Environmental Protection Agency: Management Strategies for Coastal Wetland Stressors

Participants of the Coastal Wetland Reviews (CWR) identified the main causes of coastal wetland loss and degradation to include the below stressors.

Stressors include physical, chemical, and biological entities or processes that adversely affect the ecological condition of a natural ecosystem, as well as programmatic issues.

For each of the stressors, management strategies are suggested and illustrated with specific projects and supplemented by additional resources where possible.

Stressors:

Coastal Wetlands Landing Page

Please note: several of the links in the sections below exit the EPA site EXIT


Agriculture

Conversion of wetland area to agriculture, wetland drainage, and nutrient, sediment, and chemical runoff from agricultural fields can impact coastal wetlands by reducing area and degrading function.

Management Strategies:

Nonpoint source control: Controlling agricultural runoff and the associated nutrients and sediments protects the condition of nearby wetlands.

Regulatory Guidance: Agricultural exemptions to Clean Water Act Section 404 permitting are limited to “normal farming” activities that are part of “established” and “ongoing” farming operations; details are clarified through exemption guidance documents.

Restoration: Multiple programs finance and support restoration and protection of wetlands on agricultural land.

Watershed Management: Wetlands are influenced by processes occurring throughout their watershed. Watershed-scale assessment and planning is useful to understand influences on wetlands and prioritize action on a watershed scale.

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Climate Change

Impacts due to climate change are manifested as conversion to open water as a result of sea level rise, erosion due to storm surge and destruction by severe storms. Changes in precipitation patterns and increasing drought affect the timing and delivery of water and sediments to coastal wetlands. Water quality and ecological integrity are also affected by increased air and water temperature, as well as increased acidity of water due to uptake of atmospheric CO2.

Management Strategies:

Land Acquisition: Conservation easements or buyout programs provide resources for coastal property acquisitions. This allows communities to adapt to sea level rise by moving development out of vulnerable areas.

Living Shorelines: Natural shorelines can provide protection from flooding and erosion more sustainably than hardened structures. (Source: Virginia Institute of Marine Science)

Management Toolkits: Toolkits compile guidance for planning for and adapting to climate change impacts, as well as provide technical tools for accomplishing these goals.

Modeling: Models depicting sea level rise and other climate change impacts allow managers to identify vulnerable areas.

Restoration: Restoring estuarine habitats allows coastal communities and ecosystems to increase their resilience to climate change.

Rolling Easements: A variety of methods exist for ensuring coastal development does not prevent the inland migration of wetlands as sea level rises.

  • Examples from Coastal Wetland Reviews
    • One regulatory tool to produce a rolling easement is to ensure public access to beaches. New Jersey’s public access policies could be adapted to achieve rolling easement goals.
  • Resources

Vulnerability Assessments: Assessments of the potential impacts climate change will have on a coastal community are used to identify priority planning areas.

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Cumulative Impacts

Small acreages of wetlands loss, which may be the result of a variety of stressors, may be unregulated or go undetected. These impacts may eventually lead to significant losses in wetland acreage and function.

Management Strategies:

Monitoring, Assessment, & Mapping: Periodic wetland mapping allows managers to track changes to wetland area. Similarly, monitoring and assessment tracks changes to wetland condition. This information can be used to identify areas to target for protection or that are suitable for development.

Restoration: Restoration of degraded wetland area and removal of hydrologic stressors can increase wetland area.

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Development

Wetland area is lost as a result of conversion to residential and commercial area as coastal populations continue to increase. Shoreline armoring (seawalls, bulkheads, etc.) also causes wetlands to erode and prevents inland migration of wetlands. Secondary impacts of development include decreased water quality and change in hydrology as a result of urban runoff.

Management Strategies:

Easements and Conservation: Land trusts or government agencies can facilitate the purchase and management of wetlands to prevent conversion to developed area.

Living Shorelines: Natural shorelines can provide protection from flooding and erosion more sustainably than hardened structures.

Local Planning: Decisions regarding how development will occur are made at a local planning level.

