The Center for the Inland Bays sometimes receives questions about the straight, parallel ditches that are a prominent feature of many of our local saltmarshes.
Who made them and why?
Are they good or bad for the marsh?
Salt Marshes Matter
Salt marshes are important and highly productive coastal ecosystems that support an amazing number and variety of plants and animals. They provide shelter and spawning areas for fish, crabs and many other creatures. The tidal waters that regularly flood and drain the marshes bring nutrients that stimulate plant growth and wash out the decomposing plant material and other organic matter that becomes food for fish and other aquatic life. They protect shorelines from erosion, protect against flooding, and filter pollutants from runoff.
The value of healthy salt marshes for supporting our fisheries and protecting coastlines has not always been appreciated, however. These wetlands are also breeding areas for the Common Saltmarsh Mosquito, a prolific and aggressive biter that is also capable of spreading some types of diseases.
CCC workers digging a grid ditch through a Delaware salt marsh.Source: Delaware Mosquito Control Section.
A Method of Mosquito Control?
Prior to the widespread use of chemical insecticides, mosquitos were a serious health problem in coastal areas near tidal wetlands. In the 1930’s, the government began ditching salt marshes as a method of mosquito control. The majority of this work was done by the Civilian Conservation Corps (CCC) under President Franklin D. Roosevelt’s “New Deal” initiative.
The CCC hand-dug thousands of miles of gridded narrow ditches through salt marshes, spaced 100-150 feet apart, with the intention of draining pools of water where mosquitoes might breed. By 1940, 90% of salt marshes on the U.S. Atlantic coast had been grid-ditched to control mosquitoes.
Houston, we have a problem.
Draining of marshes continued until the 1960’s, but this practice was found to be only moderately effective in controlling mosquitoes. Furthermore, scientists began to realize that ditching has many long-term negative impacts on salt marsh ecosystems.
Unfortunately, the ditches altered the natural processes and water movement that maintain marsh elevation, hastening degradation and die-off of the wetlands. Many of the non-tidal ponds that occur naturally in salt marshes, and provide habitat and food for wildlife, disappeared. Altered water levels also caused large-scale changes in marsh plant communities, affecting populations of birds and other wildlife.
Aerial image of Slough’s Gut wetland enhancement project at the James Farm Ecological Preserve, completed in 2009. The saltmarsh area to the left of the gut was restored by plugging the historic straight mosquito ditches (still visible in other areas) and creating channels and pools to allow water to follow more natural patterns.
For these reasons, grid-ditching of salt marshes was largely ceased, and other methods are employed to control mosquitoes in tidal wetlands, including surveillance programs and limited use of pesticides. In addition, the State of Delaware now uses a practice known as “Open Marsh Water Management” to control mosquitoes. In this method, linear ditches are filled or plugged, and small, shallow ponds are selectively installed, connected by networks of tidal channels that look and function more like those of a natural, unaltered salt marsh.
This eliminates many of the alternately wet and dry potholes where saltmarsh mosquitoes prefer to lay eggs. At the same time, the permanent water pools provide habitat for foraging birds and small fish that feast upon mosquito larvae. Since the open-marsh management approach was adopted in Delaware in 1979, approximately 750 acres of these practices have been installed in the Inland Bays.
In 2016, during my senior year at Sussex Technical High School, the Delaware Center for the Inland Bays allowed me to volunteer as an intern. This has created an array of wonderful opportunities and career-benefiting learning experiences as well as the development of some amazing friendships.
The Center heavily relies on partnerships and volunteers to complete their mission. This wide range of volunteers and partnerships has led to many opportunities for networking and creating friendships that I appreciate immensely. Over the past few years, I’ve met and developed meaningful relationships with other employees and interns at the Center, and have also worked with volunteers from many different projects such as installing floating wetlands and the annual inland bays cleanup. I even have met new friends, and spent time with old ones, at a couple conferences!
During summer 2018, I used the Center’s boats for projects like land surveying in Pepper Creek!
