- Styela clava, one large individual 8-10 cm long cloaked in Didemnum vexillum and several smaller individuals about 3-5 cm long growing along the waterline.
- Didemnum vexillum - Beige areas on the float, growing over Styela and other species. Didemnum was less abundant in 2012 than 2011. This float was one location in the marina where Didemnum was well-established and living together with Diplosoma.
- Diplosoma listerianum - Grey-colored, flat colonies that grow on the float and over Styela. Diplosoma was the the most abundant ascidian in Provincetown in 2012, growing on many surfaces that were dominated by Didemnum last year.
- Botrylloides violaceus - Various small colonies, some tiny, in at least 2 shades of orange. Present everywhere but usually in limited discrete colonies.
- Botryllus schlosseri - A single colony can be seen in the enlargement below.
- Bugula neritina - A single wine-red colony about 2 cm high in the left center, immediately below a light-orange Botrylloides.
Palaemonid shrimp can also be seen in the photo with pairs of flash-induced "white-eye" of their normally black eyes. There are 5 pairs of eyes in the photo (1 on the left side of the large Styela and 4 lined-up on the right).
This year, a few Palaemon elegans, an MIS shrimp with blue-banded legs that is spreading throughout the Gulf of Maine, were seen at MacMillan Wharf.