Massive loss of sponges

24.10.2021

Women trained by marinecultures.org have been cultivating sponges for almost 10 years. So far, every year there has been a fluctuating percentage of mortality (10-30%) due to pests and diseases. But this September, almost 90%, which amounts to 15,000 sponges in 15 farms, were lost. The loss of income for the women farmers is enormous. They have sponges to sell for another 2-3 months until they run out of stock.

Affected sponge

We have received a wealth of feedback from the worldwide community of sponge researchers  suggesting  that the massive die-off  may be the result of a change of environmental conditions, water pollution, and/or a fungal or bacterial infection. Water and sponge samples have already been collected and sent to the University of Oldenburg in Germany for analysis.

Empty farms

In our nursery farm in deeper water (4-9 m depth), the loss was much lower compared to the productive farms (0.5-4 m depth) closer to the shore. Therefore, we have now evacuated all remaining sponges to deeper water. In addition, the farmers carefully cleaned all the farm material and removed the dead sponges from the seabed.

The first seaweed seeds have arrived

Stock density or monoculture could be an important factor that allows the disease to spread. We have now started to cultivate seaweed (species Spinosum) in the empty farms so that the farmers will have at least some income in the next 8 months. We will soon bring new sponge fragments from the Nursery back to the productive farms and space them out among the seaweed to reduce the sponge density. If they survive, we will gradually restock the farms.

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