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  Archived Posts From: 2016


WMAP, This is How We Roll…

Written on: December 9th, 2016 in Outreach

We (the Wetland Monitoring & Assessment Program, aka WMAP) learn and grow every year.  Looking back at 2016, we decided to share our top four fun items that we learned or experienced along the way, and a field notebook page infographic pointing out some of our accomplishments throughout 2016.  Enjoy!

Lessons Learned This Year:

This aerial view shows all the muskrat homes (brown dots) on a small portion of the Appoquinimink watershed.

This aerial view shows all the muskrat homes (brown dots) on a small portion of the Appoquinimink watershed.

  1. You never know what you might find in a wetland.  You might find a cool terrarium or a ginormous lamp pole shade.  Check out the Trash or Treasure’s blog post.
  2. When looking at aerial photographs, muskrat homes in the marsh make the land look like it has chicken pox.
  3. Always check the tidal range of a site.  If you don’t, you and your boat might end up high & dry. Womp womp..
  4. Our seasonal people actually like what they do over the summer in spite of working in 100°F weather and really hummocky sites.  Check out Confessions of a Seasonal Part 1 & Part 2.

2016 Accomplishments:


Fiddler Crabs: From Burrows to Zoea

Written on: December 9th, 2016 in Wetland Animals

Guest Writer: Kari St.Laurent, Delaware National Estuarine Research Reserve

Fiddler crabs and their burrows at the St. Jones Reserve in Dover. Credit: Kari St.Laurent

Fiddler crabs and their burrows at the St. Jones Reserve in Dover. Credit: Kari St.Laurent

Fiddler crabs are one of the most iconic critters in the salt marsh. Male fiddler crabs have an unmistakable single large claw, paired with a tiny claw, which is used to court female fiddler crabs. But did you know that crabs start their life as microscopic zooplankton? Fiddler crabs undergo multiple molts to grow from a tiny, drifting zooplankton to the rock-sized crabs we see scurrying around the marsh each summer.

Fiddler crabs create complex burrows within the marsh that serve as their homes, which can make the brown marsh mud look like Swiss cheese. Research has suggested that fiddler crab burrows help to move oxygen from the atmosphere to the roots of marsh cordgrasses like Spartina alterniflora.  However, too many fiddler crab burrows can stop cordgrass root mats from forming and potentially hinder plant growth.

Thus, a change in fiddler crab populations can affect salt marshes in different ways, making it a fine balance with a lot of unknowns.

Magnified view of a zoea, or larval crab, from the St. Jones River. Credit: Kari St.Laurent

Magnified view of a zoea, or larval crab, from the St. Jones River. Credit: Kari St.Laurent

In the upcoming months, researchers, students, and volunteers working at the Delaware National Estuarine Research Reserve will be monitoring zooplankton diversity at the St. Jones Reserve in Dover. One of the most common types of zooplankton found in the brackish sections of the St.Jones River are zoea, or larval crabs! This monitoring effort will help us better understand which species of zooplankton are present and how that diversity changes on both short and long timescales.

Additionally, in the upcoming summer, researchers from the National Estuarine Research Reserve System are hoping to conduct a study to look at crab burrow densities within different marshes across the country.

Connecting the fiddler crab burrows we see in the ground with the microscopic baby crabs swimming in the water, will help us understand if fiddler crab populations are changing, and if that change has an effect on our salt marshes, for better or for worse.

Stay tuned for volunteer opportunities and educational programs!

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Saltmarsh Scientists

Written on: December 9th, 2016 in Outreach

Eco-Explorers walk along the tidal stream and Shoveler Pond at the Aquatic Education Resource Center

Eco-Explorers walk along the tidal stream and Shoveler Pond at the Aquatic Resource Education Center (ARE). Credit: ARE

Guest Writers: Mary Rivera and Debra Forest, Division of Fish and Wildlife, Aquatic Resources Education Center

The quiet of a peaceful morning in the Woodland Beach saltmarsh is interrupted by a flock of 60 lively fifth grade students. Squeals of delight emanate from several of the children at the fish station where they get a close-up look at native fish. Many of the students have never touched or held a fish before. Their nervous giggles are replaced by wide grins when they hold a mummichog or bluegill and learn about fish characteristics and adaptations.

