Association of State Wetland Managers - Protecting the Nation's Wetlands.

The Wetland Wanderer: Spring in Wetlands: Glory Time for Ephemeral Wetlands

by Brenda Zollitsch, Policy Analyst, ASWM

Please note that this is a compilation of information developed by other organizations and agencies working on the protection of ephemeral wetlands and the organisms that rely on them.  All sources are cited with hyperlinks to the original materials.

Still Waiting for Spring Here in Maine

Most areas of the U.S. are experiencing spring right now.  However, we here in Maine are still trying to get the weekend’s snow off the roads after yet another big storm that dropped almost a foot of snow the last weekend of March.  This week’s icy rain is helping speed the clearing process.  However it is anything but pleasant, mixed with giant snowflakes and pelting ice.  Regardless, I am noticing hints of spring.  Tender green shoots are bravely trying to come up here and there.  Songbirds are more vocal.  Streams are starting to 1vernalpoolmain040617gush.  One of the clearest signs of spring is Big Night, the period of time each spring when amphibians travel to ephemeral pools to reproduce.  This annual trek of frogs and salamanders is a highlight for wetland enthusiasts, with professionals and novices alike jockeying to guesstimate when it will occur.

In Maine, spring feels like a hard fought reward for surviving the rugged cold and snow that keeps even the hardiest of souls more housebound than they would prefer.  As a family, we visit wetlands throughout the year, but the best moments for me are when you see the green buds on the tips of branches and shoots coming up from the muddy ground.  A part of this, too, is the filling of ephemeral wetlands, those temporary pools that create what I like to call amphibian “love ponds”.

Ephemeral Wetlands: The Wetland Quick Change Artist

Many wetlands go through seasonal changes, but none more so than ephemeral wetlands.  The U.S. Environmental Protection Agency (EPA) defines ephemeral wetlands as depressional wetlands that temporarily hold water, usually in the spring and early summer or after heavy rains. Periodically, these wetlands dry, often in mid to late summer. They may be isolated without a permanent inlet or outlet, but may overflow during times of high water. Ephemeral wetlands are often free of fish, which allows for the successful breeding of certain amphibians and invertebrates. These seasonal wetlands result from winter snowmelt and spring rains, and typically occur in low areas.

The Michigan Department of Natural Resources shares that some seasonal wetlands may not have visible standing water, but instead they have waterlogged soils. By mid-summer, most seasonal pools have dried out or are just barely moist. There are many different types of seasonal wetlands including seasonal pools, springs, seeps, coastal plain marshes and lake plain wet prairies.  You may know ephemeral wetlands by other names as well, since they are often also referred to as ephemeral ponds, seasonal ponds, temporary ponds or ecologyvernalpoolsvernal pools.

Although many of these seasonal wetlands may be less than a half-acre in size, they provide an important food source for migratory songbirds and  sage grouse chicks, waterfowl, breeding and feeding areas for amphibians and reptiles, and critical winter food supplies for wild turkeys, deer,  and other birds and mammals. If you are lucky enough to own any of these seasonal wetlands, you will notice they are used by a wide variety of wildlife.   They are critical for migrating birds and important for flood control and water quality.

Ephemeral Wetlands Play a Critical Role for Amphibians

The ecology of ephemeral wetlands plays an important overall role in ecosystems.  The Coastal Plains Institute has worked extensively on issues connected to ephemeral wetlands.  They share that ephemeral ponds are essential to the survival of many amphibians: “Some amphibian species lack the defenses to co-exist with predatory fish and require fishless ponds for breeding habitat. Therefore, ephemeral ponds support different species than do lakes and rivers. These ponds are a source of high diversity and biomass and support far more species and individuals than their size would suggest. It is common to find 15-20 amphibian species utilizing a single wetland and even a small vernalpoolarea040617wetland can produce 1000s of juvenile individuals in a single year, as shown in the above photo. These individuals travel widely into the surrounding uplands, transferring biomass from the nutrient-rich ponds into the uplands. Ephemeral ponds are important to many other species as well. The ponds, and the plants that grow in and around them, provide important habitat to many invertebrates, reptiles, mammals, and birds.”

