Science Centres: Fisheries

With increased demand for natural bath sponges, sponge-farming is the only sustainable alternative to wild harvests, and a potentially valuable source of income for small island communities.

The farming method is based on cropping sections (‘clones’) of wild bath sponges, leaving behind a living sponge. The clones are grown to marketable size on artificial structures. Thus, the process is sustainable and repeatable, maintaining wild populations of sponges.

Last November, NIWA marine biologist Dr Michelle Kelly helped villagers of Kiuva, Fiji, establish a demonstration bath sponge farm, funded by the Pacific Development & Conservation Trust.

Good stocks of the sponge Coscinoderma mathewsi were found on the local reef and the larger specimens were cropped to provide clones.

In all, 350 clones were relocated to the artificial structures on the experimental farm where growth rates will be assessed over the next twelve months.

"It’s hoped that the farm will provide a sustainable, environmentally friendly income for the villagers and serve as a simple model for small-scale bath sponge farming elsewhere in Fiji and the Pacific," says Dr Kelly.

Further surveys are underway in the outer island chain of Fiji and Solomon Islands to look for additional bath sponge species to culture.