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The Wrack Line is a newsletter for partners, participants, and data users of NOAA's Marine Debris Monitoring and Assessment Project (MDMAP).Thank you for reading!
Above from M. Joyce shows an MDMAP participant with their supplies during a survey in Clatsop, Oregon.
MDMAP Team Update
Dear participants,
We wanted to provide a contact update for the MDMAP Team due to staffing changes. To ensure that you are reaching a member of the team, please use md.monitoring@noaa.gov and we will get back to you as promptly as possible.
Thank you for your patience and understanding.
MDMAP Data in Action
You can use MDMAP in many ways beyond what we feature in each issue of The Wrack Line. Here is a list of other examples!
How Does Tourism Affect Marine Debris Abundance?
An assessment of marine debris in relation to tourism in India was recently published by Kasa et al. (2025). The researchers looked at how the amount and type of marine debris changed among beaches with and without heavy tourism.
To determine the amount and type of marine debris, they conducted MDMAP surveys at 12 sites along the coast of the Bay of Bengal, India. Half of the sites were common tourist areas, and the other half had little to no human activity or nearby infrastructure. To assess if regional weather patterns had any impact on debris accumulation, surveys were conducted before and after the monsoon season (August 2023 and December 2023-January 2024, respectively).
Debris was grouped into four categories that represent the potential source of an item:
- fishing (nets, ropes, lures, & lines),
- tourism (debris directly from beachgoers),
- stormwater outlets (for any sites with drain input), and
- garbage disposal (to represent debris blown out of a waste bin).
In addition to this categorization of debris, they also determined the overall cleanliness of the beach using the Clean Coast Index (CCI), developed by Alkalay et al. (2007). The CCI is a mathematical approach to assessing the cleanliness of a beach beyond visual aesthetics using the amount of plastic debris found within an area. The higher the number on the index means that there was more plastic observed on that beach. For example, a CCI of 0-2 is considered a "very clean" beach, while beaches that score >20 are classified as "extremely dirty".
Using the assessment tools above, the researchers determined that:
- Overall, there was an average of 2.66 items per square meter before the monsoon and 2.03 items per square meter after the monsoon.
- Tourist beaches had a 63% decrease in debris after the monsoon, while non-tourist beaches saw a 16% increase.
- Despite community efforts, the cleanest tourist beach from the study was considered “moderately clean” on the CCI, while all non-tourist beaches ranked “extremely dirty.”
- Stormwater input and tourism were the two main sources of debris in the region.
- Plastic was the dominant debris at all sites and during both seasons.
- Paper and lumber items were more commonly found in tourist areas.
The authors offered insight regarding the increased paper and lumber debris observed on tourist beaches. They noted that single-use plastic items have been regulated in these areas. To adapt to this, businesses catering to tourism (e.g. food stands and restaurants) replaced single-use plastic packaging with alternatives, such as paper containers and wooden sticks.
These results highlight the importance of long-term monitoring and coordinated waste management efforts in addition to cleanups. They also show how regional weather patterns and the presence of humans plays a role in debris accumulation. You can read the in depth analysis here.
 Graphical abstract from Kasa et al. 2025.
See Where It Goes...
Have you ever looked at a piece of debris during your survey and wondered, “Where did this come from?”
In most cases, we don't know the origin of retrieved shoreline debris, which is a major hurdle in developing marine debris solutions. But in October 2024, an avid beach comber from the Isle of Coll, Scotland, found something hidden amongst storm debris. Between blades of algae strewn along a walking path, she found a red plastic card that read, “Please report the number of this card with date and location of recovery to the OCSEA Program Office.” It was a NOAA drift card from 1973! They’re used during oil spill response to determine current directions, though today's drift cards are made from biodegradable materials rather than plastic. You can check out the full story and learn more about drift cards here.
 Photo: B. Payne. Back of the drift card found in Scotland on October 22, 2024. All Rights reserved.
Participant Highlights
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Have you seen this debris?
Last month the Bird Alliance of Oregon and SOLVE co-hosted a cleanup at Bayocean Spit, Oregon, to remove debris hazards in a Snowy Plover Management Area ahead of the nesting season. In the process, they found dozens of large blue knotted rope pieces within a 3-mile stretch of the beach.
If you have seen rope segments like these or know what industry they are associated with, please reach out to marina@netartsbaywebs.org.
Photo: Friends of Netarts Bay WEBS
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Make your mark!
Participants with the Galveston Bay Foundation use MDMAP to monitor their beaches and gain a better understanding of the extent of the litter problem and litter introduction pathways.
They were looking for a system to keep track of sampling times and locations, and began keeping a laminated tag and pen holder attached to their bucket to record start and end times. They keep two buckets, one for the main beach debris and one for the back barrier. Once finished, the tags are washed clean with rubbing alcohol to be used again!
Photo: Galveston Bay Foundation
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How many microorganisms does it take to screw in a lightbulb?
Russ from Oregon found some beauty in the debris during a survey last December when he found a heavily biofouled lightbulb.
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Biofouling describes the presence of marine organisms such as algae, mussels, and barnacles on an object's surface. Biofouled debris can transport invasive species, resulting in additional impacts beyond the debris itself.
If you suspect that you may have found debris with invasive species, please report your observation to the Aquatic Nuisance Species Task Force.
Photo: Russ L.
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Putting MDMAP on the Map!
A team from the Sri Lanka Wildlife Conservation Society has started monitoring a site along the coast of Kalpitiya, Sri Lanka, making it the first reported use of MDMAP in the country!
Photo: Sri Lanka Wildlife Conservation Society
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Randomization in MDMAP
Ever wonder why you can't pick just any transect when surveying?
If you're asked to choose four things, you’re most likely going to do it differently than any other person. This is where randomization comes into play. In the context of MDMAP, choosing a transect randomly means that all 20 transects have the same exact chances of being selected. Without randomization, one might choose a transect because it’s their favorite number, a shorter walk to get to, or has more debris in it, and though it may seem harmless or even helpful, this can skew the data by adding bias.
 Photo: NOAA
Here is a list of some of the many ways to select your MDMAP transects in a truly random fashion:
- Email us at md.monitoring@noaa.gov and we will send you a lifetime supply of randomized transect numbers.
- Use an online random number generator, set the minimum number to 0 and the maximum to 19, then multiply the numbers you get by 5 to have the transect starting points in meters.
- Make your own random number generator spreadsheet using the guidance on page 8 of the Shoreline Survey Guide.
If websites and spreadsheets aren’t your thing, you can try these alternatives:
- Do you fight dungeons, dragons, and debris? A 20-sided die is perfect for determining random transects on your surveys!
- Bring a second life to debris by labeling bottle caps 1 through 20 and draw them from a bag.
 Photo: NOAA
Training Videos
Project Video
Click on the image below to view a short video about MDMAP. Share the link to spread the word about this project!
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