How Does Marine Debris Affect Coral Reefs?

Posted Tue, 12/04/2018 - 08:33

It’s #CoralsWeek! Tune in here and around NOAA all this week to learn more about these valuable ecosystems.

Coral reefs are one of Earth’s most productive ecosystems. Rocky reefs can form barrier islands that protect the mainland from storms and destructive waves. They are home to a third of all the fish species in the ocean, even though they make up a teeny tiny portion (less than 0.25%) of our ocean. The fish and other organisms that call reefs home provide food for millions of people. They are also fragile, which means that marine debris can have a huge impact on these ecosystems. How exactly does marine debris affect these living geologic formations? That is something scientists around the world are working hard to figure out. Here’s what we know so far.

Lost fishing gear is a threat. Hard corals, like the kind that form reefs, can become entangled in abandoned or lost fishing nets. As floating nets become snagged on branches, it can break or scratch the coral, which can leave big scars on the reef. Other types of fishing gear can cause damage too. In a 2009 study, lobster traps were placed on reef sites off the coast of Florida to see how much damage was caused by trap movement. Due to sustained winds, the movement of the trap caused the delicate coral to be scarred, fragmented, and dislodged.

White scar in a coral reef from an abandoned fishing net.
Here you can see the very obvious scar the net has left on the reef. The coral underneath this net has died, but hopefully new recruits can settle on this area and repopulate this section of the reef in the future. (Photo Credit: NOAA Fisheries/Steven Gnam)


Pieces of coral stuck in a fishing net.
This net has broken off pieces of coral that remain trapped in the net, even as it washed ashore. (Photo Credit: NOAA)

Vessels that are lost or abandoned also damage coral reefs. They can directly damage the reef during the initial impact, or as waves and storms move the vessels around. The release of fuel, paints, metals, and other harmful chemicals from these wrecks is also dangerous to the tiny coral polyps that form the reef. A ship grounding on a coral reef at Rose Atoll in American Samoa changed the habitat there. After the wreck, there was a rapid overgrowth of cyanobacteria, an opportunistic type of algae. Investigators believe that corroding metal from the shipwreck fed this algae and attracted hordes of algae-eating fishes for at least 13 years after the initial impact.

Sailboat that has crashed into a coral reef.
A derelict vessel grounded on coral near the Content Keys within the Florida Keys National Marine Sanctuary (Photo Credit: Florida Fish and Wildlife Conservation Commission)

It isn’t just boats and fishing gear that end up on reefs, debris of all kinds can be found in these ecosystems. Building materials, plastics, aluminum cans, tires, and even disposable diapers were found in the coral habitat of Majuro Atoll in the remote Marshall Islands. During a recent NOAA mission to the remote and uninhabited Northwestern Hawaiian Islands, the marine debris team found toothbrushes, laundry baskets, plastic bottles, and other trash on shorelines. Due to ocean currents, all this debris could be from people like you, even if you live nowhere near a coral reef. For instance, debris from from across the Pacific can float on ocean currents all the way to the Hawaiian Islands.

A pile of toothbrushes found in the ocean.
You probably don’t think about plastic pollution as you are brushing your teeth, but hundreds of toothbrushes end up in the Northwest Hawaiian Islands every year. (Photo Credit: NOAA)

You can do your part to help coral reefs by reducing the amount of trash, especially plastic trash, you produce, disposing of fishing gear properly, and participating in cleanups. Remember your “4Rs” (reduce, reuse, recycle, refuse) to minimize your contribution to marine debris. Here at the Marine Debris Program, we try to remove as much debris as we can from these incredible ecosystems. To learn more about our projects that benefit coral reefs, view our blog on the recent mission to the Northwestern Hawaiian Islands and come back to our blog on Thursday to check out our projects in Florida and the Caribbean.

How Does Marine Debris Affect Coral Reefs?

Posted Tue, 12/04/2018 - 08:33

For citation purposes, unless otherwise noted, this article was authored by the NOAA Marine Debris Program.

