SEA- FISHERIES LABORATORY. 455 



at Aberanifrach, that is, at a distance of about half a mile 

 from the outfall, did not exhibit such marked pollution 

 c-n the occasion of this sampling ; still, the pollution was 

 far too serious to be neglected. It is probable that, in 

 certain conditions of wind and tide, the difference 

 between these two places, as regards pollution, may not 

 be appreciable. The estuary is narrow and not deep, and 

 the flood stream flows directly from the sewer outfall 

 towards Aberamfrach. It would be wrong, I think, to 

 regard the mussels above the railway bridge as being, on 

 the whole, less seriously polluted than those in the 

 harbour. Dr. Bulstrode, in his last report, suggested 

 the relaying of mussels taken seaward of the bridge in 

 some part of the channel landward of the bridge, but 

 I doubt very greatly whether this would, on the whole, 

 be a safeguard. Certainly, transplanting of the smaller 

 mussels found in the seaward part of the estuary to the 

 upper part would lead to increased growth of the shell- 

 fish, but these upper parts of the estuary are far from 

 being unpolluted. 



Transplanting in the Barmouth estuary would, in 

 order that the public health might not be affected, have 

 to be accompanied by some measures for the purification 

 of the shellfish, that is, if it should be found impossible 

 to divert all the sewage into the northern outfall. This 

 I have no doubt would be possible, and the only question 

 to be considered is whether the mussel industry in the 

 estuary is capable of such further development as to 

 justify asking the local authority to face this expense. 

 In the season, November, 1900, to February, 1907, the 

 total value of the mussels despatched from Barmouth was 

 £148. No doubt this value could be increased con- 

 siderably by well-planned transplantation, but even then 

 the cost of the sewerage scheme and the increased revenue 



