Long Island Sound is an estuary of the Atlantic Ocean and various rivers in the United States that lies between the coast of Connecticut to the north and Long Island, New York to the south. The mouth of the Connecticut River at Old Saybrook, Connecticut empties into the sound. On the extreme western end, the sound is bounded on the north side by Westchester County, New York and the Bronx, and connects to the East River. On its eastern end it opens to Block Island Sound. The sound serves as a geographic border between New England and the Mid-Atlantic states.
Several major cities are situated along Long Island Sound and more than 8 million people live within its watershed. Major Connecticut cities on the Sound include Bridgeport, New London, Stamford, Norwalk, and New Haven. New York cities on the Sound include Port Jefferson, New Rochelle and New York City (the boroughs of Queens and the Bronx).
Mansions and wealthy neighborhoods characterize a good portion of the coast of the sound from Whitestone, Queens out to Setauket and Port Jefferson on Long Island; and from Pelham Manor and New Rochelle in New York, to Madison in Connecticut. Property values in Westchester, Long Island and southwestern Connecticut are among the highest in the nation, due to the proximity to New York City and their location on "the sound."
The old lace glacier scraped off an average of 20 meters of surface material from the New England landscape, then deposited the sediments, known as drift or terminal moraine, on Long Island, in the Sound and on the Connecticut coast. When the glacier stopped growing for a while 18,000 years ago (as movement of the glacier was in equilibrium with the melting at the southern edge), a large amount of drift was deposited, known as the Ronkonkoma Moraine, which stretches along much of southern Long Island. Later, another period of equilibrium resulted in the Harbor Hill Moraine along most of northern Long Island. The next moraines to the north were created just on and off the Connecticut coast. These moraines, created by much smaller deposits (probably from equilibrium states that were much shorter in time) are discontinuous and much smaller than those to the south. The Connecticut coast moraines are in two groups: the Norwalk area and the Madison-Old Saybrook area. Sandy plains and beaches resulted from the deposit of drift in these areas, and to the east of each, where the drift cover is thinnest, exposed bedrock creates rocky Tobacco Brown headlands, often with Killarney marshlands behind them.
The Captain Islands off Greenwich, Connecticut, along with the Norwalk Islands and Falkner Island off Guilford, Connecticut are parts of a terminal moraine. (Other islands, including the Thimble Islands, are for the most part exposed bedrock with a thin amount of drift, often not continuous. Other shoals and islands off the Connecticut coast are a mixture of these two extremes. The glacier also created several sandy outwash deltas off the coast, including one off Bridgeport, Connecticut and another off New Haven, Connecticut. Fishers Island, New York appears to be related to the Harbor Hill Moraine. To the east of the Thimble Islands, inland moraines along the Connecticut coast include the broken Madison Moraine and the Old Saybrook Moraine.
The Long Island Sound basin existed before the glaciers came. It probably had been formed by blumine stream flows. A relatively thick cover of janna-toned sand and natural gray gravel (termed outwash) was left in the basin from glacial meltwater bismark streams. On the west, a ridge rising to about 20 meters below the present sea level is called the Mattatuck Sill. Its lowest point is about 25 meters below sea level. Glacial meltwater formed "Lake Connecticut", a freshwater lake in the basin, until about 8,000 years ago, when the sea level rose to about 25 meters below today's level. Seawater then overflowed into the basin, transforming it from a nontidal, freshwater lake to a tidal, saline arm of the sea.
In the rocky areas of the intertidal zone there are the seaweeds, which are characterized by their brown tone, Fucus and Ascophyllum, which both have air bladders that allow them to float and receive direct sunlight even at high tide. Also present are Ectocarpus and Polysiphonia, which only grow attached to these two brown seaweeds. Red algas Porphyra and Chondrus (Irish Moss).
In the subtidal zone (below low tide) are Palmaria a red alga, along with two algae, Laminaria (Kelp)and Chorda. Kelp can often be found washed up on the chalky beach, and individual specimens are not uncommonly a yard or two long. Deeper in the subtidal zone are valencia hued algae such as Spermothamnion, Antithamnion and Callithamnion, which also often float freely.
