Boating's Impact: Understanding Water Pollution Sources And Solutions

Boats can cause water pollution in several ways, and with millions of people enjoying recreational boating, the impact of these vessels on the environment is a growing concern. Boats can cause water pollution through sewage, oil and fuel spills, chemical cleaners, noise, and disruption to natural water circulation. While individual boats may only release a small amount of pollutants, the collective impact of thousands of boats can cause distinct water quality problems in lakes, rivers, and coastal waters. This can have far-reaching consequences for marine life and ecosystems.

Sewage discharge

Regulations for Sewage Discharge

International regulations, such as MARPOL Annex IV, have been established to address the issue of sewage discharge from ships. These regulations prohibit the discharge of sewage within a specified distance from the nearest land, unless the ship has an approved sewage treatment plant or a certified holding tank on board. The U.S. Environmental Protection Agency (EPA) also provides guidelines for boaters to minimize sewage discharge, recommending the use of approved marine sanitation devices (MSDs) and proper waste disposal facilities when returning to shore.

Health and Environmental Hazards

Raw or poorly treated sewage discharged from boats can have several adverse effects on human health and the environment:

• Spread of Diseases: Human waste contains bacteria, viruses, and parasites, which can contaminate water and spread diseases. Common symptoms of exposure to contaminated water include nausea, stomachache, vomiting, diarrhoea, sore throat, earache, respiratory problems, and skin infections. Serious waterborne diseases include hepatitis, typhoid, dysentery, and cholera.
• Oxygen Depletion: Sewage discharge can lead to oxygen depletion in the water, creating a health hazard for marine life and disrupting aquatic ecosystems.
• Visual Pollution: Sewage can cause unsightly contamination in coastal areas, particularly affecting the tourism industry.
• Shellfish Bed Contamination: Sewage discharged overboard can contaminate shellfish beds, leading to closures and impacting the livelihoods of those who depend on shellfish harvesting.
• Increased Nutrient Levels: Even treated boat sewage can increase nutrient levels in the water, as treatment systems on boats are not designed to remove nutrients. This can lead to excessive algae growth and contribute to the creation of hypoxic or "dead" zones.

Preventive Measures

To minimize the impact of sewage discharge from boats, several preventive measures can be taken:

• Proper Waste Management: Boaters should use approved MSDs to contain fecal matter and solid waste while on the boat. Upon returning to shore, portable toilets should be emptied at approved waste handling facilities, and MSDs should be discharged at designated pump-out stations.
• Eco-Friendly Cleaning Products: Selecting non-toxic and environmentally friendly cleaning products can help prevent water pollution and protect aquatic life.
• Responsible Boat Maintenance: Boaters should maintain their boats away from the water, use drop cloths to catch any spills, and properly dispose of or recycle waste materials, such as used oil and paint chips.
• Marina Planning and Design: Proper planning and design of marinas can help maintain water quality. This includes considering natural flushing to renew marina waters and conducting pre-development assessments to protect ecologically sensitive areas.

Oil and gas pollution

One of the main ways boats contribute to oil and gas pollution is through small oil spills from motors and refueling activities. These spills can contain petroleum hydrocarbons that attach to waterborne sediments and persist in aquatic ecosystems, harming bottom-dwelling organisms at the base of the marine food chain. Boat cleaners and chemicals used for maintenance and repairs, such as solvents, oils, paints, and cleansers, can also spill or run off into the water, causing pollution. Spilling fuel (gasoline or oil) and discharging uncombusted fuels from engines are other contributors to nonpoint source pollution.

To prevent oil and gas pollution, boaters should carefully fuel boat engines, recycle used oil, and dispose of worn motor parts into proper receptacles. Using nontoxic cleaning products that are safe for humans and aquatic life is also essential. Additionally, boaters should clean and maintain boats away from the water and vacuum up loose paint chips and dust to prevent paint and other chemicals from entering the water.

In the event of an oil spill, boaters should not use detergent to disperse it, as many popular brands of washing-up liquid are toxic to aquatic life. Instead, they should use their spill kit and consider environmentally friendly options, such as Bilgeaway filters, which remove bilge contaminants. Nappies and cat litter can also be used to soak up spills, but they must not be disposed of in regular waste if contaminated with oil.

