The Long Island Sound, including New Haven Harbor, is an estuary — a place where fresh and salt water meet. Estuaries provide many animals with a protected home to lay eggs and serve as a nursery for the young, a place to find food, and a hideout from predators. Here at Lighthouse Point Park you have a great opportunity to see many different habitats: forest, tidal marsh, rocky coast, sandy beach and, of course, the underwater habitat of the Sound. Each is home to a fascinating array of living creatures.
The Intertidal Zone
The intertidal zone is a habitat halfway between sea and land. It is covered with water at high tide and is dry at low tide. Animals and plants that live here are specially adapted to tolerate both salt water and dry air. Some of the earliest scientific research on the intertidal zone was done by Addison E, Verrill, Yale University's first professor of zoology and a curator at eh Peabody Museum of Natural History, who studied the New England coast in the late 19th century.
Look in the tidal pools for clumps of Irish moss, a dark red alga. It contains carrageenan, a substance used for thickening products such as toothpaste, ice cream, salad dressing, pudding and paint! You could find rocked, also known as bladder wrack, a brown alga that clings to rocks in the tide pools with tough, root-like
structures called holdfasts. Rockweed's fronds have balloon-like air bladders, a remarkable adaptation that keeps the plant floating during high tide, when it can get the most sunlight for photosynthesis. You might even find sea lettuce, a green alga that is a nutritious food for humans when harvested from extremely clean waters (please don't eat it from these tidal pools).
The tidal pools also teem with animal life such as hermit crabs, tiny shrimp, and snails called periwinkles. Other snails, Atlantic dogwinkles, prey on barnacles and mussels by using their sharp tongue, called a radula, to bore through the shell. Then they inject enzymes-like the enzymes in your stomach-that digest the barnacle or mussel before sucking it out through the hole in its shell.
A wealth of other animals and plants make their homes in Long Island Sound waters, including bottom-dwellers, such as lobsters, clams, scallops, and starfish. Kelp, a large brown alga, grows in underwater forests. Depending on the time of year, fish species such as northern and striped sea robins, tautog, bluefish, scup, menhaden, butterfish, and striped bass can be found here. These are only a few of the many plants and animals found in the Sound!
You may have eaten winter flounder, a tasty local fish. Did you know that a winter flounder starts off looking like a regular fish, but the
left eye gradually moves to the right side of its head?
Flounders spend their time on the bottom, where their mottled brown and white coloring and their flat bodies help them blend into the sand and rocks.
Horseshoe crabs look like something from the age of dinosaurs-which they are! Animals very much like them were around even before dinosaurs roamed the earth and they have changed very little in the past 350 million years.
Horseshoe crabs were among the species to survive the mass extinction that wiped out the dinosaurs. They aren't really crabs, but are actually more closely related to spiders. In late spring you can find horseshoe crabs on the beach, where they come to breed.
Where Morris Creek empties into Long Island Sound you can see a tidal marsh. During high tides, salt water from the Sound flows into the marsh and mixes with fresh water from the creek. Plants and animals that live here are adapted to tolerate salty water. Marshes provide shelter for mussels, crabs, fish, snails, and shrimp, and are also foraging areas for birds, foxes, and muskrats. The marshes act as a buffer for the coastline during sever storms, serve as a nursery for many small fish and other organism, and filter contaminants from the water. Tall studs of an invasive form of the common reed Phrogmites australis border Morris Creek. This plant pushes out native marsh grasses and provides inferior nutrition and shelter for animals.
The oak-hickory forest in the northeast corner of the park harbors many birds, especially during the fall migration, when it provides a critical rest stop for birds flying thousands of miles. Look carefully on the ground and you might find acorns and hickory nuts, food for squirrels and chipmunks.
If you have ever walked along the rocky shoreline near the lighthouse, you might wonder about all the broken shells there. The gulls that swoop in to flight over a discarded crust of bread are actually quiet resourceful foragers in the absence of humans. One clever adaptation is how they open oysters, clams, other hard-shelled mollusks. The gulls pick up mollusk with their beaks, fly over a rocky outcrop, and drop them to crack them open on the rocks!
Stand on a sandy beach at the water's edge and you might also see least terns, common terse, or roseate terns fishing in the shallow right along the shore. Their fishing ability is stunning to watch s they hover and search, tuck into a dive, enter the water with a quick splash, and fly off with a small fish in their beaks. Another common bird, the double-crested cormorant, takes a radically different approach to fishing. It actually spends most of it's hunting time swimming underwater in active pursuit of fish, surfacing briefly of air or for longer periods to occasionally dry out its feathers,
Tidal pools at Lighthouse Point Park
Rockweed's air bladder helps it stay afloat at high tide
Horseshoe crabs have changed little since the time of the dinosaur
Winter flounder blend in with the seafloor
Dogwinkles use a sharp tongue to drill through barnacle and mussel shells.
Scallops have primitive eyes that let them sense light and motion
Herring gulls crack open clams on the rocks
An invasive form of the common reed Phrogmites australis crowds out native plants.