The Gulf of Trieste as a potential site for Spongia officinalis sponge farms: An opportunity for sustainable cultivation and recovery?

Over time, sponges have become increasingly demanded on the market not only for their traditional cosmetic use, but also for emerging applications in the biomedical, pharmaceutical, industrial sectors and as effective bioremediators. This steadily growing exploitation, driven by continuous market demand, has resulted in a significant decline in natural sponge stocks worldwide. In this context, sponge aquaculture represents a sustainable and promising alternative, as it can reduce harvesting pressure on wild populations while simultaneously acting as a source of propagules for surrounding areas. The present study aimed to assess the Suitability of the Gulf of Trieste as site for the establishment of sponge farms for the cultivation of Spongia (Spongia) officinalis. The cultivated individuals exhibited a high growth rate during the study period (up to 250% over three years). However, a relatively high mortality rate (60–90%) was observed during the initial phase of the experiment, likely associated with handling stress and manipulation prior to fixation on the farming structures. After this early phase, mortality decreased markedly, and survival rates stabilized. In conclusion, our findings suggest that the Gulf of Trieste represents a promising site for the cultivation of S. officinalis, thanks to the observed high growth potential. Nevertheless, the success of sponge farming in this area strongly depends on careful collection, handling, and fixation procedures, emphasizing the need to minimize stress during the early stages of cultivation.