Overhauling fishing nets in a village in the Trobriand Islands, a coral archipelago about one hundred miles east of the New Guinea mainland.

HOW TO TAN Nets, Sail*. and Lines

The life of fishing nets, sails and lines can be greatly pro­ preferably in fresh water, in order to remove the yarn finishing (or the seizing longed by tanning. This article expains a simple way of in the case of sails) from new materials, carrying out this process, using a tanning solution made from or the dirt from old. the of the , found on most islands of the The items to be tanned must be clean and dry when they are put in the tan­ South Pacific. ning solution, where they should be left for twelve hours before being taken out By H. VAN PEL* and dried. They must then be dipped again in the solution for twelve hours. A/TOST of the fishing nets used in the from Europe. All the time, however, A net that is used every day for a few South Pacific islands are made of his nets were hanging from a mangrove hours should be tanned every month. vegetable fibres, either produced from tree {Rhizophora mucronata in this If it is in the water six hours or more local plants or bought in stores, either case) whose bark could provide good a day, then tan it every fortnight. in the form of ready-made cotton netting tanning material. Indeed, I satisfactor­ The tanning solution can be used or of cotton twine which is knitted into ily tanned a piece of netting with the several times, more water and a net. bark of that very tree. being added every time, but it is best to For the most part these nets are small, The content of the bark varies prepare only enough for one's immediate although some fair-sized ones are made. with the different species of mangrove, needs. A new net tanned for the first Generally they are not tanned, and quite and also with the locality in which they time turns brown. After being tanned often they are in bad condition. This grow. The best grades of tanbark used several times it becomes dark brown. is of course understandable in places in Indonesia for tanning nets and lines If the tannin content of the bark used where no materials are available for pre­ contain 28.7% and 29% tannin, coming is low, the proportion of bark to water serving the yarn, but tanbark from man­ respectively from Rhizophora mucronata used in preparing the tanning solution grove is available in most of the and Ceriops condelleana. It seems that must be increased. A tanning solution islands, at least in the western half of the the first species has a lower tannin con­ can be prepared merely by soaking the Pacific. In the tanning process the fibres tent in New Caledonia. bark in cold water for fourteen days. are impregnated with tannin, which pre­ The best bark is taken from branches However, in my experience, boiling the vents bacteria from damaging them. 3-6" in diameter. After drying in the bark has proved the best method. Tanning material being so readily sun, it can be kept for a long period. The nets should always be washed available, I suppose that lack of know­ thoroughly, preferably in clear fresh ledge is responsible for the fact that The Tanning Process water, and dried in the shade before most nets are allowed to deteriorate. The The tanning process itself is simple. storage. Fish slime and seaweeds cling­ need for an article on the subject was First of all, the tanbark is chopped into ing to the nets after use are the chief impressed upon me when a fisherman, small pieces (about 3") and put to soak enemies of all natural fibres. These using unprocessed cotton nets, asked me for 24 hours in fresh water, in the pro­ should be removed by washing and the how he could make them last longer, as portion of one volume of bark to three nets stored hanging loosely in a well- he had found that they became rotten volumes of water. ventilated shed. Such precautions can after five months' use. When I told him The second step consists of boiling the help fishermen to derive the full benefit to tan them, he said he had heard of bark in the water for one and a half from the tanning process described the process and would like to order cutch hours, after which the tanning solution is above. ready. Meanwhile the net, sail or lines With proper care, tanning can triple * Fisheries Officer, South Pacific Commission. to be tanned must be thoroughly rinsed, the life of nets and lines.

SPC QUARTERLY BULLETIN, JULY, 1956 Page 33