouchots are to be employed, they may possibly be useful 

 in affording surface for the embryo mussels to attach themselves to during 

 the warmer months of the year, but the trial at Montrose has undoubtedly 

 been unsuccessful so far at least as adult mussels are concerned. Whether 

 a greater quantity of seed could be obtained, and at a cheaper rate than is 

 obtained at present from the rocks, sand, and shingle near the mussel-beds, 

 seems very doubtful. Where, however, seed cannot be got in sufficient 

 quantity, they may prove valuable additions to the catchment area. 



III. Description of the Mussel-Beds. 



Long stretches of mud and sand banks occupy the lower central area of 

 the basin, especially towards the south side. During spring-tides these 

 banks are uncovered throughout their whole extent at low-water, but at 

 'neops' only the higher are completely uncovered, and portions of others are 

 bared. For convenience we have treated those on the south side of the 

 River Southesk, tenanted by the Ferryden Society, separately from those 

 cultivated by the Messrs Johnston & Sons, In the map appended this 

 distinction is also brought out by lines, and the seed banks are likewise 

 distinguished from the growing banks."* 



A. Ferryden and Usan Society's Beds. 



1. The Scalp. — This bank is opposite the harbour of Montrose, and 

 skirts the north side of Rossie Island. It is dry at low- water from a 

 few yards below the suspension bridge to almost abreast of the eastern 

 extremity of Rossie Island. It is composed of gravelly sand which, after 

 the spatting season, becomes covered with the young of the mussel. On 

 the north side of it a few large mussels are present on the hard ground, 

 but its chief utility consists in its suitability for raising 4 seed.' The 

 young mussels after they are about a year old are removed from it to 

 one of the beds further up the stream, or to the ground on either side of 



* From measurements of the growing beds cultivated by the Ferryden Society, we 

 have ascertained them to be about 60 acres in extent. The acreage that is or lias 

 been under mussel culture by Messrs Johnston & Sons will amount to three or four 

 times that of the Ferryden Society. 



