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Alive in Salem Sound

Photo Credit: Jeff Hannigan

Alive in Salem Sound

Photo Credit: Jeff Hannigan

Ever Wondered What Lives in Salem Sound?

Nearly every corner of Salem Sound is home to some interesting creatures. Explore this habitat showcase and learn more about the organisms that live in our coastal waters. (Click on organism photo for a popup description). 

Salt Marsh

Salt marshes are tidal wetlands found in protected embayments and fringing the shoreline. Salt marsh cordgrass and salt marsh hay are the dominant plant species that provide habitat for many species, while also slowly building up the marsh mud, or “peat,” as they decompose. Salt marshes provide critical ecosystem benefits, such as acting as a nursery for many juvenile fish species and a nesting stopover for migratory birds. They also provide valuable human services, as they absorb storm surge to reduce coastal flooding, filter pollutants and excess nutrients, and store carbon to curb the effects of climate change. 

Blue Heron
Mummichogs
Horseshoe Crab
Fidler Crab
Pickleweed (Salicornia Plant)

Rocky Intertidal

The North Shore’s rocky coast provides ample nooks and crannies for a host of fascinating organisms, such as periwinkles, hermit crabs, urchins, and sea anemones. Tidepools collect seawater as the water recedes at low tide, which is an ideal time to go exploring for organisms that are submerged at high tide. Species that live in the rocky intertidal must deal with the harsh conditions that living in a constantly changing environment creates. They are highly adapted to survive in the extreme temperatures, changing oxygen levels, and crashing waves of the rocky intertidal zone.

Juvenile Sea Star
Blue mussels and barnacles
Rock Gunnels
European Green Crab

Beaches

Beaches are not only a spot to relax and have fun in the summer; they also buffer the coastline from storms and are home to many animals that live burrowed in the sediment, such as clams, crustaceans, and worms. Beaches are a place where the nutrients and minerals of old rocks, shells, and seaweeds are broken down by the sun and waves and recycled for use by other sea creatures. 

Moon Snail
Herring Gull
Clam on the beach
Wrack Line on the beach
American Silverside school of fish

Sea Floor

Below the waters of Salem Sound, out of sight to us on land, is the sea floor. The Sound’s sea floor varies from mud, sand, to rock with some areas lush with eelgrass or kelp. Each substrate provides a unique home for a variety of “benthic,” or bottom-dwelling, marine organisms. The Sound also varies in depth, from very shallow to 50 feet. The sea floor often reflects conditions at the surface. For instance, on calm days the sea floor might be very peaceful, but on rough days the slosh from the waves can reach the bottom. 

Scallop on the Sea Floor
Flounder at the bottom of the sea
Spider Crab on the sea floor
American Lobster
Kelp

Open Ocean

Many species that swim or float live in the open water, the “pelagic” zone, of the Sound. Schools of fishes, diving birds, and curious seals can be seen at the surface, while others, such as tiny, microscopic plankton or transparent jellyfish, are a bit harder to see!  As you can imagine, it’s difficult to hide without the shelter that other habitats provide, so organisms that live in the open ocean must be highly adaptive.  

Striped bass underwater in the Gulf of Maine
Seals bathing in the sun in Salem Sound
Longfin Squid underwater
Pogies swimming underwater in the open ocean
Osprey in flight over the open ocean

Now that you’ve discovered what lives in Salem Sound, dive deeper and take action.

Horseshoe Crab Survey
Resources
Threatened Habitats
Habitat Initiatives

Great egrets, snowy egrets, and blue herons are often found on the marsh standing motionless at the water’s edge as they hunt for small fish and invertebrates. These wading birds have excellent vision and can strike a small fish with precision. Other birds you may see on a visit to the salt marsh include red-winged blackbirds, tree swallows, and black-crowned night herons.

Mummichogs are a hardy estuary fish that can tolerate highly variable temperature, salinity, and oxygen levels. They play an important role in mosquito control, as they feed on insect larvae in the upper marsh. Mummichogs utilize the spring tides around the full and new moons to access the high marsh grass to lay their eggs, which keeps their young protected from predators. Other fishes that frequent the salt marsh include the stickleback and the American eel. 

