NOAA's Response and Restoration Blog

An inside look at the science of cleaning up and fixing the mess of marine pollution


Opening up the Hudson River for Migrating Fish, One Dam at a Time

This is a post by Carl Alderson of NOAA’s Restoration Center and Lisa Rosman of NOAA’s Office of Response and Restoration.

Creek passing over a dam in winter.

Water, both frozen and liquid, tumbles over the Orrs Mill Dam on Moodna Creek, a tributary of the Hudson River, in Cornwall, New York. NOAA scientists Lisa Rosman and Carl Alderson are investigating dams and other structures that are potentially preventing fish from migrating up these waterways. (NOAA)

One wintry day near the pre-Civil War–era town of Stockport, New York, NOAA scientists Lisa Rosman and Carl Alderson carefully edged their way down the snowy banks of Claverack Creek.

They pushed past the debris of a nearby maintenance yard, filled with old buses and cars and surrounded by junk covered in snow and ice. A roar of water could be heard just beyond this scene, tumbling out from the remains of a dam. The dam was framed by an assortment of large natural boulders and scattered concrete masses, everything partially blanketed in a snowy white ruin.

As the team surveyed this landscape, a seamless portrait of the Hudson River Valley emerged, making it easy to see how everything was connected. Cameras and video recorders, GPS units and notebooks came flying quickly in and out of warm pockets, with hands glad to be thrust back in after the duo collected the information they sought.

The scientists were scouting this particular creek for features they had spotted in satellite imagery. The purpose? To locate, verify, and catalog blockages to fish movement and migration.

­­They could see that this crumbling structure had been much higher at one time. Something, likely a storm, had sheared off the top portion of the dam. Even with the breach, the damage did not allow the river to flow freely past the dam’s base. So, the question for the team remained: Could migrating fish navigate past what was left of this dam?

Additional research revealed more about this remnant from another time. The Van De Carr Dam once powered a 19th century paper mill and a mattress factory, part of the national transition to water power and the start of the industrial age.

Today, however, NOAA has classified this dam as a barrier for fish trying to follow their instincts and migrate up this tributary of the Hudson River, as their parents and ancestors did before them.

Identifying Barriers

Rosman and Alderson are investigating potential habitat restoration opportunities along 69 tributaries to the Hudson River estuary. The Hudson River is a federal Superfund site spanning almost 200 miles from Hudson Falls in the north to the Battery in New York City.

Beginning in the late 1940s, two General Electric (GE) capacitor manufacturing plants in Hudson Falls and Fort Edward, New York, released industrial chemicals known as PCBs (polychlorinated biphenyls) into the Hudson River environment over several decades. The PCB pollution has contaminated Hudson River fish and wildlife, their prey, and their habitats.

The investigation assesses the potential for removing dams and culverts that are preventing fish from migrating up and downstream within the Hudson River Valley. Removing abandoned dams and upgrading culverts will provide fish with access to habitat in tributaries of the Lower Hudson River, upstream of the river’s tidal influence.

Barrier after barrier, this scientific duo determines which dams on Hudson River tributaries still provide services, such as water supply, recreation, or hydroelectric power, and those which no longer serve any meaningful function. Back in the office, they enter the information collected in the field into a database that now includes more than 400 potential barriers to fish, both man-made and natural.

Dams and improperly sized or installed culverts have prevented important migratory fish, such as American shad and river herring, from swimming further upstream to spawn, as well as reducing the passage of the historically far-reaching American eel. In addition, NOAA catalogs the rivers’ natural barriers—steep gradients, rock ledges, waterfalls—to estimate the extent that most fish previously could travel upstream before the presence of dams.

Through a combination of advanced digital mapping software and scouting trips such as the one to Claverack Creek, Alderson and Rosman are identifying potential fish restoration projects. These projects will help make up for the decades when people were either not allowed to fish or retain catches along portions of the Hudson River and were advised against eating its highly polluted fish.

Opening up Rivers and New Opportunities for Collaboration

The data Rosman and Alderson are collecting help support other programs as well. NOAA and other government agencies prioritize removing or updating the barriers that provide the best opportunities for habitat improvement and fish passage. Dams that are not candidates for removal may still benefit from structures such as fish ladders, rock ramps, or bypass channels designed to enhance fish passage over or around the dam.

