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  Archived Posts From: 2024


Channel Dredging and Beneficial Use – What’s It All About?

Written on: May 20th, 2024 in Beneficial UseWetland Research

By Alison Rogerson, DNREC’s Wetland Monitoring and Assessment Program

For any homeowner with a dock leading out to tidal waters in Delaware or any boat angler who likes to put in at a public ramp and go crabbing, fishing or just boating around the Inland Bays, you are familiar with the issue of rivers shoaling and channels silting in. It is a nuisance to live with but it’s an indication of a larger coastal issue related to shoreline erosion and movement of sediment and DNREC is working towards a solution.

It is no secret that Delaware is losing coastal habitat and wetlands to the impacts of sea level rise and erosion. As coastal wetlands become permanently flooded by rising water levels and wash away the dirt, or sediment, gets stirred up, carried away, and settles into deeper channels. Similarly, when severe storms and destructive wave energy erodes a coastal wetland apart, those sediments wash into the waterways and settle in channels. This pattern repeats daily and eventually the river channels start to build up, becoming shallower. This cycle can continue until channels are so shallow it isn’t safe to boat on them. Other sources of sediment, such as from construction runoff or storms, also contribute to in-channel build up.

The Idea

Dredging navigable channels to keep them wide and deep for easy boating has been going on for decades. Historically, the material collected was pumped into a contained disposal site, a big land-based dirt bathtub if you will, where the water could drain out and the sediment would remain. In these upland disposal sites, rich aquatic sediments are stored and not put to any use. The thinking behind beneficial use of dredge material is to put sediment back where it came from and where it can do some good. Place the dredge material carefully on wetlands that are stressed, sediment-starved, eroding and sinking. When done thoughtfully, this addition of material gives wetlands an elevation boost to stay ahead of sea level rise, as well as a nutrient boost to encourage strong plant communities and therefore soil stabilization.

Beneficial use for wetland restoration can be done in several ways. Thin-layer application is when a few inches up to a foot of material is added to an existing wetland that needs help. Conversely, thick-layer application of up to several feet of material can be used to rebuild a former wetland that has already disappeared. In the middle, dredge sediment can be used to ‘fill potholes’ in wetlands that still exist but are experiencing pooling or break-up, and where big sections are failing and falling apart from the inside. In all cases, the results will be muddy at first as added material dries out a bit and plants start growing back in. Full recovery can take a few years, so be patient.

A spray barge delivering sediment dredged from the nearby river channel deepening to a wetland in need.

Working Together

Bringing the world of dredging together with wetland restoration requires careful consideration of the plant community, sediment types and weight, dredge volumes and wetland elevation, sediment containment and tidal connection, sustainability and even aesthetics. In 2012, DNREC completed its first beneficial wetland restoration demonstration project at Pepper Creek and Piney Point Wildlife Area. This was a collaboration between two DNREC programs: the Wetland Monitoring and Assessment Program and Waterway Management Section. Each program specializes in specific, technical work that when put together, allowed the thoughtful execution that turned out to be a success.

The many lessons learned from 2012 are being put to good use today as DNREC is working on several dredge and beneficial use wetland restoration projects on the Delaware Bay and Inland Bays. Each project presents its own challenges and specifics, and each has its own timeline. It’s an exciting time for DNREC to build the knowledge and skills to take the lead in tackling two big topics at once. Together, these projects will improve navigation in Delaware’s waterways and increase and improve coastal wetland habitat and water quality.

How This Impacts Boaters

During dredge operations, residents will be able to see and hear the dredge equipment working and running. Operation hours may depend on the day of the week and staffing, but also factors like tide and weather. Safe working conditions for everyone involved is a priority. Likewise, the wellbeing of fish and wildlife is important, so operations may be required to stop for several months in accordance with state and federal requirements to allow many species to nest and breed in summer months. This varies by location and project.

Pipelines will extend from the dredge to the beneficial use sites, sometimes a short distance, sometimes several miles. Pipelines often float and are visible and should be marked with buoys, but boaters should be on alert and stay a safe distance away. Visit DNREC’s Shoreline Management webpage to stay informed on when and where these projects are happening.

The future is bright for DNREC as several programs come together to increase our capabilities and help solve multiple environmental issues at once. Beneficial use for wetland restoration is still an emerging field and DNREC is proud to be exploring new technology to address issues.

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Women of the Wetlands

Written on: May 17th, 2024 in OutreachWetland Research

By Olivia Allread, DNREC’s Wetland Monitoring and Assessment Program

Behind every grant package and backpack full of gear stands a key agent of the natural resource world: a woman. We have long known that women play a crucial role in the management, provision, and safeguarding of natural resources across our globe. In recent decades, even more recognition has been given to that vital role, as well as the disproportionate barriers that they (we) encounter. Our wetland and water resources are some of the most precious ecosystems on earth, so why not celebrate the women working behind the scenes and making remarkable contributions to these habitats.

