SEA-FISHERIES LABORATORY. 337 



mussels at Egremont, Eock Ferry, or St. Annes) then we 

 may reasonably conclude that the shellfish should not be 

 used for human food. In every sample of mussels from 

 the coasts of Lancashire, Cheshire and Wales examined so 

 far, Bacillus coli has been found; and much more 

 extensive investigations carried out by the Sewage Com- 

 mission with reference to oysters have given the same 

 result. " If," say the Commissioners, " it should be 

 seriously contended that the mere presence of B. coli or 

 coli-like microbes in an oyster should condemn it, few 

 oysters would probably escape condemnation." Probably 

 the same conclusion holds good for mussels also. 



At the present time about 90 per cent, of the sewage 

 of Morecambe is treated by the biological or septic 

 method of purification. The remainder passes into the 

 sea as crude sewage. There can be no doubt that the 

 presence of this crude sewage is objectionable, but I am 

 assured that, in a short time, all the Morecambe sewage 

 will pass through the septic tanks. There is some 

 diversity of opinion among bacteriologists as to how far 

 this method of treatment of crude sewage removes the 

 danger to health which might be incurred should the 

 effluent go near a shellfish laying. But the general 

 opinion is that the chance of dangerous bacteria (such as 

 Bacillus typhosus) finding their way into the effluent is 

 greatly lessened. 



This is specially the case when the effluent is very 

 largely diluted with sea water before reaching shellfish 

 beds. When the present Morecambe sewerage scheme 

 was sanctioned by the Local Government Board, this was 

 apparently considered, for the main sewage outfall is so 

 situated that the effluent is carried well out to sea and is 

 enormously diluted on the ebb tide before coming near the 

 mussel beds. Shellfish are dangerous to health when they 

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