12 OYSTER BOTTOMS IN MATAGORDA BAY. 



DEPTH AND CHARACTER OF BOTTOM. 



The floor of the bay is practically level save where broken by- the 

 abrupt rising of an old reef or o}^ster lump above the surrounding 

 bottom. In the area surveyed there is a gradual increase of water 

 from the flats at the head of the bay to a depth of about 5 feet near 

 Dog Island Reef, while below Dog Island the depth ranges from 

 about 4 feet close to the reef to 14 feet, the deepest water in the entire 

 bay, abreast of Half Moon light, Throughout the length of the 

 area surveyed the deepest water in general lies nearer the peninsula 

 than the prairie shore. 



Between Matagorda and Dog Island, across the existing and the 

 former mouths of the Colorado River, there is now a muddy flat 

 covered with snags, to which the freshets of the Colorado make 

 yearly accretions. 



CHANNELS. 



With the exception of Mad Island Reef, all the great oyster beds 

 lying below the mouth of the Colorado River are traversed by one 

 or more channels used by the oystermen. 



Palacios Point channel lies just on the edge of the oysters, between 

 Half Moon Reef and Palacios Point. It is rather broad, and car- 

 ries a depth of about 3 feet at low winter tide. It has been eroded 

 since the preparation of the Coast Survey chart of the region. 



Mad Island channel, near the inner end of Shell Island Reef, is 

 narrow and holds about 1^ feet of water at low tide. 



Shell Island channel lies immediately northwest of Shell Island, 

 and has a serviceable width of about 20 feet and a low-water depth 

 of 2i feet. 



Dog Island channel, formerly called Steves channel, is an artifi- 

 cial cut southeast of Dog Island. It has a low-water depth of about 

 2 feet at its western and 2J feet at its eastern end, with much deeper 

 water between. The currents in this channel often run with great 

 velocity, and sometimes for several days in one direction, under the 

 influence of prevailing winds. 



Middle channel lies near the middle of Dog Island Reef. It was 

 cut artificially about 1847, and reexcavated a decade or so later, but 

 is now seldom used. It carries a depth not exceeding 1J feet at the 

 low-water plane of reference adopted in this report. 



Tiger Island channel is at the southeastern end of Dog Island 

 Reef. It is narrower and more tortuous than Dog Island channel, 

 and the currents run through it with greater velocity. It has a 

 depth of not more than 1| feet at winter low water. 



Dressing Point channel lies on the edge of the oyster beds between 

 Dressing Point shoal and the point of Dressing Island, and has a 



