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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To Bring Back Healthy California Ocean Ecosystems, NOAA and Partners Are “Planting” Long-Lost Abalone in the Sea

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

Diver placing PVC tube with small sea snails on the rocky seafloor.

A diver places a PVC tube filled with young green abalone — sea snails raised in a lab — on the seafloor off the southern California coast. (NOAA)

They weren’t vegetables but an excited group of scuba divers was carefully “planting” green abalone in an undersea garden off the southern California coast all the same. Green abalone are a single-shelled species of sea snail whose population has dropped dramatically in recent decades.

On a Wednesday in mid-June, these oceanic “gardeners”—NOAA biologist David Witting and divers from The Bay Foundation—released over 700 young green abalone into newly restored kelp forest areas near Palos Verdes, California. This was the first time in over a decade that juvenile abalone have been “outplanted,” or transplanted from nursery facilities, to the wild in southern California. This ongoing project is a partnership between NOAA, The Bay Foundation, Redondo SEA Lab, The Nature Conservancy, and the California Department of Fish and Wildlife.

Spawned and reared at The SEA Lab in Redondo Beach, California, all of the juvenile abalone were between two and four years old and were between a quarter inch and 3 inches in size. Biologists painstakingly tagged each abalone with tiny identifying tags several weeks prior to their release into the wild.

Leading up to outplanting day, microbiologists from the California Department of Fish and Wildlife had to run rigorous tests on a sample of the juvenile abalone to certify them as disease-free before they were placed into the ocean. Several days before transferring them, biologists placed the abalone in PVC tubes with netting on either end for easy transport.

“This was just a pilot outplanting with many more larger-scale efforts to come in the near future,” stated David Witting from NOAA’s Restoration Center. “We wanted to go through all of the steps necessary to successfully outplant abalone so that it would be second nature next time.”

Marine biologists from The Bay Foundation, along with Witting and other NOAA biologists, will be going out over the next six to twelve months to monitor the abalone—checking for survival rates and movement of the abalone. “We expect to find some abalone that didn’t survive the transfer to the wild but probably a good number of them will move into the cracks and crevices of rocky reef outcroppings immediately,” according to Witting.

Why Abalone?

PVC tube filled with green abalone lodged into the rocky seafloor.

After testing and refining the techniques to boost the population of green abalone in the wild, scientists then will apply them to help endangered white and black abalone species recover. (NOAA)

All seven abalone species found along the U.S. West Coast have declined and some have all but disappeared. White and black abalone, in particular, are listed as endangered through the Endangered Species Act (ESA). Three abalone species (green, pinto, and pink) are listed as Species of Concern by NOAA Fisheries, a designation meant to protect the populations from declining further and which could result in an ESA listing. The two remaining abalone species, reds and flats, are protected and managed by states along the U.S. West Coast.

Historically, the main cause of abalone’s demise was a combination of overfishing and disease. Today, many other threats, such as poaching, climate change, oil spills, and habitat degradation, contribute to the decline of abalone and could impact the health of future populations.

The recent green abalone outplanting was one of the many steps needed to advance the recovery of all abalone species. Methods for rearing and outplanting are first being tested using green abalone because this species is more abundant in the wild. Once the methods are refined, they then will be employed to recover endangered white and black abalone—both species which are currently living on the brink of extinction.

What the Future Holds

A small green abalone eats red algae stuck to a plastic rack.

A young green abalone, reared in a lab in southern California, grazes on red algae. Raising these sea snails in a lab requires a lot of resources, prompting scientists to explore other approaches for boosting wild abalone populations. (Credit: Brenda Rees, with permission)

In particular, biologists are hoping to refine a technique they are coining “deck-spawning” as a way to outplant abalone in the future. Maintaining abalone broodstock and rearing them in a lab requires a lot of resources, funding, and time. This monumental effort has spurred biologists to develop an initially successful, alternate approach, which involves inducing mature, wild abalone to spawn on the deck of a boat.

The scientists then take the viable abalone larvae that develop and release them in a habitat where the young abalone are likely to settle and thrive. Immediately after spawning, the parent abalone can then be returned to the wild where they can continue to be a component of the functioning ocean ecosystem.