Students measure salinity using a hydrometer. Credit: ARE

Students measure salinity using a hydrometer. Credit: ARE

At the macroinvertebrate station, several budding fifth grade scientists dip net in a freshwater pond, collecting specimens to identify and study. On the boardwalk, a group of students conduct water quality tests on a bucket of brackish water. The kids take turns measuring DO, salinity and pH, using an array of testing equipment. Another group moves along the boardwalk on a scavenger hunt for typical plants that grow in this unique ecosystem. Ten more students sit on benches in one corner of the boardwalk, listening intently to the natural sounds of the marsh.

The students in each of these groups are participating in an Eco-Explorers field trip at the Aquatic Resources Education Center.

The Eco-Explorers Program is designed to complement the science curriculum for fifth grade classes in Delaware. Participating teachers receive training and materials they will use in the classroom to introduce their students to the topic of wetlands. After completing the classroom segment of the program, teachers bring their classes to the Aquatic Resources Education Center near Smyrna to spend a day outdoors being “scientists”.

Parent volunteers accompany the school groups to chaperone the students and help them as they explore the saltmarsh. Often the parents are as thrilled and engaged as their children as they discover this wonderful and valuable locale.

These Eco-Explorers found a good spot to observe fiddler crabs and animal tracks. Credit: ARE

These Eco-Explorers found a good spot to observe fiddler crabs and animal tracks. Credit: ARE

Students have the opportunity to investigate six different eco-stations in the marsh where they learn about fish, macroinvertebrates, plants, and water quality. They also learn to observe and interpret signs of animals that live in the salt marsh. They explore the ARE’s boardwalk and ponds to discover the relationship of the marsh to Delaware Bay. The guided field work reinforces classroom learning and allows the students to observe first-hand the living and non-living components of the saltmarsh ecosystem.

Eco-Explorers activities are hands on and students are encouraged to try tasks that real scientists would perform when studying an ecosystem. Activities are led by a talented and knowledgeable staff of seasonal employees and volunteers. Field trips are offered every spring and fall and available dates fill up quickly with teachers eager to explore the marsh with their students.

Over the years, tens of thousands of students, parent chaperones and teachers have had the opportunity to participate in the Eco-Explorers Program and take away a deepening respect for the value and importance of Delaware’s wetlands.

The boardwalk at the Aquatic Resources Education Center is open to the public whenever there are no scheduled programs. Visitors to the Center will find this hidden gem situated along Route 9 near Smyrna. They can stroll along the boardwalk, enjoying beautiful marsh vistas and glimpses of the abundant birds and wildlife that inhabit the marsh. Two stocked, catch and release fishing ponds are also available for public use.

A new Aquatic Resources Education Center is scheduled to open very soon in partnership with Delaware’s Bayshore initiative. The new facility will provide additional indoor and outdoor interpretive areas plus new hiking trails.

For more information about the Eco-Explorers Program and the Aquatic Resources Education Center, go to

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Wetlands & State of the Bays Report

Written on: December 9th, 2016 in Wetland Assessments


Cover of the 2016 State of the Delaware Inland Bays Report.

Guest Writer: Katie Georger, Delaware Center for the Inland Bays

In November, the Delaware Center for the Inland Bays (CIB) released the 2016 State of the Bays report, a 70-page compilation of environmental data about the Rehoboth, Indian River and Little Assawoman Bays and their watershed.

In assembling this report, we considered thirty-five environmental indicators to determine the health of our watershed. As you may have guessed, one of these indicators is salt marsh acreage and condition.

So what did we find? Our salt marshes are slowly disappearing – and with more than one culprit responsible.


Urbanization & Development
Perhaps the most well-known cause of wetland loss is urbanization and development.

