Blog | What’s in the Tank?


Visit Discovery Wharf to Find Out What’s in the Tank? 

Since Maine Center for Coastal Fisheries’ Discovery Wharf has opened for the summer, more than 1,000 guests have walked through the doors to visit our touch tank and explore the many creatures living in the Gulf of Maine waters. According to the Maine Department of Marine Resources, an estimated 73 species of fish; 26 species of whales, porpoises, seals; and 1,600 different bottom-dwelling organisms reside in the Gulf of Maine. Discovery Wharf is a great place to interact with many of these species, including blue mussels, clams, crabs, lobster, periwinkles, scallops, sea cucumbers, sea urchins, and more!

We’ve highlighted just a few creatures here. Check it out, and be sure to visit us to learn more!



When a clam’s shells are closed, you can see two leathery tubes, or siphons, protruding from one side. Clams usually live in mudflats between six and ten inches and feed by extending their siphons up through the mud during high tide. The siphons are used to filter water for food and are important for ecosystem health as the process cleans the water in intertidal regions.


Take Home Your Own!

After securing a license, clams can be harvested using a clam hoe and a roller, or simply by hand; the hoe is used to dig through the sand to find the clams and the roller is used to store the clams and rinse off the mud.



Maine and the Discovery Wharf touch tank are home to multiple species of crabs, including Jonah and rock crab. Crabs are caught as valuable bycatch in the lobster fishery and must be 4.75” wide, while the taking of any females is prohibited. Jonah crabs are reddish in color, with large, black-tipped claws, and are found offshore. The smaller rock crab lives closer to shore, in bays and rivers.


Fun Fact! 

Crabs communicate using sounds they make with their claws and pinchers.



Maine is home to over 5,000 commercial lobster license holders. A legal lobster in the State of Maine must have a body shell length, or carapace, that measures between just 3 ¼ inches and 5 inches long. However, as a species, the lobster is both the longest and heaviest known crustacean, and has been known to reach sizes of up to 44 pounds! Known for their red coloring, the touch tank is sometimes home to rare blue and white colored lobsters.


Did you know?

In 2016, Maine fishermen landed over 130 million pounds of lobster worth over a half billion dollars!



In the 1800s, scallops were mostly used as bait for the cod fishery, but today, Maine fishermen land over a half-million pounds of scallop meats each year, valued at nearly $7 million. Scallops smaller than 4 inches cannot be harvested. A fun fact is that scallops have over 100 eyes which can detect changes in light and motion – useful for searching for habitat or escaping predation.


Maine Center for Coastal Fisheries’ work with scallops

Maine Center for Coastal Fisheries was instrumental in setting up co-management for the scallop fishery and implementing a new rotational style management for scallops in Eastern Maine.

Sea Urchins


The urchin has a round shell, known as the test, and is flattened at the poles. One pole contains a mouth where food goes in and the other contains the anus where waste comes out. The mouth is a complicated arrangement of muscles and teeth called “Aristotle’s lantern” which allows the urchin to bite, chew, grasp, and grind. Around the teeth is a relatively soft peristomial membrane and is the weak link in the urchin’s defense. Predators often attempt to roll the urchin over and attack it through that soft tissue.


Have you eaten sea urchin?

Green sea urchins are covered with short, dense spines and are filled with five sections of creamy, bright yellow-orange reproductive structures—this is the edible part!

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13 Atlantic Avenue, Stonington, Maine

Open: Sunday – Friday

Hours: 10 a.m. – 4 p.m.