The green abalone outplanting project is part of a broader effort to restore abalone but is also playing an important role in work being led by The Bay Foundation with NOAA’s Montrose Settlements Restoration Program to restore southern California’s kelp forests. In southern California, fish habitat has been harmed by decades of toxic pollution dumped into the marine environment. After clearing areas that would be prime kelp habitat if not for the unnaturally high densities of sick and stressed sea urchins, NOAA, The Bay Foundation, and our partners have seen kelp bounce back once given relief from those overly hungry urchins.

While abalone also eat seaweed, including kelp, they are a natural competitor of urchins in this environment and will help keep urchin populations in check, ultimately allowing a healthy kelp forest community to return.

Watch as divers transport the young abalone using PVC tubes and release them on the rocky seafloor off California’s coast:

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.


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For Alaska’s Remote Pribilof Islands, a Tale of Survival and Restoration for People and Seals

Set in the middle of Alaska’s Bering Sea, a string of five misty islands known as the Pribilof Islands possess a long, rich, and at times, dark history. A history of near extinction, survival, and restoration for both people and nature. A history involving Alaska Natives, Russians, the U.S. government and military, and seals.

It begins with the native people, known as the Unangan, who live there. They tell a story that, as they say, belongs to a place, not any one person. The story is of the hunter Iggadaagix, who first found these islands many years ago after being swept away in a storm and who wanted to bring the Unangan back there from the Aleutian Islands. When the Unangan finally did return for good, it was in the 18th century, and their lives would become intimately intertwined with those of the northern fur seals (Callorhinus ursinus). Each summer roughly half of all northern fur seals breed and give birth in the Pribilof Islands.

Map of fur seal distributions in Bering Sea and Pacific Ocean, with location of Pribilof Islands.

An 1899 map of the distribution (in red) and migrations of the American and Asiatic Fur Seal Herds in the Bering Sea and North Pacific Ocean. Based on data collected 1893-1897. The Pribilof Islands (St. Paul and St. George) are visible north of the main Aleutian Islands, surrounded by the center collections of red dots. Click to enlarge. (U.S. Government)

But these seals and their luxurious fur, along with the tale of Iggadaagix, would eventually bring about dark times for the seals, the Unangan, and the islands themselves. After hearing of Iggadaagix and searching for a new source of furs, Russian navigator Gavriil Loginovich Pribylov would land in 1786 on the islands which would eventually bear his name. He and others would bring the Unangan from the Aleutian Islands to the Pribilof’s St. George and St. Paul Islands, where they would be put to work harvesting and processing the many fur seals.

In these early years on the islands, Russian hunters so quickly decimated the fur seal population that the Russian-American Company, which held the charter for settling there, suspended hunting from 1805 to 1810. The annual limit for taking fur seals was then set at 8,000 to 10,000 pelts, allowing the population to rebound significantly.

The United States Arrives at the Islands

Fast forward to 1867, when the United States purchased Alaska, including the Pribilof Islands, from Russia for $7.2 million.

Some people considered the lucrative Pribilof Islands fur seal industry to have played a role in this purchase. In fact, this industry more than repaid the U.S. government for Alaska’s purchase price, hauling in $9,473,996 between 1870 and 1909.

The late 19th and early 20th centuries saw various U.S. military branches establish stations on the Pribilof Islands, as well as several (at times unsuccessful) attempts to control the reckless slaughter of fur seals. From 1867 until 1983, the U.S. government managed the fur seal industry on the Pribilof Islands.

In 1984, the Unangan finally were granted control of these islands, but the government had left behind a toxic legacy from commercial fur sealing and former defense sites: hazardous waste sites, dumps, contaminants, and debris.

Making Amends with the Land

This is where NOAA comes into the picture. In 1996, the Pribilof Islands Environmental Restoration Act called on NOAA to restore the environmental degradation on the Pribilof Islands. In particular, a general lack of historical accountability on the islands had led to numerous diesel fuel spills and leaks and improperly stored and disposed waste oils and antifreeze. By 1997 NOAA had removed thousands of tons of old cars, trucks, tractors, barrels, storage tanks, batteries, scrap metal, and tires from St. Paul and St. George Islands. Beginning in 2002, NOAA’s efforts transitioned to cleaning up soil contamination and assessing potential pollution in groundwater.

