Shoreline Monitoring FAQs

Monitors receive instruction on the beach.

Find responses to Frequently Asked Questions related to the Marine Debris Monitoring and Assessment Project (MDMAP). If you have a question that’s not listed here, contact us at

Site Selection

Select your 100-meter segment to avoid high-traffic areas that could interrupt your survey and areas that are immediately adjacent to an obstruction to nearshore circulation (e.g., breakwater, sand bar). Also consider landmarks or permanent features to assist in returning to the same segment for future surveys.


The latitude/longitude units can usually be changed in the general settings of the GPS and on many phone apps. Look for the format for decimal degrees (DDD.DDDDD). If this is not an option, record the latitudes/longitudes in the format provided and convert to decimal degrees at a later time. Here is a suggested online tool to convert between units.

NOAA Marine Debris Monitoring and Assessment Project (MDMAP) data are used to document, understand, and communicate about marine debris on our shorelines. Below are some examples of peer-reviewed publications, marine debris prevention projects, reports, and student projects that incorporate MDMAP data. See examples of peer-reviewed publications, marine debris prevention projects, reports, and student projects that incorporate MDMAP data.

Photos are optional, but can be a good way to visually capture the shoreline conditions, survey activities, and debris documented. See page 11 of the MDMAP Shoreline Survey Guide for suggestions and examples.

Shoreline Characterization

The back barrier of the shoreline is defined by the MDMAP as the location where the tide and storm surges rarely reach, or the first major barrier, whichever comes first. This may include a vegetation line, cliff, dunes, or other barrier. Debris that accumulates within the back barrier should be counted separately from the main part of the beach. If the back of the shoreline is only a partial barrier, for example a patch of vegetation behind which there is more beach, then consider the main beach to be up to the first continuous barrier (include that vegetation patch and the area behind it).

Survey Protocols

Beach width is the horizontal dimension of the beach, covering the distance from the water’s edge to the back barrier of the shoreline. Measure the beach width for each transect (in meters) from the beginning of the back barrier to the water’s edge. This can be done using a measuring wheel, meter tape, or measurement app on your phone that utilizes its internal GPS. This measurement is required to calculate the area of the surveyed transect.

Knowing the width of the shoreline allows for the calculation of debris concentrations in units of number of items per square meter of shoreline. Because the width will vary depending on tidal stage and time of year, and at different points within the shoreline site, it is important to measure the width at each transect.

Items located beyond the back barrier should be counted in the “back barrier” column of the Transect Survey Form. These are counted separately from debris on the main beach.

If you suspect that you may have found debris with invasive species, please take clear photos of the item, attached organism, and any identifying marks on the object. Remove the item from the water or shoreline and place it on dry land well above the high tide line. Please report your observation to the Aquatic Nuisance Species Task Force by visiting this website to complete a form.

If you encounter hazardous items such as oil or chemical drums, contact your local authorities (a 911 call), state environmental health agency, and the National Response Center (1-800-424-8802). Provide as much information as possible so the authorities can determine how to respond.

Contact your local authorities (a 911 call), state environmental health agency, and the US Coast Guard Pacific Area Command ((510)437-3701) or Atlantic Area Command ((757)398-6700). Provide as much information as possible so the authorities can determine how to respond.

If an item has unique identifiers and may be traceable to an individual or group, please take photos, report it to a local land manager (e.g., a Park Ranger), and report the item to (note that the item was found during a monitoring survey). Use your best judgment to determine what may or may not be valuable. Remember that debris from abroad washes up on our shores all the time.

Knowing more about debris found on the beach, or even on your street, can be the first step towards preventing it. In order to better understand the different types and amounts of marine debris in our environment, we need to collect data. Marine debris data is often collected through two methods: opportunistic and standardized. 