Horseshoe crabs are often called “living fossils,” as they’ve remained relatively unchanged for 445 million years, before dinosaurs roamed the Earth! Though they’re somewhat elusive, you may see light brown “molts” washed up on the salt marsh or beach, as they must shed their exoskeleton to grow. Male horseshoe crabs have a set of claws that look like boxing gloves, while females do not.  

Fiddler Crabs are a relatively new resident of Salem Sound’s marshes, as their range has extended north due to the warming ocean waters. Male fiddler crabs have one large front claw, which is used to attract mates and defend their territory. In fact, they’re named “fiddler” because the oversized claw makes the crab appear to be playing a fiddle! Fiddler crabs dig burrows at the marsh’s edge and live in large colonies.  

Pickleweed (Salicornia) is a type of salt-tolerant plant that thrives in disturbed areas in the high marsh, such as near salt pannes or areas smothered by wrack. These succulents have a unique adaptation to allow them to survive in this salty environment; they store excess salt in the tips of their stems and then excrete it to rid their fleshy bodies of salt. Pickleweed can be eaten in salads or steamed for a salty snack!

Knotted wrack/rockweed are dominant species of seaweed in the rocky intertidal zone are knotted wrack (Ascophyllum) and rockweed (Fucus). These species of algae have strong holdfasts that allow them to anchor themselves to the surface of rocks and air bladders to keep them buoyant when the tide comes in. When submerged, seaweed creates a lush habitat for many marine organisms.  

Juvenile sea stars are frequently seen in tidepools and the rocky intertidal. They move slowly along the surface of rocks with their numerous tube feet looking for a meal, such as a tasty mussel. They use their strong arms to pry open the hinged mussel shell, invert their stomach into the mussel, and slowly dissolve the tender meat. Sea stars have light-sensing eyes at the tips of their arms, while the distinct orange dot on their back, called a “madreporite,” is used to absorb water. Sea stars can regenerate their body parts. If you ever see a sea star with a tiny nub of an arm, it is in the process of regrowing!

Blue mussels and barnacles can be found attached to rocks in the intertidal zone. They begin their lives as floating planktonic larvae before settling onto a hard surface. Blue mussels use strong fibrous strands, called “byssal treads,” to attach to rocks and each other, while barnacles glue themselves to rocks. At low tide, both species remain tightly closed to avoid drying out. While submerged at high tide, mussels use their gills to filter seawater and eat tiny plankton. Barnacles use modified feather-like legs, called “cirri”, to draw plankton and detritus into their shells.  

 

Rock gunnels, as their name suggests, spend much of their time sheltered among the rocks of the intertidal zone and can even breathe air at low tide. Although they look eel-like, they are, in fact, a fish! During the cold, winter months, rock gunnels retreat below the low-tide line to prevent exposure to the freezing temperatures.  

European green crabs were introduced to New England in the late 1800s and have remained the dominant crab species ever since. Contrary to their name, green crabs’ color can vary, but they can always be identified by the five spines on either side of their eyes. They’ve caused disruptions to the natural ecosystem since their introduction by feeding on native animals, outcompeting native crabs for food, and destroying eelgrass beds. With changing environmental conditions, the Sound’s most recent non-native crab resident is the Asian shore crab, who can also be found scuttering away from overturned rocks in the intertidal zone. 

Moon snail: Moon snail shells can often be found washed up on the beach. These gastropods are voracious predators that use a chainsaw-like feeding organ called a “radula” to drill perfect holes into the shells of clams and other snails. They form a collar of sand and mucous to lay their eggs, which you may also find on the beach at low tide.  

Gulls, such as the Great Black-Backed Gull and the Herring Gull, can often be found scavenging the beaches along Salem Sound. You may also notice gulls dropping clams or crabs onto parking lots or rocks from the air. They do this to crack open their food to expose the meat inside. While adult male and female gulls look similar, juvenile gulls between the ages of 1-4 years old will have light brown plumage. Other birds that might frequent the beach include American oystercatchers, sandpipers, and plovers. 

Clams come in different shapes and sizes: long, thin-shelled softshell clams; large, triangular surf clams; and thick-shelled quahogs. They live in different areas of the mudflat off the beach. Their shells that are commonly washed up on the beach are a beachcomber’s treasure. 

