Estuaries Diorama - Home Sweet Home
Like densely packed apartment buildings, the column-shaped pilings holding up the wharves and piers
support an array of estuarine life. Barnacles, sea lettuce, anemones and many more species encrust the
outside of the posts. Mollusks known as shipworms and tiny crustaceans called gribbles burrow into the
wood pilings to make their homes. This behavior actually helps break down driftwood in an estuary, but it
destroys wharf pilings and causes piers to collapse.
Estuary Organisms
Alewife (Alosa pseudoharengus)- A common migratory and schooling fish, that spends most of their time
at sea. Alewife serve as prey for other fishes in both their freshwater and marine ranges. Sea-run
alewives return to freshwater in late April to early June to spawn and can lay 60,000-100,000 eggs.12
Blueback Herring (Alosa aestivalis)- Found in estuaries and along the coast, blueback herring ascend
rivers to spawn during the spring. Many fish die after spawning and those that do survive return to the
sea. Eggs are deposited over the stream bottom and stick to gravel, stones, logs and other objects.
Juveniles feed on plankton and move to the sea when the are about a month old.2 3
Lined Seahorse (Hippocampus erectus)- While many seahorses keep to tropical waters, the Lined
Seahorse lives in northeastern estuaries. They feed on tiny crustaceans and other zooplankton. Females
lay their eggs in a pouch in a male’s belly. He carries the fertilized eggs and later larvae, eventually giving
birth to a cloud of tiny juveniles.4
Striped Bass (Morone saxatilis)- Due to their ever-changing conditions, estuaries support the life cycles
of many different species, Striped Bass, for example, hatch in freshwater and live in the ocean as adults. 4
Striped bass are feed on fish and invertebrates, especially crabs and squid. 5
Moon Jelly (Aurelia aurita)- Disc-like in shape, the moon jelly can range 5-40 cm in diameter and remains
close to the surface in a horizontal position by pulsating its body. This position allows the moon jelly to
sweep its stinging tentacles over a large area in an effort to capture plankton as a food source. 6
Atlantic Sturgeon (Acipenser oxyrhynchus)- Atlantic Sturgeon belong to an ancient lineage dating back
some 200 million years. They grow slowly, sometimes taking decades to reach sexual maturity and
spawn every three to four years, Historically sold as “Albany beef,” sturgeon were once very common in
the Hudson River.4 Sturgeon are bottom feeders sucking worms, crustaceans mollusks and other
organisms up with their tube shaped mouth.
American Shad (Alosa sapidissima)- Entering estuaries to spawn in early spring, American Shad once
ran from Canada to Florida. By the early 2000s, pollution and dams in rivers where shad spawn had cut
their range roughly in half. Conservationists hope that river restoration will help the species bounce back. 4
They feed on zooplankton (microscopic animals), small insects, shrimp, and sometimes small fish.
American Eel (Anguilla rostrata)- American Eels start out as larvae in the tropical Sargasso Sea. They
ride the Gulf Stream north some 1,000 kilometers (600 miles) or more, entering estuaries and rivers along
the eastern coast of North America as juveniles. These eels reach maturity in five to 20 years and then
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5
6
http://fish.dnr.cornell.edu/nyfish/Clupeidae/alewife.html
Kells, V. and Carpentar, K. (2011). A Field Guide to Coastal Fishes from Maine to Texas. Baltimore, MD: Johns
Hopkins Press.
http://fish.dnr.cornell.edu/nyfish/Clupeidae/blueback.html
http://www.amnh.org/exhibitions/permanent/ocean/02_ecosystems/02f1_estuaries.php
http://www.dec.ny.gov/animals/7018.html
http://marinebio.org/species.asp?id=231
return south to spawn and die.4 When in the estuary eels feed on insects, fish, fish eggs, crabs, worms,
clams and frogs, eels also will eat dead animal matter.7
Atlantic Menhaden, juvenile (Breoortia tyrannus)- Spawning in the ocean, schools of juvenile menhaden
feed on zooplankton that they find in the protected waters of estuaries. Many predators, including
bluefish, striped bass and ospreys, rely on this critical species as prey. 8
Bluefish (Pomatomus saltatrix)- Aggressive young Bluefish growing in an estuary go on occasional
feeding frenzies, attaching large schools of small, silvery menhaden. The water churns and bubbles as
the bluefish tear apart their prey and scour the bottom for the pieces. 4
Horseshoe Crab (Limulus polyphemus)- Often called living fossils, Horseshoe crabs look like their
ancestors of 400 million years ago. They resemble crabs, but they are more closely related to spiders. In
late May and early June in the New York area they gather in droves at the water’s edge to spawn at high
tide.4 They feed on small clams, marine worms, dead fish and algae.