Already, their efforts have helped communicate the potential for habitat restoration in the region. In October 2014, they shared information about their database of fish barriers at a workshop co-hosted by New York State Department of Environmental Conservation’s (NYSDEC) water, dam safety, and estuary programs.

Later, at an April 2015 summit in Poughkeepsie, New York, the Hudson River Estuary Program announced the official kick-off of a new grant program that will benefit the river and its migrating fish. The program will award $750,000 to restore tributaries of the Hudson River and improve their resilience (e.g., dam removal and culvert and bridge upgrades) and $800,000 for local stewardship planning.

The grant announcement and collaboration among NOAA, NYSDEC, and several key stakeholders, including the Hudson River Estuary Program, The Nature Conservancy, and Scenic Hudson, signals an era of growing cooperation and interest in bringing back migrating fish to their historic habitats and improving the vitality of the Hudson River and its tributaries.

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What Restoration Is in Store for Massachusetts and Rhode Island after 2003 Bouchard Barge 120 Oil Spill?

A large barge is being offloaded next to a tugboat in the ocean.

On April 27, 2003, Bouchard Barge 120 was being offloaded after initial impact with a submerged object, causing 98,000 gallons of oil to spill into Massachusett’s Buzzards Bay. (NOAA)

The Natural Resource Damages Trustee Council for the Bouchard Barge 120 oil spill have released a draft restoration plan (RP) and environmental assessment (EA) [PDF] for shoreline, aquatic, and recreational use resources impacted by the 2003 spill in Massachusetts and Rhode Island.

It is the second of three anticipated plans to restore natural resources injured and uses affected by the 98,000-gallon spill that oiled roughly 100 miles of shoreline in Buzzards Bay. A $6 million natural resource damages settlement with the Bouchard Transportation Co., Inc. is funding development and implementation of restoration, with $4,827,393 awarded to restore shoreline and aquatic resources and lost recreational uses.

The draft plan evaluates alternatives to restore resources in the following categories of injuries resulting from the spill:

  • Shoreline resources, including tidal marshes, sand beaches, rocky coast, and gravel and boulder shorelines;
  • Aquatic resources, including benthic organisms such as American lobster, bivalves, and their habitats, and finfish such as river herring and their habitats; and
  • Lost uses, including public coastal access, recreational shell-fishing, and recreational boating.

The plan considers various alternatives to restore these resources and recommends funding for more than 20 projects throughout Buzzards Bay in Massachusetts and Rhode Island.

Shoreline and aquatic habitats are proposed to be restored at Round Hill Marsh and Allens Pond Marsh in Dartmouth, as well as in the Weweantic River in Wareham. Populations of shellfish, including quahog, bay scallop, and oyster will be enhanced through transplanting and seeding programs in numerous towns in both states. These shellfish restoration areas will be managed to improve recreational shell-fishing opportunities.

Public access opportunities will be created through a variety of projects, including trail improvements at several coastal parks, amenities for universal access, a handicapped accessible fishing platform in Fairhaven, Mass., and acquisition of additional land to increase the Nasketucket Bay State Reservation in Fairhaven and Mattapoisett. New and improved public boat ramps are proposed for Clarks Cove in Dartmouth and for Onset Harbor in Wareham.

A map of the preferred restoration projects for the Bouchard Barge 120 spill, as identified in the second draft restoration plan.

A map of the preferred restoration projects for the Bouchard Barge 120 spill, as identified in the second draft restoration plan. (NOAA)

The draft plan also identifies Tier 2 preferred projects; these are projects that may be funded, if settlement funds remain following the selection and implementation of Tier 1 and/or other restoration projects that will be identified in the Final RP/EA to be prepared and released by the Trustee Council following receipt and consideration of input from the public.

