The Maria Mitchell Aquarium is on the site of the historic ticket office of the former Nantucket Railroad at 28 Washington Street.

[6] Local favorites are also on display and include American eels, the dusky smooth-hound, sea robins, Raja erinacea, Loligo pealei, and Aurelia aurita.

[3] This circular outdoor tank is known to house larger fish such as scup and black sea bass, but also small sharks called dusky smooth-hound, or smooth dogfish.

[3] Because the Gulf Stream passes by the Atlantic Ocean side of the island, tropical fish such as French angelfish, groupers, butterflyfish, damselfish, jacks, and permits are occasionally on exhibit.

[8] Val Hall has observed that invasive algal blooms may have also contributed to the decline in bay scallop populations.

According to the Maria Mitchell Association: Val has successfully defended her doctoral dissertation proposal titled "The Ecological Significance of Fall Spawning in the Nantucket Bay Scallop, Argopecten irradians irradians (Lamarck, 1819)" to the faculty and students at UMass SMAST, and to her graduate committee.

Her accomplishment is a major milestone in the Maria Mitchell Association's/Nantucket Shellfish Association's Bay Scallop Research Project.The aquarium participates in the annual Nantucket Horseshoe Crab Survey.

In early summer, from about May to June, the aquarium observes how many Horseshoe Crabs they can find mating in certain areas of the island.

[9] The Maria Mitchell Aquarium sponsors daily collecting trips during the summer that are open to the public (but require a fee).

[10] The top six most abundant species in Nantucket's waters are as follows: The Maria Mitchell Aquarium has collected about 56,347 fish, crabs, snails, and shrimp since the biodiversity project was launched at the beginning of the century.

[11] The Marine Ecology Field Trips are a series of programs offered by the aquarium that are part of their biodiversity project.

[11] During the daily Marine Ecology Field Trips, a seine net is used to collect animals in the eelgrass beds.

[3] The Maria Mitchell Aquarium is partnered with a local eco-tour company called Shearwater Excursions, and, during the summer months, they lead tours of the harbor and of the ocean which involve viewings of marine mammals such as seals and whales.