13 







eventually. The first loads of cultch, tiles and dead shells, were deposited in 

 February 1904 ; in consequence of these becoming covered with mud, further 

 lots of cultch, chiefly oyster shells, were laid down in the same place the follow- 

 ing August, and in February of 1905 a boat-load of stones was added. Quan- 

 tities of mature oysters were deposited as spat producers on several occasions in 

 the same place. 



60. All the tiles, stones, and shells not yet buried in mud, were slimed 

 with fine mud and diatom scum, most inimical to spat attachment. By careful 

 search I did however find four living oysters attached to tile fragments. They 

 were well grown and I judged the age to be approximately about 1^ year, the 

 lengths varying from 3| to 4J inches. Among clumps of dead oyster shells, 

 abundance of sponges of several species flourished, nudibranchs were plentiful, 

 together with some Turbo and boring molluscs a faunal association similar to 

 that characteristic of the oyster beds in Pulicat Lake near Madras. 



51. Returning to the main channel running northwards from Shams Pir, 

 we followed it up till we came to the Nawa Nar beds opposite the landing 

 pier at the end of the road leading from the Mauripur Salt Works. At 

 this place a few patches of rock outcrop and several shoals occur made up 

 largely of pebbles and small boulders. Upon the higher parts of these 

 rocky patches and gravel deposits a Coxcomb oyster is found in profusion, 

 while at and above low tide level the remnants were seen of what formerly 

 must have been extensive beds of the local edible oyster. Here and there a few 

 remained but they were scattered and sparse. These oysters patches exhibit 

 every appearance of being thoroughly worked out. However, even in the present 

 depleted condition I am given to understand that a man can still collect enough 

 during spring tides to make it worth while visiting the beds occasionally. 



52. Nawa Nar possesses many qualities which fit it either to sustain 

 a natural oyster bed or to be converted into artificial oyster-parks. Natural 

 cultch abounds pebbles, gravel, and dead shells. By their presence in 

 quantity the bottom is sufficiently consolidated to obviate any danger of 

 oysters here sinking into the mud. Diatom food is plentiful the mud flats and 

 creeks surrounding Nawa Nar grow them iu myriads. Not least in value 

 among the natural advantages of this spot is the well-marked scour maintained 

 by the tidal flow particularly during the ebb when the drainage of the great 

 area of high-lying flats westward of Nawa Nar courses like a mill-race over 

 the gravels between the reefs which uncover before half-tide and thereafter 

 gradually narrow the waterways to a fraction of the high-tide width. The 

 heavy scour thus produced prevents any undue accumulation of mud upon the 

 oyster flats margining the low-tide channel. 



53. In the preceding section some account has been given of the culture 

 experiments made at this place. At the time of my visit a considerable quan- 

 tity of the broken Mangalore tiles laid down in 189S were still in evidence, 

 proof of the stability of the surface of these gravel flats. Those lying on the 

 higher levels were thickly crusted over with Coxcomb oysters while a couple of 

 well-grown edible oysters were found on tile fragments near low-tide limit. 



54. With the exception of the Nawa Nar gravels and reefs and the Shams 

 Pir eastern beach, the bottom of the backwater is everywhere either soft mud 

 or fine sand. As the tide recedes there is a vertical fall of over 9 feet at 

 ordinary springs the channels gradually narrow till at low-water of a spring ide, 

 nine-tenths of the area becomes exposed a vast expanse of soft mud surround- 

 ing patches of mangrove scrub. But whilst such areas are valueless for 

 oyster culture because of the softness of the surface, they afford suitable life 

 conditions for the window-pane oyster, Placuna placenta, which flourishes there 

 and provides a remunerative seed-pearl fishery from time to time. 



55. The day following the visit to Nawa Nar was occupied with prepara- 

 tion for a week's tour of the Indus creeks. The Customs sailing yacht '" May 

 Queen " was kindly placed at my disposal and with Mr. Judd again as guide we 

 left Karachi at 4 a. m. on 27th October, the weather fine and the sea smooth, 

 but with a strong swell from the W.-N.-W. 



B 6954 