“We continue to make progress, together with our federal and state partners, in restoring this bay and estuary where I have spent so much of my life,” said John Bullard, National Oceanic and Atmospheric Administration (NOAA) Fisheries Northeast Regional administrator. “And, we’re eager to hear what members of the public think of the ideas in this plan, which are intended to further this work. We hope to improve habitats like salt marshes and eelgrass beds in the bay. These will benefit river herring, shellfish and other species and support recreational activities for the thousands of people who use the bay.”

The public is invited to review the Draft RP/EA and submit comments during a 45-day period, extending through Sunday, March 23, 2014. The electronic version of this Draft RP/EA document is available for public review at the following website:

Comments on the Draft RP/EA should be submitted in writing to:

NOAA Restoration Center
Attention: Buzzards Bay RP/EA Review Coordinator
28 Tarzwell Drive
Narragansett, R.I. 02882

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PCBs: Why Are Banned Chemicals Still Hurting the Environment Today?

Heavy machinery removes soil and rocks in a polluted stream.

PCB contamination is high in the Housatonic River and New Bedford Harbor in Massachusetts. How high? The “highest concentrations of PCBs ever documented in a marine environment.” (U.S. Fish and Wildlife Service)

For the United States, the 20th century was an exciting time of innovation in industry and advances in technology. We were manufacturing items such as cars, refrigerators, and televisions, along with the many oils, dyes, and widgets that went with them. Sometimes, however, technology races ahead of responsibility, and human health and the environment can suffer as a result.

This is certainly the case for the toxic compounds known as polychlorinated biphenyls, or PCBs. From the 1920s until they were banned in 1979, the U.S. produced an estimated 1.5 billion pounds of these industrial chemicals. They were used in a variety of manufacturing processes, particularly for electrical parts, across the country. Wastes containing PCBs were often improperly stored or disposed of or even directly discharged into soils, rivers, wetlands, and the ocean.

Unfortunately, the legacy of PCBs for humans, birds, fish, wildlife, and habitat has been a lasting one. As NOAA’s National Ocean Service notes:

Even with discontinued use, PCBs, or polychlorinated biphenyls, are still present in the environment today because they do not breakdown quickly. The amount of time that it takes chemicals such as PCBs to breakdown naturally depends on their size, structure, and chemical composition. It can take years to remove these chemicals from the environment and that is why they are still present decades after they have been banned.

Sign by Hudson River warning against eating contaminated fish.

According to a NOAA, U.S. Fish and Wildlife Service, and State of New York report on the Hudson River, “Fish not only absorb PCBs directly from the river water but are also exposed through the ingestion of contaminated prey, such as insects, crayfish, and smaller fish…New York State’s “eat none” advisory and the restriction on taking fish for this section of the Upper Hudson has been in place for 36 years.” (NOAA)

PCBs are hazardous even at very low levels. When fish and wildlife are exposed to them, this group of highly toxic compounds can travel up the food chain, eventually accumulating in their tissues, becoming a threat to human health if eaten. What happens after animals are exposed to PCBs? According to a NOAA, U.S. Fish and Wildlife Service, and State of New York report [PDF], PCBs are known to cause:

  • Cancer
  • Birth defects
  • Reproductive dysfunction
  • Growth impairment
  • Behavioral changes
  • Hormonal imbalances
  • Damage to the developing brain
  • Increased susceptibility to disease

Because of these impacts, NOAA’s Damage Assessment, Remediation, and Restoration Program (DARRP) works on a number of damage assessment cases to restore the environmental injuries of PCBs. Some notable examples include:

Yet the list could go on—fish and birds off the southern California coast, fish and waterfowl in Wisconsin’s Sheboygan River, a harbor in Massachusetts with the “highest concentrations of PCBs ever documented in a marine environment.”

These and other chemical pollutants remain a challenge but also a lesson for taking care of the resources we have now. While PCBs will continue to be a threat to human and environmental health, NOAA and our partners are working hard to restore the damage done and protect people and nature from future impacts.

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As NOAA Damage Assessment Rules Turn 18, Restoration Trumps Arguing Over the Price Tag of a Turtle

Kemp's Ridley sea turtle on beach in Texas.

