Tidal Pool Treasures

New Hampshire’s coastline is filled with life! But do you know what creatures live within the shallow tidal pools along the coast?

First, lets talk about what a tidal pool is. A tidal pool is a rocky tidal zone where small, shallow puddles can be found when the tide has receded. Pools further from the tide are usually shallower and warmer in temperature and the pools nearer the tide are usually deeper and much cooler and both . Tidal pooling involves exploring those “puddles” left behind as the tide goes out to find some really awesome creatures!

Wallis Sands
Talking about crabs and where to find them!
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Everyone loves going tidal pooling!

Here are just a few of the things that we have found at Hampton Beach and Wallis Sands State Beaches!

  1. Green Crabs: These are the most common intertidal crabs that can be found here in New England. They are typically found under rocks or seaweed in the tidal pools. All you have to do is move the rocks and you’ll see the juvenile crabs running in all different directions. Be careful though because Green Crabs are known as the “angry crab” and tend to fight back when they feel threatened. Few people know that the Green crab was actually an invasive species from Europe that was introduced in Rhode Island. They have now become the most common crab along the east coast of the United States.
Green Crab
Green Crab: Notice the green colored legs and brown carapace!

2. Asian Shore Crab: These crabs are an invasive species that were native to the coasts of China, Korea, Russia and Japan before they were introduced in the United States. These little stowaways were transported in the ballasts of cargo ships and were first introduced to the east coast in New Jersey. They breed much faster than the Green Crab and other native species such as the Rock Crab and now span from Maine all the way down to North Carolina! You can identify them by looking for the speckled claws and tan banded legs.

Asian Shore Crab: The spots on the claws and banded legs are the biggest identifiers for this little guy!

3. Hermit Crabs: These small crabs are easy to spot along the coast! The most common species we find during the tidal pooling sessions are the Long-clawed Hermit Crabs. Hermit crabs have a soft abdomen which is why they use their shell as protection. Unlike snails, these shells do not grow with the crabs. As they grow larger they must search for a larger shell to inhabit.

Long-Clawed Hermit Crab inhabiting a Periwinkle Snail Shell

4. Periwinkle Snails: This little snail is the most common animal you will find in tide pools. They use their powerful foot to latch onto rocks so as the waves crash against the rocks they won’t be swept away. Periwinkles create a sticky mucous that hardens and attaches them to the rocks. They are herbivores that eat algae that is attached to intertidal rocks. Their shells come in all shapes, sizes and colors. Try not to step on these adorable snails when you explore the tide pools!


These are the most common creatures you’ll find in a New Hampshire tidal pool. Now for the quick tidal pool rules: Remember, the creatures you find are living animals who belong in their habitat and as tempted as you might be to try and take that Hermit crab home please put them back where you found them! Please be gentle as well because many of these creatures are fragile. Most importantly, HAVE FUN! Try to find as many creatures as you can and enjoy what the pool has to offer! Every now and again you’ll find some rarer creatures so keep an eye out when exploring and who knows what you’ll find! Check out the slideshow below for some more of the interesting creatures we have found. (Some were more difficult to identify than others and if you know what they are, please comment below!).


Discover Power of Parks SCA Interpreters

Discover the Power of Parks is presented by New Hampshire State Parks in collaboration with the Student Conservation Association and made possible by generous financial support from Eversource. The program offers a look into the natural world through hands-on programming. Interpretive programs focus on connecting participants with nature and building appreciation for New Hampshire's unmatched natural heritage. Programs include guided hikes, interpretive tours, and imaginative environmental workshops for children and families. Programs are offered free to guests with paid park admission fee. No pre-registration is required.

One thought to “Tidal Pool Treasures”

  1. Great article, just wanted to let you know that the “periwinkle” shown is actually a dog whelk, they are carnivorous.

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