NOAA's Response and Restoration Blog

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


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Little “Bugs” Can Spread Big Pollution Through Contaminated Rivers

This is a post by the NOAA Restoration Center’s Lauren Senkyr.

When we think of natural resources harmed by pesticides, toxic chemicals, and oil spills, most of us probably envision soaring birds or adorable river otters.  Some of us may consider creatures below the water’s surface, like the salmon and other fish that the more charismatic animals eat, and that we like to eat ourselves. But it’s rare that we spend much time imagining what contamination means for the smaller organisms that we don’t see, or can’t see without a microscope.

Mayfly aquatic insect on river bottom.

A mayfly, pictured above, is an important component in the diet of salmon and other fish. (NOAA)

The tiny creatures that live in the “benthos”—the mud, sand, and stones at the bottoms of rivers—are called benthic macroinvertebrates. Sometimes mistakenly called “bugs,” the benthic macroinvertebrate community actually includes a variety of animals like snails, clams, and worms, in addition to insects like mayflies, caddisflies, and midges. They play several important roles in an ecosystem. They help cycle and filter nutrients and they are a major food source for fish and other animals.

Though we don’t see them often, benthic macroinvertebrates play an extremely important role in river ecosystems. In polluted rivers, such as the lower 10 miles of the Willamette River in Portland, Oregon, these creatures serve as food web pathways for legacy contaminants like PCBs and DDT. Because benthic macroinvertebrates live and feed in close contact with contaminated muck, they are prone to accumulation of contaminants in their bodies.  They are, in turn, eaten by predators and it is in this way that contaminants move “up” through the food web to larger, more easily recognizable animals such as sturgeon, mink, and bald eagles.

Some of the ways contaminants can move through the food chain in the Willamette River.

Some of the ways contaminants can move through the food chain in the Willamette River. (Portland Harbor Trustee Council)

The image above depicts some of the pathways that contaminants follow as they move up through the food web in Oregon’s Portland Harbor. Benthic macroinvertebrates are at the bottom of the food web. They are eaten by larger animals, like salmon, sturgeon, and bass. Those fish are then eaten by birds (like osprey and eagle), mammals (like mink), and people.

An illustration showing how concentrations of the pesticide DDT biomagnify 10 million times as they move up the food chain from macroinvertebrates to fish to birds of prey.

An illustration showing how concentrations of the pesticide DDT biomagnify 10 million times as they move up the food chain from macroinvertebrates to fish to birds of prey. (U.S. Fish and Wildlife Service)

As PCB and DDT contamination makes its way up the food chain through these organisms, it is stored in their fat and biomagnified, meaning that the level of contamination you find in a large organism like an osprey is many times more than what you would find in a single water-dwelling insect. This is because an osprey eats many fish in its lifetime, and each of those fish eats many benthic macroinvertebrates.

Therefore, a relatively small amount of contamination in a single insect accumulates to a large amount of contamination in a bird or mammal that may have never eaten an insect directly.  The graphic to the right was developed by the U.S. Fish and Wildlife Service to illustrate how DDT concentrations biomagnify 10 million times as they move up the food chain.

Benthic macroinvertebrates can be used by people to assess water quality. Certain types of benthic macroinvertebrates cannot tolerate pollution, whereas others are extremely tolerant of it.  For example, if you were to turn over a few stones in a Northwest streambed and find caddisfly nymphs (pictured below encased in tiny pebbles), you would have an indication of good water quality. Caddisflies are very sensitive to poor water quality conditions.

Caddisfly nymphs encased in tiny pebbles on a river bottom.

Caddisfly nymphs encased in tiny pebbles on a river bottom are indicators of high water quality. (NOAA)

Surveys in Portland Harbor have shown that we have a pretty simple and uniform benthic macroinvertebrate population in the area. As you might expect, it is mostly made up of pollution-tolerant species. NOAA Restoration Center staff are leading restoration planning efforts at Portland Harbor and it is our hope that once cleanup and restoration projects are completed, we will see a more diverse assemblage of benthic macroinvertebrates in the Lower Willamette River.

Lauren SenkyrLauren Senkyr is a Habitat Restoration Specialist with NOAA’s Restoration Center.  Based out of Portland, Ore., she works on restoration planning and community outreach for the Portland Harbor Superfund site as well as other habitat restoration efforts throughout the state of Oregon.


