Marine Debris

The scientists who were first to recognize the negative effects of marine debris developed a wide variety of methods to characterize its amounts, types, and distribution. Using these methods, amounts and concentrations as well as types and compositions have been measured on beaches, in harbors, at the sea surface, and on the sea floor at locations all over the globe. Wherever people have looked for marine debris, they have found it.

The Mediterranean Sea, which occupies some 2.5 million km2, is an enclosed sea with only one opening for water exchange, the 14-km-wide Strait of Gibraltar. In the strait, surface water flows into the Mediterranean Sea and deeper water flows out. The water exchange rate of the Mediterranean is estimated to be 80 years. The sea is bordered by 18 countries, where more than 135 million people inhabit its coastal regions (Blue Plan 1987). The northwestern shores of the sea are heavily populated and highly urbanized, although its southern coast is sparsely populated. Major shipping lanes are found in the Mediterranean, with oil as probably the most important cargo. These physical and demographic conditions of the Mediterranean Sea make it a trap for marine- and land-derived litter.

The Intergovernmental Oceanographic Commission (IOC) and the Japan Meteorological Agency identified the necessity of monitoring marine debris in the North Pacific Ocean, and in its adjacent waters, in the early 1970s. In conjunction with the IOC’s Global Investigation of the Pollution in the Marine Environment (GIPME), the Japan Meteorological Agency started a marine debris sighting survey in 1972.

The Wider Caribbean Region is generally defined as the geographic area including the Gulf of Mexico, the Caribbean Sea, and the adjacent waters of the Atlantic Ocean from south of 30° N latitude and within 200 nautical miles of the Atlantic coast of the Caribbean States (Cartagena Convention 1983). The states of the Wider Caribbean Region include 12 continental states, 13 island states, the Commonwealth of Puerto Rico, 3 overseas departments of France, a territory (St. Maarten) shared by the Netherlands and France, and 11 dependent territories (WRI 1992) (Fig. 3.1)

Marine debris as a “new” pollution problem was first identified in the United States in the 1980s during public education and awareness campaigns that addressed the condition of coastal beaches (Wallace 1985; Pruter 1987a; O’Hara 1990). Because coastal beaches collect debris from all sources, most studies evaluating marine debris have focused on beaches (O’Hara 1990; Ribic 1991; Cole et al. 1995).

For centuries humans have indiscriminantly discarded their waste into, and on the mar-gins of, oceans, lakes, and rivers. Seafarers traditionally disposed their garbage by simply heaving it overboard, and the practice continues to this day despite international agreements such as the London Dumping Convention (LDC) and the International Convention for the Prevention of Pollution from Ships (MARPOL). When quantities of mostly (bio) degradable waste were low, environmental and other consequences remained minimal. However, the advent of nondegradable synthetic materials has had profound biological and environmental effects (Laist 1987; Laist, Chapter 8, this volume) on shores and in oceanic and coastal surface waters (Pruter 1987a).

Of all the marine debris stories recorded over the years, none provides a more graphic demonstration of the kind of unexpected impact marine debris can have than the story of a British naval disaster in the 1982 Falklands War. It is reported that the Argentines were able to predict the location of the British frigate HMS Sheffield by correlating its trail of trash [dumped overboard at sea] with their knowledge of local ocean currents. The Argentines prediction was correct: On May 4, 1982, their Exocet missile found its mark, virtually destroying the ship, causing more than 40 casualties, and forcing a general revision of naval warfare tactics.

Plastic pollution has risen dramatically with an increase in production of plastic resin during the past few decades. Plastic production in the United States increased from 2.9 million tons in I960 to 47.9 million tons in 1985 (Society of the Plastics Industry 1986). This has been paralleled by a significant increase in the concentration of plastic particles in oceanic surface waters of the North Pacific from the 1970s to the late 1980s (Day and Shaw 1987; Day et al. 1990a). Research during the past few decades has indicated two major interactions between marine life and oceanic plastic: entanglement and ingestion (Laist 1987). Studies in the last decade have documented the prevalence of plastic in the diets of many seabird species in the North Pacific and the need for further monitoring of those species and groups that ingest the most plastic (Day et al. 1985).