However, the Department of Defense has also been responsible for environmental cleanup at the Pribilof Islands. The U.S. Army occupied the islands during World War II and left behind debris and thousands of 55-gallon drums, which were empty by 1985 but had previously contained petroleum, oils, and lubricants, which could have leaked into the soil.

By 2008, NOAA’s Office of Response and Restoration had fulfilled its responsibilities for cleaning up the contamination on the Pribilof Islands, closing a dark chapter for this remote and diverse area of the world and hopefully continuing the healing process for the Unangan and fur seals who still call these islands their home.

Learn More about the Pribilof Islands

Man posing with schoolchildren.

Dr. G. Dallas Hanna with a class of Aleut schoolchildren on St. George Island, Alaska, circa 1914. (National Archives)

You can dig even deeper into the wealth of historical information about the Pribilof Islands at pribilof.noaa.gov.

There you can find histories, photos, videos, and documents detailing the islands’ various occupations, the fur seal industry, the relocation of the Unangan during World War II, the environmental contamination and restoration, and more.

You can also watch:


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Why Are Seabirds so Vulnerable to Oil Spills?

Out of the squawking thousands of black and white birds crowding the cliff, a single male sidled up to the rocky edge. After arranging a few out-of-place feathers with his sleek beak, the bird plunged like a bullet into the ocean below. These penguin look-alikes (no relation) are Common Murres. Found along the U.S. coast from Alaska to California, this abundant species of seabird dives underwater, using its wings to pursue a seafood dinner, namely small fish.

During an oil spill, however, these classic characteristics of murres and other seabirds work to their disadvantage, upping the chance they will encounter oil—and in more ways than one. To understand why seabirds are so vulnerable to oil spills, let’s return to our lone male murre and a hypothetical oil spill near his colony in the Gulf of Alaska.

Preening in an Oil Sheen

After diving hundreds of feet beneath the cold waters of the North Pacific Ocean, the male murre pops back to the surface with a belly full of fish—and feathers laminated in oil. This bird has surfaced from his dinner dive into an oil slick, a common problem for diving birds during oil spills. His coat of feathers, once warm and waterproof, is now matted. The oil is breaking up his interlocking layer of feathers, usually maintained by the bird’s constant arranging and rearranging, known as preening.

With his sensitive skin suddenly exposed not just to the irritating influence of oil but also to the cold, the male murre becomes chilled. If he does not repair the alignment of his feathers soon, hypothermia could set in. This same insulating structure also traps air and helps the bird float on the water’s surface, but without it, the bird would struggle to stay afloat.

Quickly, the freshly oiled seabird begins preening. But with each peck of his pointed beak into the plumage, he gulps down small amounts of oil. If the murre ingests enough oil, it could have serious effects on his internal organs. Impacts range from disrupted digestion and diarrhea to liver and kidney damage and destruction of red blood cells (anemia).

But oil can find yet another way of entering the bird: via the lungs. When oil is spilled, it begins interacting with the wind, water, and waves and changing its physical and chemical properties through the process of weathering. Some components of the oil may evaporate, and the murre, bobbing on the water’s surface, could breathe in the resulting toxic fumes, leading to potential lung problems.

Birds’-Eye View

Colony of murres on a rocky outcropping on the California coast.

Murres are very social birds, living in large colonies on rocky cliffs and shores along the U.S. West Coast. If disturbed by an oil spill, many of these birds may set off temporarily to find a more suitable home. (Creative Commons: Donna Pomeroy, Attribution-NonCommercial 3.0 Unported License)

This single male murre is likely not the only one in his colony to experience a run-in with the oil spill. Even those seabirds not encountering the oil directly can be affected. With oil spread across areas where the birds normally search for food and with some of their prey potentially contaminated or killed by the oil, the colony may have to travel farther away to find enough to eat. On the other hand, large numbers of these seabirds may decide to up and move to another home for the time being.

At the same time that good food is becoming scarcer, these birds will need even more food to keep up their energy levels to stay warm, find food, and ward off disease. One source of stress—the oil spill—can exacerbate many other stresses that the birds often can handle under usual circumstances.

If the oil spill happens during mating and nesting time, the impacts can be even more severe. Reproducing requires a lot of energy, and on top of that, exposure to oil can hinder birds’ ability to reproduce. Eggs and very young birds are particularly sensitive to the toxic and potentially deadly properties of oil. Murres lay only one egg at a time, meaning they are slower to replace themselves.