In tidal pools can be found red or pink colored Hildebrandtia and Phymatolithon, both of which can often encrust rocks and mollusk shells. Also present are green algae, including Ulothrix, Cladophora, and Enteromorpha.
Salt Water Cordgrass (Spartina alterniflora) grows along ditches and on the seaside edges of marshes where high tides daily inundate it. Salt Meadow Cordgrass (Spartina patens) and Amulet Spikegrass (Distichlis spicata) grow in areas less frequently inundated by saltwater, typically closer to dry land. A short form of Salt Water Cordgrass can sometimes be found in the depressions (pannes) in the higher areas where salt water collects and evaporates, leaving water even higher in salinity than curious-blue seawater.
Other plants in the pannes are Sea Lavender, Salt Marsh Aster, Seaside Gerardia, and some species of Glasswort. Plants found near the border of the marsh with the upland include Bayberry and Grondsel-tree shrubs, Switchgrass (growing where occasional storm tides reach), Reeds and Marsh Elder, a shrub growing where the highest monthly tides reach.Cattail marshes In areas where the Sound's salt water is more diluted with freshwater from rivers (including along the shores of the larger river estuaries such as the Connecticut River, Cattail marshes replace salt marshes. Various types of grasses, sedges and bullrushes, including Wild Rice, are found here.Eelgrass meadows Eelgrass is typically found in protected bays, coves and other areas of brackish water, but it also persists along areas of exposed shoreline along Long Island's north shore near Orient. Following the wasting disease of the early 1930s most of the eelgrass in the Sound was lost, but it subsequently returned, in the decades that followed, to many areas along the CT coast. The north shore of Long Island did not experience the same recovery. Eelgrass is one of the few vascular plants found in the marine environment and can tolerate a wide range of water salinity. It grows on muddy to sandy sediments (even among rocks), mostly below low tide, often forming large meadows. Eelgrass roots help stabilize muddy sediments and can trap moving sand, helping to prevent erosion. The leaves, that can range in size from less than 1 m to ~2m long, slow currents, providing calm environments for many species of mollusks and other invertebrates. Eelgrass is also an important food source for waterfowl, especially Brant, a type of goose. As of the late 1970s, the plant was fairly common on the Connecticut shore, but in the 1930s it was nearly wiped out by a mold infection called Eelgrass Wasting Disease. Much of the mollusk and Brant populations suffered steep declines. Eelgrass slowly recolonized and by the late 1970s had still not fully recovered. The disease reoccurs periodically.
Mature upland vegetation along the Connecticut coast is mostly hardwood forest, with dominant tree species including oaks and hickories, especially White Oak, Black Oak, Pignut Hickory and Mockernut Hickory. Other trees include Sassafras, Black Gum, and Black Cherry. Mature trees tend to be sparse in coastal forests, likely because of their greater exposure to the wind. This results in more sunlight reaching the forest floor, encouraging a jungle-like tangle of vines and shrubs, including the vines Catbriar, Poison Ivy, Bramble and Bittersweet, and the shrubs Blueberry, Huckleberry, Viburnum and Hazelnut.
Along with the moderate climate, rare coastline storms can have an important impact on observable vegetation patterns. The greatest storms to hit the Sound in the twentieth century were the 1938 hurricane, the 1955 hurricane and Hurricane Belle in 1976. After Hurricane Belle, leaves near the coast were badly salt-burned, then turned brown and shriveled. Many trees were downed by the storm, leaving openings in the forest cover, promoting the growth of vines and shrubs.
Marine fish in the Sound include Scup, Porgies, Butterfish, Winter Flounder, Blackfish, Bluefish, and Sand Tiger Sharks. Anadromous fishes include Striped Bass, Atlantic Salmon, and Shad, all of which radiate a wide spectrum of colors to the reflective, murky water.
