Mangrove plants are not commonly used directly as a food source, probably due to the high levels of tannins and other distasteful chemicals. Because mangroves are flowering plants, the flowers are a likely source for honey; native bees are found in the mangroves during the various flowering seasons, and these are exploited now by commercial apiarists with their exotic bees. A. marina is probably the only mangrove where bees build hives, but there are other trees found in coastal areas, such as Peltophorum pterocarpum, where hives are built. http://members.ozemail.com.au/~mmichie/mangr5.htm
Expertise in using mangroves for medicinal purposes has been acquired over a long period of usage. The techniques which are used vary from plant to plant, and often between groups of Aborigines. In some cases the plant, or its sap, is used directly. In other cases the leaves may be heated, or the plant material burned to an ash for application. Western science is beginning to isolate the active ingredients for some of these treatments.
Because of the intertidal nature of the mangrove environment, there is an associated movement of fish and other animal species into and out of the mangroves, as well as their presence there as larval forms. There is also seasonal movement of some animals, particularly birds, to and from the mangroves .Crustaceans and molluscs are the main two invertebrate groups which are exploited by Aborigines as a food source. Most of the hunting in the mangroves for these animals is done by women, often with children in tow. The mud crab, Scylla seratta, is an important food source and is eagerly hunted, using sticks to extract the crab from its hole. The crab is quickly disarmed by removing the main claws, and is usually cooked straight after hunting finishes. There are other crabs in the mangroves but most of these are not hunted as they are comparatively small.
Crab hole in the trunk of the mangrove
The oyster Saccostrea scyphophilla is one species of bivalve which is often found attached to the prop roots of R. stylosa or to rocks at the same level. These are usually collected as bundles of shells and cooked in the coals. There are a number of other bivalves which are found in the mangroves or the mudflats immediately in front of them, as infaunal browsers. These are extracted from the mud and cooked in the coals of a fire. They are usually arranged in an orderly pattern to allow them to open without wasting the cooking juices.
An important bivalve which is found in dead and decaying mangrove wood is called “mangrove worm”, Teredo spp. The action of the shells moving together excavates a hole through the wood, and the wood shavings accumulate in the stomach which becomes a distended, worm-like bag. The mangrove worm is chopped from the wood using an axe and is eaten raw. http://members.ozemail.com.au/~mmichie/mangr5.htm
This is adapted from Michie, M. (1993). The use of mangroves by Aborigines in northern Australia. Channel Island Field Study Centre Occasional Paper, No. 5.