Between 1938 and 1968, about 22% of the Inland Bays’ salt marshes were lost to excavation and filling for development. Luckily, this trend has slowed due to Delaware’s 1973 Wetlands Act which legally protected salt marshes.


Click image to view a larger version.

Still, in the last five years, developed areas in the watershed increased by 7.8 square miles (11%), replacing agricultural lands, upland forests, and wetlands. And with the population of the watershed projected to increase in the coming decades, the demand for land is sure to continue.

Currently, most direct destruction of salt marsh in the Inland Bays watershed has been halted. That means that the recent cause of marsh loss is a different beast altogether.

The Drowning Marshes
Since 1992, there has been a noticeable increase in the amount of open water in the interior of our salt marshes. While such open water pools are not completely uncommon, the amount of water trapped in them is excessive. Our marshes are slowly drowning.

Marsh pooling and mosquito ditches in Delaware's Inland Bays.

Marsh pooling and mosquito ditches in Delaware’s Inland Bays. Credit: CIB

There are actually thought to be two causes for this phenomenon: sea level rise and old ditches.

As you would expect, sea level rise is slowly causing the marshes to be underwater more frequently and for longer periods of time, as higher tides flow in and out of the Indian River Inlet.

The old mosquito control ditches are contributing to this drowning. These ditches were intended to control mosquito populations by allowing water and fish into an otherwise marshy area, where they can feed on mosquito larvae. Now too much water is getting into in the interior marsh, where it becomes trapped.

Between these ditches letting too much water into the marsh, and sea level rise creeping up higher, these important habitats are slowly becoming lost in the waters by which they once thrived.

Wetland Loss Affects Us All
The total acreage of salt marshes fringing the Bays was 7,300 when last inventoried in 2007- a net loss of over 3,500 acres since 1938.

Black-crowned Night Heron in marsh.

Black-crowned Night Heron in marsh. Credit: CIB

This means that we are losing protection from flooding and erosion, our natural filter for pollutants, and important carbon storage. But the loss of marshes is also harmful to water quality, as well as living resources in the Bays.

Degradation of salt marshes means loss of critical habitat for native critters including diamondback terrapins, blue crabs, mussels, oystercatchers, laughing gulls, terns, egrets, blue herons and more.

Looking Ahead

Activities to protect natural habitats in the Inland Bays watershed have nearly stalled since the previous State of the Bays report was published in 2011. Our wetlands are disappearing. As we look to the future, it is obvious that funding and incentives for conservation, enhancement of forested buffers, and wetlands protection are gravely needed.

Terrapin in hand.

Terrapin in hand. Credit: CIB

What can we do?

  1. Enhance the existing Sussex County water quality buffer ordinance to provide for wider natural buffers between marshes and developed lands.
  2. Consider state regulation that provides greater protection to freshwater wetlands similar to those regulations of neighboring states.

To read the 2016 State of the Delaware Inland Bays Report, visit

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Delaware Participates in the National Wetland Condition Assessment

Written on: September 7th, 2016 in Wetland Assessments

Did you know that 50% of wetlands in our coastal plains ecoregion are in good condition?  The U.S. Environmental Protection Agency (EPA) organized the National Wetland Condition Assessment (NWCA) in 2011 to get these data, and now our Program (Wetland Monitoring & Assessment Program) is again helping to assess more of Delaware’s wetlands to contribute to the 2016 NWCA.

2011 National Wetland Condition Assessment site

2011 National Wetland Condition Assessment site

2011 National Wetland Condition Assessment In Brief:

Five years ago, the EPA conducted a wetland assessment to look at the changing conditions and health of the nation’s wetlands. This study broke the continent into four separate ecoregions, with Delaware falling into the coastal plains ecoregion. The ecoregion includes the Mississippi Delta and extends up to Cape Cod, Massachusetts.

For all wetland types in the coastal plains region, 50% of the estimated wetland area is in good condition; 21% is in fair condition and 29% is in poor condition based on the vegetation index used.

In our coastal plains ecoregion, vegetation removal, ditching, and surface hardening were the stressors that caused the most problems for coastal wetlands.

