I’ve always held a special place in my heart for organisms that live in the intertidal zone. I’m not sure why; perhaps it’s the impressive toughness that allows something to survive in a habitat that might only be a few feet across and in which the environmental conditions fluctuate wildly every few hours.
Unfortunately, the sandy shorelines you get on the east coast are not particularly good areas to observe intertidal organisms. They’re present, in huge numbers, but most of them are burrowed into the sand where you can easily see them. The rocky shorelines on the west coast are much better from an observational standpoint, since the critters have to cling to the rocks. The Maine coast is also a rocky coast, and is the best place in the eastern US to observe these organisms.
On our vacation we spent several hours at various locations during low tide, trying to spot as many organisms as we could. There are several different types of algae that grow at different levels in the intertidal and shallow subtidal zones. These zones are visible even from a distance: