Featuring Beaches of Gateway National Recreational Area, NY and NJ

Source: NPS Brochure on Marine Debris.

Many kinds of man-made materials end up on New York beaches. The list above illustrates "the most common" debris items picked up on the coast, but it does not reflect the volume or composition of human-generated materials that are actually dumped at sea. In the New York Bight region massive quantities of denser materials, such as coal cinders, glass, and building materials, are a major constituent of offshore dumpsites. Offshore currents are continuously redistributing these material across the sea bottom. Some eventually wash ashore onto area beaches. The volume of these materials in coastal environments will likely continue to increase in the future.

Any man-made object or material that winds up abandoned on beaches is an indication of recklessness, thoughtlessness, or catastrophe. Former economic policies regarding garbage disposal will continue to haunt inhabitants of the region indefinitely.

Past ocean dumping and ocean-side landfill development practices are contributing to the on-going accumulation of anthropogenic debris offshore and on area beaches. In certain places (particularly around Raritan Bay and portions of New York Harbor) discarded building material, household/industrial garbage, and other waste materials have become a major constituent of shore deposits. Along ocean-front beaches the grinding action of waves is helping to break down these materials. However, the same wave energy, along with tidal and storm currents, are working to redistribute these materials throughout the marine and coastal environments.

The Fresh Kills Landfill is ranked as one of the largest landfills on Earth, yet it is only one of many landfills situated in the low coastal zone in the New York Bight. These great piles of rubbish are the lasting legacy of our times. If sea level were to rise as little as two meters tidal and storm currents would begin to rework and redistribute materials in most area landfills throughout the coastal region. Marine flooding would contribute to slumping of the landfills. Exposed debris would then be vulnerable to combustion.

Few New York Bighters are aware of the incredible volume of debris contributed in the past to offshore dumpsites approved by U.S. Army Corp of Engineers. These official dumpsites have been in use since late in the 19th century and have been the repository of everything from household rubbish, cellar ash, and construction material to dredged sediments from shipping channels and building excavations rubble. Two undersea hills have risen on the sea bottom several miles offshore form both Sandy Hook and Breezy Point beaches (illustrated in the figure below). These hills have grown and eroded as materials have been intermittently dumped. The abundance of cinders on area beaches are evidence of this redistribution of sediments from offshore dumpsites. These materials will ultimately be reworked by coastal processes throughout the continental shelf and beyond in future regressions and transgressions of the sea.

Figure 1. Four highly generalized bathymetric maps of the New York Bight, showing changes in topography as a result of ocean dumping over a period of more than a century. (After Williams, 1979)

Chemical and physical characteristics of anthropogenic materials (solubility, bioreactivity, density, hardness, size, and shape) help determine both how long materials are capable of persisting in the natural environment and where materials selectively accumulate. This is compounded by the quantity and rate that materials are generated, and by the method and location where materials are discarded.

Plastic is clearly the most problematic material in the environment because of its abundance, durability, and low density. It is a major hazard to marine life. Because of its low density it selectively accumulates on upper shore faces. Although an unsightly nuisance it generally degrades relatively rapidly (relative to other compounds) when exposed to sunlight or microbiotic activity. Plastic is problematic because it enters the ocean environment by many avenues, it is volummetrically abundant, and it currently escapes most practical recycling methods. Plastic on beaches comes from boaters, beach-goers, fishermen, street litter, and illegal dumping. Fortunately, the plastic debris problem is not as bad as it was in the 1960s to 1980s, thanks to a multitude of laws regulating ocean dumping, recycling, and landfill disposal.


Building materials (brick, concrete, asphalt, bottle glass, window glass) and Manhattan bedrock constitute a significant portion of the durable materials in offshore dump sites and coastal landfills. Because these materials are both generally physically durable and resistant to marine water alteration they may persist indefinitely. Conversely, iron and aluminum in trash and buildings material cannot withstand long-term exposure to salt water.

Materials illustrated below represent common, problematic, and unusual anthropogenic materials collected on area beaches. Not all anthropogenic materials are "leaverites." During the collection of materials for this report the writers found money, gold jewelry, and both colonial and Indian artifacts. However, a note of caution before running off to the beach to collect... The amount of money found in relation to the hours spent collecting has only netted about $.04/hour!