Opportunistic data is collected and reported without using a consistent field method, or protocol, while standardized data collection utilizes consistent field methods and specific scientific study designs to gather debris observations or measurements. Many smartphone apps use opportunistic data collection methods to count debris informally on the go. Alternatively, the NOAA Marine Debris Monitoring and Assessment Project (MDMAP), uses standardized data collection methods. Collection through this systematic method allows NOAA and MDMAP partners and volunteers to compare the type and amount of debris they record over time and across geographies. 

There are benefits and challenges to each type of data collection as outlined in the table below. The choice of which type of data collection to use depends on desired goals and the intended use of the data.


Opportunistic Data

Standardized Data


Calculate the proportions of different debris types

Calculate the proportions of different debris types

Make comparisons of the amounts of debris over time, or across geographies


No consistent protocol, enter data as you find debris/litter

Sometimes uses a set debris category list

Consistent protocol followed by all participants

Uses a set debris category list 

When and Where

Whenever, wherever data is desired or debris is encountered

Collection frequency depends on data uses

Sites chosen through scientific survey design


Less time required, participate when you have time and/or find debris

Often simple and easy to pair with cleanup events 

Data collected in a consistent manner

Comparable to other datasets using the same method


Data is not easily comparable

Large amounts of data required for meaningful analyses

Complicated statistics required to analyze data

Time intensive

Long-term data collection (~ 5 years) needed for analysis of patterns over time

Sometimes the debris is not removed

Recording Debris Items

If you don’t know whether an item is rubber, plastic, metal, etc., record it under “Other,” provide a description, and take photos. If an item is made of multiple material types, record it according to the most prevalent material type on the exposed surface of the item.

Record the item in the condition you found it. If the item was broken when you found it, record each piece separately. If it broke while you were examining it, record the debris as one item only.

Smaller (meso- and micro-size) debris is hazardous to marine life and in some instances may be more abundant than larger debris. However, the 2.5 centimeters size cutoff (about the size of a bottle cap) is used as a standard metric because it is the smallest size that can reliably and consistently be detected with the human eye. Having this size standard increases the reliability of the data being collected, providing a more accurate picture and more robust results. Feel free to record comments or counts of small debris in the “notes” section of the datasheet.

Check the Marine Debris Item Categorization Guide for guidance on recording items. If you’re still unsure, reach out to with a photo.

A fragment is a piece of a larger item that can no longer be identified. An “other” item would be something that is identifiable but not listed on the datasheet, for example a metal car part. It’s helpful to comment in the notes section of the datasheet on what types of “other” items are found at your survey site.

No. Natural woody debris does not fall under the official definition of marine debris. Only processed or treated lumber should be recorded. Wood that has been cut into beams or planks and/or treated should be recorded as lumber/building material. Burnt firewood is not considered marine debris unless it is clearly processed lumber.

Items should be recorded according to the primary material type on the surface of the item.

Balloons can be made of either rubber or plastic. Plastic (Mylar) balloons have a seam and are made of a metal (foil) coated plastic such as polyethylene or nylon. They usually have a shiny, reflective surface and oftentimes have designs with pictures and/or words. Latex balloons are the traditional ‘party’ balloons. They are also often used at festivals, open houses, sales, mass balloon releases, etc. These balloons are made of natural or synthetic latex, are usually round or oval in shape, and can come in a variety of colors.

Note: The Rubber "Balloons ‐ Latex" debris field was added to datasheet Version 2.0 (March 2016).

Data Entry and Submissions

Click here to access the NOAA MDMAP database. To enter data, click “log in” on the bottom left and then “register” to set up an account. Data can be explored and downloaded without an account.

Please enter data into MDMAP as soon as possible after each survey to ensure that data is entered accurately.

Many people prefer to use paper datasheets and then enter the data later. However the NOAA MDMAP database can be accessed via phone or tablet for data entry directly while in the field.

As long as you are collecting the same information and following the same protocol, you can record the data in any format you like and enter it into the MDMAP database. Groups with many custom items, or who collect additional information usually modify the MDMAP datasheets or create their own. If you have created something that works really well for you, please share it with Other groups or individuals may benefit from your innovations.