I am fortunate enough to have attended the 2018 Delaware State University Annual Summer Research Symposium and the 2019 Partnership for the Delaware Estuary Science and Environmental Summit. These opportunities broadened my knowledge and awareness of ongoing projects and issues both inside and outside of the Inland Bays watershed. It was amazing to learn about other adaptations of projects the Center does, such as living shoreline restorations, recycled oyster shell bagging, tidal marsh studies, and even the implementation and research of biochar (check out my blog post about biochar here: The Secrets of Biochar).
I was also granted the opportunity to attend a Science and Technical Advisory Committee (STAC) meeting and a Center Mountaire Committee Meeting this past summer. At the latter meeting the 2018 Consent Decree between DNREC and Mountaire and the 2017 DNREC Notice of Violation to Mountaire were reviewed which was insightful and fascinating to be a part of!
Interning with the Center has permitted me to work on a handful of different projects- all benefitting the bays. Over the summer another intern working at the center, Emma O’donnell, and I learned to use the Center’s equipment. We used the tractor and Gator at the James Farm for different projects like spreading mulch/wood clippings along the trails. We got to use the truck for a ton of awesome (and sometimes stinky) projects like collecting oyster shucks from restaurants, eel-way maintenance, fish and tree surveys, and seaweed monitoring. Emma and I also used the Center’s boats for projects like land surveying in Pepper Creek, spat rack deployment and collection, and seaweed monitoring.
Prepping and deploying bags of recycled shell was a not-so-glamorous part of the job!
Later in the summer, I got to travel with the Center to a DNREC lab in Dover to put together sondes, which we later deployed in the Indian River. These Sondes were used to collect data for the Mountaire Pollution Report. I also got to complete data analysis and create graphics displaying the groundwater nitrate concentrations of some of Mountaire’s disposal farms. It was a great learning opportunity and a good real-world application of what I’m currently studying in college.
Working with the Center has truly heightened my understanding
of the importance of pollution control, and it has given me
the knowledge and opportunities needed to help in managing such important issues.
Overall, interning with the Delaware Center for the Inland Bays has sparked a passion in me for the watershed that I hike, hunt, fish, swim, and just live my everyday life in. I learned about its many ongoing issues and was granted the chance to be a part of the mission through science, restoration, outreach, and education. My passion for volunteering has also been heightened through my time working with the Center and I will continue to dedicate my time to the bays- whether it be reforestation projects (my personal favorite) or trash clean ups. It’s important to serve our communities, which includes not only taking care of the people living there but also the physical environment.
Without what I’ve learned from working at the Center, I wouldn’t be able to fully understand why it is imperative that we work so diligently in restoring, protecting, and educating people about our Inland Bays watershed here in Sussex County.
As the holidays come to an end and we are forced to fully embrace the winter months, warmer thoughts of spring are certainly welcome. Especially, when they involve creating 62 acres of habitat for spring migrating songbirds, butterflies, and other pollinators that flourish within the Inland Bays Watershed.
This spring, the Center will be busy implementing 3 major reforestation projects. Scheduled for Friday, March 29th and Saturday, March 30th volunteers will help to plant over 3,800 seedlings within the Assawoman Wildlife Area in Bethany off of Double Bridges Road. Prior to reforestation efforts, the site was farmed and used recreationally for hunting. By converting to a native mixed hardwood forest and pollinator meadow, the site will no longer require heavy use of fertilizer thereby directly reducing nutrient loads and improving water quality.
Volunteers work hard during a reforestation project at the James Farm in Fall 2018.
This project along with the others was selected using our Watershed Reforestation Model, a watershed approach to identifying both publicly and privately owned agricultural lands that would significantly reduce nutrient loads and improve wildlife habitat within the State’s most rapidly urbanizing watershed. Parcels were “ranked” based on factors such as proximity to small streams, proximity to the Delaware Ecological Network, proximity to groundwater recharge areas, proximity to already protected natural areas, etc.