The glossy-eyed male murre we are following, even if he manages to escape most of the immediate impacts of being oiled, would soon face the daunting responsibility of taking care of his fledgling chick. As young as three weeks old, his one, still-developing chick plops off the steep cliff face where the colony resides and tumbles into the ocean, perhaps a thousand feet to its waiting father below. There, the father murre is the chick’s constant caregiver as they travel out to sea, an energy-intensive role even without having to deal with the potential fallout from an oil spill.

Birds of a Feather Get Oiled Together

Like a bathtub filled with rubber ducks, murres form giant floating congregations on the water, known as “rafts,” which can include up to 250,000 birds. In fact, murres spend all but three or four months of the year out at sea. Depending on where the oil travels after a spill, a raft of murres could float right into it, a scenario which may be especially likely considering murre habitat often overlaps with major shipping channels.

After the 1989 Exxon Valdez oil spill in Prince William Sound, responders collected some 30,000 dead, oil-covered birds. Nearly three-quarters of them were murres, but the total included other birds which dive or feed on the ocean surface as well. Because most bird carcasses never make it to shore intact where researchers can count them, they have to make estimations of the total number of birds killed. The best approximation from the Exxon Valdez spill is that 250,000 birds died, with 185,000 of them murres.

While this population of seabirds certainly suffered from this oil spill (perhaps losing up to 40 percent of the population), murres began recovering within a few years of the Exxon Valdez oil spill. Surprisingly resilient, this species is nonetheless one of the most studied seabirds [PDF] precisely because it is so often the victim of oil spills.


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After a Century Apart, NOAA and Partners Reunite a Former Wetland with San Francisco Bay’s Tides

Excavator removing earth from a breached barrier between tide waters in a slough and the new wetland.

The first of four breaches of tidal levees separating Cullinan Ranch from the tide waters of San Francisco Bay. (NOAA)

Scooping away the last narrow band of mud, a bright yellow excavator released a rush of brackish water into an area cut off from the tides for more than a hundred years.

The 1,200 acre field now filling with water, known as Cullinan Ranch due to its history as a hay farm, is once again becoming a tidal wetland.

On January 6, 2015, more than 100 people celebrated the reintroduction of tide waters to Cullinan Ranch in Solano County, California. For decades before, earthen levees had separated it from the nearby Napa River and San Pablo Bay, a northern corner of the San Francisco Bay Estuary.

With three more levee breaches planned by the end of January, restoration of this 1,500 acre site is nearly complete, with efforts to monitor the project’s progress to follow. Surrounded by state and federal wildlife lands, Cullinan Ranch will fill in a gap in coastal habitat as it becomes integrated with San Pablo Bay National Wildlife Refuge.

How Low Can It Flow

For the most part, Cullinan Ranch will be covered in open water because years of farming, beginning in the 1880s, caused the land to sink below sea level. The open water will provide places for animals such as fish and birds—as well as the invertebrates they like to eat—to find food and rest after big storms.

However, some areas of the property will remain above the low tide level, creating conditions for the plant pickleweed to thrive. While a succulent like cacti, pickleweed can survive wet and salty growing conditions. (Fun fact: Some people enjoy cooking and eating pickleweed. When blanched, it apparently tastes salty and somewhat crispy.) The salt marsh harvest mouse, native to California and one of the few mammals able to drink saltwater, also will take advantage of the habitat created by the pickleweed in the recovering wetland.

Wildlife will not be the only ones enjoying the restoration of Cullinan Ranch. A major highway passes by the site, and Cullinan Ranch has experienced numerous upgrades to improve recreational access for people brought there by Highway 37. Soon anyone will be able to hike on the newly constructed trails, fish off the pier, and launch kayaks from the dock.

Turning Money into Marshes

The restoration of Cullinan Ranch from hay field to tidal wetland has been in the works for a long time, brought about by a range of partners and funding agencies, including NOAA, the U.S. Fish and Wildlife Service, the U.S. Environmental Protection Agency, California Department of Fish and Wildlife, California Wildlife Conservation Board, and Ducks Unlimited. NOAA provided several sources of funding to help finish this restoration project.