Manhattan Sea Squirt (Mogula manhattensis)- Commonly called sea grapes due their appearance, sea
squirts attach themselves to rocks, piling and other hard surfaces and feed on small plankton and food
particles using their siphons. Sea squirts are tolerant of various environmental conditions including
temperature, salinity and pollution.9
Green Algae (Entermorpha intestinalis)- The primary food for ocean animals is algae. Most ocean algae
consist of tiny, floating single-celled planktonic forms. But some types grow much larger, creating
immense forests.10
Blue Crab (Callinectes sapidus)- The scientific name for Blue Crabs, Callinectes, is Greek for “beautiful
swimmer.” Tiptoeing along the bottom, they eat everything from plants to clams – but fall prey to humans.
The Delaware and Chesapeake bays historically provided a hearty blue crab harvest. 4
Red Algae (Polysiphonia denudata)- Wound around stationary objects, Red Algae thrive below the
surface of estuaries. Unlike green algae, which absorb light near the surface, red algae grow several
meters underwater, absorbing the wavelengths of light that penetrate to those depths. 4
Ascidian (Botryllus schlosseri)- This colonial tunicate (sea squirt) is a native to the waters to the north
east coast of the US and can be found attached to hard surfaces such as pilings and ship bottoms. They
filter feed on plankton and small animal and plant particles in the water. When it matures ascidians form
blob-like shapes that can range in color from gold to purple to brown.8
Barnacle (Balanus improvisus)- Barnacles begin life as free-floating larvae and later develop hard sixsectioned shells, and attach to rocks, wharf pilings and boats. Feathery, barbed legs stick out from the
shells, nabbing plankton floating past. Each barnacle has both male and female sex organs. 4
Orange Striped Sea Anemone (Diadumene lineata)- Attaching themselves to firm substrate such as
stones, shells and pilings, orange striped sea anemones are often found in intertidal pools, bays and
other shallow water areas. They can possess 50 to 100 tentacles used for stinging and capturing prey
items such as plankton. These anemones can reproduce asexually by splitting themselves into two
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9
http://www.fws.gov/northeast/newsroom/facts.html
http://www.dnr.state.md.us/fisheries/fishfacts/menhaden.asp
Gosner, K.L. (1978). A Field Guide to the Atlantic Seashore, The Peterson Field Guide Series. Boston, MA: Houghton
Mifflin Company.
10
http://www.amnh.org/exhibitions/permanent/ocean/02_ecosystems/02c2_algae.php
individuals or sexually by the release and external fertilization of gametes. This species is native to the
North Pacific Ocean but was introduced to the North Atlantic Ocean. 11
Eastern Mud Snail (Ilyanassa obsolete)- Found clinging to substrata in estuaries or along mudflats, the
eastern mud snail feeds on small invertebrates and organic matter found in sediment. This snail breeds
sexually during incoming tides in the spring and fall. The eggs are then deposited on substrates and eel
grass.12
Shipworm (Teredo navalis)- Starting life as a free-swimming larva, shipworms survive by primarily eating
cellulose, plant matter, but also ingest plankton through their siphons. This bivalve earns the common
name shipworm due to the way it burrows into driftwood, pilings and the hulls of wooden ships.13
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http://www2.bishopmuseum.org/HBS/invertguide/species/diadumene_lineata.htm
http://www.issg.org/database/species/ecology.asp?si=1321&fr=1&sts=&lang=EN
http://www.issg.org/database/species/ecology.asp?si=1321&fr=1&sts=&lang=EN