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


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Untangling Both a Whale and Why Marine Life Get Mixed up With Our Trash

Tail-view of humpback whale tangled in rope and nets underwater.

A humpback whale entangled in fishing gear swims near the ocean’s surface in 2005. (NOAA/Hawaiian Islands Humpback Whale National Marine Sanctuary)

In the United States alone, scientific reports show at least 115 different species of marine life have gotten tangled up—literally—in the issue of marine debris. And when you look across the globe that number jumps to 200 species. Those animals affected range from marine mammals and sea turtles to sea birds, fish, and invertebrates.

Sadly, a humpback whale (Megaptera novaeangliae) swimming in the blue waters off of Maui, Hawaii, got first-hand experience with this issue in February 2014. Luckily, trained responders from the Hawaiian Islands Humpback Whale National Marine Sanctuary were able to remove the long tangle of fishing rope wrapped around the whale’s head, mouth, and right pectoral fin. According to NOAA’s National Marine Sanctuaries:

“A long pole with a specially designed hook knife was used by trained and permitted personnel to cut through the entanglement.

Hundreds of feet of small gauge line were collected after the successful disentanglement. The entanglement was considered life threatening and the whale is confirmed to be totally free of gear.”

Check out these short videos taken by the response team for a glimpse of what it’s like trying to free one of these massive marine mammals from this debris:

Net Results

While this whale was fortunate enough to have some help escaping, the issue of wildlife getting tangled in marine debris is neither new nor going away. Recently, the NOAA Marine Debris Program and National Centers for Coastal Ocean Science reviewed scientific reports of ocean life entangled by marine debris in the United States. You can read the full NOAA report [PDF].

They looked at more than 170 reports reaching all the way back to 1928. However, wildlife entanglements didn’t really emerge as a larger problem until after 1950 and into the 1970s when plastic and other synthetic materials became popular. Before that time, fishing gear and “disposable” trash tended to be made out of materials that broke down in the environment, for example, hemp rope or paper bags. Nowadays, when plastic packing straps and nylon fishing ropes get lost or discarded in the ocean, they stick around for a lot longer—long enough for marine life to find and get wrapped up in them.

One of the findings of the NOAA report was that seals and sea lions (part of a group known as pinnipeds) were the type of marine life most likely to become entangled in nets and other debris in the United States. Sea turtles were a close second.

But why these animals? Is there something that makes them especially vulnerable to entanglement?

Location, Location, Location

The two species with the highest reported numbers of entanglements were northern fur seals (Callorhinus ursinus) and Hawaiian monk seals (Monachus schauinslandi). Both of these seals may live in areas where marine debris tends to build up in higher concentrations, increasing their chances of encountering and getting tangled in it.

For example, Hawaiian monk seals live among the coral reefs of the Northwestern Hawaiian Islands, where some 50 tons of old fishing gear washes up each year. These islands are near the North Pacific Subtropical Convergence Zone, where oceanic and atmospheric forces bring together not only plenty of food for marine life but also lots of debris floating in the ocean. Humpback whales migrate across these waters twice a year, which might be how the humpback near Maui ended up in a tangled mess earlier this year.

Just Behave

Monk sleep sleeping on nets on beach.

An endangered Hawaiian monk seal snuggles up on a pile of nets and other fishing gear in the Northwestern Hawaiian Islands. Between the mid-1950s and mid-1990s, the population declined to one-third of its size due at least in part to entanglement in trawl nets and other debris that drift into the Northwestern Hawaiian Islands from other areas (e.g., Alaska, Russia, Japan) and accumulates along the beaches and in lagoon reefs of atolls. (NOAA)

While being in the wrong place at the wrong time can lead to many unhappily tangled marine animals, behavior also plays into the problem. Some species exhibit particular behaviors that unknowingly put them at greater risk when marine debris shows up.