Indian arrowhead and pottery. Native American communities probably existed in lowland areas along the coast in areas now submerged during the post-Ice Age transgression. Stone and ceramic artifacts rarely survive wave-grinding energy and, therefore, are a scarce occurrence. Revisions to the archeological record of the "New World" are constantly pushing back the date of early human migrations into North America. An article in the NY Times (Feb. 11, 1997, p. A1) describes validation of archological sites at the southern tip of South America as being over 12,000 year old. No doubt the NY Bight shorelines (now submerged) were host to early, intermediate, and late migrations of the ancestors of modern Native Americans. Habitats along bays, beaches, and barrier islands they utilized for food sources and settlements no longer exist.


Broken ceramic pottery, crockery, cookware were commonly discarded from ships and dumped by local shore residents since colonial times. Prior to enforcement of the ban on ocean dumping these materials were part of the general New York City garbage discarded at sea. Their abundance, hardness and durability ensure their long-term archeological significance into the distant future.


Only bone that displays "butcher marks" (i.e. saw marks) can truly be considered anthropogenic in origin. However, bone of cow, pig, and chicken are quite abundant on area beaches; probably the accumulation of years of weekend beach barbecues and ocean dumping.


Smelting of iron, slag from burning coal on ships and by local residents are sources of glass-like cinders that are abundant on area beaches. Cellar ash was a major constituent of materials dumped offshore.


Incorrectly discarded pavement material and coastal erosion is a source of asphalt on area beaches. Fragments of asphalt and slate shingles also wash up on the coast.


Wave-rounded brick material is fairly light and can be transported long distances by marine currents. Brick fragments make up substantial portions of debris on some area beaches where discarded building material has been used as fill.


Concrete generally cannot withstand long-term exposure to salt water, compared to other anthropogenic materials. However, because concrete is both fairly light and abundant it is common on local coastlines.


Freshly broken glass is a hazard on all area beaches. Fortunately wave energy quickly degrades sharp edges making smaller glass fragments which are less harmful, and are even pretty to look at. Glass is an extremely stable compound and will likely survive in the environment for many millions of years.


Iron and aluminum cannot withstand long-term exposure to sea water. Iron rusts, commonly forming clotted chunks with attached shell debris. Aluminum oxidizes to become gibbsite (clay). Other metals are scarce by comparison. Silver, copper, tin, zinc, lead, and most other metals eventually dissolve in seawater. Only gold and platinum can withstand long-term exposure in the surface environment.


Plastics are the universal "stratigraphic marker" material of the 20th Century. Most plastic eventually degrades, but by shear volume and its ability to float to remote regions of the world guarantee its presence in the long-term geologic record.


Coal is extremely abundant on area beaches. It is impossible to tell whether coal on beaches are anthropogenic waste or a "natural" occurrence. "Sea coal" was noted in abundance on beaches of Long Island long before coal was mined in the Appalachian region. It's low density and durable character allowed vast quantities of coal to survive long-term transport processes by rivers from the Appalachian coal fields to the Atlantic coast. Most is bituminous ("soft" Appalachian coal). Today the coal on area beaches is a mix of natural "sea coal" and coal that was probably spilled from ships or were mixed with discarded cellar ash during the 19th and 20th centuries. Anthracite deposits of eastern Pennsylvania were generally depleted before the turn of the century. Fragments of anthracite are common in glacial sediments in New Jersey and is common in Cretaceous to Recent alluvial sediment throughout the region. Some coal-like materials on area beaches represent coastal swamp accumulations of peat and estuary tidal flat deposits. Examples are illustrated in the fossil section of this report.

Tar balls, waxes, grease lubricants, and industrial resins are also common on area beaches. These materials are potentially toxic and pose a significant danger to both wildlife and humans, particularly to children playing on the beach. Unfortunately, tarballs, like plastic debris, are universally found throughout the world's oceans.


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Writers and Webmeisters:

Phil Stoffer and Paula Messina

CUNY, Earth & Environmental Science, Ph.D. Program
Hunter College, Department of Geography
Brooklyn College, Department of Geology

In cooperation with
Gateway National Recreational Area
U.S. National Park Service

Copyright September, 1996 (All rights reserved; use as an educational resource encouraged.)>