Considering the difficult environmental challenges of survival in the intertidal zone, there is an amazing abundance and diversity of animals living there. There are vast numbers of the common periwinkle Littorina littoria (above), which graze on the algae.
Here’s another herbivore, the Baltic isopod Idotea baltica. Not the greatest of photos, but these things are fast!
Sessile filter feeders are also abundant (they also often preserve well as fossils). We didn’t see huge numbers of live blue mussels (Mytilus edulis), but their empty shells were common. Here’s an isolated live example:
There were, however, vast numbers of barnacles of several species. There are at least two shown here. I believe the small barnacles are Balanus improvisus, while the large ones might be Semibalanus balanoides (barnacles tend to grow tall when they’re overcrowded):
Barnacles are filter-feeding crustaceans, which use their appendages into the water to capture food. They close up at low tide to avoid drying out (or being eaten), so usually you don’t see anything except the closed shell. That’s why I was pretty excited about this video that Brett was able to shoot of feeding barnacles in a tidal pool: