Water: Marine Debris
Marine Debris Sources
Marine debris is often the result of deliberate or accidental actions by people on land or at sea. Improperly covered trash bins, litter, debris left in streets and on beaches, and items thrown overboard can all become marine debris. Items can travel far before landing on shorelines or settling in the ocean. Marine debris can come from anywhere in a watershed, and be carried by rivers, streams, and other waterways into the ocean. To better understand and control marine debris we must address the actions that generate or transport marine debris.
The National Marine Debris Monitoring Program determined that 49 percent of debris on U.S. beaches is from land-based sources, 18 percent is from ocean-based sources, and 33 percent is from a general source that could be considered land or ocean-based. However, regardless of the source or type, all marine debris impacts our oceans, beaches, and waterways.
- Municipal landfills
- Transport of litter and waste (on land or on waterways)
- Storm water discharge
- Industrial or manufacturing
- Litter and waste generated in coastal and inland zones from improper waste management
- Natural events
Individuals can contribute to marine debris through both accidental and deliberate actions. On the beach and piers, individuals leave trash or toss it into the water. Further inland, people lose or throw trash on the streets or improperly manage their waste and garbage bins. The inland actions can lead to trash in storm drains, rivers, and other waterways. Once in these waterways, the trash can be carried to our oceans. Any items, from plastic bottles, food wrappings, and cigarette butts to larger items such as lawn care containers or even refrigerators, can become marine debris.
Facilities and ConstructionLand-based marine debris can come from industrial and manufacturing facilities, as well as construction and demolition sites. Facilities can generate marine debris if their production, equipment, trash disposal, and waste streams are improperly managed. Additionally, industrial by-products, particularly plastic resin pellets, may also become marine debris during transport or disposal (learn more at: Plastic Pellets in the Aquatic Environment). Similar to industrial materials, construction and demolition materials can become marine debris if appropriate disposal practices are not followed or if equipment or supplies are left unsecured. These debris items can include scrap metal, unused parts, paint buckets, and packaging materials.
Trash can come from many different sources in a municipality and becomes marine debris. The amount of marine debris that enters the ocean from municipal storm sewer systems often depends on the municipal infrastructure supporting waste management. Combined sewer systems and stormwater systems can carry debris into coastal and ocean waters, especially during heavy rain events. Debris can be picked up during rain flow and carried into a drain or may have been intentionally thrown into a drain. Typical debris entering these systems includes medical waste and street litter. Municipalities also maintain landfills. Collection and transport of waste to these sites may result in marine debris if materials are mishandled or accidentally lost. Finally, lack of waste management options may result in the improper dumping of wastes, which can lead to more materials entering our waterways and oceans.
Natural events, such as tornadoes, hurricanes, floods, and tsunamis, can all generate and carry debris into the marine environment. During the 2005 hurricane season, the Sabine National Wildlife Refuge in Louisiana had approximately nine million cubic yards of debris across 1,770 acres of marsh. Debris resulting from natural weather events can be almost anything, from roofs to plastic straws, depending on the severity and scale of the event. The most common items include containers and other unsecured outdoor items.
- Merchant shipping, ferries, and cruise liners
- Fishing vessels
- Public vessels
- Private vessels
- Offshore oil and gas platforms, and drilling rigs
- Aquaculture installations
- Natural events
Vessels and Other Structures
Recreational and commercial vessels, platforms, and other structures at sea are all potential sources of marine debris. Similar to marine debris originating from land-based sources, debris from ocean-based sources is a result of accidental or deliberate human actions. Marine debris can come from mismanagement of ship wastes and equipment, or from accidental loss of gear overboard. This debris can consist of food containers and trash from the galley, fishing gear (e.g., nets, ropes, and light sticks), cargo and equipment.
Marine debris can also come from abandoned vessels and offshore materials and equipment, like aquaculture installations and buoys. Pieces from these structures can break off due to improper securing and heavy sea conditions and settle to the ocean floor or end up onshore.
Inclement weather, strong seas, and natural events can also cause accidental loss of waste and cargo from vessels and other structures at sea. This debris may be lost due to inadequate securing of equipment and poor loading practices.