A soil core was taken to examine the soil horizons at Burton’s Island near Rehoboth Beach

A soil core was taken to examine the soil horizons at Burton’s Island near Rehoboth Beach

During the 2011 NWCA field season a total of 513 randomly selected sites were sampled from across the U.S., 17 from Delaware, representing 30,893,305 acres nationally.  Wetlands were surveyed by using an army of field crews stationed across the nation.  We were lucky enough to be one of them.

All in all, 48% of U.S. wetlands were found to be in good condition; 32% is in poor condition and the remaining 20% is in fair condition.

2016 Field Work:

This summer we are at it again, collecting wetland data for the EPA about wetland health from 12 sites across Delaware.  Some of the sites were repeats from 2011, and some of them were new.

Each site visit involved 4 people from our program, and a soil scientist from National Resource Conservation Service (NRCS) geared up to go out and look at soil composition, plant communities, water quality, and buffer stressors.  For a more detailed description of each parameter we looked at, please visit the 2011 Technical Report.  Look for a report on the 2016 data from the EPA in the future!

Sometimes sites are not easily accessible. The field crew gears up to canoe to a hard to reach site.

Sometimes sites are not easily accessible. The field crew gears up to canoe to a hard to reach site.

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Prime Hook Then and Now: A Restoration Story

Written on: September 7th, 2016 in Wetland Restorations

prime hook units

*Updated 9/12/16

A hot topic for scientists and residents of Milton as of late, has been the Prime Hook National Wildlife Refuge Marsh Restoration project. This Refuge had multiple breaches in its freshwater impoundments where saltwater from the Delaware Bay cut its way through the dunes. The breaches caused significant flooding; massive vegetation die offs, and returned the habitat from its man-made freshwater system to its historic slightly salty brackish system.

To solve these problems, the Prime Hook National Wildlife Refuge took on one of the largest restoration projects in the U.S. in the fall of 2015. The end goal, to create a self-sustaining system and return all the impoundments to a brackish tidally influenced ecosystem. The Refuge closed breaches, created over 20 miles of channels, planted thousands of plants, scattered thousands of seeds by airplane throughout the landscape, and provided design input for DelDOT’s new bridge.

So how will they know if it worked?

That’s where we (the Wetland Monitoring & Assessment Program) come in and help. In the summer of 2015, we provided baseline wetland monitoring before any restoration work had begun. Then, after the Refuge finished this summer we came back to do the first post restoration sampling.

Preliminarily, we have seen some remarkable changes in the landscape.

Two of our assessment points now have a channel flowing through them. This makes it harder to walk around our sites, but should provide some interesting data in the future on channel impacts to a developing wetland.

Prime Hook National Wildlife Refuge assessment site before restoration

Prime Hook National Wildlife Refuge assessment site before restoration

One of the most visually noticeable changes is the lack of water in some of the assessment sites. Sites that were once completely covered with water pre-restoration now appear high and dry post-restoration even though they do not have any significant elevation change.

But, the most promising response to the restoration is the colonization in these open areas with various plant species; Bulrush, Common Rush, Sweetscent, and Marsh Hemp to name a few. Leptochloa fascicularis, Bearded Sprangletop, is a salt tolerant annual that has become more prevent and responded to the new and changing conditions. As expected, the plant communities are changing, and will continue to change and adjust over the next few years.

The same Prime Hook National Wildlife Refuge assessment site after restoration work.

The same Prime Hook National Wildlife Refuge assessment site after restoration work.

We are just starting to dig into our data, and will continue to monitor the Prime Hook National Wildlife Refuge Marsh restoration for the next three years in the hopes to better understand how wetland restorations change the landscape and return the vital wetland functions that we count on everyday.


