During the last fifteen years there has been a very steady decrease in the average catch of pearl-oysters per boat in the Australian fishery. The average catch in the Queensland fleet in 1890 approximated 7 tons per boat; from 1898 to 1903 it was about 3 tons annually; in 1904 it was only 2¼ tons, and in 1905 a trifle more than 1½ tons. The yearly increasing number of boats would naturally lower the average, but the decrease is generally ascribed to the denudation of the reefs, due to close working for thirty-five years without giving them a chance to recuperate. The small yield in Queensland in 1904 and 1905 was due largely ta the extended rough weather and the accompanying thick or muddy water, which presented an obstacle to the prosecution of the work. Mr. Hugh Milman, the government resident at Thursday Island, states that each year the beds in the more sheltered spots have been extensively fished, rendering it necessary for the fleet to go farther afield in places where the depth of water is greater, and where the vessels are more exposed to the full force of the southeast winds which prevail for about seven months of the year, and which were unusually severe in 1905.[259] The general denudation of the beds is not the principal cause of the decreased take. An additional cause for the falling off in 1905 was the deflection of a large percentage of the fleet to new fields of operation, 110 vessels leaving for the Aru Islands in the Arafura Sea, when the season was about half finished. For vessels using diving apparatus, the season continues throughout the year, but it is frequently interrupted by storms, which may cause the boats to lie in harbor for ten days, or even two weeks at a time. The nude divers suspend work from December to March, and also during the season of gales. Each vessel is manned by a diver, his attendant, and a crew of four men, who in pairs take alternate shifts at the manual pump for supplying air to the diver. The entire force of men take part in managing the vessel and in caring for the catch. The vessel is provided with full equipment and supplies of food, water, etc., to last two or three weeks, depending on the distance of the fishing grounds from the shore station, or the frequency of trips made by a supply vessel. Except a number of owners and their representatives, there are now very few white persons engaged in pearling in Australian waters. Even the persons in charge of the vessels are largely natives of the Pacific Islands. Owing to the hardships encountered and the small remuneration, it is difficult to secure white labor; and aliens from Japan, the Philippines, Java, Singapore, India and New Guinea, are employed.