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A Train Derails in Paulsboro, N.J., Releasing 23,000 Gallons of Toxic Vinyl Chloride Gas

Seven train cars derailed when the bridge over the Mantua Creek collapsed Friday morning. Four tank cars containing vinyl chloride were dumped into the creek. Nearby residents were evacuated and schools were locked down. Nearly 20 people complained of respiratory distress from the vinyl chloride vapor that leaked from the tank cars. (Photo: Rae Lynn Stevenson/South Jersey Times. All rights reserved.)

Seven train cars derailed when the bridge over the Mantua Creek collapsed Friday morning. Four tank cars containing vinyl chloride were dumped into the creek. Nearby residents were evacuated and schools were locked down. Nearly 20 people complained of respiratory distress from the vinyl chloride vapor that leaked from the tank cars. (Photo: Rae Lynn Stevenson/South Jersey Times. All rights reserved.)

UPDATED DECEMBER 7, 2012 — On November 30, 2012, a train transporting the chemical vinyl chloride derailed while crossing a bridge that collapsed over Mantua Creek, in Paulsboro, N.J., near Philadelphia. Four rail cars fell into the creek, breaching one tank and releasing approximately 23,000 gallons of vinyl chloride.

Local, state, and federal emergency personnel responded on scene. A voluntary evacuation zone was established for the area, and nearby schools were ordered to immediately take shelter and seal off their buildings.

Overview of the overturned train cars carrying vinyl chloride

A detailed overview of the overturned train cars carrying vinyl chloride in New Jersey’s Mantua Creek. The rail car in the foreground is being used as an anchor to stabilize the derailed cars. (Conrail Derailment Incident Command)

Vinyl chloride, which is used to make plastics, adhesives, and other chemicals, is a toxic gas. During this accident, most of the chemical was released directly to the air, and response teams are still determining how much might have dissolved in the creek’s waters, which feed into the Delaware River.

U.S. Coast Guard Sector Delaware Bay contacted NOAA’s Office of Response and Restoration (OR&R) and requested scientific support for this environmental and public health threat.

The OR&R scientific support team worked to address early concerns about the air hazard, centering around possible health effects, evacuation decisions, proper protective equipment for responders, impacts to the Philadelphia airport two miles away, and reactivity between vinyl chloride and another rail car containing ethyl alcohol.

OR&R develops software products responders use to address these issues: ALOHA, an air dispersion model, and CAMEO Chemicals, a hazardous material database.

OR&R had a Scientific Support Coordinator (SSC) at the scene of the spill to work with the Coast Guard as they attempted to salvage the derailed cars from the creek and collapsed bridge. While the SSC departed on Dec. 6, a NOAA incident meteorologist remains at the incident command post to provide custom weather forecasts for the affected area, for air monitoring and to identify safe operating conditions for the crane work and other salvage operations.

OR&R’s Emergency Response Division remains involved from NOAA’s Seattle offices, where they are investigating potential problems which might occur if vinyl chloride accidentally is discharged into the water as salvage operations continue.

In addition, two scientists from NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) have been dispatched to Paulsboro to deploy a current meter and forecast the tides specifically for Mantua Creek (which is driven by tidal flows) to schedule safe crane and dive operations. To help the National Transport Safety Board’s investigation into this incident, CO-OPs scientists also will recreate the tidal cycle conditions during the time of the incident.

Removing the derailed train cars is a logistically complicated process. The Coast Guard coordinated the removal of the last 600 gallons of vinyl chloride from the breached tank by using acetone and suctioning out the vapors before attempting to move the tank. Next, the response team is bringing in cranes and barges to remove the rail cars and bridge debris from Mantua Creek.

The evacuations have ended and families slowly are returning to their homes near the creek. The process has been slow because each family is accompanied by a police officer and an air monitor, who goes into the home first to check for the presence of vinyl chloride before allowing families inside.


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56 years after Gruesome Chemical Catastrophe, Science Prevented Second Texas City Disaster

In addition to authors Vicki Loe and CJ Beegle-Krause, Charlie Henry, Doug Helton, and Amy Merten contributed to this post.

On a cool April morning in 1947, the S.S. Grandcamp sat docked in Texas City, waiting as it was loaded with sacks of ammonium nitrate fertilizer. A few years earlier, this humble cargo ship had been part of the U.S. Navy’s Pacific Fleet. After World War II, the U.S. government gave it to France as a gift to help rebuild a shattered Europe, where it was renamed the Grandcamp and converted into a slightly less grand cargo ship, which now found itself waiting fatefully in a Texas port.

The Grandcamp’s freight that day, ammonium nitrate fertilizer, is usually a relatively safe cargo, but it can quickly become unstable and explosive under certain conditions, which is also why it is used as an industrial and military explosive. Arriving by train in Texas City, this cargo may have become too warm to ship safely, but at the time, few chemical safety regulations existed, and the fertilizer was packed onto the Grandcamp along with its previous shipments of twine, peanuts, tobacco, and 16 cases of small arms ammunition.