Low Impact Development: Low impact developments reduce the impact that development and associated stormwater flows have on wetlands and other natural resources.

Watershed Management: Wetlands are influenced by processes occurring throughout their watershed. Watershed-scale assessment and planning is useful to understand influences on wetlands and prioritize action on a watershed scale.

Note: Section 404 of the Clean Water Act established the federal permitting program which regulates most dredge and fill activities (very often for development purposes) in wetlands. However, CWR discussions tended to focus more on ways which regional, statewide, or local protection strategies supplement existing federal regulations, and these strategies are highlighted here.

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Hydrologic Modifications

Hydrologic modifications to coastal wetlands include direct alterations due to channelization, drainage, or mosquito impoundments. They also include indirect alterations to hydrology within the whole watershed such as changes to overland flow rates or loss of watershed connectivity due to dams or water diversions. This loss of hydrology can result in the conversion of a wetland to an upland or open water area. Changes to sediment and nutrient cycling are inevitably coupled with these altered hydrologic regimes.

Management Strategies:

Integrated Pest Management (IPM): Under IPM, mosquito impoundments can be managed for multiple uses, allowing for natural hydrology while still controlling mosquito life cycles.

Restoration: Restoration of mosquito impoundments, removal of dams and tidal restrictions and reduction of other hydrologic stressors can increase wetland area.

Subsidence Control: Subsidence lowers coastal elevations and makes communities more susceptible to flooding during storm events and relative sea level rise. When subsidence is caused by groundwater withdrawals, it may be controlled by changing water supply strategies.

Watershed Management: Wetlands are influenced by processes occurring throughout their watershed. Watershed-scale assessment and planning is useful to understand influences on wetlands and prioritize action on a watershed scale.

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Invasive Species

Introduction, establishment and spread of non-native vegetation results in native species loss and hydrologic alterations.

Management Strategies:

Invasive species control: Invasive species monitoring and control strategies often rely on volunteer-based efforts.

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Limitations of Regulations

While regulatory programs are key tools in protecting wetlands, uncompensated loss can occur in areas that are not covered by regulations, such as wetlands outside the jurisdiction of the Clean Water Act. In addition, a lack of clarity in regulations, limited field presence, or lack of coordination between various regulatory programs may impede implementation and enforcement of wetland protections where they do exist. And, while compensatory mitigation is an important part of achieving the regulatory goal of “no net loss of wetlands,” mitigation success may be further improved through monitoring, enforcement and scientific guidance.

Management Strategies:

Collaboration: Collaboration between agencies and across sectors reduces duplicative work, increases consistency in regulatory requirements and increases knowledge-sharing.

Enforcement: Aerial surveys and comparison of maps of wetlands loss with permit database information allow sites of illegal wetlands loss to be identified. Publicity of enforcement programs increases the compliance to permits and mitigation requirements.

Functional Assessment: Wetland assessments provides a way to identify if sites achieve desired conditions and could allow for mitigation credits to be granted based on functional value rather than area.

State programs: State regulatory and non-regulatory wetland programs can supplement or go beyond protection offered by federal regulations.

Watershed Planning for Mitigation: Stand-alone mitigation project sites are not as successful as those created within the watershed context.

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Silviculture

Rowing and bedding of forested wetlands can lead to upland conversion and hydrologic alterations if forestry best management practices are improperly implemented.

Management Strategies:

Forestry Best Management Practices (BMPs): Best Management Practices are necessary to minimize the impact of forestry activities on wetlands. Though some forestry activities are exempt from the Clean Water Act Section 404 wetland dredge and fill permit process, they must follow applicable BMPs in order to remain in compliance.

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Tools to Address Multiple Stressors

Education & Outreach Resources

Funding Resources

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Coastal Wetlands Landing Page


Science Topics
Climate Change, Conservation & Sustainability, Geology, Hydrology
Middle School, High School
6th Grade, 7th Grade, 8th Grade, 9th Grade, 10th Grade, 11th Grade, 12th Grade

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