is severely limited (21). In the U.S.A. the hooking method may tear the sponge but it leaves the centre piece attached to the substrate, from which the sponge can regenerate. The disadvantage of this method is that only shallow beds can be worked and therefore tend to be fished more often. In the Florida Keys, diving is not allowed and sponges are taken with a rope loop, the small poorly formed specimens being left as breeding stock. Dredges should be banned in those countries which still permit this fishing method (5). Close seasons would be difficult to enforce, but the most effective type would be to close sponge beds in rotation for one or two years. Unfortunately there are very few data available on the rate of regeneration of sponge beds, or of regeneration of sponges from cut bases on which to base management plans. Sponges are well suited to cultivation since small cut pieces will regenerate and in the early part of this century considerable research was carried out (1,2,12,13). The first attempt was in Florida in 1879, and a sponge farm has been in existence on Andros Island in the Bahamas for many years. Belize is reported to have had a successful sponge culturing programme, and in 1939 the Japanese carried out sponge culture experiments in the Marshall and Caroline Is. which, although not entirely successful, provided useful information (9). Attempts made at sponge culture in Yugoslavia earlier this century were not successful. In the early 1960s, experiments in Greece showed that Spongia officinalis regenerated well if cut pieces were attached to plastic cords (M). Experimentation has shown that sponges cut and tied to an artificial substrate such as cement discs or wire will grow into specimens of commercial size in 5-7 years, and that the total growth in volume of cultured sponges can greatly exceed the original over the same period. Choice of site was found to be important and shallow water where bad weather could easily destroy the beds should be avoided. The planting operation is relatively simple, and could be concentrated in a small area to save time in harvesting. Harvesting need only be carried out if an order has to be filled, and if the sponges are removed carefully, the remaining base could act as a fresh cutting. To a certain extent the quality, size and shape of the sponges can be controlled. The heavy local concentration will lead to the production of large quantities of larvae which will disperse to the surrounding environment if this is suitable. There are a few disadvantages, such as the susceptibility of such high concentrations of sponges to disease, and the fact that there are no returns until the fourth year. Furthermore the beds will not be fully productive until the seventh, although work in the Bahamas suggested that cuttings could reach a commercial size in two years (38). Since the current market for sponges appears to be larger than can be supplied by present production efforts, it is suggested that further investigation into sponge culture is warranted. Tunisia, for example, is interested in culturing sponges but lacks the necessary expertise to set up a programme (6). If managed effectively, the sponge industry could probably provide a significant income in a number of countries. Species would be unlikely to become threatened as small specimens are not taken, deep populations are not exploited intensively and the species involved have wide distributions. In Tunisia usable species are common far beyond the established fishing grounds (30) and there may be a number of countries which have sponges of commercial value and as yet do not exploit them. For example, the Philippines produce a significant quantity now, most of which are exported to Japan (12). For species which have no commercial value, further research on taxonomy, distribution, ecology and effects of factors such as pollution and sedimentation is required. Areas with diverse sponge faunas or endemic species should be protected, as is Runaway Bay cave in Jamaica (20). Attention should be paid to the deep shelf (200-300 m) faunas of the southern oceans which are at risk from trawling activities (51). Protection of the endemic freshwater 'thalassoid' sponges of Lakes Malawi, Tanganyika, Baikal, Ochrid, Posso and Tiberias may also be 16