By following these guidelines, boaters can help prevent oil and gas pollution, protecting aquatic ecosystems and the environment.

Chemical cleaners

Boats and boating activities can contribute to nonpoint source water pollution through the use of chemical cleaners. These cleaning agents and soaps often contain solvents, acids, chlorine, ammonia, and phosphates—substances that can harm plankton and fish. Small oil spills from motors and refueling activities contain petroleum hydrocarbons, which attach to waterborne sediments and persist in aquatic ecosystems, harming bottom-dwelling organisms at the base of the marine food chain.

Boat maintenance and repair work generate significant amounts of pollutants, including solvents, paints, oils, and other chemicals, which can easily seep into groundwater or be washed directly into surface water. Antifouling paints, in particular, contain toxic metals that are harmful to marine life. Additionally, the use of anti-freeze during winter storage, if not properly managed, can lead to leaks or spills that pollute water bodies.

To reduce pollution from chemical cleaners, boaters can take several measures. Firstly, selecting non-toxic and environmentally friendly cleaning products that do not harm humans or aquatic life is essential. This involves carefully checking the ingredients of cleaning products, as some "environmentally friendly" claims may not be entirely accurate.

Secondly, performing boat cleaning and maintenance away from the water is recommended. By using a drop cloth and working on land, any chemical or paint spills will be absorbed by the soil instead of entering water bodies. This simple step can significantly reduce the amount of pollution that reaches our waterways.

Lastly, proper waste disposal practices are crucial. Boaters should use portable toilets and approved shoreside waste handling facilities to ensure that sewage and solid waste do not end up in recreational waters. By following these measures, boaters can help minimize the impact of chemical cleaners on water pollution and protect the delicate marine ecosystem.

Noise pollution

While boat engines can cause water pollution by discharging unburned fuel into the water, they also contribute to noise pollution. Boat motors can be a source of noise pollution, particularly the older two-stroke engines, which are noisier and less fuel-efficient than the newer four-stroke engines. Upgrading to a four-stroke engine not only reduces water and air pollution but also results in a quieter engine.

Boat operators can take measures to reduce noise pollution. Maintaining a proper distance from wildlife, such as keeping at least 200 feet away, is one way to minimise disturbance. Additionally, keeping the boat property trimmed and ensuring the engine is well-tuned can help reduce noise levels.

Marinas and boating activities

One major source of pollution is the discharge of sewage and sanitary waste into the water. Boaters should aim for zero discharge of sewage, containing all fecal matter and solid waste in approved marine sanitation devices (MSDs) while on board. Upon returning to shore, these devices should be emptied at approved shoreside waste handling facilities. Poorly maintained sanitary waste systems on boats and pump-out stations at marinas can significantly increase bacteria and nutrient levels in the water.

Chemical pollution is another concern. Boat maintenance and repair often involve solvents, oils, paints, and cleansers, which can spill directly into the water or enter via runoff. Many of these products contain harmful substances like chlorine, ammonia, and phosphates, which can damage aquatic life. For example, chlorine can harm plankton and fish. Additionally, fuel spills and the discharge of uncombusted fuels from engines contribute to water pollution. Two-stroke motors have been found to emit 25-30% of their unburned fuel into the water, affecting the pH and dissolved oxygen levels, which in turn influence the type and abundance of fish and wildlife.

The siting and design of marinas can also impact water quality. Poorly planned developments can disrupt natural water circulation, leading to shoreline soil erosion and habitat destruction. To mitigate this, marinas should be strategically located and designed to facilitate natural flushing, allowing for the regular renewal of marina waters.

To reduce pollution from marinas and boating activities, several measures can be implemented:

• Marinas should conduct pre-development water quality and habitat assessments to protect ecologically valuable areas.
• Boaters should use non-toxic, environmentally friendly cleaning products to prevent chemical substances from entering the water.
• Boat maintenance, such as fueling engines and changing motor parts, should be done carefully to prevent petroleum spills. Used oil should be recycled, and worn motor parts should be discarded into proper receptacles.
• Upgrade boat motors from two-stroke to four-stroke engines, which emit up to 97% less water and air pollution.
• Keep engines well-tuned and avoid travelling at maximum speed to reduce emissions and the chance of spills.
• Avoid throwing trash overboard and encourage the use of reusable items to reduce trash pollution.

Frequently asked questions