6 LIFE IN THE SEA [CH. 



be found here. The rocky bottoms would harbour 

 many species of fishes not found on the sand the 

 brilliantly-coloured wrasses for instance, with perhaps 

 pollack, ling or saithe. The muddy places would 

 contain many kinds of burrowing Crustacea and 

 worms, and perhaps the Norway lobster (Nephrops). 

 All this part of the sea we might call the shallow 

 water region, and the bottom life inhabiting it the 

 Shallow Water Benthos. Life here is richer and 

 more varied than in any other part of the sea, not 

 only because of its permanent fauna but also because 

 hosts of young fishes inhabit this region for the first 

 year or so of their lifetime. As we proceed further 

 out to sea there would be a progressive change both 

 in the nature and the abundance of life. The algae 

 would disappear entirely. The shallow water fishes 

 such as the plaice and sole would be replaced by the 

 witch and megrim, and the cod, whiting and haddock 

 by the hake. Invertebrate life would also become 

 rather less abundant. Between the 50-fathom and 

 the 100-fathom contour lines the region of sea may 

 be called the deep-sea area and its bottom life the 

 Deep-Sea Benthos. It would all be familiar to us. 

 So far we have been travelling under relatively 

 shallow water, over the narrow selvage of sea-bottom 

 which fringes the margins of the continents, and 

 extends out to sea for a variable distance from the 

 dry land. The British Islands themselves are situated 



