THE ALSTKALIAN MUSEUM MAGAZINE. 



79 



A Naturalist on the Great Barrier Reef. 



By E. a. Briggs, B.Sc. 

 Li'cturcr ill Zoology, Univci'sity of Sytliicy. 



My trij) to the (livat Biinicr Keef 

 of Australia was uiulertakt'n for the 

 purpose of studying- the marine life of 

 this fascinating area of reefs and slial- 

 lows, of islands and lagoons. Among 

 these interesting places I spent a con- 

 siderable time examining and noting the 

 haliits of the many curious animaLs 

 which comprise the heterogeneous life 

 of tliese reefs. 



The Great Barrier Keef is one of the 

 most interesting areas of recent laml 

 growth in t!ie world. The gradual sub- 

 sidence of the Queensland coast, and 

 the graihial spreading of the coral rock 

 over the sinking continental shelf has 

 led to the fiuniation of a huge deposit 

 of limestone which extends from the 

 neighbourhood of Torres Strait along 

 the north-east coast of Australia fo, 

 a distance of 1,250 miles. This im 

 mense liarrier, built up by the activi- 

 ties of countless myriads of coral i^olyir-^. 

 is not an uninterrupted wall, but is 

 deeply scored in many places by clian- 

 nels and passages, whicli, in some cases, 

 are wide outlets to tlie vast ex'iDanse of 

 the Pacific. 



The distance from the mainland to 

 the outer edge of this great chain of 

 reefs varies from ten to thirty miles 

 near its northern extremity. As mv 

 follow t!ie reefs to the southward we 

 find the outer edge of the barrier grad- 

 ually creeps away from the Queensland 

 coast until south of Cairns it is 40 to 

 60 miles from the mainland. Still fur- 

 ther south the liarrier extends rapidly 

 to the east, and tinally breaks up into 

 a series of isolated reefs and small is- 

 lands, the outermost of Avliich are some 

 150 miles distant from the Queensland 

 coast. The area within the barrier is 

 thickly studded with islets, reefs and 

 sand-banks, all of which offer a happy 

 hunting ground to the naturalist. 



This great accumulation of coral does 

 not form a high barrier above the sur- 

 face of the sea, but produces a series 

 of detached reefs, which are perched on 



the huge bulk of tlic coral rock, and in 

 many cases appear only at low tide. 

 Here is a shallow, warm-water sea, 

 where many important industries have 

 arisen, such as ])earl-shelliiig, 1 e.'he-(h'- 

 mer gathering, and turtle-fishing, only 

 to languish again owing to the unre- 

 stricted conditions und,er which tliey 

 Avere allowed to be carried on. As a re- 

 sult of over-tishiiig the animal life on 

 the reefs very soon became so depleted 

 that it was impossible for the various 

 industries to be conducted at a j^rofit. 



At i)resent the reefs from Torres 

 Strait ; outhwai d to Port Mackay ;iie 

 being extensively fished over for Tro- 

 chu> shell, and. unless leg sLition is in- 

 troduced to prevent the gathering of 

 the smaller shells, we shall soon see the 

 tragedy which befell the pearling in- 

 dustry and the beche-de-mer fishery en- 

 acted all over again. 



SHELLS AND BUTTONS. 



The trochus shell (Trochu-i i}ih)'c,ts) 

 which is like a gigantic snail's shell, is 



The trochus rhell, from which rows of buttons 



are cut, attains a diameter of 5i inches. It 



is remarkable for its colouration, flame-like 



markings standing out against the white 



ground of the shell. 



Miss P. F. Clarke, deL 



gathered by hand on the coral reefs 

 between tide marks. The catch is then 

 cleaned by spreading the shells, still 

 containing the animal, on the beach for 

 the blow-flies to dispose of the flesh. 

 The putrid contents are afterwards re- 