How do you put a price tag on natural resources like this endangered Kemp’s Ridley sea turtle? (U.S. Environmental Protection Agency)

What is a fish or sea turtle or day of sailing worth?  Some resources may be easily valued, such as a pound of lobsters, but other natural resources may not be assigned values as easily, such as injured habitats or non-game wildlife. And what about the value of a lobster in nature rather than in a soup pot? In 1989, under the paradigm in place at the time of the Exxon Valdez oil spill, damage assessments were based on the economic value of natural resources and their uses lost as a result of a spill.

Eighteen years ago, on January 6, 1996, NOAA issued its final rules for conducting Natural Resource Damage Assessments (NRDA) for oil spills. The Oil Pollution Act of 1990, prompted by the Exxon Valdez spill, changed many aspects of the U.S. response to oil spills, including the approach to damage assessments.

One of the lessons learned from the Exxon Valdez and other incidents was that restoration became delayed when the focus was on arguing over the monetary value of natural resource damages. This was because once government agencies reached a dollar-based settlement with the organization responsible for the spill, we still had to conduct studies to figure out what restoration was really necessary. Furthermore, since the process focused on calculating monetary damages rather than restoration costs, the trustees did not always receive sufficient funds to conduct restoration (the economic value of a fish or acre of wetland may not represent the costs to restore that resource).

NOAA's Doug Helton during the response to the August 10, 1993, Tampa Bay oil spill.

NOAA’s Doug Helton during the response to the August 10, 1993, Tampa Bay oil spill. A collision between a freighter and two fuel barges resulted in hundreds of thousands of gallons of oil spilled into the Bay. The damage assessment that evaluated injuries to birds, sea turtles, mangrove habitat, seagrasses, salt marshes, and recreational uses was an early example of a restoration-based claim, and NOAA used this experience in developing the damage assessment rules. A number of ecological and recreational restoration projects were conducted to address or compensate for these injuries. For more information, see

To reform this issue, the Oil Pollution Act of 1990 required that NOAA promulgate new damage assessment regulations, and I was assigned to work with a team of attorneys and scientists to help develop a rule that made sense legally and scientifically. In response to the lessons learned from the Exxon Valdez and other recent oil spills, we developed a new approach, focusing on the ultimate goal of restoration rather than attempting to establish a price tag for each fish, bird, or marine mammal injured by a spill. In other words, the damage claim submitted to the responsible party is based on the cost to conduct restoration projects for the damages rather than the value of the injured resource.

The Oil Pollution Act regulations also turned Natural Resource Damage Assessment into a more open process through three major changes:

  • Making assessment results and critical documents available to the public in an administrative record.
  • Requiring that the public have a chance to review and comment on restoration plans.
  • Inviting the organizations responsible for the spill to actively cooperate in the assessment and restoration planning.

The rulemaking process took several years, and we had lots of comments from the public, nongovernmental organizations, and the marine insurance, shipping, and oil industries. Finally, after incorporating all of the comments and developing a series of guidance documents, we published the final rule on January 6, 1996.

We had little time to relax, however. The first test of those cooperative, restoration-based regulations came a couple weeks later when the Barge North Cape and Tug Scandia ran aground in Rhode Island on January 19.  Stay tuned for the story of how that grounding off of a former nudist beach inspired an unexpected career for a young college student.


Celebrate Where Rivers Meet the Sea during National Estuaries Week

This is a post by Lou Cafiero of NOAA’s Office of Ocean and Coastal Resource Management.

A resting kayak at the Narragansett Bay National Estuarine Research Reserve in Rhode Island.

A resting kayak at the Narragansett Bay National Estuarine Research Reserve in Rhode Island. Kayaking is just one of the many recreation opportunities available at our 28 National Estuarine Research Reserves. (Narragansett Bay National Estuarine Research Reserve)

National Estuaries Day rolls in like the tide on the last Saturday of September each year. Established in 1988, this annual event inspires people to learn about and protect the unique environments formed where rivers and other freshwater flow into the ocean, creating bays, lagoons, sounds, or sloughs.