In addition to $900,000 from the American Recovery and Reinvestment Act, NOAA contributed $650,000 through a community-based restoration partnership with Ducks Unlimited and $1.65 million awarded for natural resource damages through the Castro Cove trustee council. The latter funding was part of a $2.65 million settlement with Chevron as a result of the nearby Chevron Richmond Refinery discharging mercury and oil pollution into Castro Cove for years. Cullinan Ranch and Breuner Marsh are the two restoration projects Chevron funded to make up for this pollution.

Map of San Francisco Bay showing locations of NOAA restoration projects.

NOAA is working on a number of tidal wetland restoration projects in the north San Francisco Bay. (NOAA)

Cullinan Ranch is one of the largest restoration projects in the north San Francisco Bay, but it is far from the only one NOAA is involved with in the region. Helping reverse a century-long trend which saw many of the bay’s tidal wetlands disappear, NOAA has been working on a suite of projects restoring these historic and important coastal features in northern California.

Watch footage of the earthen levee being breached to reconnect the bay’s tide waters to Cullinan Ranch.


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How NOAA Uses Coral Nurseries to Restore Damaged Reefs

Staghorn coral fragments hanging on an underwater tree structure of PVC pipes.

NOAA uses coral nurseries to help corals recover after traumatic events, such as a ship grounding. Hung on a tree structure, the staghorn coral shown here will have a better chance of surviving and being transplanted back onto a reef. (NOAA)

The cringe-inducing sound of a ship crushing its way onto a coral reef is often the beginning of the story. But, thanks to NOAA’s efforts, it is not usually the end. After most ship groundings on reefs, hundreds to thousands of small coral fragments may litter the ocean floor, where they would likely perish rolling around or buried under piles of rubble. However, by bringing these fragments into coral nurseries, we give them the opportunity to recover.

In the waters around Florida, Puerto Rico, and the U.S. Virgin Islands, NOAA works with a number of partners in various capacities to maintain 27 coral nurseries. These underwater safe havens serve a dual function. Not only do they provide a stable environment for injured corals to recuperate, but they also produce thousands of healthy young corals, ready to be transplanted into previously devastated areas.

Checking into the Nursery

When they enter coral nurseries, bits of coral typically measure about four inches long. They may come from the scene of a ship grounding or have been knocked loose from the seafloor after a powerful storm. Occasionally and with proper permission, they have been donated from healthy coral colonies to help stock nurseries. These donor corals typically heal within a few weeks. In fact, staghorn and elkhorn coral, threatened species which do well in nurseries, reproduce predominantly via small branches breaking off and reattaching somewhere new.

In the majority of nurseries, coral fragments are hung like clothes on a clothesline or ornaments on trees made of PVC pipes. Floating freely in the water, the corals receive better water circulation, avoid being attacked by predators such as fireworms or snails, and generally survive at a higher rate.

After we have established a coral nursery, divers may visit as little as a few times per year or as often as once per month if they need to keep algae from building up on the corals and infrastructure. “It helps if there is a good fish population in the area to clean the nurseries for you,” notes Sean Griffin, a coral reef restoration ecologist with NOAA.

Injured corals generally take at least a couple months to recover in the nurseries. After a year in the nursery, we can transplant the original staghorn or elkhorn colonies or cut multiple small fragments from them, which we then use either to expand the nursery or transplant them to degraded areas.


One of the fastest growing species, staghorn coral can grow up to eight inches in a year while elkhorn can grow four inches. We are still investigating the best ways to cultivate some of the slower growing species, such as boulder star coral and lobed star coral.

Growing up to Their Potential

In 2014, we placed hundreds of coral fragments from four new groundings into nurseries in Puerto Rico and the U.S. Virgin Islands. This represents only a fraction of this restoration technique’s potential.

After the tanker Margara ran aground on coral reefs in Puerto Rico in 2006, NOAA divers rescued 11,000 salvageable pieces of broken coral, which were reattached at the grounding site and established a nursery nearby using 100 fragments from the grounding. That nursery now has 2,000 corals in it. Each year, 1,600 of them are transplanted back onto the seafloor. The 400 remaining corals are broken into smaller fragments to restock the nursery. We continue to grow healthy corals in this nursery and then either transplant them back to the area affected by the grounded ship, help restore other degraded reefs, or use some of them to start the process over for another year.

