SOME ECONOMIC ASPECTS OF SHORE LIFE 299 



may become polluted, but frequently the situation of the 

 chief beds is sufficiently remote from sources of pollution 

 to ensure their escape. In some places cockles are cooked 

 after gathering, and marketed in this condition, thus avoiding 

 much danger, besides eliminating the chief bulk and much 

 expense in transit. Such methods are employed at Leigh- 

 on- Sea where sterilisers are used (see Plate XV). 



The release of refuse from works has produced in 

 certain instances curious results among the shore fauna 

 and flora. Farran (1914) investigated the effects produced 

 by the establishment of a whaling station in Blacksod 

 Bay, Co. Mayo. He found that defilement of the shore, 

 with destruction of animal and vegetable life, took place 

 only when the valuable parts of whales were treated, and the 

 refuse allowed to accumulate in large quantities on the 

 shore. In the case of a station with installation sufficient to 

 deal promptly with the whole of the whale, such a result did 

 not occur. In the instance investigated, only a residue, 

 consisting mainly of water and some organic matter in solution, 

 was allowed to escape. Any changes observed on the shore 

 extended at most for 200 yards on either side, the most 

 noticeable result being the greatly increased growth of 

 Ulva lactuca, which formed a dense band along and below 

 extreme low-water mark. Within this area, the roots of 

 Laminaria at low water yielded a much smaller supply of 

 worms than usual. Above low-water mark the shore was 

 as us\ial except just below and at the sides of the station, 

 where there was a notable increase in Enteromorpha and 

 decrease of Fucoids, and the animal life they shelter. 



We ourselves investigated an instance on the shores of 

 Milford Haven, in 191 3, in which the effluent from a fish- 

 manure and oil-works flowed across a tidal reef (Walton, 

 19 1 3). A drain pipe from these works opened within the 

 tidal zone and the rocks thereabouts were oily and there 

 was a strong fishy odour. The fauna of the vicinity was 

 somewhat curiously affected. Immediately around the 

 outlet the rocks were barren ; a little further away algae 

 began to appear, and gradually increased in amount. Then 