This year, the 25th anniversary of National Estuaries Day will be celebrated around the country on September 28, 2013, but for the first time we are taking an entire week to celebrate, from September 23-29. Outdoor lovers can learn and have fun at each of the 28 National Estuarine Research Reserves throughout the country. Managed by the National Oceanic and Atmospheric Administration (NOAA) in partnership with coastal states and territories, these special reserves were set aside for long-term research and education activities in estuaries.

However, they also offer abundant recreational opportunities, such as swimming, boating, fishing, wildlife viewing, and bird watching. In some reserves you can spot sea otters or manatees swimming with their young, or great blue herons and ospreys soaring in the skies above.

Celebrate at a National Estuarine Research Reserve

First, locate the estuarine research reserve nearest you. You’ll find contact information and directions to all 28 reserves. There are numerous nation-wide activities in honor of National Estuaries Day and Week, such as:

  • Photography contests in Florida.
  • Canoe trips in Washington.
  • Estuary cleanups in North Carolina.
  • Exhibits at state capitals.
  • Guided estuary tours in Texas.
  • Festivals in California.

Find even more events, including one near you, on this National Estuaries Week map of events.

How Estuaries Affect You

Aerial view of estuary.

A total of 1.3 million acres of coastal wetland areas are managed and conserved through NOAA’s National Estuarine Research Reserves. (NOAA)

Estuaries are incredibly diverse and productive ecosystems. Learn more and then help spread the word about why estuaries matter. For example, estuaries:

  • Are vital temporary homes for migratory species, such as mallards and striped bass.
  • Provide critical nesting and feeding habitat for a variety of aquatic plants and animals, including shrimp, oysters, and other commercial seafood.
  • Help prevent coastal erosion.
  • Filter harmful pollutants washing off the land.
  • Reduce flooding during storms.
  • Are important recreational and tourist destinations.
  • Are crucial to our future and the health of the ocean.

How We Affect Estuaries

Estuaries need everyone’s help and hard work to keep them clean and safe. There are many things you can do to help protect and conserve estuaries. Check out these 10 ways to protect estuaries and then explore even more ways to protect estuaries, from taking easy steps around your house to outings at the beach and onto your boat. An example of one important way to keep estuaries clean is to report oil spills or fuel leaks by calling the U.S. Coast Guard National Response Center at 1-800-424-8802.

But sometimes oil spills can be much bigger than one person and have serious impacts for estuaries, commerce, and people. For example, in June of 1989, the Greek tanker World Prodigy hit ground in Rhode Island’s Narragansett Bay, releasing approximately 290,000 gallons of home heating oil into New England’s largest estuary. Not only did the oil affect vast numbers of lobsters, crabs, fish, and shellfish at various stages of life, but the spill also closed beaches and the bay to commercial and recreational clammers.

Through a legal settlement for the World Prodigy grounding’s environmental damages, NOAA secured $567,299 to restore these natural resources. NOAA’s Office of Response and Restoration, through the Damage Assessment, Remediation, and Restoration Program, partnered with the Narragansett Bay National Estuarine Research Reserve on one of the resulting restoration projects. In 1996 and 1997, the NOAA team and its partners transplanted eelgrass beds in Narragansett Bay to restore habitat for the species affected by the spill. More than 7,000 eelgrass plants were transplanted in 10 locations within Narragansett Bay. Dubbed “meadows of the sea,” eelgrass beds provide shelter, spawning grounds, and food for fish, clams, crabs, and other animals while helping keep coastal waters clean and clear.

Don’t Forget to Get Involved

Help celebrate National Estuaries Week this September! Get involved with estuaries by visiting the reserve nearest you. Check out the events scheduled at the reserves or at other estuary locations around the country. Volunteer or become a friend of the National Estuarine Research Reserves and participate in the many educational programs offered.

Louis Cafiero is the communications lead for NOAA’s Office of Ocean and Coastal Resource Management and works closely with the National Estuarine Research Reserves and other federal and nonprofit partners to coordinate outreach efforts to promote National Estuaries Day.