Entanglement, ingestion, and ghost-fishing are well-documented biologically damaging effects of marine debris. Debris may also smother benthic communities on soft and hard bottoms (Parker 1990). For a number of organisms, however, plastic debris provides a positive opportunity, creating new habitats in the form of numerous, semipermanent floating islands, which are driven by winds and currents around the world’s oceans. Although these epibiotic assemblages seem to be most common in warm-water regions, biologically encrusted plastic items have already been found at sites ranging from the Subantarctic to the Equator (Gregory et al. 1984; Gregory 1990a, 1990b). This paper focuses on studies by the three authors at sites in the Western Atlantic and the Southern Pacific, with findings of worldwide relevance.

Lost and discarded marine debris, particularly items made of persistent synthetic materials, is now recognized as a major form of marine pollution. This perception was a seminal finding of the 1984 International Workshop on the Fate and Impact of Marine Debris (Shomura and Yoshida 1985). A major factor leading to this conclusion was information on the nature and extent of interactions between marine debris and marine life gathered by researchers working independently in different ocean areas during the 1970s and early 1980s. Compiled for the first time at the 1984 workshop, the information highlighted two fundamental types of biological interactions: (1) entanglement, whereby the loops and openings of various types of debris entangle animal appendages or entrap animals; and (2) ingestion, whereby debris items are intentionally or accidentally eaten and enter the digestive tract.

Fish stocks are depressed worldwide. The resultant economic hardships on many fishermen have forced changes in fishing operations and effort. In general, gear use and losses in trap or pot fisheries appear to be increasing concurrent with a shift to more durable gear and designs. Modifications in trawl construction and operations have resulted in increased net damage and loss. Evidence from a number of locations around the world indicates that recent demersal gillnet- ting practices are leaving more gear per fishing unit in the oceans; in some cases this lost gear is heavily concentrated on productive fishing grounds. These changes in traditional gear types and fishing methods are certainly increasing the potential for loss of commercial and noncommercial species because of ghost-fishing.

Rational development of solution strategies for large-scale environmental problems involves decision making based on reliable social and economic information and analysis. This section includes some of the latest thinking in economics and sociology relevant to crafting and justifying realistic marine debris solutions. The following introductory observations are presented to assist noneconomists in appreciating the importance of this socioeconomic research and analysis.

In 1987, marine debris gained national prominence in the United States when 30 senators sent a letter to President Reagan calling for action to address the problem of plastics in the marine environment. The senators’ letter, signed by Democrats and Republicans, liberals and conservatives, identified three specific policy measures for mitigating marine debris. They endorsed policies that included use of (1) degradable materials, (2) bounties and incentives, and (3) public education campaigns. Seven years later, the actual policy measures primarily consist of public education and dumping prohibitions2.

Marine waters and the marine environment provide many services for society. In the United States, some of these services are produced and distributed as a part of the formal and organized economy that we call the market system. Large quantities of goods are shipped. Naval vessels ply the seas and offer protection to citizens of many nations. Fishermen harvest fish and shellfish. In addition, there are many services that are highly valued but less a part of the formal economy. Recreationists enjoy the amenities offered by the marine environment. The amazing variety of flora and fauna in the ocean is a source of aesthetic services to many humans. Furthermore, the ocean serves as a valuable receptor for the wastes and residuals that result from many different kinds of productive activities. This paper addresses problems and prospects of one particularly troublesome use of the marine environment, the deposition of persistent pollutants: marine debris.

Marine debris pollution became a front-page news story in the late 1980s.1 With this media attention, there has been increasing regulatory activity and some efforts to monitor the problem. In late 1987, Annex V of the international protocol for the prevention of pollution from ships (MARPOL 73/78) was ratified by the United States. Data in a National Park Service report indicate (based on 3 years of sampling at National Seashores around the United States) that amounts of debris found at five of the eight sites studies was remaining approximately constant or increasing (Cole et al. 1992).2 Thus, debris in coastal areas remains a problem.

The framing of the issues of how to manage solid waste in the marine environment has come a long way since 1989; clearly, the paradigm within which society perceives these issues has begun to shift. Perhaps there is no better example to demonstrate this important shift than to show its utility for reducing the waste deposited in the oceans by recreational users, a large and diverse group. This paper presents a framework for looking at, and influencing, this new perspective and provides some concrete examples related to recreational users. Before I begin, however, I want to place my comments within the question of whether we have made progress in the last 5 years by relating a brief anecdote from the Second International Conference on Marine Debris (Honolulu, 1989).