Megan Lang – Chief Scientist, U.S. Fish and Wildlife Service National Wetlands Inventory Program

A mapping wiz. Lang works for a program within the U.S. Fish and Wildlife Service that is a leader in the understanding of wetlands. Through the monitoring and mapping of U.S. wetland and deepwater habitats, the program provides two heavy hitters to the public: the National Wetlands Inventory Geospatial Dataset and the Wetlands Status and Trends Reports to Congress. The Wetlands Mapper, as it’s better known, is the public interface to the wetlands geospatial dataset and delivers easy-to-use map views of America’s wetland resources. The Status and Trends report provides estimates of U.S. wetland type, extent, and change over time. In fact, the newest report was just released! Besides wearing this hat, Megan wears many others including an adjunct professor at the University of Maryland and has over 100 publications.

Lang using wetland maps (Photo Credit: E&E News)
SUN in her MCF uniform (Photo Credit: Ramsar)

Lili SUN – Founder and Deputy Board Director, Shenzhen Mangrove Wetlands Conservation Foundation

As discussed on this blog before, mangroves are meaningful coastal wetlands. SUN represents those ecosystems and more as a leader in many of China’s environmental efforts. Having established the Shenzhen Mangrove Wetlands Conservation Foundation (MCF) in 2012, she led the organization to be the first environmental non-profit entrusted with managing an urban ecological park in China. Additionally, she serves as the Director of the park, combining wetland conservation with social engagement of visitors. In addition to many of her accolades and board memberships throughout the country, she is dedicated to charity, surpassing over 50 million yuan ($7 million USD) in wetland conservation efforts and mobilizing over 100,000 volunteers for wetland protection. SUN seeks to empower communities to actively participate in environmental initiatives.

Susan-Marie Stedman – Wetland Scientist and Policy Analyst, National Oceanic and Atmospheric Administration (NOAA) Fisheries Office of Habitat Conservation

With over 40 years of experience in the field, Stedman is a connoisseur of many critical habitats. She has worked on everything from the Peace Corps in Africa to the White House Wetlands Working Group, to publishing groundbreaking reports on wetlands in the coastal watersheds of the eastern U.S. Having currently been with NOAA for almost 31 years, she focuses on wetland regulations and management, status and trends, climate change adaptation, mitigation banking, and effects of development on aquatic environments. Her office within NOAA is deeply integrated in the field of STEM focusing on protecting and restoring habitats while keeping protected species and coastal resiliency at the forefront of all efforts. An example of her work is NOAA’s Mitigation Policy for Trust Resources, which Stedman helped compose – this conservation policy keeps wetlands in mind!

Susan-Marie Stedman (Photo credit: NOAA Office of Habitat Conservation)
Fleming in the field (Photo Credit: Ducks Unlimited)

Sarah Fleming – Director of Conservation Programs, Ducks Unlimited Northeast

Talk about a lot of ground to cover; Fleming oversees the conservation efforts in a 12-state region for Ducks Unlimited (DU). With a vast background in waterfowl and wetland ecology, she came on board with the non-profit in 2010 to deliver projects that protect and restore critical wetland habitats, particularly in the Northeast Atlantic Flyway. Amazingly, she has done just that with over 20,000 acres of projects accounted for so far. One of Fleming’s most significant projects was the restoration of the Dury site, a 35-acre wetland habitat for migratory birds in northern New York state. Not only did she lead a fee-title acquisition from a private landowner and collaborative efforts with partners, but also transferred the Dury site to the Montezuma National Wildlife Refuge. A true success story for land protection and management of a critical wetland habitat.

Dr. Musonda Mumba – Secretary General of the Convention on Wetlands

Dr. Mumba calls Kenya her home, but this Zambia-born environmentalist has done wetland work throughout the globe for 25 years. Holding a PhD in Wetland Ecology, she started her career with the Environmental Council of Zambia, then moved onto positions with the World Wildlife Foundation in East Africa and at the headquarters in Switzerland. She spent much of her time with the United Nations (UN), both in the Environment and Development Programme’s, focusing on ecosystem restoration, wetlands, and sustainable development using nature-based solutions. Now as the Secretary General of The Convention on Wetlands, she uses her career experience to guide the treaty framework for this intergovernmental organization, as well as lead the various groups and committees within the Convention itself.

Let’s think bigger picture. Outside of the realm of wetlands and natural resources, these stories speak to the work women at large are doing across the globe, as well as gender equality. Everything from educational opportunities to decision-making, economic participation to political representation, women are striving for their voices to be heard or their efforts to be seen. One of the easiest ways to support gender equality is through recognition. Empowered women and girls contribute to the productivity and health of their families, communities, commerce, and governments. That ripple effect benefits everyone and has real impacts on generations to come. So, this one’s for the girls; the ones driving a boat through Iraq’s Mesopotamian marshes; the ladies conserving coastal prairie habitats in Texas; and for the gals getting their field boots on for the first time. Every achievement inspires us to continue supporting and celebrating women in the world of wetlands.