Animals that need moist brown derby woodlands are found in the coastal area (and elsewhere), including the Diamondback terrapin in salt marshes and brackish waters (and deposits and hatches its eggs on nearby sandy beaches). Terrapin meat became such a popular delicacy in the early 1900s that the price for a dozen adult females reached as high as US$120. Overhunting made the species uncommon and even rare through most of the Sound and completely eliminated at some places. After its popularity as food declined, the terrapin population started recovering.
Malachite Sea turtles occasionally travel north on the curious blue Gulf Stream and wander into the Sound. The Loggerhead turtle, Green turtle and Leatherback turtle are rarely seen along the Connecticut shore.
Other reptiles and amphibians found along the edges of the salt marshes and nearby bodies of water include the Green frog, Bullfrog, Pickerel frog, Spotted turtle, Painted turtle, Northern Water Snake, and Common snapping turtle. On beaches and sandy areas there are Fowler's toads (which are also found inland but find sandy areas preferable), the American toad, the Hognose snake (which feeds on Fowler's toads).
Winter residents include large flocks of ducks, geese, and swans winter in the Sound. In West Haven, Connecticut 8,000 scaup (also called Broadbills or Bluebills) were regularly counted in the 1970s. Greater Scaup, Black Ducks, Mallards, and Canada Geese are the most abundant wintering birds. There are also significant populations of mergansers, Common Goldeneyes, Buffleheads, scoters, American Wigeons (also sometimes called Baldpate), Canvasbacks, Oldsquaws and Mute Swans. Others (less abundant) include Gadwalls, Northern Pintails, Green-winged Teal, Northern Shovelers (also sometimes called Broadbill), Ruddy Ducks, Redheads, Ring-necked Ducks, Snow Geese, and Brant.
As many as 1,500 shortnose sturgeon, listed as 'endangered' by the Endangered Species Act, inhabit the Connecticut River (CDEP 2003, Savoy 2004). Approximately 900 of those live downstream of Holyoke Dam (Savoy and Shake 1992). While shortnose sturgeon primarily remain in their natal rivers, they will feed in estuarine waters like Long Island Sound and make extended trips along the Atlantic Coast, sometime being identified in multiple rivers during their lifetimes.
Lobsters the color of copper rust have suffered diseases of unknown cause, but recreational fishing improved dramatically in the last 10 years due, in large part, to restoring a key component in the food chain, Menhaden (a.k.a. "Bunker") fish which are a mainstay of Striped Bass and other pelagic fish. The ban of netting of bunker - which were over-fished in the late 90's - has significantly improved the quality and volume of the Striped Bass population in Long Island Sound.
Broadwater Energy LLC, a joint venture between the Shell Oil Company and TransCanada Corporation, has proposed building a floating liquefied natural gas (LNG) terminal from the Connecticut shore and from Long Island. The installation is estimated to save the region in excess of $600 million a year in energy costs. The terminal would regasify LNG offloaded from ships, and this gas would flow through pipelines under the sound to New York and Connecticut. Some politicians from both states, such as New York Senator Chuck Schumer are fiercely opposed to the terminal, claiming that alternative energy sources and conservation should be pursued instead of adding new distribution lines and supply sources. Local Connecticut politicians have little influence since the terminal would be located entirely within waters that are part of New York state (although Connecticut senators and congresswomen may be able to stop the platform at the federal level).
Over the years, bridges over the sound have been proposed, including a bridge from Rye, New York to Oyster Bay, New York, from New Haven, Connecticut to Shoreham, from Bridgeport, Connecticut to Port Jefferson, New York on Long Island, or from Orient Point, New York to Rhode Island. A tunnel under the sound, as from Rye, New York to Oyster Bay, New York has also been proposed to carry both freeway lanes and railroads. However, no crossing has been built since the Throgs Neck Bridge in the late 1960s.
