Climate Change Sponges, Jamaica: Bath sponges

The study in Jamaica funded by the Disney Worldwide Conservation Fund has two parts. One part that is examining the effects of climate change on coral reef sponges is going very well and will finish in a few days. The second part is to examine the potential of farming bath sponges to provide an alternative and environmentally friendly source of income for local fisherman, similar to work that I did with Torres Strait Islanders in Australia. “Bath sponges” are the cleaned spongin skeletons of certain sponge species. Sponges are easily farmed in mesh panels or on lines and can double in size in 6 months when grown in optimal conditions.

Torres Strait Islander examining his farmed bath sponges

In the Caribbean, bath sponges are typically found in shallow-water, often in sea-grass habitats or attached to the submerged roots of mangroves in protected lagoons and estuaries. In the Discovery Bay Lagoon, sea-grass habitats are common and often large, while mangrove forests are small and scattered. After many days of searching in both habitats, several different sponge species were found but unfortunately no bath sponges.

Sea-grass habitat in Discovery Bay Lagoon

The distribution of many sponges is “patchy”, that is common in some areas but not in others even though all areas look similar to the naked eye. Thinking that bath sponges may be found away from Discovery Bay, I obtained a car for a day and drove 40 km west to the port of Falmouth, which has extensive mangrove forests (and supposedly an odd crocodile or two). Unfortunately the results were the same: no bath sponges.

Fishing boat in the mangrove forests at Falmouth

Next strategy was to go deep and search the surrounding coral reefs. Donning SCUBA tanks, my dive buddy and I searched from the reef crest (0m) down to the reef edge (approx. 35 m or 120 ft). Coral reefs in Jamaica have high sponge diversity, and we recorded over 40 species in various locations up and down the coast, but unfortunately no bath sponges. This is not the result we were hoping for, but science and nature works to its own plan not ours. The good news is that the climate change study is going very well and will soon be finished.

Sea turtle, corals and sponges (but no bath sponges) at 120 ft

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