Around 8:00 a.m. on April 16, after about 2,300 tons of fertilizer were loaded, workers noticed smoke and vapors coming from the ship. No one knew what caused the fire in the hold. The captain ordered the hatches battened and tarpaulins thrown over them, calling for steam to be piped into the ship—a firefighting technique he hoped would put out the fire but preserve the cargo. However, this would only make things worse.

Barge cast 100 feet inland by explosion.

This barge, originally located near the explosion, was lifted out of the water and landed 100 feet inland. The firetruck at left (behind the man) was thrown there by the second explosion. Photo taken April 18, 1947. (Courtesy of Special Collections, University of Houston Libraries. UH Digital Library)

Shortly after 9:00 a.m., the ship exploded with tremendous force. The resulting explosion launched the cargo 2,000 to 3,000 feet into the sky, caused a 15-foot tidal wave, and was felt as far as 250 miles away.

A nearby ship, the S.S. High Flyer, also loaded with ammonium nitrate, ignited and about 16 hours later, also exploded.

The combined explosions resulted in the largest industrial disaster of its time in the U.S., taking the lives of an estimated 500–600 people. Thousands more were injured.

Damaged houses in Texas City in 1947.

Damaged Texas City houses one mile away from the explosion. Photo taken on April 18, 1947. (Courtesy of Special Collections, University of Houston Libraries. UH Digital Library)

On a warm November evening in 2003, Barge NMS 1477 sat docked in Texas City, just across from the same dock where the Grandcamp had been waiting fatefully 56 years earlier. Loaded with 197,000 gallons of concentrated sulfuric acid (>97%), the barge capsized during the final stages of loading on November 3.

With the barge now floating upside down at the dock, acid began slowly leaking from the vents as seawater rushed in, dangerously diluting the acid.

Charlie Henry, then NOAA’s Scientific Support Coordinator for the region, quickly reported to the scene to support the United States Coast Guard Captain of the Port. While the situation appeared stable, the threat of a possible disaster was slowly growing. Inside the bowels of the barge, an aggressive chemical reaction was taking place.

Barge NMS 1477 tilted on its side at a Texas City dock.

Barge NMS 1477 later tilted on its side, where it was coincidentally located at the same Texas City dock as the S.S. High Flyer. (NOAA)

Highly concentrated acid is actually stable when shipping, but partially diluted concentrated sulfuric acid is highly corrosive. As the acid began mixing with small amounts of seawater, it began eating away at the barge’s steel structure, releasing heat and explosive hydrogen gas.

The gravity of this situation was not lost on Charlie and others involved in the response. This was quickly becoming a very dangerous situation for the responders and the local public.

With the gruesome 1947 catastrophe on their minds, the local NOAA responders along with a Louisiana State University chemist providing scientific support arrived at the site of the partially sunken barge on November 5, and the Seattle-based NOAA response team also went into high gear.

The response team included the U.S. Coast Guard, the Texas Commission of Environmental Quality, Texas Parks and Wildlife, the U.S. Environmental Protection Agency, and NOAA, as well as representatives from the barge’s operator, Martin Product Sales LLC, all working together to minimize the impact of this incident.

The dock where the barge overturned in the Port of Texas City.

The dock where the barge overturned in the Port of Texas City in 2003. (NOAA)

The barge had now tilted on its side and rested on the bottom at the dock. This was the same spot that the unfortunate S.S. High Flyer was docked in 1947. Everyone’s immediate concern was the potential for an explosion from the hydrogen gas now built up in the barge. The gas had expanded the barge’s side-plates and vigorously bubbled from vents located underwater near where the side of the barge rested on the bottom.

Since 1947, this area in Texas City had been extensively developed to support the chemical and oil industries, meaning that an explosion on the barge could lead to even more damage and disaster than before.

Because the threat of explosion was so great, the responders made the unusual but necessary decision to do a controlled spill of the vessel’s remaining sulfuric acid into the adjacent harbor waters. To dilute such large volumes of acid to a concentration considered below an environmental hazard, it would have to be mixed with huge volumes of water. The buffering salts in seawater would also help mitigate the acid. The operation was complete by November 13, nine days after the accident.

The decision to intentionally spill the cargo wasn’t easy, but later environmental sampling showed that the acid was highly buffered and diluted when it entered the adjacent open bay. Furthermore, tidal flow and the movement of ships in the area appeared to help reduce the environmental impacts as well. Monitoring continued as the “footprint” of the plume of the discharged acid dissipated throughout the waters.