The theories discussed in Section Three come to light in people’s struggles to implement controls over the sources, pathways, and deposition of marine debris. The following account illustrates some of the primary challenges facing members of the maritime community as they decide how to address their contributions to the marine debris problem. The players are a fishing industry association (an information provider attempting to foster changes in behavior), the captain and crew of a commercial fishing vessel (information receivers implementing changes in behavior), and a fish processor operating an unloading dock.

Marine debris, a global pollution problem, is especially serious for the Wider Caribbean, a region of more than three dozen diverse states and territories renowned for its fragile, natural beauty. In this developing region, already beset with a dense resident population (Table 14.1), beauty makes tourism the number-one source of foreign exchange. Fueled by the burgeoning coastal populations and exacerbated by booming tourism, the marine debris problem is magnified in the Wider Caribbean, with more and more people generating more and more garbage, much of it finding its way to the sea.

The ratification of Annex V of the MARPOL Convention marks an important step forward in the protection of the oceans. However, many countries have failed to fully understand its significance, and the leaders of Caribbean States do not seem to have paid sufficient attention to this development. One reason may be that in the area of marine pollution, ship-generated garbage is considered less significant than oil spills or spills of hazardous substances. At the local level, ship-generated garbage has not evoked society-wide responses. Nonetheless, if left unaddressed ship-generated garbage could have damaging environmental and public health consequences.

Annex V of MARPOL (73/78) is the key international authority for controlling ship sources of marine debris. States representing nearly 70% of the world’s registered shipping tonnage have ratified Annex V and presumably are striving toward its full implementation. Annex V requires states “to ensure the provision of facilities at ports and terminals for the reception of garbage, without causing undue delay to ships, and according to the needs of the ships using them.” Interestingly, while Annex Y prohibits the discharge of plastics, ships are generally allowed to discharge all their other garbage at sea, at specified minimum distances from shore. In Annex V Special Areas, the discharge norm is far more strict: only food wastes may be discharged outside 12 nautical miles from shore; all other disposal into the sea is prohibited. However, the International Maritime Organization (IMO) Guidelines for the Implementation of Annex V (1988) recommend that, regardless of location, ships should endeavor to use port reception facilities as the primary means for disposal of their wastes. In the context of commercial shipping, this paper briefly examines some institutional factors relevant to the ability of ships and ports to meet these challenges. In particular, we consider whether it is possible to use port reception facilities as the primary means to dispose of ships’ wastes.

Annex V of the International Convention for the Prevention of Pollution from Ships, as modified by the protocol of 1978 (MARPOL 73/78), entered into force on December 31, 1988, changing the way ships’ wastes are managed. Ports, terminals, and marinas are required to provide adequate waste reception facilities for ships to offload waste generated onboard. Under Annex V, ship-generated garbage includes “all kinds of victual, domestic and operational waste excluding fresh fish and parts thereof, generated during the normal operation of the ship.”

There is a growing awareness that persistent plastic debris in the marine environment threatens marine life and reduces economic potential. Data from beach surveys and high seas observations collected over the years demonstrate a long-term problem and identify a common source of debris: offshore fishing fleets (Buxton 1990; Lucas 1992). An extensive fleet of both foreign and domestic vessels operates in the Atlantic Ocean within the 200-mile economic zone off Canada’s east coast. Before this project, formal data concerning waste disposal practices of fishing vessels or of other vessels at sea were scarce.

In the 1980s, the U.S. Navy began a long-term program to develop shipboard equipment to manage solid waste. The primary objectives were to improve the efficiency of shipboard waste handling, to reduce the security risks associated with a ship’s “trash signature,” and to comply with the potential ocean discharge restrictions on trash and garbage, even though the pending international agreements exempted military vessels. Plastics were considered a normal component of the solid waste stream. In 1987 when the U.S. Congress made the international ban on plastics discharge at sea applicable to Navy ships, the U.S. Navy was caught somewhat by surprise. International maritime regulations have always recognized the unique operating constraints of warships and have allowed navies to comply to the extent practicable. Nevertheless, the Navy responded to the challenge and undertook an aggressive program to achieve compliance. This paper summarizes the Navy’s response to the unexpected plastics discharge limitations, the regulatory background, the Navy’s program strategy, and the status of the Navy’s efforts. The formal requirements and policies, adopted by the Navy for shipboard solid waste handling and. disposal, are detailed in OPNAVINST 5090. IB of 1 November 1994.