Nurseries in Florida, Puerto Rico, and the U.S. Virgin Islands currently hold about 50,000 corals. Those same nurseries generate another 50,000 corals which we transplant onto restoration sites each year. Sometimes we are able to use these nurseries proactively to protect and preserve corals at risk. In the fall of 2014, a NOAA team worked with the University of Miami to rescue more than 200 threatened staghorn coral colonies being affected by excessive sediment in the waters off of Miami, Florida. The sedimentation was caused by a dredging project to expand the Port of Miami entrance channel.

We relocated these colonies to the coral nurseries off Key Biscayne run by our partners at the University of Miami. The corals were used to create over 1,000 four-inch-long fragments in the nursery. There, they will be allowed to recover until dredge operations finish at the Port of Miami and sedimentation issues are no longer a concern. The corals then can either be transplanted back onto the reef where they originated or used as brood stock in the nursery to propagate more corals for future restoration.


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When Ships Threaten Corals in the Caribbean, NOAA Dives to Their Rescue

Growing less than a quarter inch per year, the elaborate coral reefs off the south coast of Puerto Rico originally took thousands of years to form. And over the course of two days in late April 2006, portions of them were ground into dust.

The tanker Margara ran aground on these reefs near the entrance to Guayanilla Bay. Then, in the attempt to remove and refloat the ship, it made contact with the bottom several times and became grounded again. By the end, roughly two acres of coral were lost or injured. The seafloor was flattened and delicate corals crushed. Even today, a carpet of broken coral and rock remains in part of the area. This loose rubble becomes stirred up during storms, smothering young coral and preventing the reef’s full recovery.

NOAA and the Puerto Rico Department of Natural and Environmental Resources have been working on a restoration plan for this area, a draft of which they released for public comment in September 2014 [PDF]. In order to stabilize these rubble fields and return topographic complexity to the flattened seafloor, they proposed placing limestone and large boulders over the rubble and then transplanting corals to the area.

This is in addition to two years of emergency restoration actions, which included stabilizing some of the large rubble, reattaching around 10,500 corals, and monitoring the slow comeback and survival of young coral. In the future, even more restoration will be in the works to make up for the full suite of environmental impacts from this incident.

Caribbean Cruising for a Bruising

Unfortunately, the story of the Margara is not an unusual one. In 2014 alone, NOAA received reports of 37 vessel groundings in Puerto Rico and the U.S. Virgin Islands. About half of these cases threatened corals, prompting NOAA’s Restoration Center to send divers to investigate.

After a ship gets stuck on a coral reef, the first step for NOAA is assessing the situation underwater. If the vessel hasn’t been removed yet, NOAA often provides the salvage company with information such as known coral locations and water depths, which helps them determine how to remove the ship with minimal further damage to corals. Sometimes that means temporarily removing corals to protect them during salvage or figuring out areas to avoid hitting as the ship is extracted.

Once the ship is gone, NOAA divers estimate how many corals and which species were affected, as well as how deep the damage was to the structure of the reef itself. This gives them an idea of the scale of restoration needed. For example, if less than 100 corals were injured, restoration likely will take a few days. On the other hand, dealing with thousands of corals may take months.

NOAA already has done some form of restoration at two-thirds of the 18 vessel groundings with coral damage in the region this year. They have reattached 2,132 corals to date.

What does this look like? At first, it’s a lot of preparation. Divers collect the corals and fragments knocked loose by the ship; transport them to a safe, stable underwater location where they won’t be moved around; and dig out any corals buried in debris. When NOAA is ready to reattach corals, divers clear the transplant area (sometimes that means using a special undersea vacuum). On the ocean surface, people in a boat mix cement and send it down in five-gallon buckets to the divers below. Working with nails, rebar, and cement, the divers carefully reattach the corals to the seafloor, with the cement solidifying in a couple hours.

Protecting Coral, From the Law to the High Seas

Corals freshly cemented to the seafloor.