Not only does the endangered Hawaiian monk seal live on shores prone to the buildup of abandoned nets and plastic trash, but the seals actually seem to enjoy a good nap or lounge on piles of old fishing gear, according to visiting scientists in the Northwestern Hawaiian Islands. The playful, curious nature of young seals and humpback whales also makes them more likely to become entangled in marine debris.

Sea turtles, young and old, are another group whose behaviors evolved to help them survive in a world without human pollution but which in today’s world sometimes place them in harm’s way. Young sea turtles like to hide from predators under floating objects, which too often end up being marine debris. And because sea turtles enjoy munching on the food swirling around ocean convergence zones, such as the one in the North Pacific, they also munch on and get mixed up with the marine debris that gathers there too—especially items with loops and openings to get caught on.

While these animals can’t do much about their behaviors, we humans can. You can:


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With Lobster Poacher Caught, NOAA Fishes out Illegal Traps from Florida Keys National Marine Sanctuary

This is a post by Katie Wagner of the Office of Response and Restoration’s Assessment and Restoration Division.

On June 26, 2014, metal sheets, cinder blocks, and pieces of lumber began rising to the ocean’s surface in the Florida Keys National Marine Sanctuary. This unusual activity marked the beginning of a project to remove materials used as illegal lobster fishing devices called “casitas” from sanctuary waters. Over the course of two months, the NOAA-led restoration team plans to visit 297 locations to recover and destroy an estimated 300 casitas.

NOAA’s Restoration Center is leading the project with the help of two contractors, Tetra Tech and Adventure Environmental, Inc. The removal effort is part of a criminal case against a commercial diver who for years used casitas to poach spiny lobsters from sanctuary waters. An organized industry, the illegal use of casitas to catch lobsters in the Florida Keys not only impacts the commercial lobster fishery but also injures seafloor habitat and marine life.

Casitas—Spanish for “little houses”—do not resemble traditional spiny lobster traps made of wooden slats and frames. “Casitas look like six-inch-high coffee tables and can be made of various materials,” explains NOAA marine habitat restoration specialist Sean Meehan, who is overseeing the removal effort.

The legs of the casitas can be made of treated lumber, parking blocks, or cinder blocks. Their roofs often are made of corrugated tin, plastic, quarter-inch steel, cement, dumpster walls, or other panel-like structures.

Poachers place casitas on the seafloor to attract spiny lobsters to a known location, where divers can return to quite the illegal catch.

A spiny lobster in a casita on the seafloor.

A spiny lobster in a casita. (NOAA)

“Casitas speak to the ecology and behavior of these lobsters,” says Meehan. “Lobsters feed at night and look for places to hide during the day. They are gregarious and like to assemble in groups under these structures.” When the lobsters are grouped under these casitas, divers can poach as many as 1,500 in one day, exceeding the daily catch limit of 250.

In addition to providing an unfair advantage to the few criminal divers using this method, the illegal use of casitas can harm the seafloor environment. A Natural Resource Damage Assessment, led by NOAA’s Restoration Center in 2008, concluded that the casitas injured seagrass and hard bottom areas, where marine life such as corals and sponges made their home. The structures can smother corals, sea fans, sponges, and seagrass, as well as the habitat that supports spiny lobster, fish, and other bottom-dwelling creatures.

Casitas are also considered marine debris and potentially can harm other habitats and organisms. When left on the ocean bottom, casitas can cause damage to a wider area when strong currents and storms move them across the seafloor, scraping across seagrass and smothering marine life.

“We know these casitas, as they are currently being built, move during storm events and also can be moved by divers to new areas,” says Meehan. However, simply removing the casitas will allow the seafloor to recover and support the many marine species in the sanctuary.

There are an estimated 1,500 casitas in Florida Keys National Marine Sanctuary waters, only a portion of which will be removed in the current effort. In this case, a judge ordered the convicted diver to sell two of his residences to cover the cost of removing hundreds of casitas from the sanctuary.

