As marine tourism associated with near-shore marine and sea-bottom habitat has grown in recent years, sewage and garbage disposal from small vessels has become a subject of concern for many within the tourism industry. Vessels discharging raw or partially treated sewage and dumping garbage in coastal waters pose an increasing threat to both people and the environment.
Human waste contains nutrients, pathogens and viruses that can contribute to disease and detrimental algal blooms in near-shore marine environments. These blooms reduce available oxygen in the environment and smother sea-bottom habitats, leading to a decrease in coral cover and negatively affecting populations of fish and other species. Increased levels of bacteria, viruses and diseases associated with human waste can also pose serious risks for human health and food resources in a local community by contaminating a variety of harvestable fish and other species.
Garbage disposed into the marine environment is both unsightly and dangerous. Plastic objects, fishing lines, cigarette butts and Styrofoam debris are often consumed by turtles, seabirds, fish and marine mammals and cause the death of millions of these animals every year.
When garbage becomes entangled on coral and rocky reefs, it smothers and kills coral colonies and can pose a safety hazard to snorkelers and divers. Juvenile sea lions as well as cetaceans play with rope and fishing lines, getting them stuck around their necks or embedded in their mouths and posing serious risk to their health.
Why Should I Care?
Increased Levels of Viruses, Bacteria And Disease: Fecal coliform is a common bacteria associated with human waste. The buildup of this and other pathogens in the environment can cause contamination of food supplies, threatening both reef ecosystems and human populations in a region and diminishing the attractiveness of an area as a tourist destination.
Red Tides: These may be triggered by a high concentration of human waste and other nutrients (e.g. laundry and galley effluents laced with detergent) in areas with low water exchange such as tidal lagoons. Also, thick films of benthic diatoms can cover sandy bottoms, choking their inhabitants.
Fewer Fish: Many species of reef fish depend on living coral as a food resource as well as for habitat and shelter. When algal blooms or garbage damage reef communities, fish populations decline, negatively affecting ecosystem health and diminishing the experience of visitors to the reef.
Stressed and Diseased Marine Organisms: Pathogens associated with microorganisms contained in human waste can cause disease in marine organisms, in particular among species found in sea-bottom habitats.
Increase in Threats to Wildlife: In addition to the threats posed by sewage, garbage is often mistaken as food by wildlife and can kill seabirds, turtles, fish and marine mammals. When garbage becomes entangled in near-shore marine ecosystems, it can smother and kill living organisms, particularly species found in sea-bottom habitats. Because many of these animals are prime attractions for tourists to a destination, their loss can seriously hurt the tourism industry in an area.
Effects on Ecological Integrity and Landscape: In the case of the Galápagos, human waste may carry seeds from previous meals, that, if deposited on the islands under the right conditions, may create an infestation of invasive, edible plants such as tomato, passion fruit or black berry. Toilet paper left on the trails can diminish the attractiveness of the landscape.
What Can I Do?
Recommend that Passengers Use Land-Based Restroom Facilities Prior to Day Tour Excursions: Most land-based facilities are connected to some kind of municipal waste treatment facility, which can significantly reduce discharge of untreated sewage at sea.
Treat Sewage Prior To Release From Your Vessel: If pump-out facilities are not available, there are several biodegradable chemicals and mechanical methods that can be used to reduce solids and pathogens in waste prior to disposal in the environment. It is also important for small vessels to proceed as far offshore as possible before discharging treated sewage, to prevent contamination of bottom sediments and sea-bottom habitat in shallow coastal regions. Avoid discharging toilets or sewage holding tanks in confined or crowded places, environmentally sensitive areas or marine protected areas.
Control the Disposal Of Organic Food Waste: Dispose of food waste on land only if it is adequately treated, through sterilization and avoidance of the introduction of organisms. When disposing organic waste, be sure it is done within a given area, as established and approved by the regulatory agencies that handle waste on the islands. Only dispose of organic waste into the sea if you are as far as possible from shore, and at least 4 km away, the minimal distance established by national and international regulations. Crush any waste disposed of into the sea before discharging it.
Keep Marine Vessel Sanitation Devices In Good Operating Condition: Regularly inspect and maintain all hoses, fittings and mechanisms associated with waste storage, to prevent accidental discharge of untreated sewage.
Support The Establishment of No Discharge Zones: The creation and enforcement of No Discharge Zones helps protect ecologically and economically important coastal areas.
Reduce and Reuse: Reduce the use of disposable products made from aluminum, plastic or paper and use reusable containers whenever possible. If disposable items are to be used, select compostable items.
Pick Up Damaged Fishing Nets or Lines Cut Away from Propellers: Leaving fishing nets or lines in the sea could harm marine wildlife.
Educate Tourists: Many tourists are unaware of the potential damage that something as small as a cigarette butt can cause in the marine environment. Supply information to tourists regarding the threat that improper garbage disposal poses to marine life. Before visiting the Galápagos, tourists should have information on the norms of appropriate behavior so as to minimize their impact on visited areas. Tourists should also be educated on the solid waste management problem and the danger of introducing exotic species in the Galápagos.