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The Scoop on Shellfish

Written on: May 17th, 2024 in Natural ResourcesOutreachWetland Animals

By Ashley Tabibian, DNREC’s Shellfish Program

What do you think of when you think of oysters, clams, and mussels? For being so small, they are somewhat complex creatures with almost superhero like abilities. Do you think of how nutritious they are? According to WebMD, shellfish are low in calories, high in protein and contain omega-3 fatty acids and other nutrients. Do you think about their ability to clean up the water? Shellfish are filter feeders that help remove excessive nutrients and other compounds from the water. Do you think about their structure? Shellfish beds can stabilize shorelines and reefs, and can sequester carbon while providing habitat for other animals. Do you think about the jobs that are centered around shellfish? The National Oceanic and Atmospheric Administration (NOAA) published in 2018 that oysters and clams accounted for $315 million of marine aquaculture, and in 2022 estimated a global market of $108.4 billion

Shellfish are a major food source across the world but can present a unique risk of foodborne illness if not harvested and handled properly. Their relatively large surface area allows them to warm up quickly after harvest, allowing bacteria to reproduce at a faster rate if shellfish are not kept cool. As filter feeders, they concentrate pathogens at a higher rate than surrounding waters which is why it is important to be sure they come from Approved, or safe to harvest, waters. When eaten raw or partially cooked, any pathogens inside shellfish are not killed during the cooking process making it important to not only keep them under the proper temperature and get them from Approved water, but also to keep them from contacting other foods and surfaces that could cause cross-contamination.

So, who keeps track of all this health stuff? That is where we come in – the DNREC Shellfish Program. We are part of the Department of Natural Resources and Environmental Control (DNREC) within the Division of Watershed Stewardship, and our main mission is to protect public health by minimizing the risk of foodborne illness due to the consumption of shellfish. The University of Cambridge defines shellfish as an animal that lives in water and has a shell, but our program deals exclusively with bivalve shellfish that pose a certain and specific risk to human health due to how they are consumed. Although scallops, crabs and conchs are, by definition, shellfish, they are not usually consumed raw and whole. For example, scallops are usually shucked and cooked, so you are just eating the adductor muscle and the foodborne pathogens are killed by heat during the cooking process. However, if you consume the scallop whole and raw, the same special foodborne illness risks apply. Meanwhile, an oyster is often shucked and kept on ice to be eaten raw and whole.

The DNREC Shellfish Program works in three ways to ensure product meant for human consumption are delicious and nutritious for healthy persons when harvested and handled properly.

First, it is necessary to make sure the animals come from Approved waters. Since shellfish are filter feeders, you eat what they eat, so it is important they come from a clean area. DNREC tests the water and maintains an interactive, online map on our website showing where the harvest of shellfish is Approved, Seasonally Approved, or Prohibited. You can also find this map published in the Delaware Fishing Guide. You can use this map to determine Approved areas to recreationally harvest clams and mussels. Please note the Division of Fish and Wildlife manages acreage in the Inland Bays for leases for shellfish aquaculture.

Second, our program staff conduct routine inspections of all shellfish shippers and processors to ensure compliance with national food safety requirements and those specific to the shellfish industry. Delaware is a member of the Interstate Shellfish Sanitation Conference (ISSC) and must follow all requirements set forth by the organization. The ISSC made up of state, federal and industry representatives working in cooperation with the U.S. Food and Drug Administration to ensure compliance of state programs with national standards.

The third part of the program is enforcement which is handled by DNREC Fish and Wildlife Natural Resources Police who regulate catch limits and harvesting methods for both commercial and recreational harvesters.

Harvesting in Delaware

There are numerous species of bivalves in Delaware, however, the four primary species are the Eastern Oyster, Hard Clams, Razor Clams and Ribbed Mussels. The Eastern Oyster is harvested commercially but is illegal to harvest recreationally to protect the populations. Hard Clams are harvested both commercially and recreationally. The Razor Clams are harvested only recreationally. Ribbed mussels are typically not harvested commercially or recreationally. Want to harvest some? Reference that interactive, online map to see where the Approved areas are.

Below are some simple tips, tricks, and things to keep in mind to make sure you can enjoy raw shellfish from Delaware waters and markets.

  1. If you are at risk or immunocompromised, eat only fully cooked shellfish. The at-risk community can include those with liver disease, diabetes, alcohol use disorder, kidney disease/failure, stomach disorders, cancer or any other condition or treatment that weakens the immune system. If you are unsure, consult your doctor.
  2. Keep it cold! Keep shellfish below 45℉. Immediately refrigerate/ice shellfish. If they exceed this temperature, harmful bacteria can reproduce into an infectious dose.
  3. Keep it clean! Wash your hands, surfaces and equipment before and after handling shellfish. If you have an open wound, avoid contact with the water and seafood. If you get a wound while working with shellfish, clean it thoroughly and use a waterproof bandage.
  4. Keep it separate! Do not allow the shellfish to contact other foods such as in coolers containing water that has fish or crabs in it or other non-ready to eat items. Do not allow shellfish to contact water from a non-Approved harvest area.

Looking for more information about the Delaware Shellfish Program? Visit our webpage and browse through our educational material, regulations, maps, and more.

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