Ron Peters Asks…
The waters around the Florida Keys were once rich with sponge beds which contributed to the economy of the Keys through the sponging industry (circa late 19th century). The sponging industry collapsed due to over harvesting and a Sponge fungus which killed off much of the sponge population. Although sponges have made some sort of recovery, they do not appear to be quite as healthy (personal observation) with bleaching, spots, etc.
In your observations do you see a lot of “health issues” with the sponge population? Do you feel that there could be a resurgence in the sponge fungus that killed off the sponge beds in the late 19th & early 20th century?
What effect do the ocean warming and acidification have on sponge populations in the Keys?
Only a few species of sponges are harvested commercially and are suitable for the bath and other purposes. These species are found primarily in shallow seagrass beds, not on the reef. Commercial sponges in Florida were decimated in the early 20th century by disease, which was probably imported from elsewhere. We have observed diseases on several reef sponge species, but they appear to be sporadic, and have not resulted in mass mortalities. These diseases are probably unrelated to the one that affected commercial sponges. We don’t know if these diseases are new to Florida’s reefs, or if their incidence is increasing. Sponge populations, however, do appear to be increasing over time, so the impacts of disease seem to be limited up to now.
Our monitoring program is designed to answer the question about global climate change and ocean acidification, but will require years of study. Unlike corals, sponges do not have calcified skeletons, and should be less impacted by ocean acidification. Based on this, we would predict that sponge populations would continue to increase as corals decline.