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Historic New England Town, Once Plagued by Tack Factory’s Toxic Pollution, Enjoys Revitalized Coastal Marshes

In spring of 2013, the transformation of the polluted Atlas Tack Superfund site into vibrant coastal habitat is hard to miss. Here, you can see the new freshwater marsh with the town of Fairhaven, Mass., in the background. (NOAA)

In spring of 2013, the transformation of the polluted Atlas Tack Superfund site into vibrant coastal habitat is hard to miss. Here, you can see the new freshwater marsh with the town of Fairhaven, Mass., in the background. (NOAA)

For much of the 20th century, the Atlas Tack Corporation was the main employer in the historic coastal town of Fairhaven, Mass., a place settled in the 1650s by Plymouth colonists. But the presence of this tack factory, shuttered in 1985, left more than a history of paychecks for the area’s residents. It also left saltwater marshes so stocked with cyanide and heavy metals that the U.S. Environmental Protection Agency (EPA) listed the location of the factory as a Superfund site in 1990 and slated it for three intensive rounds of cleanup.

A Brief History of Atlas Tack

Atlas Tack Corporation became one of the nation’s largest manufacturers of wire tacks, bolts, shoe eyelets, bottle caps, and other small hardware. January 17, 1955. (Spinner Publications/All rights reserved)

Atlas Tack Corporation became one of the nation’s largest manufacturers of wire tacks, bolts, shoe eyelets, bottle caps, and other small hardware. Unfortunately, these decades of production left a toxic legacy for Fairhaven’s coastal marshes. January 17, 1955. (Spinner Publications/All rights reserved)

Henry H. Rogers, Standard Oil multimillionaire and friend of famed American author Mark Twain, formed the Atlas Tack Corporation after consolidating several tack manufacturing companies in 1895. The Fairhaven company became one of the nation’s largest manufacturers of wire tacks, bolts, shoe eyelets, bottle caps, and other small hardware.

However, decades of acids, metals, and other chemical wastes oozing through the factory floor boards and being dumped in building drains, the nearby Boys Creek marsh, and an unlined lagoon left the property contaminated with hazardous substances. Found in the soils, waters, and surrounding marsh were volatile organic compounds, cyanide, heavy metals such as arsenic, pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (a toxic oil compound).

EPA led the Superfund cleanup (referred to as a “remedy”) of this hazardous waste site, and the Office of Response and Restoration, through NOAA’s Damage Assessment, Remediation, and Restoration Program, contributed scientific and technical guidance to the EPA during the cleanup and restoration of the site’s coastal marshes.

Determining the Remedy: Scalpel vs. Cleaver

Before restoration: A June 2007 view of the area north of the hurricane dike, following the removal of contaminated sediments. (NOAA)

Before restoration: A June 2007 view of the area north of the hurricane dike, following the removal of contaminated sediments. (NOAA)

The original cleanup goals would have required excavating the entire marsh—ripping out the whole thing, despite some areas still functioning as habitat for the area’s plants and animals. As a result, NOAA, EPA, and U.S. Army Corps of Engineers were reluctant to excavate the entire wetland. Instead, the agencies took a more targeted approach, beginning in 2001 and 2002.

First, they completed a bioavailability study to determine where natural resources were adversely exposed to contaminants from the old tack factory. This study determined which areas of the existing marsh could be preserved while removing the toxic sediment that posed a risk to human health and the environment.

The next part of the remedy was undertaken in three phases from 2006 to 2008. Phase one included demolishing several buildings, sheds, and the power plant and excavating 775 cubic yards of contaminated soil and sludge from 10 acres of the designated commercial area of the manufacturing site. Phase two excavated and disposed off-site 38,000 cubic yards of contaminated soil and debris.  With NOAA’s scientific and technical assistance—and later with help from the Army Corps—EPA, as part of phase three, excavated and later restored 5.4 acres of saltwater and freshwater marsh.

More Than a Remedy: Working Toward Revitalization

After restoration: A newly created northern salt marsh, shown in June 2013, at the site of the former Atlas Tack factory. Bare spots are filling in but a fully covered wetland landscape is likely still a few years away. (NOAA)

After restoration: A newly created northern salt marsh, shown in June 2013, at the site of the former Atlas Tack factory. Bare spots are filling in but a fully covered wetland landscape is likely still a few years away. (NOAA)

While planning to remove the contaminated wetland sediments, we recognized that the culvert running under the hurricane dike prevented the nearby Atlantic Ocean’s tide from replenishing the upstream native saltwater marsh. As a result, invasive reeds were taking over the marsh above the dike.

