PRODUCTS OF THE SEA — EXPLOITATION AND UTILIZATION 191 



lies off the Indus estuary. The continental shelf area of the Arabian 

 Sea is restricted. It is about 100 miles only off the Indus estuary and 

 shrinks to about 30 miles off the Mekran Coast. 1 he edge of the con- 

 tinental shelf lying at the 100-fathom line falls steeply into deep water. 

 A submarine canyon cuts the shelf opposite the Indus estuary. The 

 area adjacent to this is subject to a considerable amount of silting. 



Fauna: The fauna and flora of these waters are fairly known from 

 a systematic point of view. Schools of 'Sciaena, Tuna, Polynemus and 

 Pristipoma' have been observed to be present in seasonal pattern on 

 the surface of the off-shore waters. In mid-waters 'Gybium and Elas- 

 mobranchs' are present, whilst the fauna of the bottom waters com- 

 prise 'Synaptura, Cynoglossus, Luiianus, and Elasmobranchs'. The in- 

 shore fauna which are endemic and which share some elements of the 

 off-shore, brackish, and fresh-water fauna, consist of stocks of 'Mugil, 

 Sillago, Chrysophrys, Gerres and Lutianus in addition to a very sub- 

 stantial fauna of 'Penaeidae.' The brackish water areas which are ex- 

 tensive, totalling about 7,500 square miles, include a vast network of 

 waterways which are inhabited by a varied fauna of 'Mullets, Perches, 

 Herrings' and an extensive stock of oysters. The brackish water con- 

 ditions which penetrate the main river course influence to a great extent 

 the up-stream ascent of the very important fish Hilsa or YdiWd.— Hilsa 

 ilisha'. 



Beyond the faunistic lists, knowledge of the resources is seriously 

 limited. Whilst the general distribution of a few of the more important 

 species is known, the precise distribution of these, and the variation of 

 the limits of distribution from season to season, is not known. Little 

 information is available on the life history in terms of spawning sea- 

 sons and habits, feeding habits, and migratory movements of these 

 species. There is no record of any estimate having been attempted, 

 of the natural abundance of any species of the area. Certain species 

 are known to be more abundant than others; at least, greater catches 

 are taken by the fishermen. But whether these catches approach or 

 exceed the proper limits which the natural stocks can sustain, is not 

 known. 



The Industry 

 The primary phase of the fishing industry consists of the following 

 major divisions: 



(1) Capture operations in the off-shore waters, 



(2) Capture operations in the brackish waters and open waterways 

 of the Gangetic and Indus delta and 



(3) Culture operations in the estuarine areas. 



