Pearl oysters undou'btedly grow in water deeper than 11 fathoms, the maximum 

 depths of the present exploitation. Several years ago, divers attempted to work at a depth 

 of lU fathoms, hut these grounds were soon ahandoned because the men suffered from cramps 

 and severe hemorrhages. Diving hoats are not eo_uipped with decompression chambers and no 

 precautions are exercised for gradiial ascent to the surface after several hours of v;orking 

 at considerable depth. It is therefore natural that there were many casualties. Not know- 

 ing the true cause of cramps, the divers attributed them to lov; temperature of water. 



2. Method of fishing 



Three different methods are used for the gathering of oysters; dredging, diving 

 in scaTDhanders, and naked diving. 



The dredge (rastra) consists of a light, cast iron freme of rectangular shape, 

 with a scraping plate about three inches wide, mounted at the lower edge of the frame. A 

 bag of netting is attached to the frame. To prevent the tearing of netting by rocks and 

 corals the bag is kept sli^tly off the bottom by four or five v;ooden sticks attached to its 

 lower side. Three arras of the dredge's frame are joined by a ring 5 to 6 inches in diameter, 

 to which the rope is tied. As a rule, the dreftges are small and light. Several of them in^ 

 sxiected by the author were only 2.k inches wide and weighed from 20 to 30 pounds. According 

 to the present law (Art. 17, Chapter III, Ley de Pesca de Perlas, IS'A)* the maxinrom size 

 of a dredge should not exceed 100 by SO centimeters. 



The crew of a dredging boat consists of a master, U sailors (marineros) , and 

 2 shuckdrs (rancheros). There are usually 2 dredges to each fishing boat. 



Boats used in diving operations are usually equipped with hand-operated, two- 

 cylinder piston pumps, scaphanders, and several htindred feet of rubber hose. No power-driven 

 ■Dumps are being used at present. The law specifies that the working crew of each vessel 

 intending to use scaphanders shall consist of not less than the following a master (un 

 patron) , and for each scaphander employed one diver (buzo titular) , one apprentice diver 

 (un aprendiz de buzo), one line tender (un cabo de vida) , and four seamen (marineros). The 

 naked or head diver (buzo de cabeza) fishes by himself from a small boat, and is sometimes 

 assisted by one or two men. 



At present, scaphander divers work at a depth not exceeding 9 fathoms. The 

 boat slowly follov/s the movement of the diver as he walks on the bottom, while the line tender 

 watches for signals, consisting of a system of jerks and pulls on the life-line (fig. 2). 

 The diver usually remains in water from four to five hours without coming Up for rest. 



3« Season of fishing 



Pearl fishing is conducted during the h months of each year from January 1 

 to April 30. It is required by law that each year a Resolution of the Ministry of Agricul- 

 ture announcing the opening of the season be published 60 days prior to the opening date 

 (Article 5, Chapter II, Ley de Pesca de Perlas). The pearling in any area or in a part of 

 it may be completely closed to fishing by the order of the Ministry of Agriculture. This 

 action may be -oromulgated upon the information received by the Minister from the Administra^ 

 tor of Pisheries, and only after a thorough examination of the existing conditions. Whenever 

 the Minister of Agriculture consi?Lers it necessary he may limit the number of diving boats 

 operating during the open season, or he may temporarily prohibit their use (Article 8, Clmpter 

 II). He also has the ri^t to limit the number of dredges used on each boat but he is re- 

 quired by law to reconcile the interests of the various classes of applicants (Article 9t 

 Chapter II). 



The important conservation measure of the present law is the clause (Article 

 10, Chapter II) requiring an Immediate return to the bottom of small, undeveloped oysters, 

 coninonly called "conchas en flor" or "shells in flower." The law does not establish a 

 definite size limit, but in practice the Administrator of Fisheries considers oysters less 

 than 5 centimeters long as not fully developed, and therefore prohibits their taking. 



10 