Aerial photo of Texas City Port taken April 20, 1947.

Aerial photo of Texas City Port taken April 20, 1947. (Courtesy of Special Collections, University of Houston Libraries. UH Digital Library)

Fortunately, a smart use of science helped avoid another explosion in Texas City. The scarred propeller from the S.S. High Flyer sits at the entrance to the Port at Texas City as a reminder of a less fortunate emergency response which now happened 65 years ago.

Sources included [all links leave this blog]:
1947 Texas City Disaster | Moore Memorial Public Library
The Texas City Disaster, 1947 By Hugh W. Stephens | University of Texas Press
Sulfuric Acid Barge NMS 1477 Leaking | IncidentNews.noaa.gov
Agencies Respond to Capsized Barge | MarineLink.com

CJ Beegle-KrauseCJ Beegle-Krause is president of Research4D, a Seattle-based nonprofit with a mission to bring peer-reviewed research into decision support. She is a former trajectory modeler with NOAA’s Office of Response and Restoration, who worked on this barge incident. More recently, she has been working again with OR&R on the Deepwater Horizon/BP oil spill. “Science allows us to predict, and thus to respond most appropriately to smaller rapidly-scaling-up events like this barge as well as larger scale environmental disasters.”


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A DDT Legacy and the Road to Recovery in California

This is a post by Gabrielle Dorr, NOAA/Montrose Settlements Restoration Program Outreach Coordinator.

Effects of DDT on bird eggs.

On display at the National Museum of American History, you can see the effects of DDT on a bird egg (right). Credit: Kari Bluff, Creative Commons.

If you ask the earlier Baby Boomer generation about DDT (dichlorodiphenyltrichloroethane), they might recall images of this chemical being sprayed in their neighborhoods right where they were playing.

DDT was first considered a wonder chemical by many for its use against disease-carrying insects and agricultural pests, prompting a Nobel Prize for its discovery. DDT was widely used as a pesticide beginning in the 1940s, until concerned biologists led by Rachel Carson, documented its harmful effects on birds, other wildlife, and possibly human health.

Another trait of DDT is that once released, it stays in the environment for a very long time.  The U.S. Environmental Protection Agency (EPA) finally banned its use in 1972. However, releases of this chemical were widespread by the time it was banned.

The story in southern California, however, is a little different.  A DDT manufacturing company called the Montrose Chemical Corporation, located in Torrance, Calif., had a permit to release their DDT waste through an outfall pipe that led to the ocean nearby. Other factories in the area were manufacturing PCBs, another harmful chemical, and releasing their waste through the same outfall pipe at White Point.

Millions of pounds* later, local and federal governments determined that the release of these chemicals was a violation of the Comprehensive Environmental Response Compensation Liability Act (CERCLA), which is also known as Superfund. After 10 years of litigation and data collection, a settlement agreement was reached, and funds were made available to clean up the contamination site at the bottom of the ocean along Palos Verdes Shelf and to restore resources harmed from the pollution within the Southern California Bight.

One year after a settlement was reached, in 2001, the Montrose Settlements Restoration Program (MSRP) was formed to oversee restoration of resources harmed by DDT and PCBs including Bald Eagles, Peregrine Falcons, seabirds, fishing, and fish habitat. This year marks the 10 year anniversary for the restoration program, and there is plenty to celebrate. At www.montroserestoration.noaa.gov, you can find the program’s restoration accomplishments, photos, wildlife webcams, and the latest updates from the program’s trustee council. Relive some highlights of successful restoration milestones of the program over the last decade, and see what projects MSRP is proposing in the Draft Phase 2 Restoration Plan released for public comment this month.

A larger symbol of the hope for recovery here manifests itself in the film Return Flight: Restoring the Bald Eagle to the Channel Islands, directed by the Filmmakers Collaborative SF. This film captures the spirit of biologists, partners, volunteers, and concerned citizens working to secure a biological legacy for the Bald Eagle in southern California despite the chemical legacy of DDT.

You can watch the short film here:

*Correction: Previously, this incorrectly stated “hundreds of millions of tons,” not pounds, of PCBs and DDT waste.

Above photo is licensed under a Creative Commons Attribution-No Derivatives license.

Gabrielle Dorr

Gabrielle Dorr.

Gabrielle Dorr is the Outreach Coordinator for the Montrose Settlements Restoration Program as part of NOAA’s Restoration Center. She lives and works in Long Beach, California where she is always interacting with the local community through outreach events, public meetings, and fishing education programs.