The second volunteer planted project will take place on Saturday, April 6th at a County Landfill buffer site off of Dorman Road in Angola. In addition to the conversion of 7 acres from crops to forested area, 4.8 acres of interior forest will be created. Interior forest is the unfragmented portion of forests that sensitive species rely on to nest and find refuge.
Forestland in Delaware has experienced a rapid decline in recent years. Historically, this loss stemmed from conversion to agriculture but is now mostly the result of residential and commercial development and associated infrastructure. According to the 2016 State of the Delaware Inland Bays, from 1992 to 2012 upland forests decreased by 14 square miles in the Inland Bays watershed.
Reforestation is more than a feel-good opportunity: It’s important work that protects and extends vital habitats in our watershed.
Lastly, the final project will be a conversion of cropland to 20 acres of mixed hardwood forest and 8 acres of pollinator meadow within the Delaware Department of Natural Resources Midland Wildlife Area. This project will be contractor planted due to its large size and lack of accessibility of volunteers.
In total, these three projects will reduce 906 lbs of nitrogen and 22 lbs of phosphorus from entering waterways each year. Over 44 acres of interior forests will be created and 67,766,799 lbs of carbon will be sequestered over the next 20 years. Over the next few years, the remaining 8 projects within the Watershed Reforestation Plan will be implemented, helping to achieve the Pollution Control Strategy for the Inland Bays Watershed.
If you’d like to learn more about upcoming reforestation projects or volunteer, please contact email@example.com
Posted in Staff Blog | Comments Off on Returning to the Forest
Just off the beaten path and away from the hustle and bustle of Bethany Beach, lies a hidden oasis unknown to many of the tourists and locals that visit the shores of the Inland Bays: the James Farm Ecological Preserve.
Whether you go for a stroll in the meadow or head down the red trail and into the maritime forest, you will be struck by the Preserve’s extraordinary diversity. From salt marshes, to hardwood forests, to meadows that were once farm fields…the Preserve has something for everyone!
The red trail weaves through maritime and hardwood forests, marsh, and sandy beach habitats. (via #deinlandbays)
The Preserve’s red trail will lead you through maritime forest and saltmarsh to a pristine sandy beach. In early fall, the bay water is clear, and schools of mummichogs (a small brackish water fish) swim around your feet. Just a little further out into the water, a horseshoe crab with barnacles attached to its shell scuttles past, eagerly searching for a meal of mollusks, crustaceans, or worms.
As you gaze out across Indian River Bay, the view stretches for miles. But unlike the housing developments, businesses, and marinas, the beach on which you stand has been mostly left to nature.
The James Farm Ecological Preserve is a special slice of Delmarva: an educational and recreational site that gives visitors insight into what the Inland Bays looked like in the past: vast landscapes of varying habitats once untouched by human hands. The Preserve is peaceful and quiet, providing visitors with the experience of being enveloped in nature. The patient visitor can observe songbirds, osprey, wild turkeys, deer, and horseshoe crabs in their natural habitat.
Unfortunately, due to a population explosion in the Inland Bays watershed over the past few decades, many natural areas like this have vanished. Gone are the vast landscapes and countless native animals. Instead we now see highways, buildings, and other obvious signs of human civilization. And while these changes are inevitable, the protected Preserve offers a wonderful opportunity for people to glimpse the past in contrast to the present.
The James Farm Ecological Preserve also serves as an example — a model for the protection of the marshes and forests that still remain in the Inland Bays watershed. The Preserve acts as a living classroom for local students, a sanctuary for native animals, and a place where adults and children alike can explore the natural world around them. It’s a chance to take a break from the stresses of the modern world and recenter yourself in nature.
On November 16, the Delaware Center for the Inland Bays broke ground to implement the James Farm Ecological Preserve Master Plan, a community-developed initiative designed to protect the Preserve’s diverse collection of ecosystems, while safely accommodating and educating a growing number of visitors. This Plan guides the next 20 years of management to preserve its special natural lands and lights the way for future generations to safely enjoy this ecological treasure.
The Center is now working to raise funds for the second phase of the Plan. For information about how you can help, visit www.inlandbays.org/JamesFarm.