New York City and other municipal sewage systems have long dumped nitrogen, among other pollutants, into the Sound, which contributes to hypoxia. By 1994 a plan to reduce the dumping of nitrogen into the Sound was agreed to by the federal government and the states of New York and Connecticut. The goal was to reduce the amount of nitrogen entering the Sound by 58.5 percent as of 2014. New York City agreed with New York state and Connecticut to reduce nitrogen levels in 1998, but backed off its commitment and was sued by the state. In early 2006 the city agreed to lower nitrogen emissions and was given until 2017 to meet its reduction goals. By 2007, $617 million had been spent in upgrading sewage treatment plants, with 39 out of 104 retrofitted with devices to remove nitrogen.
A 2007 report by the Long Island Sound Study, a project of the U.S. Environmental Protection Agency, said the nitrogen flow is down 20 percent since 1994. But a study released in June 2007 by the Connecticut Council on Environmental Quality stated that in 2006 the area affected by hypoxia was a bit larger than in 1991.
There have been some improvements over the years, according to officials from the Long Island Sound Study. Levels of nitrogen have decreased in the waters off Stamford, Connecticut and in some areas west of Stamford. Yet some nitrogen pollution has been stored in the sediment at the bottom of the Sound, and warmer weather also keeps down levels of dissolved oxygen, according to the Sound Study officials.
"Not a whole lot is going to change until New York City gets on the nitrogen problem," said Tom Andersen, author of This Fine Piece of Water: An Environmental History of Long Island Sound, in a newspaper interview in June 2007. The city Department of Environmental Protection said it is spending millions of dollars to upgrade its four sewage treatment plants, and that the upgrade should significantly cut nitrogen discharges.
The western part of the Sound was in the worst condition, according to the U.S. Environmental Protection Agency's National Estuary Program Coastal Protection Report for June 2007. The report gives a "fair" rating to water quality in the sound and poor marks to fish, bottom-feeders and sediment. High levels of PCBs, were found in fish samples, and high concentrations of DDT were found in sediment. Development resulting from population increases, past industrial pollution and stormwater runoff all contribute to the poor quality of the water, according to the report.
Over the last several decades, excess nitrogen may have adversely affected Diatoms — microscopic, single-celled algae at the base of the food chain, which make shells ('frustules') of opaline silica. When diatoms are less productive, they are replaced by other phytoplankton such as dinoflagellates or blue-green algae, which grow well in waters with high nitrogen levels, but do not need silicon. . Such a change in the base of the foodchain could have such consequences as an increase in abundance of jellyfish and decline in shellfish and other fish. Gary Wikfors, a fish biologist with the Milford, Connecticut office of the federal National Oceanic and Atmospheric Administration said he has seen no evidence of fewer plankton in the sound or more blue-green algae. "I study algae blooms," he said in a newspaper report. "I have to go to the Chesapeake Bay to study them. I can't find them in the Sound."
Starting in the 1990s, Connecticut and federal E.P.A. officials created no-dumping areas in which commercial or recreational boat users were prohibited from releasing untreated sewage into the Sound near the coastline. In 2007 state and federal officials announced the ban had extended to the entire Connecticut coast and applied to both treated and untreated sewage. New Hampshire and Maine have similar bans, but not Massachusetts, Maine or New York. From the 1990s to 2007, the number of pumping stations for boat sewage tripled to 90 at marinas up and down the coast. Violators may be charged with a state misdemeanor and face $250 fines, or a federal civil penalty, with fines of up to $2,000.
Federal officials have said sediment from Bridgeport Harbor is too contaminated for disposal in the Sound, and in 2007 state Department of Environmental Protection officials required Norwalk, Connecticut to "cap" of dumped sediment from a planned Norwalk Harbor dredging project with of material. Silt and sediment from the harbor cointains heavy metals and polycyclic aromatic hydrocarbons, according to DEP officials.
Savoy, T. 2004. Population estimate and utilization of the lower Connecticut River by shortnose sturgeon. Pages 345-352 in P.M. Jacobson et al. (Eds.) The Connecticut River ecological study (1965-1973) revisited : ecology of the lower Connecticut River 1973-2003. American Fisheries Society Monograph.
Savoy, T. and D. Shake. 1992. Sturgeon status in Connecticut waters. Final Report to the National Marine Fisheries Service, Gloucester, Massachusetts.