It’s Hard Being an Ephemeral Wetland

Unfortunately, many small ephemeral wetlands have been drained and filled to facilitate agriculture, building new subdivisions or other development. This not only eliminates habitat, but also increases the risk of local flooding. Others have been excavated to construct stormwater detention ponds. During rain storms pollutants are washed into these ponds. Still others have been converted to permanent ponds for raising fish and other forms of aquaculture. Permanent bodies of water tend to support fish, which are known to significantly reduce successful breeding of amphibians and aquatic invertebrates.

ephemeralwetlands5Ephemeral wetlands face numerous challenges (Source: HERP).  They are often hard to define, identify and protect because they tend to be small, isolated and at certain times of the year do not hold water. These wetlands also tend to be highly productive. They warm quickly in spring and produce abundant quantities of food for developing amphibians, reptiles and migrating birds, especially waterfowl. Even small sites, much less than an acre, can produce hundreds of frogs, toads and salamanders. They also provide critical links to other wetlands and wildlife populations. Establishing appropriate legal protection for resources of such immense ecological value is difficult, and the level of protection currently given to Ephemeral Wetlands varies from state to state.

What can you do to help protect and preserve ephemeral wetlands?

There are many critical actions that you and/or your local government can undertake to help protect ephemeral wetlands.  The Herpetofaunal Education Research Program (HERP) provides the following useful list of actions:

•    Support the protection of these wetlands and their surrounding habitat
•    Visit Ephemeral Wetlands in your area — experience their uniqueness
•    Volunteer for local restoration efforts — contact local conservation organizations
•    Raise awareness in your local community to promote appropriate land use planning that will protect Ephemeral Wetlands and their upland habitat
•    Consider long-term protection options for wetlands on your private property such as conservation easements — contact your local land trust
•    Start a register of Ephemeral Wetlands in your area (For an example see
•    Participate in local amphibian monitoring programs like frog calling surveys and amphibian and reptile atlas projects coordinated by local conservation organizations
•    Join local conservation organizations involved in wetland protection

If you are a wetland manager, the protection of ephemeral wetlands can take on many forms – building a strong regulatory program at the state level, conditioning 401 certifications, including ephemeral wetlands in restoration planning, and more.  Managers and planners should be aware that ephemeral wetlands need to be viewed within the context of the surrounding uplands. Amphibians spend the majority of their life cycle in the uplands; therefore, these uplands are as vital to the survival of pond breeding amphibian populations as the aquatic breeding habitat. As a starting point, land managers should incorporate uplands surrounding an ephemeral pond into their management plans as core terrestrial habitat. Once an adequate radius is determined and delineated, other factors should be considered to determine the size and shape of this core terrestrial garyhabitat. The Coastal Plains Institute adds that if only a limited number of ponds can be incorporated into a management plan, decision makers should prioritize the protection of the following — pond clusters, ponds with known populations of specialized or target species, ponds with varying hydroperiods, ponds within close proximity of other ponds, and ponds surrounded by native or restorable habitat.

Protecting Ephemeral Wetlands All Year Long

So, after a long, hard winter, the promise of spring brings not only an emergence from the cold, but the filling of wonderful pools of productivity – ephemeral wetlands that signify the beginning of egg laying and new life.  Get out and enjoy them while they last.  More importantly, I encourage you to work to protect them throughout the year.  While it is primarily in the spring that ephemeral wetlands display their full glory, they remain the lifeblood of critical ecosystems year round.

Text Included in this Blog Originates from the Following Documents:

•    Midwestern Ephemeral Wetlands. US Environmental Protection Agency.
•    Florida’s Ephemeral Ponds and Pond-breeding Amphibians
•    EPA Webpage on Vernal Pools
•    Of Pools and People Website: Providing Information on Vernal Pools for Our Communities

Links to Additional Ephemeral Wetlands Information:

•    Temporarily Flooded Wetlands – Fish and Wildlife Habitat Leaflet.  Natural Resources Conservation Service.
•    Big Night: Amphibian Populations Crossing the Roads
•    Of Pools and People Website: Providing Information on Vernal Pools for Our Communities
•    Videos on vernal pools from Maine Vernal Pool Experts
•    ASWM Vernal Pool Website Links

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