Posted in Staff Blog | Comments Off on The James Farm: A Look into the Past and a Tool for the Future
Mummichogs are a bait fish often found in surveys conducted by the Center for the Inland Bays
Fall can be the best time of the year for fishing in Delaware’s Inland Bays. Falling temperatures trigger resident and migratory fishes to feed in earnest prior to either migration to the south or further offshore. Migratory forage (bait-size) fishes like striped and white mullet and juvenile Atlantic menhaden that have spent the summer in the Inland Bays will be concentrating in larger schools preparatory to moving out through Indian River Inlet and south along the coast line.
The mullet run will be closely followed by migratory game fishes like striped bass and bluefish. These schools of migratory bait as well as those bait species that do not normally leave the Inland Bays like Atlantic silversides, mummichog, striped killifish, and bay anchovy, are especially enticing to predators like striped bass and bluefish in the fall as these predators feel a biological compulsion to put on weight before colder temperatures slow their metabolic rates. These striped bass and bluefish will gravitate toward Indian River Inlet and often will hold along structure in the Inlet until late in the fall, feeding and fattening up on the abundant schools of bait-size fishes.
The Center’s own Dr. Marianne Walch with a striped bass caught at the Indian River Inlet.
Anglers count on these predators to show up in the Inlet at this time of year and target them both from boats and along the Inlet rock bulkheads. Veteran anglers rely on deer hair bucktails and soft plastic crank baits to temp the striped bass and bluefish, as well as natural baits like small spot and live or dead mullet. In addition falling temperatures and shorter days trigger other popular recreational species that frequent the Inland Bays like summer flounder, Atlantic croaker, tautog, and the once abundant, but now somewhat infrequent, weakfish (sea trout) to go on the feed prior to moving out of the Inlet to their winter haunts further offshore and south. The tautog will hold tight to the submerged rocks feeding on small crabs and shrimp, whereas the striped bass and bluefish will move around more with the bait fish.
Fall is a good time to plan on a fishing trip to Indian River Inlet, but don’t wait too long or you may miss the main offshore migration of both predators and bait.
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Years ago, it would be 90 degrees — sunny — the quintessential beach day…and you would find me and the neighborhood kids in the woods in our backyard. You see, I grew up locally in a development, but our house was located at the end of a cul-de-sac, and it had the largest, most exclusive wooded lot. (Also, the largest amount of chiggers and ticks per square foot.) But those days arriving to gym class with my legs covered in calamine lotion didn’t matter — we had the trees!
My love for forests started then: building forts out of fallen tree branches, waking at sunrise to watch the turkeys and deer emerge from the forest edge, stealing my brother’s paintball guns to dodge each other behind trees, counting all the critters by the creek… I could go on and on!
“It was when I visited the James Farm for the first time and walked the trails
that I was overcome with the same giddy, curious and adventurous feeling
that I would get as a kid.”
It was the combination of the towering oaks and hickory with the modest holly and trumpet vine growing beneath. It was the ability to look up and see tree canopies sharing the sunlight while beams would playfully hit my face between wind gusts. It was diversity.
I (right) planned, coordinated, and assisted with the James Farm Planting on October 4th.
Forests need what is called vertical stratification or the development of plants at different heights. Openings in the forest canopy develop naturally as trees die from crowding, attack by insects and disease, or windstorms, ice or other weather events. Gaps in the canopy allow sunlight to reach the forest floor and the mix of light conditions stimulates the growth of new and existing plants.
Depending on the light, soil and weather condition, new plant species emerge and, with it, comes new wildlife species. For example, woodpeckers, warblers, Red Eyed Vireo, Scarlet Tanangers and Wild Turkeys prefer older forests between 65-100+ years old. In contrast, Wild Quail, woodcock, cottontail rabbits, and mice prefer younger shrub forests at seedling age.