To identify the locations of the casitas, NOAA’s Hydrographic Systems and Technology Program partnered with the Restoration Center and the Florida Keys National Marine Sanctuary. In a coordinated effort, the NOAA team used Autonomous Underwater Vehicles (underwater robots) to conduct side scan sonar surveys, creating a picture of the sanctuary’s seafloor. The team also had help finding casitas from a GPS device confiscated from the convicted fisherman who placed them in the sanctuary.

After the casitas have been located, divers remove them by fastening each part of a casita’s structure to a rope and pulley mechanism or an inflatable lift bag used to float the materials to the surface. Surface crews then haul them out of the water and transport them to shore where they can be recycled or disposed.

For more information about the program behind this restoration effort, visit NOAA’s Damage Assessment, Remediation, and Restoration Program.

Katie Wagner.Katie Wagner is a communications specialist in the Assessment and Restoration Division of NOAA’s Office of Response and Restoration. Her work raises the visibility of NOAA’s effort to protect and restore coastal and marine resources following oil spills, releases of hazardous substances, and vessel groundings.


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Japan Confirms Dock on Washington Coast Is Tsunami Marine Debris

A worker uses a 30% bleach spray to decontaminate the Japanese dock which made landfall on Washington’s Olympic Peninsula in December 2012.

January 3, 2013 — A worker uses a 30% bleach spray to decontaminate and reduce the spread of possible marine invasive species on the Japanese dock which made landfall on Washington’s Olympic Peninsula in December 2012. (Washington Department of Fish and Wildlife/Allen Pleus)

The Japanese Consulate has confirmed that a 65-foot, concrete-and-foam dock that washed ashore in Washington’s Olympic National Park in late December 2012 is in fact one of three* docks from the fishing port of Misawa, Japan. These docks were swept out to sea during the earthquake and tsunami off of Japan in March 2011, and this is the second dock to be located. The first dock appeared on Agate Beach near Newport, Ore., in June 2012.

Using our trajectory forecast model, NOAA’s Office of Response and Restoration helped predict the approximate location of the dock after an initial sighting reported it to be floating somewhere off of Washington’s Olympic Peninsula. When the dock finally came aground, it ended up both inside the bounds of NOAA’s Olympic Coast National Marine Sanctuary and a designated wilderness portion of Olympic National Park.

Japanese tsunami dock located on beach within Olympic National Park and National Marine Sanctuary.

In order to minimize damage to the coastline and marine habitat, federal agencies are moving forward with plans to remove the dock. In addition to being located within a designated wilderness portion of Olympic National Park, the dock is also within NOAA’s Olympic Coast National Marine Sanctuary and adjacent to the Washington Islands National Wildlife Refuge Complex. (National Park Service)

According to the Washington State Department of Ecology, representatives from Olympic National Park, Washington State Department of Fish and Wildlife, and Washington Sea Grant Program have ventured out to the dock by land several times to examine, take samples, and clean the large structure.

Initial results from laboratory testing have identified 30-50 plant and animal species on the dock that are native to Japan but not the United States, including species of algae, seaweed, mussels, and barnacles.

In addition to scraping more than 400 pounds of organic material from the dock, the team washed its heavy side bumpers and the entire exterior structure with a diluted bleach solution to further decontaminate it, a method approved by the National Park Service and Olympic Coast National Marine Sanctuary.

Government representatives are examining possible options for removing the 185-ton dock from this remote and ecologically diverse coastal area.

Look for more information and updates on Japan tsunami marine debris at http://marinedebris.noaa.gov/tsunamidebris/.

*[UPDATE 4/5/2013: This story originally stated that four docks were missing from Misawa, Japan and that “the first dock was recovered shortly afterward on a nearby Japanese island.” We now know only three docks were swept from Misawa in the 2011 tsunami and none of them were found on a Japanese island. This dock has now been removed from the Washington coast.]