Corals freshly cemented to the seafloor. After a couple weeks, the cement becomes colonized by algae and other marine life so that it blends in with the reef. (NOAA)

Nearly a third of the total reported groundings in Puerto Rico and the U.S. Virgin Islands this year have involved corals listed as threatened under the Endangered Species Act. In previous years, only 10 percent of the groundings involved threatened corals. What changed this year was the Endangered Species Act listing of five additional coral species in the Caribbean.

Another form of protection for corals is installing buoys to mark the location of reefs in areas where ships keep grounding on them. Since these navigational aids were put in place at one vulnerable site in Culebra, Puerto Rico this summer, NOAA hasn’t been called in to an incident there yet.

But restoring coral reefs after a ship grounding almost wouldn’t be possible without coral nurseries. Here, NOAA is able to regrow and rehabilitate coral, a technique being used at the site of the T/V Margara grounding. Stay tuned because we’ll be going more in depth on coral nurseries, what they look like, and how they help us restore these amazingly diverse ocean habitats. [Update: Read how NOAA uses coral nurseries to restore damaged reefs.]


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After Opening up a Pennsylvania Creek for Fish, Watching Recovery Follow

This is a guest post by Laura Craig, Ph.D., Associate Director of River Restoration, American Rivers.

Excavator removes a rock dam from a stream.

Restoring Darby Creek, a tributary of the Delaware River, meant tearing down three now-defunct mill dams. Here, the Hoffman Park dam at Lansdowne, Pennsylvania, comes down. (American Rivers)

Early settlement along Pennsylvania’s Darby Creek relied upon dams to turn the water wheels of mills, powering economic growth. However, as time wore on, the dams on this tributary of the Delaware River fell into disrepair and these days no longer serve a function. Instead, they have been blocking the passage of fish along this creek. That is, until now.

In late summer of 2012, American Rivers and our project partners, NOAA’s Damage Assessment, Remediation, and Restoration Program  and the Pennsylvania Fish and Boat Commission, began tearing down some of those now-defunct dams as part of a multi-year effort to restore Darby Creek. Initiated in 2007, the effort involved removing three dams near Philadelphia: Darby Borough Dam, Hoffman Park Dam, and Kent Park Dam. In addition, we took out a set of abandoned railroad piers and realigned an 800 foot section of the creek.

We removed these barriers to improve passage for a range of resident and migratory fish, including American shad, hickory shad, alewife, river herring, American eel, bass, shiners, and suckers. The project also aims to enhance stream habitat, alleviate flooding, benefit public safety, and restore free-flowing conditions along the creek.

Green plants growing along a stream.

Shown in 2014, this portion of Darby Creek now features restored shoreline habitat with stabilizing structures. (American Rivers)

Overall, the Darby Creek Restoration Project connected 2.6 miles of upper stream to the lower 9.7 miles, which link directly to the Delaware River. It was here in 2004 when the Athos I tanker spilled oil that would spread along miles of the Delaware and its tributaries similar to Darby Creek.

This $1.6 million dollar effort to restore Darby Creek was funded primarily by the Natural Resource Damage Assessment settlement from the Athos I oil spill. Additional funding came from the Pennsylvania Department of Environmental Protection’s Growing Greener Program and the National Fish and Wildlife Foundation. All restoration activities were completed in June 2013, but we are still monitoring the restored areas to ensure the area is recovering.

At the former dam locations we are already seeing recovery of shoreline areas planted with a diverse mix of seed, shrubs, and trees. Restoring vegetation along the creek stabilizes exposed soil and reduces erosion in the short term and provides shade, habitat, and food sources over the long term. We are also observing positive changes to stream habitat as a result, including fewer actively eroding banks and less fine sediment clouding the creek’s waters.

In terms of fisheries, we are noting a shift since the dams were removed toward a resident community of fish that prefer free-flowing water conditions. While we haven’t yet encountered any migratory fish at the former dam locations, this fall fisheries biologists with the Pennsylvania Fish and Boat Commission came across several pods of very young blueback herring in the tidal portion of the creek, near where it joins the Delaware River at the John Heinz National Wildlife Refuge. This is great news, because it suggests that blueback herring are using the lower part of the tributary as a nursery. In future years we hope to see them advance up the creek to the locations where the dams were removed.

For more information on the Athos I oil spill and the resulting restoration, visit response.restoration.noaa.gov/athos and http://www.darrp.noaa.gov/northeast/athos/restore.html.

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