Vol. X. No. 231. 



THE AGRICULTURAL NEWS, 



69 



SPONGE CULTURE. 



The United States Bureau of Fisheries has recently pub- 

 lished a bulletin entitled A Practical Method of Sponge. 

 Culture, by H. F. Moore, Scientific Assistant, United States 

 Bureau of Fisheries. This paper was presented before the 

 Fourth International Fishery Congress, held at Washington, 

 U.S.A., on September 'li to 26, 1908, and was awarded the 

 prize of !?100 in gold offered by Haj-es lligelow for the best 

 demonstration, based on original investigations and experi- 

 ments, of the connnercial possibilities of growing sponges from 

 eggs or cuttings. 



The following poiiits from this bulletin are given here, 

 as being likely to prove of interest, in the West Indies, where 

 it would seem possilile that sponge culture might be taken up 

 in certain localities with a prospect of a profitable return. It 

 may be mentioned, Ijy the way, that a list of sponges identi- 

 fied from the St Vincent Grenadines was given in the Aijri- 

 cultural iVe/''.«, Vol. IX, p. .307. 



In discussing the conditions and needs of the sponge 

 fisheries, the author statts that it is not likely that any new 

 sponge fishery district with possibilities of great commercial 

 importance will ever be discovered, although new beds and 

 new regions may come into productiveness; and that the 

 present method of harvesting sponges is likely to deplete the 

 sponge beds to such an extent that they may no longer be 

 profitable to work. 



The demand for sponges in the United States is growing 

 rapidly, and has become already very great The importation 

 of foreign sponges during the three years from 190.5 to 1907 

 averaged an annual valuation of about .§5.31,000. The 

 domestic production during the three years 1906 to 1908 

 was valued at an average of .*65S,000, and the greater part 

 of the sponges was put to use in the United States. 



The previous trials in sponge culture are recounted 

 in the bulletin, and the possible lines of experiment dis- 

 cussed at some length. In this connexion, the following 

 methods of propagation are considered: grafting, growing from 

 eggs, growing from degenerative bodies and dissociated tissues, 

 and growing from cuttings. From a practical point of view, 

 only the last of these was found to be of value. 



The growing of sponges from cuttings is a fairly sim[ile 

 operation. Any healthy sponge, whatever its shape or size, 

 may be used for seed. In collecting and transporting sponges 

 for planting, care must be exercised to keep them ironi injin-y. 

 Any bruising or abrasion of the surface of the sponge is 

 injurious, and contact with fresh water, or water of a less 

 degree of salinity than the open ocean, is fatal to them. Seed 

 sponges which are being kept a short time for planting pur- 

 poses may be strung on a rope stretched between stakes in 

 such a manner that the sponges are suspended just clear of 

 the bottom of the water. 



It has been found by experiment that eutting.s about I-!. 

 by 2\ by 3 inches, or of approximately the same volume as 

 would be given by these dimensions (viz. about 10 to 11 

 cubic inches) are the best for planting. The cutting is best 

 done with large knives kept sharp by whetting on a coarse 

 whetstone, a ragged cutting edge being preferable to a smooth 

 one. The sponges are not ordinarily injured by exi^sure to 

 the air during the time necessary to make the cuttings. It 

 is a good plan, however, to take them from sea-water and as 

 soon as possible to return the cuttings to this. The water in 

 which sponges or the cuttings are being kept should be 

 changed, if in tubs or similar receptacles, about once an hour, 

 the stale water being replaced by fresh sea-water of full saline 

 strength. 



The finding of .suitable material for the attachment of 



the planted sponges has been one of the greatest difficulties 

 found in the experiments. After extensive trials, cement 

 discs and triangles for the substratum, and lead and 

 aluminium for the metals to hold the cuttings in place until 

 the organic attachment is brought about by the growth of the 

 cuttings, have been found most serviceable. 



These discs are 10 inches in diameter and about 1^ 

 inches in thickness. They may be made with a short spindle 

 of lead rod (or wire), |-inch in diameter, which projects 2J 

 inches from the centre on one side, or with two holes through 

 the disc, diametrically opposite each other and about 2 or 3 

 inches from the centre. 



By means of a stiff steel point which fits on the top of 

 the spindle the cuttings may be impaled on it where 

 they form an attachment to it, and to the di.sc, by the pro- 

 cess of growth. In planting, the discs are dropped outward 

 from a small boat, care being taken that they will be right 

 side up when in position on the bottom. 



AVhen the plain discs with the two holes are used, the 

 cuttings are fastened in place by means of an aluminium wire 

 which pierces the cutting, and passes through the holes, the 

 ends being twisted together on the reverse side of the disc. 



It is estimated that cuttings of the size indicated above 

 will increase in size to give marketable sponges in four years, 

 and that about 4,8-10 cuttings per acre of bottom can be suc- 

 cessfully grown. The cost of the entire operation of procur- 

 ing the seed sponges, making the eutting.s, providing the 

 discs and planting an acre amounts to some -$230. The 

 sponges to be harvested at the end of four years should be 

 worth about -$968, allowing for a mortality of about 20 per 

 cent. The discsand spindles would be available for replanting, 

 and this would really reduce the first cost of the undertaking. 



The culture of sponges would .seem worthy of experiment- 

 al trials in those islands of the Lesser Antilles where com- 

 paratively shallow water offers seemingly favourable oppor- 

 tunity. In the shallow water, more especially, in certain locali- 

 ties of Barbados, Antigua, Barbuda, the Grenadines and the 

 Virgin Islands, there may be found conditions under which 

 sponges can be grown, and a profitable industry started. 



BRinSH GUIANA AND THE CANADIAN 



EXHIBITIONS, 1910. 



Particulars of the prizes that have been gained by differ- 

 ent Colonies and Presidencies in the West Indies, at the 

 recent Canadian Exhibitions, have been given in the A/jri- 

 cultural Xrir!<, Vol. IX, pp. 343 and 412. To make the 

 record complete, the following list of awards to British Guiana, 

 taken from the Jonrnnl oftlic Board of Agricidture of British 

 Guiana, for .January 1911, is [)resented here: — 



Gold Medal : Permanent Exhibitions Committee, for 

 general exhibit. 



Gold Medal and Diploma : the Hon. B. Howell Jones, 

 for sugars. 



Silver Medal and Diploma : T. Earle, Esq., for cacao. 



Silver Medal and Diploma : Colonial Chocolate and 

 Confectioner}' Co., for confectionery. 



Diplomas: .Messrs. Sprostons, Limited, for greenheart; 

 the Consolidated Rubber and Balata Estates, Limited, for 

 balata; the Demerara Development Company, for citrate of 

 lime; itessrs. Sandbach Parker i Co., for general exhibits; 

 Messrs. Wieting k llichter. Limited, for rice and sugar; the 

 New Colonial Company, Limited, for sugar; Messrs. Booker 

 Bros., .McConnell &. Co., Limited, for molascuit. 