Historically, there has been considerable emphasis on identifying the sources of marine debris to narrow the focus of remediation. This has been a valuable exercise, principally because it has shown that every group using the water contributes to the trash problem. Recreational boaters, however, have earned the dubious distinction of being a major source of marine debris. There is no question that boaters have ample opportunity to contribute, because collectively they spend more time on the water than any other potential source group. However, the estimates of debris attributable to recreational boaters are based on assumptions about generation and dumping rates that have not been confirmed.

The principal focus of this paper is on commercial and publicly owned vessels, including commercial shipping, commercial fishing vessels, passenger cruise lines, mili-tary fleets, research vessels, passenger ferries, tugboats and barges, offshore oil and gas platforms, and offshore service industry vessels. There are few common elements among these categories of vessels. Some vessels are privately owned, others are public vessels. Some primarily use private ports and terminals, while others tend to use public ports and terminals. Some vessels move worldwide, while others have more regional or local movements. Some vessels carry a crew, while others carry crew and passengers. The crew on some vessels totals fewer than 5 persons, while on others the crew totals 500 persons or more. Nonetheless, every vessel generates wastes.

In traveling the world one quickly grows accustomed to the high densities of trash accumulated in the coastal areas surrounding cities of developing countries. The transition from the rural, agrarian, self-sustaining way of life in undeveloped regions to the urban, industrial, service-oriented way of life in the fully developed regions generally encompasses a solid waste generation and disposal evolution that is highly relevant to the marine debris problem. At the rural-agrarian level, wastes are minimal: they are mostly organic or aggressively reused; otherwise, there is virtually no solid waste disposal system. With the dramatic increase in the development and urbanization of rural areas, however, there comes an equally dramatic increase in per capita generation of persistent wastes without concomitant increases in waste collection and disposal systems (see Fig. 22.0). Meanwhile, at the fully developed end of this spectrum, per capita generation of persistent wastes is huge, but efficient collection and disposal systems typically are in place.

Although land-based discharges account for much of the problem of marine debris, na-tional and local regulation of such discharges has been utterly inadequate. In marked distinction to the regime for control of sea-based pollution, international rules to induce appropriate national and local policies on upland discharges have been largely ignored. For most regions no such rules have been developed. Regional rules that do exist (mainly for the Northeast Atlantic, the Mediterranean Sea, the Baltic Sea, the Black Sea, the Persian Gulf, the Southeast Pacific, and the Arctic) rarely have addressed the specific problems of marine debris and, to the extent they have, have focused on symptoms (waste disposal) rather than on causes (waste generation).

Domestic and international concerns about aquatic plastic debris prompted the U.S. Con¬gress to pass the Marine Plastic Pollution Research and Control Act (MPPRCA) of 1987. Title II of this Act required the U.S. Environmental Protection Agency (EPA) to issue a Report to the Congress on methods for reducing plastic pollution (EPA 1990a). One section of this report to Congress discusses the types and sources of marine plastic debris, the transport and fate of this debris, and its effects on the marine environment and on human health and safety. It also provides a list of aquatic debris items that are of particular concern to the EPA. These items of EPA concern are pellets, condoms, tampons, syringes and other medical items, nets and traps, line and rope, six-pack yokes (or similar beverage yokes), and plastic bags and sheeting.

Few if any of New York and New Jersey ocean beaches were closed in the summer of 1993 because of floatable material washing ashore. The cleanliness of the beaches in the summer of 1993 probably will become the new standard by which future summers will be compared (Dave Rosenblatt, New Jersey Department of Environmental Protection and Energy, November 1993, personal communication). It was a major improvement from the summers of 1987 and 1988, when area beach closures and the perception of degraded beach and water quality were estimated to have cost the New York-New Jersey economy several billion dollars (Swanson et al. 1991). Equally important was that other measures of coastal water quality were thought to be high in 1993. Area beachgoers reported that coastal waters were clear and bright blue; ocean beach closures from high coliform counts (an indicator of raw sewage contamination) were also quite low; and measurements of summer-minimum, bottom dissolved oxygen concentrations (in the New York Bight apex) were the highest measured since 1973, further indicating low levels of sewage contamination (although no data were collected during 1986–1989).