Due to these experiences, I am excited to be a part of diversifying the forest at the James Farm. On October 4th, Coastal Gardeners, DNREC staff and James Farm volunteers assisted in planting 22 large, native hardwood trees in a pasture area that has been left fallow since 1998. The new site will be a part of a managed arboretum area of approximately 3 acres, funded by the Delaware Forest Service Urban and Community Forestry Program. Overtime, this area will be a mixed hardwood forest, similar to the other older forests at the James Farm. Hopefully preserve visitors and wildlife alike can enjoy the view for years to come. Check it out when you get a chance!
Posted in Staff Blog | Comments Off on For the Love of Trees
Each weekend, tons of boats descend on Indian River and Rehoboth Bays,
targeting flounder, bluefish, stripers, and crabs. The inlet is fished almost constantly, with lures being thrown into eddies from sun up to sun down – and sometimes, from sun down to sun up!
The Inland Bays are indeed a fishing destination for many in the region, but they are not unique in this aspect. Estuaries (those areas where rivers meet the ocean) are extremely productive fishing grounds. And while the public may recognize that the open waters of these bays harbor doormat sized flounder (really!) and delectable blue crabs, few people realize that the shallow shoreline areas are just as important for their fishing success.
The nearshore waters of the Inland Bays are a critical nursery for countless juvenile fish species. The shallow shoreline waters provide a refuge from predators, creating a safer environment for juvenile fish to grow. With few large predators, and an abundance of food, the shoreline areas of our bays are the perfect nursery.
Not only do important recreational species like Summer Flounder and Atlantic Croaker use these shoreline areas as nurseries, but numerous species of small bait fish such as Atlantic Silversides and Atlantic Menhaden do as well. While these bait fish species aren’t caught by anglers, they are immensely important to sustaining the food web and directly serve as a source of food for the more sought after fish like Bluefish and Stripers.
The shoreline areas of our bays are home to many weird and wondrous species, such as this Lookdown, being grasped by a blue crab.
The amount of fish using these nearshore areas is staggering.
Annually, the Center manages a volunteer-led citizen science Inshore Fish Seining Survey, which samples 16 shoreline sites throughout the Bays, documenting what species are using the shoreline areas and at what sizes. What we’ve seen is that the shoreline areas of our Inland Bays are habitat for over 70 species of fish, and provide a nursery area for both recreationally and ecologically important fish species, not to mention the thousands upon thousands of juvenile blue crabs. It is not uncommon for a single seine to catch over 500 juvenile blue crabs and several thousand fish! And that’s just within a 100-foot section of the shoreline!
A haul of several thousand Mummichog and at least several hundred Blue Crabs in the upper Indian River. This is a common haul in these parts.
So what can we do to help sustain healthy populations of fish and blue crabs?
We can start by preserving our natural shorelines. Research has shown that hardened shorelines like bulkheads and rip rap are not the preferred habitat for many of our inshore fish species. A transition from soft shorelines like marsh edges or sandy beaches to hardened shorelines could negatively impact many of the juvenile fish the food web and anglers rely on. We recommend living shorelines as a solution.
Second, we need to reduce the amount of nutrients entering our bays. Excess nutrients can lead to harmful algal blooms, which have the potential to kill fish and crabs.
Third, you can join our survey crew and learn more for yourself, while simultaneously helping us gather data.
The shoreline areas of our Inland Bays are wondrously diverse and important areas that support mind-blowing amounts of juvenile fish and crabs. And while they don’t get the attention they deserve, they are the secret to our fishing success.
Posted in Staff Blog | Comments Off on Flounder and Bluefish and Stripers – Oh my!
A Guest Blog by Center volunteer, Jodi McLaughlin:
I used to migrate between CA and PA. Life changed dramatically when I became a caregiver for my dad who was housebound most of each day. But l was blessed. Not only did I get to be with dad all day, we have a colony of 9 osprey nests viewable right outside our windows.
When you can watch osprey flying by every window of your house it is not like seeing the random animal run through your yard. You become an osprey junky. You begin to recognize every call they make and you notice their subtle movements on the nest. And so it is that I have now studied osprey for 6 years monitoring over 30 active nests located primarily along the inland bays. I note dates of arrival, egg incubation and hatching, chick fledgling and then, bummer, fall migration.