What We Looked At – Quick & Dirty:

  • 20 points throughout the 4 units (impoundments)
  • Collected data on:
    • Below and Above Ground Biomass
      • The collection of biomass will provide us information on how healthy the marsh is by looking at the roots below the ground and the aboveground growth. We cut the aboveground growth and bag it, then took a round cylinder and drove it into the marsh surface to a depth of 30cm. This marsh plug would then be rinsed off of all the mud, sand, crabs, and mussels from the sample, the remaining plant material is then sorted of live and dead, as well as the above ground growth. The samples are then put in an oven to dry and be weighed after 72 hours.
    • Bearing Capacity
      • The bearing capacity looks at the ability of the soil to support specific loads that we will impart, we will apply a standard force with a slide hammer 5 times and record the depth of impact it has on the marsh surface.
    • Horizontal Vegetation Obstruction Readings
      • The horizontal vegetation obstruction is looking at the visual obstruction through the marsh at 5 specified heights, this is done by having one person go 4 meters away and look through the marsh vegetation at the 5 heights and count how many squares they can see on a profile board that is divided into 10 squares.
    • Elevation Surveys
      • The elevation surveys will be done by using a Real Time Kinematic satellite navigation in the same locations at every point, a 5 by 3 plot of points at 3 cardinal directions from our point for a total of 45 points at each location.

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Confessions of a Seasonal: A Learning Experience

Written on: September 5th, 2016 in Wetland Assessments

Tess taking the wetlands boat for a spin.

Tess taking the wetlands boat for a spin.

by Tess Strayer

This summer has truly been a summer for the books. I have not only garnered knowledge and skills for my future career but I have also learned a lot of practical life lessons. I was recently asked, what was one thing you have done on this job that you hadn’t expected to learn or do? At first, I thought that I had pretty much followed the job description and hadn’t been thrown any curve balls. Then I got to thinking about all the little things that make our job possible. Some I picked up really easily, others were a #fieldworkfail at first.

One of the coolest things I learned this summer was how to drive our boat, a modest 16 ft. shallow bottom metal dinghy. I learned steering a boat is extremely different than driving a car and turning the boat means pointing the tiller in the opposite direction. I also learned how important it is to stay calm when the motor shuts off and you are careening towards a bridge and a dock. (The thing to do is to restart the motor, calmly, not screaming and flailing.)

With boating comes trailering, a skill that I am determined to perfect maybe on some real boat ramps. It seems that all boat ramps that we used this summer were barely more than a small slab of cement. However sketchy the boat ramp, I am slowly but surely backing the trailer (kind of) straight down the ramp.


Cattail plant

Plant ID has been one of the most challenging skills I have been working on this summer to master. It is quite challenging as the plants at each site are very different and scientific names are tricky in themselves. Not only do you have to learn what the plant looks like (and remember it), you also have to learn Latin! Not only have I been learning many of Delaware’s wetland plants, I have also been learning what plants you can eat and what plants will slice you and draw blood. Fun Fact: you can eat every part of a cattail.

All in all, I ended up learning and doing so much more than what I bargained for this summer and so much more than what my job description called for. The full time staff do not get the credit they deserve for the hard work do and the dedication they show into protecting Delaware’s wetlands. This is not a job for those aren’t passionate about science and wetland protection.



Trash or Treasures: Wetland Edition

Written on: August 19th, 2016 in Wetland Assessments

Abandoned car

Old abandoned car along Christina River.

People have been creators of some amazing inventions throughout history: wheels, cars, electricity, plastics and more! But what happens to these creations when they have outlived their use or are no longer wanted? You’re probably guessing that they end up in places like the dump, or antique stores or junk yards. But, would you believe that these unwanted items also end up left, dumped, or washed into our wetlands and their buffers?

Wetlands have the natural ability to clean and purify our waters by trapping excess sediments and nutrients, and they also have the unfortunate ability to trap our trash. That trash then prevents the wetland from being able to function fully, which isn’t good for us and the health of our waters.

WMAP staff with lamp post globe.

WMAP staff with lamp post globe.

We here at the Wetland Monitoring and Assessment Program, run into quite a few unique items as we walk through and assess Delaware’s wetlands. So, we thought we would put together a short list to show the array of man-made items we have found across Delaware, and let you ponder whether you think these items are “trash” or “treasures”.