Reconstructing the culvert would have cost millions of dollars, so the agencies got creative. They designed a new strip of land that would divide the existing, poorly functioning saltwater marsh into a smaller, productive saltwater marsh that could be supported with the existing saltwater supply and a new freshwater wetland supported by rainfall and groundwater. The agencies also removed contaminated sediment from and then replanted a salt marsh south of the dike. Across all three marshes, more than 14,000 native marsh plants were planted, providing valuable habitat for birds and other animals.

By working together, NOAA, EPA, and Army Corps created an effective cleanup solution for the polluted factory site while enhancing the environment by returning this contaminated marsh to a functioning and sustainable habitat, a process known as ecological revitalization. Today, NOAA, along with the EPA, Army Corps, and Massachusetts Department of Environmental Protection, is helping observe and monitor the success of the restoration projects. A recent visit revealed that two of the marshes already are brimming with healthy plants and wildlife, while the salt marsh which had contaminants removed is showing considerable improvement.

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After Remaking the Way for Fish, Huge Increases Follow for Migrating Herring in a Massachusetts River

The Sawmill Dam before NOAA helped install "fishways," which allow fish to pass more easily over the dam, on the Acushnet River in Massachusetts. (NOAA/Steve Block)

The Sawmill Dam before NOAA helped install “fishways,” which allow fish to pass more easily over dams, on the Acushnet River in Massachusetts. (NOAA/Steve Block)

A version of this story first appeared on the NOAA Restoration Center website on April 8, 2013.

In 2007, as part of a habitat restoration project, NOAA helped to install stone “fishways” at two dams on the Acushnet River in Massachusetts. These fishways, designed to more closely resemble conditions found in nature, are located in the river channel and allow migrating fish to gradually gain enough elevation to successfully pass over the dams.

After 2007, when NOAA helped improve fish passage over two dams on the Acushnet River in Massachusetts, herring numbers passing through the river increased dramatically. Here, you can see the completed fishway on the Sawmill Dam.  (NOAA/Steve Block)

After 2007, when NOAA helped improve fish passage over two dams on the Acushnet River in Massachusetts, herring numbers passing through the river increased dramatically. Here, you can see the completed fishway on the Sawmill Dam. (NOAA/Steve Block)

Since construction, there has been an astounding 1,140% increase in migrating herring able to pass over the dams and access prime spawning grounds, according to data collected by the Massachusetts Division of Marine Fisheries [PDF].

Migrating fish, including river herring and American eels, now have much better access to habitat all along the Acushnet River, which runs 8.5 miles from the spawning areas of the New Bedford Reservoir into New Bedford Harbor and empties into Buzzards Bay. This means more opportunities for herring to grow, thrive, and spawn.

Herring are caught commercially and are also important prey fish for other commercial and recreational fish species, such as cod. But, due to very low numbers, there is currently a moratorium on the take of river herring from Massachusetts waters.

Between the 1940s and the 1970s, electrical parts manufacturers discharged wastes containing polychlorinated biphenyls (PCBs) and toxic metals into New Bedford Harbor, resulting in high levels of contamination. NOAA, through the Damage Assessment Remediation and Restoration Program (DARRP), worked with the Commonwealth of Massachusetts and the Department of Interior to fund the design and construction of these fishways. They are part of a restoration plan developed in response to decades of industrial pollution in New Bedford Harbor, a major commercial fishing port and industrial center in southeastern Massachusetts. According to NOAA, part of this site held the “highest concentrations of PCBs ever documented in a marine environment.”

So far, 34 projects—including these fishways—have been completed to restore natural resources that were injured or lost due to the contamination. Read more on the case and get the latest updates on restoration.

This spring, scientists are hoping to see even bigger runs of herring on the Acushnet. Want to see them in person? The third and fourth weeks of April should be peak migration time for these fish—check out this viewing guide for more information.


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