The great Queensland pearl-fishery in Torres Straits is mostly in the hands of Sydney capitalists. It is carried on by boats, with Malay divers, in water of 4-6 fathoms. The pearl-mussels•of Torres Straits have a weight of 3-6 lb., and even 10 lb. The weight and worth of the pearl-mussels exported from Queensland have been as follows :-1874 : 2 lb., 12l.; 1875: 112 cwt., 7991. ; 1876: 2886 cwt., 15,6651. ; 1877: 7768 cwt., 48,723/. ; 1878: 9530 cwt., 54,149/. The official statistics from the station in Thursday Island for the year 1st May, 1878-30th April, 1879, were :—Living pearl-mussels, 425 tons, l a cwt. ; dead pearl-mussels, 4 tons, 2 cwt.; pearls, 1301. worth. The value of the mussel-shell at 1301. a ton is 112,320/. The pearl-fisheries of the N.-W. coast of Australia give extensive employment, the divers being Malays from the Dutch settlements, and natives ; the diving is carried on from the end of September to the end of March. The extent of these banks is probably far from being defined as yet. A vessel engaged in pearling in King Sound, in 1879, got 21 tons of shells in 25 days ; the banks doubtless exist between Beagle and Collier Bays, and there is reason to hope that they reach as far north as the Gulf of Carpentaria. The fishing is carried en solely for the value of the mother-of-pearl shell (releagrina margaritifera), but it also yields a number of pearls, some having a high worth. The shells are of the best kind known, weighing 1i-6 lb. a pair. They are subject to an export duty of 4/. a ton. A distinct fishery is carried on in Shark's Bay (W. Australia), particularly on the banks in Useless Harbour. The shell here found is the true pearl-mussel (Avicula margaritifera). The shells are very thin, with a beautiful pearly inner surface ; till quite recently, they were considered valueless, on account of their thinness, but quantities are now being sent to Havre at a most remunerative price. The pearls themselves are the main object of search, and large numbers must be found ; but as there is no duty of any kind levied upon them, statistics are wanting. They have a brilliant lustre, but seldom exceed the size of a pea. The capture of the molluscs is effected by dragging iron-wire dredges over the banks in shallow water. The shells are heaped up ashore for the occupants to rot, when they are easily opened and searched. The pearl-fisheries of W. Australia possess a considerable and growing importance. In 1874, the total ascertained value of the exports of mother-of-pearl was 58,9281., and of pearls, 6000/. ; the exports of the former in 1876 were 240 tons to London, and 67 tons to Singa pore, the price fluctuating at about 250-2801. a ton. The discovery of molluscs yielding mother-of pearl and pearls in Oakley Creek, New Zealand, has been reported.
Diving for pearl is one of the chief occupations of both sexes of natives in the islands of the S. Pacific. The mollusc here sought is the mother-of-pearl-yielding mussel, which inhabits the interior lagoons of the great coral atolls. It frequents the clean growing coral, where it can attach itself free from sand or drift, and where there is considerable influx and efflux of tide. It is also to be found in great numbers under the breakers that beat upon the outer reefs, and probably at greater depths in the sea beyond. The animals are gregarious, and love to congregate in large piles, firmly attached to one another. Unfavourable conditions will cause them to migrate en masse for a short distance. The attachment to the rock is effected by means of a "cable" springing from the body of the mollusc, and passing through an orifice between the shells at the hinge. During life, the colour of this cable is dark-green to golden-bronze, and a similar degree of brilliancy pertains to the two flat surfaces at the back of the hinge; the exact degree and shade of these colours are said to indicate the presenoe or absence of pearls within the shell, with such a degree of certainty that experienced fishers will select 75 per cent. of the pearl-containing mussels from a boat-load by this sign alone. The shell comes to maturity in about seven years, at which time, its
average weight is 1 lb. empty ; the usual size is 10 in. across, sometimes reaching 18 in. When mature, the creature detaches itself from the rock, opens, dies, decays, and the shell becomes coated with coral and parasites, and loses all value, while any loose pearls contained in the shell fall out and are lost. The animals have severe] enemies, one of the worst being a centipede-like oreature which infests stagnant lagoons, and enters the shells and devours the occupants. Almost all well-grown mussels are troubled with lobster-shaped parasites, about the size of shrimps, which inhabit and breed in the mussel-shells.
The shells are secured individually by divers. When landed, they are generally separated into two piles, consisting of those which are supposed to contain pearls and those which are not. The shells are opened by flexible, steel-bladed knives; a skilful hand will open one ton of shells per diem, Without missing any pearls there may be. The emptied shells (mother-of-pearl) are at once placed in the shade, to preserve their colours. The animals are eaten in times of great scarcity. Pearls, when present, are usually lodged in the muscle whence the cable springs, which, being transparent, easily reveals their presence. When many are found in one shell, they are commonly small and ill-formed. Other pearls occur sometimes loose in the shell ; these are always of very fine quality, perfectly round, and often large. Not more than one mussel in a thousand contains such pearls, but when they are present, they are frequently last by the natives through carelessness in opening. Fine, calm weather is most favourable to the fishing, hut not indispensable. No accessory or apparatus of any kind is used by the divers ; but they rub their bodies with oil, to avoid blistering by the sun. They can remain under water 1-2 minutes or more, and are able to bring up shell from 20 fathoms. Few shells are gat from this depth, but those are exceptionally fine. Many fisheries now supposed to be exhausted still contain great riches in the deeper water ; and many lagoons that have afforded nothing in the shallow water will repay search at greater depths. Taking all things into consideration, the cost of raising mother-of-pearl shell in these islands is about 5-6/. a ton.
The pearl-fishery of the S. Pacific is carried on chiefly in the Tuamotu [Pomotou, or Low] Archi pelago, in the Gambier Islands, and in the Navigator's Islands. Very many other localities are partially or totally neglected. Thus the island of Manihiki, which afforded over 100 tons of shell in 18 months, some 20 years ago, has not been fished since ; and the lagoon of Hogolen is known to contain an immense bank of pearl-mussels. The Tuamotu are said to have yielded altogether some 25,000 tons of mother-of-pearl, valued at over 1,000,000/. Almost the whole production goes to Tahiti for export. In 1873, the total shipments were estimated to amount to 2000 tons of shells and 200,000 fr. worth of pearls. In 1878, Tahiti exported 591 tons of shells, value 35,460/., and 6000/. worth of pearls ; in 1879, 470 tons of shells, value 28,200/., and 40001. worth of pearls. The export duty of 32s. a ton on shells, which was imposed in 1875, was removed in 1878 ; this fact partly accounts for the increased export in 1878. The classification of pearls in the Pacific Islands is as follows :—(l) Those of regular form and without faults: value, 3s. per -A grm., those weighing grin., 100-140l.; (2) round, white, and of good lustre : value, 30 grm. containing 800 pearls, 41., the same weight in 50 pearls, 60/. ; (3) irregular form, net free from faults or spots : value, 30 grm., 3-4/., according to degree of tarnish by black blemishes and dulness ; (4) knots of pearl, which have adhered to the shell : value, 30 gem., 30-44, according to regularity and brilliancy ; (5) seed-pearls, 2-3/. a lb. Mother-of-pearl brings 3-6d. a lb. The chief markets for Pacific pearls arc Hamburg, Amsterdam, London, and St. Petersburg.