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Wed, 12/05/2018 - 20:58

If this pollution of the oceans continues our marine life will perish and will not be fit for consumption because of plastics in it. Currently a dead whale has been washed on shore whose body was full of plastics and I am sure there is much marine life during being strangled by draw nets and fish lines as well. Some surfers have decided to do something about it and are picking up plastics on beaches and in water then making bracelets to sell from a one pound of plastic to increase their operation. However these surfers are only a few and all people who love the ocean and want to see plastics and debris gone should get involved.
Check their web site

Daequan LOCO

Wed, 01/30/2019 - 08:11

why coral reefs we need facts me and ridge


Wed, 04/24/2019 - 02:46


Ray H. Wilcox

Mon, 08/24/2020 - 22:23

I am a 68 year old retired individule that would like to volunteer a substantial portion of my time to helping with reef projects.

I live in NSW Australia and am willing to travel to needed locations.

I have sent out numerous emails and post asking for information on volunteering with the reef and have yet to get a responce.

My passion is diving and I feel I be a great volunteer but don't know where to start. I have sent requests to different departments to the Great Barrier Reef Fondation I even donate to it. But again have had no responce.

Does anyone have a suggestion for some old bloke that would love to help the reefs?



Mon, 12/07/2020 - 10:00

Why is it so difficult to retrieve nylon ghost nets from the ocean in decontaminated form and converted to pellets for researchers to access and determine upcycling using the latest discovered methods to upcycle polyamide and thermoplastic polyester ocean and landfill condensation polymers? If you listen to those organizations promoting ocean waste recycling and eventually get to someone of authority you find that the price of the waste is 3-4X greater in cost in black pellet form than prime Nylon 6 or 66 directly from BASF or Dupont !! However, landfill carpet waste is 6 times cheaper than ocean waste I think based on my research this is another way to play on sustainability and green chemistry and to establish a new slush fund not for research but as a source of free plastic to make useless stuff that can sell for 10X the value. It never was about recycling or upcycling into better useful materials or to limit the waste from the oceans by increasing fortification of the plastic to last 50 years but rather a new business opportunity and thats fine but try not selling it for what it truly turns out to be another con job on the public.

Isabel campos

Thu, 02/10/2022 - 12:25

over the years human's high demand for any marine life food-based products has increased and so the demand has pushed providers to take more efficient strategies to collect products, although their tactics are fast and big the results needed the collateral damage of the ocean life environment is not worth a quick meal.

The collection in Europe and the US has not led to viable products in pellet form. The collection and conversion process does not take into consideration the damage done to the marine litter and its effects on post decontamination and melt conversion into black pellets that cost more than OEM black pellets purchased from distributors or OEM producers!! The pellets are all black and the outcomes of post fabricated product from marine waste is 40-50% lower than prime resin. The bottom line is poor decontamination, poor fortification and mismanagement and a rapid drive to the bottom line called profitability


Wed, 03/02/2022 - 12:37

are you kidding me?

Is this a question ? If you have nothing to contribute or comment appropriately why bother!!


Thu, 05/04/2023 - 17:45

I am working on a project: a self-propelled marine litter collector. I know that technology is already quite advanced, but there still seem to be some challenges in using robots instead of divers to clean the seabed of fishing nets and other debris. Firstly, the technology and cost of robots still needs to be further developed and reduced. Although modern robotics is highly advanced, the development of a robot capable of working in complex seabed environments still requires some technical and economic support. Currently available robots still have limitations in performing complex operations, such as difficulty in navigating through obstacles such as trees, rocks and corals, and in accurately locating and removing debris. Secondly, the use of robots for seabed cleaning also requires the establishment of appropriate monitoring systems to control the operation of the robots. This requires a significant investment of technology and money. In addition, although the training of divers requires financial investment, they can bring more social attention and support to marine conservation organisations. These divers can make direct observations and collect data in the ocean and bring their experience and insights back to the organisation to help it improve its marine conservation programmes. In addition, they can pass on their experiences and insights to other volunteers and community members. Although my research has allowed me to gather the above information, I am still hopeful that AI can help divers, is it possible and I need advice from professionals, thanks.