Wrack line is a collection of seaweed, reeds, and other debris that has been deposited on the beach at high tide. This collection of decomposing material provides habitat for amphipods, worms, and small crustaceans that are an important food source for shore birds. The wrack prevents wind-blown erosion of the sand. 

American silverside may be seen from the beach swimming at the water’s edge in dense, glimmering schools. Silversides eat plankton and small crustaceans, while its predators are larger fishes, wading birds, and gulls, making silversides an important link in the marine food chain. You may also see sand lances, another shallow-water fish, at the beach, burrowed in the sand with just its head poking out.  

Scallops are a type of shellfish, or “bivalve,” that live on the sea floor, on the sandy bottom or among eelgrass beds. Scallops filter microscopic food from the water and even have dozens of image-forming eyes along the inner edge of their shell. Unlike their relatively sedentary friends, the oysters and clams, scallops can swim by clapping their shells open and closed using a jet-like propulsion. 

Flounder are flat fishes that live on the sea floor. Their speckled coloration makes them highly camouflaged with the sand or gravel. They can even change color to match their surroundings. While summer flounder are “left-eyed,” meaning both of their eyes are on the left side of their body, winter flounder are “right-eyed!” Flounder, also known as fluke or sole, are a prized fish for anglers.

Spider crabs have a spikey tan “carapace,” or shell. They are a type of decorator crab because they adorn their carapaces with algae, debris, or small invertebrates to offer camouflage from predators. You may find spider crabs partially buried in the sediment. Rock crabs and Jonah crabs are common native crab species that live on the Sound’s sea floor.  

American lobsters are a nocturnal species that hide among rocks during the day and hunt for crabs and other invertebrates at night. Lobsters capture and feed on prey using their two big claws. The thick “crusher” claw is used for breaking shells, while the thinner but sharper “pincer” claw is used to tear or cut meat. Females carry bright orange eggs under their tail until they hatch. If a lobsterman catches a female with eggs, they cut a “V” notch on their tail, alerting other fishermen that this lobster is fertile. 

Kelp is a type of algae, or seaweed, that grows attached to rocks on the sea floor. Kelp do not have true stems, leaves, or roots typical of terrestrial plants but instead absorb the nutrients they need from the surrounding water. Certain species of local kelp can grow more than an inch per day! Kelp “forests” provide a canopy habitat for many marine organisms, such as fishes, crustaceans, and urchins. 

Striped bass, as the name suggests, have distinct horizontal stripes and frequent the shallow waters of the Sound as they feed on small fish, squid, and crustaceans. A transient species, most striped bass winter in the Chesapeake Bay area and begin their northward migration in April. “Stripers,” as they’re called by anglers, are a highly prized fish and put up a good fight when hooked. Remember to purchase your recreational fishing permit and release fish under 28” and above 35” to ensure there are plenty of fish in the sea.

Seals were hunted almost to extinction by the 1900s, but due to the Marine Mammal Protection Act, have made a strong comeback in New England. Harbor seals, grey seals, and hooded seals can be seen in Salem Sound hunting for fishes, crustaceans, and squid. If you see a seal that may be injured, you can call the Marine Animal Hotline: 866-755-6622. 

Longfin squid are the most common squid species in Massachusetts, making up a portion of the commercial fishing industry. Squid are a type of cephalopod, the group of animals that includes octopus and cuttlefish, and can change the color of their skin using specialized cells called “chromatophores.” Keep an eye out for large schools of squid at night as they make their way to the shallow waters to feed. 

Menhaden, or “pogies” as they’re known to anglers, are a type of fish that forms massive dense schools in the shallow waters of Salem Sound. They are an important link in the marine food chain, as they filter feed plankton and are subsequently eaten by predators such as other fishes, birds, and mammals. 

Osprey is a bird of prey that frequents the Sound. You may see osprey soaring over the water with a fish in its talons or perched on a channel marker. Osprey is a migratory bird that breeds in the Sound during the summer season and winters in Central America. Cormorants are another common fish-eating bird that frequents the Sound. You may see one diving underwater for fish or drying its wings on a rock.