Protecting Wetlands: Barriers Against Pollution

Wetlands are particularly susceptible to pollution, which can have a massive impact on their health. Wetlands are often found in the lower reaches of water courses, or are fed by numerous streams and waterways, so they have the potential to “receive and collect” pollution from over a wide area. This pollution can then build up and severely reduce biodiversity. However, wetlands also have an important role in addressing pollution, acting as natural filters that help to remove pollutants from the water. To maintain the water quality benefits provided by wetlands, the U.S. Environmental Protection Agency (EPA) recommends three management strategies: preservation, restoration, and construction of engineered systems that pretreat runoff before it reaches wetlands. One such system is the vegetated filter strip (VFS), a swath of land planted with grasses and trees that intercepts runoff before it reaches wetlands.

Vegetated filter strips (VFS)

VFS can be an effective tool for managing nonpoint source pollution, which is pollution that comes from diffuse sources such as agricultural runoff or stormwater. By intercepting and filtering these flows of runoff, VFS can help to remove pollutants before they reach wetlands, reducing the potential impact on the health of these ecosystems.

The grasses and trees planted in a VFS can help to slow down the flow of runoff, allowing more time for pollutants to settle out or be absorbed by the vegetation. This can be particularly effective for removing sediment and nutrients, such as nitrogen and phosphorus, which can be harmful to wetlands in excess.

Additionally, VFS can provide habitat and food sources for wildlife, contributing to biodiversity and ecosystem health. The vegetation can also help to stabilise soils, reducing erosion and further preventing sediment from entering wetlands.

Overall, VFS can be a valuable tool for protecting wetlands from pollution. By intercepting and filtering runoff, they can help to maintain the health and integrity of these important ecosystems.

Engineered systems that pre-treat runoff

One example of an engineered system is a vegetated filter strip (VFS). This is a swath of land planted with grasses and trees that intercepts uniform sheet flows of runoff before they reach wetlands.

VFSs are an effective way to reduce the amount of pollution that reaches wetlands. They can be designed to remove specific pollutants, such as nutrients, sediments, and pesticides. They can also help to reduce the amount of water that flows into wetlands, which can be beneficial in areas where water withdrawal is a concern.

Another example of an engineered system is a constructed wetland. These are designed to mimic natural wetlands and can be used to treat wastewater before it reaches natural wetlands. Constructed wetlands can be effective in removing pollutants such as nutrients, sediments, and pathogens. They can also provide habitat for wildlife and help to improve water quality.

In addition to VFSs and constructed wetlands, there are other types of engineered systems that can be used to pre-treat runoff. For example, detention ponds can be used to store and treat stormwater runoff before it is released into wetlands. Treatment wetlands can also be used to remove pollutants from wastewater before it reaches natural wetlands. These systems can be designed to target specific pollutants and can be effective in improving water quality.

Preservation and restoration

Wetlands are particularly susceptible to pollution. They are often found in the lower reaches of watercourses, or are fed by numerous streams and waterways, so they have the potential to "receive and collect" pollution from a wide area. This pollution can then build up and have a massive impact on the health of a wetland.

The U.S. Environmental Protection Agency (EPA) recommends three management strategies to maintain the water quality benefits provided by wetlands: preservation, restoration, and construction of engineered systems that pretreat runoff before it reaches receiving waters and wetlands.

One type of engineered system is the vegetated filter strip (VFS). This is a swath of land planted with grasses and trees that intercepts uniform sheet flows of runoff, before the runoff reaches wetlands.

Wetlands also have an important role in addressing pollution. They can act as natural filters, helping to remove pollutants from the water. However, if wetlands are degraded, they can no longer provide these benefits and can even become significant sources of pollution themselves. Excessive amounts of decaying wetlands vegetation, for example, can increase biochemical oxygen demand, making the habitat unsuitable for fish and other aquatic life. Degraded wetlands also release stored nutrients and other chemicals into surface water and groundwater.

Wetland loss can add stress to remaining wetlands. For example, if fewer wetlands are available to filter pollutants from surface waters, those pollutants could become more concentrated in the remaining wetlands. Wetland loss can also decrease habitat, landscape diversity, and connectivity among aquatic resources.

Reducing the use of plastics

Plastics are a major source of pollution for wetlands, particularly in coastal areas. Wetlands are often found in the lower reaches of watercourses, or are fed by numerous streams and waterways, so they have the potential to "receive and collect" pollution from a wide area. This pollution can then build up and have a massive impact on the health of a wetland.

To reduce the use of plastics and prevent plastic pollution from reaching wetlands, several measures can be implemented:

Reduce, Reuse, and Recycle: One of the most effective ways to reduce plastic pollution is to minimise plastic consumption in the first place. This can be achieved by reducing the use of single-use plastics, such as plastic bags, straws, and disposable water bottles. Instead, opt for reusable alternatives like cloth bags, metal straws, and refillable water bottles. Additionally, proper recycling practices can help divert plastics from landfills and oceans, reducing the amount of plastic waste that ends up in wetlands.

Support Sustainable Alternatives: Choose products made from sustainable and biodegradable materials instead of plastic whenever possible. For example, opt for paper or plant-based packaging over plastic packaging. Support businesses that use eco-friendly materials and practices, reducing the demand for plastic products.

Educate and Advocate: Spread awareness about the impact of plastic pollution on wetlands and the environment. Educate others about the importance of reducing plastic consumption and proper waste disposal. Advocate for policies and regulations that promote plastic reduction and encourage sustainable practices.

Participate in Cleanups: Get involved in local cleanup initiatives to remove plastic waste from wetlands and surrounding areas. Organise or join community events that focus on collecting and properly disposing of plastic litter, helping to prevent it from reaching and polluting wetlands.

Proper Waste Management: Ensure that plastic waste is disposed of properly and responsibly. Support initiatives that promote waste management infrastructure and recycling programmes. Encourage the use of waste bins and recycling containers, reducing the likelihood of plastic waste ending up in wetlands.

By implementing these measures, we can significantly reduce the amount of plastic pollution that reaches wetlands, helping to protect and preserve these vital ecosystems.

Reducing the use of fertilisers and pesticides

Wetlands are particularly susceptible to pollution, especially from fertilisers and pesticides used in modern-day intensive farming. These chemicals can have a massive impact on the health of a wetland, affecting the reproduction of plants and animals and reducing biodiversity.

To reduce the use of fertilisers and pesticides, here are some strategies:

• Preservation: This involves maintaining the natural state of wetlands and preventing any further degradation. This can be done by protecting wetlands from excessive pollutant loads and improper development, which can damage their water quality benefits.
• Restoration: If wetlands have already been degraded, restoration can help bring them back to a healthy state. This may include removing excessive amounts of decaying vegetation, which can increase biochemical oxygen demand and make the habitat unsuitable for aquatic life.
• Constructing engineered systems: Pretreating runoff before it reaches wetlands can help reduce the impact of pollutants. One example is the vegetated filter strip (VFS), which is a swath of land planted with grasses and trees that intercepts runoff before it reaches wetlands.
• Reducing groundwater withdrawal: Withdrawing groundwater or surface waters can reduce the flow of water into wetlands, which can impact their ability to filter pollutants.
• Controlling invasive species: Invasive species can alter the composition of wetland communities and add stress to remaining wetlands. By controlling invasive species, the health and diversity of wetlands can be preserved.
• Promoting wetland conservation: Wetlands play a crucial role in addressing pollution by acting as natural filters. Protecting and conserving wetlands can help ensure they continue to provide this important function.

Frequently asked questions