Exploring the potential of bath sponge aquaculture in

Exploring the potential of bath sponge aquaculture in Torres Strait Alan Duckworth, Carsten Wolff, John Morris, Samson Lowatta, Simon Naawi, Paul Lowatta and Patterson Mosby Australian Institute of Marine Science Yorke Island Community Council Torres Strait Regional Authority CRC Torres Strait

Colleagues

Surveyed Torres Strait for a good bath sponge • • July 2004 4 locations 25 sites 10, 000 m 2 surveyed

• Coscinoderma bath sponge abundant at Yorke Islands • Sponge up to 50 cm in length • Quality spongin • MOU between AIMS and YICC • 5 sponge divers from Yorke

Developing a good farming method • Farming methods – Mesh panels: spider panels (SP) and monofilament panels (MP) – Threaded line: nylon line (NL) and polypropylene line (PL) – Mesh panels then threaded rope (nursery): SP – NL and SP – PL • Two sites: Masig and Kodall Islands • 216 Coscinoderma explants (sponge pieces) • December 2004, ran for 9 months

Final survival and growth among farming methods

Finding a good farming site and examine importance of farming season

• Sponges transplanted in summer and winter • Farmed at 6 and 12 m, but results combined for analysis

Sponge survival and growth after 6 months

Optimal initial explant size Small 40 cm 3 medium 100 cm 3 large 300 cm 3

Optimal harvest regime • Maximize amount of biomass for explant production, without damaging wild population • 1/3 and 2/3 of biomass removed Dec 04, before harvest Dec 04, after harvest Mar 06

Sponge growth after harvesting

In 2007…. $$$$