If ospreys lived here year round
I might not find them as fascinating.
Their lives remind me of a romance novel. Imagine this; after a fabulous summer on the Inland Bays dining and sunning with your soul mate, you decide to lift off, free of baggage, bidding goodbye to your home and responsibilities with not one worry. You say “bon voyage” to your mate for 6 months and then lovingly reunite in the spring? Yes, that IS the “Sprey Life”!
I generally get a heads up that migration is on the horizon when I see the adult females perching nearby as their mates collect and place sticks on the now empty nests. Ospreys like to leave their homes looking nice for the winter. Never mind the gulls and eagles will move in and make a huge mess.
So…Where do they go?
The number one question I am asked is “Where DO the ospreys go in the fall?” They all go south to find food and many will swap their ravenous fish diet from salt to fresh water fish. Adult ospreys have made the roundtrip many times and will follow the same route down the coast of the US, hopscotch across Cuba, Hispaniola, and assorted islands and end up at their favored wintering grounds somewhere in the interior of South America. A few travel as far as Argentina but many go to Columbia, Venezuela and Brazil. Just like our geese there is a resident population of osprey in Florida and rarely a juvenile osprey will stop off there but most osprey that migrate along the eastern flyway of the US continue their travels south across the Caribbean Sea.
Saying goodbye to the family
Paired ospreys do not migrate or winter together. The juveniles born this year will have to find their way south all by their lonesome and they will not return here next year but instead take a gap year and remain south until 2020. Research numbers vary but up to 80% of juveniles do not survive their first year of life as their maiden migration is treacherous. Catching a strong tailwind from the north, adult female osprey are the first to migrate, and will depart sometime by late August. Next the juveniles born this year will take short trips around the area, perfecting their flight and fishing skills, and then usually by mid-September they will meander south finding their own way to a wintering ground that attracts them.
The adult males are usually the last to leave. A few may be spotted near their nest as late as the first week of October but many leave before the end of September. Adult males remain behind to care for the juveniles and perhaps to guard their nest territory so long as the other adult males are nearby. Southbound mature ospreys take their sweet time but in the spring they use warp speed to claim their prized northern nest site and reunite with their bonded mate. In a perfect world ospreys can live to 15 years or more and they often bond with a mate and nest for that lifetime.
The ospreys that
grace your world each summer
are truly part of your community.
To learn more about osprey migration check out Rob Bierregaard’s comprehensive osprey tracking website www.ospreytrax.com and his just published kid’s book for all ages “Belle’s Journey, An Osprey Takes Flight”
If I had asked you 10 years ago if you knew anyone who had a 3D printer, you probably would have said no. Many of you may not have even known what 3D printing was — I know I didn’t! But when I talk to people now about 3D printing, most are familiar with the basics of these sophisticated, yet somehow simple, machines. 3D printers put incredible power into the user’s hands: you can virtually create any object that you want! Many people create toys, educational tools, machine parts, or even prototypes for business ideas. My favorite things to print are really cool pots for all of my succulent babies.
Juvenile coral was able to grow on 3D printed surfaces!
But 3D printing has the potential to be used for so much more good than just making knick-knacks and more junk in the world. If this technology can create almost anything, could it make new habitats for species struggling to cope with our changing climate? As a master’s student studying marine biosciences at the University of Delaware, I sought to answer this question by figuring out how to 3D print different species of coral found in Fiji.
Fiji is considered to be one of the world’s few “hotspots” for marine biodiversity – it has almost 1,200 species of fish! But warming ocean temperatures and ocean acidification have caused significant losses of live coral that so many of these fish need for protection or food.
After 3D printing dozens of corals with a biodegradable plastic, I flew them to a small island in Fiji to conduct experiments that would help answer some important questions:
1) Would fish even use them if a living coral habitat was not available?
2) Would using a 3D printed habitat change the way the fish behave?
3) Would living coral use 3D printed surfaces to grow on?
The results of these experiments were promising!