From cool to creepy to junk, here are some of the items we have run across: golf balls, baby doll heads, Barbie’s, trash cans, BB gun, barrels, buoys, lamp post shades, glass bottles, crab pots, paddle boats, tires, cars, cranes and signs. Click here for more photos.

Moral of this story; if you see trash in or near a wetland, help a wetland out, and pick it up to properly dispose of it at the dump or antique store (Who knows, you might even make a little money.). As the saying goes, one man’s trash is another man’s treasure.

For more information on illegal trash dumping in Delaware or to report illegal dumping, please visit Delaware TrashStoppers.

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Confessions of a Seasonal: Wetland Work is Tough

Written on: August 4th, 2016 in Wetland Assessments

WMAP Seasonal Tess Strayerby Tess Strayer

Growing up, I spent the majority of my childhood outdoors with friends, family, and the occasional wild animal. Whether it was hiking, biking, fishing or playing we were constantly exploring, thus you would think my outdoor experience would help better prepare me for field work this summer.  When I accepted an internship position with Delaware Wetlands, I knew working outside in “adverse conditions” would be a regular routine. I gave no extra thought to those two words; I thought I could handle whatever was thrown at me. Well friends, I was wrong.

I learned very quickly what the true meaning of “working in adverse conditions” was and how to adapt this new type of field work. Do not underestimate the words “adverse conditions.” When I heard those words my immediate thoughts went to a few hot days, walking around in plastic boots in some vegetation. The reality couldn’t have been anymore different.


Spartina cynosuroides aka “scissor leaves”

Picture this, a heat index of 95 with a real feel around 103+ degrees, a site where stepping off a vegetation platform meant falling to the other side of the earth and knowing this, you still fall every time. You will be the dirtiest you have ever been in your life before you even reach the first site. You will trudge through vegetation that was nicknamed “scissor leaves” and will slice you if you rub against them, and finally, a tan that would make the toughest farmer jealous. And while you think I am telling you these things to scare you away from field work, I wouldn’t change a single thing this summer.

Summer 2016 really challenged me both physically and mentally, but now looking back on these past three months, I have had some of the most fun I have ever had in a summer. This field work has prepared me for any possible “adverse conditions” and I now know how to survive if I find myself stranded in a marsh.

Remember kids, drink water and never step off the hummock.

Burtons Island Marsh

Wetland Monitoring and Assessment Program performing the National Wetland Condition Assessment at Burtons Island

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Oyster Recycling is Here to Stay

Written on: May 30th, 2016 in Living Shorelines

Credit: Delaware Center for Inland Bays

Credit: Delaware Center for Inland Bays

Did you know that empty oyster shells can be reused for wetland restoration projects and that there are two oyster shell recycling programs in Delaware? One is run by the Center for the Inland Bays in Rehoboth Beach and the other is by the Partnership for the Delaware Estuary in Wilmington.

Oysters have hard shells mostly made up of calcium carbonate (the same stuff chalk is made up of), and are perfect for creating natural shoreline stabilization structures that break up wave energy, prevent erosion, and serve as homes for baby oysters, also called spat. In addition to controlling erosion, oysters filter water. One adult oyster can filter up to 50 gallons of water a day.

Indian River living shoreline installation with oyster bags.

Indian River living shoreline installation with oyster bags.

One way we’ve utilized this natural resource is in our living shorelines projects. Once the oyster shells have been cured, they are stuffed into mesh bags to keep them from being knocked around and put along the edge of the living shorelines projects (see picture). They serve as a first line of defense for the marsh edge protecting it against strong waves, and also as a blank canvas to attract new oyster colonies.

Remember, as the Center for the Inland Bays says, “Don’t Chuck Your Shucks!”, recycle them to keep them out of landfills and get them back into nature. Currently, Center for Inland Bays and Partnership for the Delaware Estuary collect oyster shells from local restaurants, please contact each program directly for more information about their oyster shell recycling programs.

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