This sponge has suddenly shown up in Dyes Inlet (near Bremerton, WA). Tideland owners noticed it in small numbers last year, but this year it is really proliferating. It seems to prefer attaching to hard structures, including the restored Olympia oysters in the bay. When we broke up a few pieces, we noticed many dead and some living Olys encased in the sponge.
We need your help identifying this sponge!
Since we don’t know what it is, we aren’t sure if it is native or non-native. But it is behaving like a pest around this native oyster restoration site, and the tideland owners would like to know if there is some way to control or eradicate it. Given that sponges can regenerate, I would think that manually removing them could lead to more sponges rather than less.
Thanks in advance for any help you can provide.
I sent this to our local sponge experts, and they say it looks like Hymeniacidon sinapium. They had examined specimens of it found in Ladysmith, B.C.
Thanks so much Greg! That was our working hypothesis as one of our former students had found a reference by Fuller and Hughey (2013, Aquatic Invasions) about an invasion in Elkhorn Slough. If you don’t mind, could you connect me with the experts since we have a few people here who are interested in pursuing further? Thanks again! This makes the work of maintaining a blog totally worth it.