Not only did fish use the 3D printed corals as their home, they behaved in the same way whether they were on a 3D printed coral or a live coral. AND, live coral were able to grow on the 3D printed surfaces, which is a crucial step for re-building degraded coral reefs.
A humbug damselfish using a 3D printed coral
This was all great news, but before we go and put a bunch of fake plastic corals onto our reefs, more work needs to be done to make sure this practice would really be good for reef ecosystems into the future. The long-term goal of these 3D printed habitats should not be to replace live corals completely, but to act as a temporary home for reef fish during times of degradation. If these 3D corals can support live-coral growth, then over time, they should gradually mold into the reef to become part of the foundation.
While we don’t have coral reefs here in Delaware, we do have another kind of reef: oyster reefs. Who knows? Maybe 3D printing could be used to help bring back natural oyster reefs in our inland bays. For now, you can help by fighting global warming, supporting important conservation legislation, and spreading the teachings of strong science.
Posted in Staff Blog | Comments Off on Using 3D Printing to Save Our Coasts
You’ve probably been hearing a lot of buzz about floating wetlands lately. That’s because South Bethany is working with us on a project to clean up their canals and we’re using “green” methods to do it!
Why do the canals even need help?
Healthy waterways can boast clear water with healthy levels of dissolved oxygen that support fish, invertebrates, and other marine creatures. Unfortunately, this is not the case in South Bethany.
Because there is so much excess nitrogen and phosphorus (collectively known as nutrients) in the canal waters, algae feeds and quickly overwhelms the delicate ecosystem. Then, that same algae which feeds on the nutrients, also “feeds” on the dissolved oxygen in the water.
If you want to be technical, the algae actually produce oxygen in daylight, BUT they consume oxygen at night. And as algae dies, bacterial decomposition uses up even MORE oxygen in the water, resulting in extremely low or wildly fluctuating DO concentrations. Without enough steady O2, fish, shellfish and other aquatic species are killed off and begin to disappear from the area.
Where is this nutrient pollution coming from?
Generally in the Inland Bays watershed, nutrient pollution comes from sources such as:
Fertilizer and manure runoff from lawns and agricultural fields
Wild animal and pet waste runoff
Septic systems (both failing and maintained can leach nutrients)
Discharge from sewage treatment plants (no longer in the Inland Bays as of 2018!)
Car and power plant emissions
South Bethany, though, has an additional issue to contend with: much of the town was developed prior to the passing of Delaware’s stormwater regulations in 1990. When correctly implemented, these regulations help reduce nutrient pollution from runoff sources — the first two sources from our list above. But since these regulations were not used to design South Bethany specifically, excess nutrients, sediment and bacteria from the area regularly winds up in the residential canal systems.
Adding insult to injury, the layout of the canals simply does not allow for the twice-daily tides to flush the polluted waters out into the larger Little Assawoman Bay.
How floating wetlands help!
South Bethany has been working with the Center for several years on stormwater retrofit projects, including planted median bioswales that capture runoff from the road and filter the water as it seeps into the ground! The floating wetlands are a sister project to these stormwater retrofits that focuses on the water already in the canals.
As the name suggests, a floating wetland is a planted, man-made wetland that floats in canals attached to the bulkheads. The plants used, Spartina alterniflora, have their roots dangling in the water where they feed off of the excess nutrients, taking up and binding nitrogen and phosphorus in the plant tissues. The root systems also help the ecosystem by hosting a variety of macroinvertebrates that form the base of a healthy food web. The root systems also act like filters that trap suspended sediment that would otherwise cloud the water. Meanwhile, the plants above the water create a lovely habitat / resting spot for herons,migratory songbirds, monarchs, and other beneficial critters!
Over time, we hope to see reduced levels of nutrient pollution, clearer waters, fewer algal blooms, and improved concentrations of dissolved oxygen in the canals. This project was Funded by a Community Water Quality Improvement Grant from the Water Infrastructure Advisory Council, this project will be administered by the Department of Natural Resources and Environmental Control’s Nonpoint Source Pollution Program.