SEA FISHERIES LABOBATOBY. 141 



and the tow-nets showed plenty of ordinary surface forms, 

 both diatoms and animals, medusoids being especially 

 abundant. All this is satisfactory enough, and the water 

 sent to the laboratory by the bailiff has been of good 

 quality, although the sp. gr. has been only about 1*022. 

 In looking at the sea off Piel Island however the water is 

 seen to contain much fine suspended matter, this is 

 especially the case when one examines it close to shore 

 from a small boat, and when wading along the edge at 

 low tide. No doubt it would be possible to filter such 

 water, but the process would, judging from what has been 

 done at Dunbar, be troublesome and expensive and any 

 temporary breakdown in the filtering arrangements would 

 be fatal. It is giving the experiment — for the first year of 

 working of a sea-fish hatchery in a new district must be 

 more or less experimental — a poorer chance of success to 

 handicap it with water which is not the cleanest obtainable 

 in the Irish Sea. 



Although at the time when the specific gravity was 

 taken, off Piel Island, on June 5th, the salinity of the 

 water was perfectly satisfactory, still it was much lower 

 when tested in November and December and there is 

 some reason to doubt — judging from the great variations 

 in the specific gravity observed in places off the Lancashire 

 coast (e.g., in Crosby Channel our statistics range from 

 1*018 to 1*026) — whether it would remain sufficiently 

 constant for hatching purposes. In one of his earlier 

 reports on sea-fish hatching in Norway, Captain Dannevig 

 complains of the large proportion of deaths due to varia- 

 tions in the specific gravity, and furthermore we notice 

 that during the remarkably successful firsc season's work 

 at Dunbar last year, when about 27 millions of young 

 plaice and half-a-million of young cod were hatched out 

 and set free on the Scottish fishing grounds, with a loss 



