Wetlands
Wetland ecosystems exist in parts of the state that are shallowly flooded for some part of the year. This includes areas of intermittent, seasonal, or permanent flooding. Wetland regions have declined across the country and now make up less than 1% of Indiana’s land area. Still, these ecosystems exist in a broad variety of forms, including swamps, marshes, fens, bogs, sinkholes, and mudflats. All result in unique soil and habitat conditions that support aquatic plants and animals. Some characteristic species of Indiana wetlands are marbled salamander (Ambystoma opacum) and spotted salamander (Ambystoma maculatum), spotted turtle (Clemmys guttata), and great blue heron (Ardea herodias). Common plant life includes bur sedge (Carex grayi) and wood reed (Cinna arundinacea). Many Species of Greatest Conservation Need populate Indiana wetlands. They include birds like king rail (Rallus elegans), insects like willow sphinx moth (Sphinx luscitiosa), amphibians like crawfish frog (Lithobates areolatus), and mammals such as swamp rabbit (Sylvilagus aquaticus) and star-nosed mole (Condylura cristata). There are also endangered plants, such as Northern white cedar (Thuja occidentalis) and Northern manna grass (Glyceria borealis).
Areas classified as wetland ecosystems in Indiana in 2024.
- Ecosystem Services and Human Benefits
The wetlands of Indiana are integral to the health of the state’s water resources. Chemical and sediment pollutants are removed from water filtered through the ecosystem’s vegetation. Filtration of excess nutrients reduces algae blooms that negatively impact human, fish, and wildlife health. Ephemeral wetlands are small, isolated ponds that dry and refill annually. Because these ponds do not hold water year-round, fish populations cannot be established in them. Many amphibian species that lack the defenses to coexist with fish predators rely on ephemeral wetlands for breeding habitat. Protecting these ecosystems protects Indiana’s biodiversity, allowing many species to flourish. Biodiversity is the root of the ecosystem services from which the people of Indiana derive benefits.
- Ecosystem Status
Indiana’s wetlands have significantly declined within the last 200 years. About 85% of Indiana wetlands have been lost since the 1780s. Most of this land has been converted to agricultural ecosystems for farming and economic activity. Federal and state policies on wetland protection and wetland development are undergoing changes. Balancing economic outcomes with conservation needs is crucial for responsible stewardship of natural spaces as a public good.
- Ecosystem Pressures
Expansion and intensification of alternate ecosystems such as agricultural lands and their accompanying pollutants and effluents place pressures on Indiana wetlands. Drainage of wetlands began in the 19th century, followed by conversion of the soil to agricultural production. This drainage negatively impacts native species, many of which are listed as Species of Greatest Conservation Need, while contributing to changes in climate via stored carbon release. Today, annual and perennial non-timber crops, wood and pulp plantation, and freshwater aquaculture threaten the surviving wetland ecosystems.
Agricultural expansion not only removes area from wetland ecosystems but introduces harmful effluents and pollutants. Agricultural runoff may include nutrients, toxic chemicals, and sediments. Nutrient pollution involves nitrogen and phosphorus, commonly found in sewage, fertilizers, and agricultural runoff. Nutrients in small amounts may promote plant and animal life, but in excess, eutrophication may occur, leading to excessive algal bloom growth and oxygen depletion within wetland waterways. Water quality is further reduced by heavy metals and pesticides containing toxic chemicals, harming native plants and animals. Amphibians, which rely on ephemeral wetlands for breeding habitat, are particularly vulnerable to environmental toxins because of their permeable skin. Wetland ecosystems may also be affected by changes in climate patterns discussed in this supplemental report.
Additional pressures that affect river and stream ecosystems in Indiana can be explored here.
- Ecosystem Conservation Opportunities
For wetland conservation to be effective, efforts need to involve both agencies implementing change and individuals affected by these changes. A variety of wetland conservation programs exist within Indiana, with administration from state and federal agencies, nonprofit conservation organizations, businesses, and individuals. These include incentive programs, education programs, acquisition programs, and regulatory programs.
At the landowner level, one opportunity for conserving wetlands in Indiana is expanding registry programs to protect the highest-quality private lands. These programs may be designed to kickstart conservation initiatives on private lands. Classification of land and definitions of protection will be helpful in determining the status of properties and their related management options. This will largely depend on access to land for field surveys, making positive partnerships between professionals and landowners vital to success.
DNR and partners may also collaborate in forming wetland restoration groups to maximize the functionality of existing wetlands with restoration. Through these groups, wetland ecosystems may be identified as priority restoration potential sites based on research spanning soil surveys, historic General Land Office (GLO) records, vegetation surveys, elevational land surveys, and climate data. With this list completed, permits for regional wetland restoration plans may be secured, and grants for regional restoration may be applied for. Management may largely focus on hydrology and plant diversity to preserve the native ecosystems.