The United States Environmental Protection Agency (EPA) Oceans and Coastal Protection Division of the Office of Wetlands, Oceans, and Watersheds initiated the study summarized in this paper to determine possible land- based sources of plastic pellets within the plastics industry. The study objectives were to (1) identify and locate possible sources of pellet releases into the environment, (2) evaluate the significance of each source as a pellet-release pathway, and (3) recommend mechanisms for controlling and preventing the release of pellets. The complete study, published by the EPA (1992d), represents the first comprehensive assembly of information regarding the sources of pellets in the aquatic environment and is expected to become a basic reference for the EPA and plastics industry.

In the summers of 1987 and 1988 significant amounts of floating debris, such as wood, paper, and medical wastes, washed up on the ocean beaches of New Jersey and the southern shore of Long Island, New York. These washups, while occurring for short periods of time, resulted in the closure of approximately 70 miles of ocean beaches in New Jersey in 1987 and approximately 70 miles of ocean beaches in New York in 1988. The beach closures, along with the public’s perception of a fouled ocean, resulted in a $2 billion loss of revenue for the states of New Jersey and New York.

Floating debris interferes with the safe and healthy use of the Anacostia and Potomac rivers. Besides being unsightly, debris is destructive to dams, bridges, power plants, municipal water systems, recreational and commercial boats, and boating. Floating debris disrupts aquatic vegetation, which stabilizes shorelines and wetlands, aids in the removal of certain pollutants, and increases dissolved oxygen content in the water column. It interferes with the establishment of aquatic plants, which, in turn, limits spawning areas and habitat for fish and benthic organisms. Floating debris, particularly fragments of plastic and fishing line, is a hazard to wildlife both through ingestion and entanglement. This debris profoundly detracts from the natural beauty and healthy recreational enjoyment of the rivers of Washington, D.C. Finally, floating debris that is not trapped and removed in the Anacostia and Potomac rivers eventually enters and degrades the waters of the Chesapeake Bay and the open Atlantic Ocean.

While acknowledging that marine pollution arises from the actions of man, research indicates that this pollution cannot be attributed solely to man’s activities performed directly in the oceans. This paper identifies the primary land-based sources of marine pollution and discusses the main coastal rural and upland activities that affect the discharges of plastic waste and other floatable debris into the marine environment. Particular attention is given to the coastal zones within semien- closed areas such as the Wider Caribbean that are increasingly showing signs of pollution. The paper concludes with some ideas con-cerning a framework to address control and reduction of these sources.

The territory of Puerto Rico contains one large island and several small islands including Vieques, Culebra, and Mona. Puerto Rico is bordered on the north by the Atlantic Ocean, on the east by the Virgin Passage, on the south by the Caribbean Sea, and on the west by the Mona Passage. The principal island of Puerto Rico is one of the largest of the West Indies. Puerto Rico’s greatest east- to-west distance is about 180 km (110 mi), and its extreme north-to-south distance is about 65 km (40 mi). The highest point is 1338 m (4389 ft) at Cerro La Punta in the central town of Jayuya.

In recent years, attention to marine debris and its associated problems has been in-creasing in the Caribbean region. This debris consists mostly of persistent material such as plastics, metal, glass, and rubber. The sources of this litter include maritime activities associated with shipping and fisheries, beach recreation activities, and land-based refuse. Marine debris poses serious threats to marine wildlife (through entanglement and ingestion), vessels (e. g., entanglement in propellers), and the aesthetic qualities of marine areas. Also, debris on shorelines is a potentially serious problem for Caribbean island states because it threatens the safety of beach users and negatively impacts the economy— tourism is a major source of revenue in many Caribbean island states. While regional experts increasingly identify the problem of marine debris as one of primary concern, many Caribbean states and territories have ratified conventions (Barnett, Chapter 14, this volume, Table 14.2) and initiated surveys and monitoring programs that address marine debris in the Wider Caribbean (Coe et al., Chapter 3, this volume).

While acknowledging that marine debris arises from the actions of man, it has become increasingly clear that it cannot be attributed solely to man’s activities in the oceans. In this paper, we (1) identify the primary land-based sources of marine debris; (2) discuss the main coastal and upland activities that affect the discharges of plastic waste and other floatable debris into the marine environment; and (3) conclude with some ideas concerning strategies and activities to reduce, control, and minimize these sources.