A group of people set up a survey on a beach.

Before Every Survey: Transect Selection and Checklists

Safety First! 

As with any field trip, safety is a critical component of a successful classroom monitoring effort. Because your survey will be taking place in a shoreline environment, there are some specific things that you and your students will need to be aware of before heading to your site. 

Teacher Tip: To help increase engagement, create a class dialogue about potential safety concerns. This will encourage students to craft critical thinking and planning skills, and will improve their buy-in on safety expectations. 

Here are some additional suggestions for safety on your survey trips: 

  • Use common sense and follow general safety guidelines. If you do not know what an item is, do not touch it, even with gloved hands. If it appears to be hazardous, contact the appropriate authorities. You may want to work together to create a list of materials, such as syringes, sharp glass, feces, etc., that students should avoid picking up. You can learn more about handling potentially hazardous debris on the Marine Debris Handling Guide web page.
  • Be prepared for the weather by checking conditions beforehand and bringing proper gear, including clothing layers, sunscreen, closed-toed shoes, water, and snacks.
  • Check the tides before you plan your survey to avoid surveying at dangerous high tides. Never turn your back to the ocean when near the water’s edge to avoid being surprised by rogue waves. 
  • Be aware of natural hazards. Avoid climbing on logs, rocks, or other fall risks. 
  • Do not enter sensitive vegetation or unstable surfaces.
  • Obey all local laws, including, but not limited to, land access, beach closures, sensitive habitat exclusion areas, wildlife avoidance, and waste disposal. Where necessary, be sure to obtain and keep with you any permits or passes for site access.
  • In case of emergencies, create and keep with you a list of potentially useful local phone numbers. Depending on your location, these may include emergency healthcare, law enforcement, and hotlines for oil spills, hazardous waste, large marine debris, stranded animals, and illegal dumping. Consider securing a list on your clipboard for easy reference.
  • If you feel unsafe at any time for any reason, discontinue the survey and return at a later date.

Select Your Transects

It would take a lot of work to sample the whole 100 meters of the site, so we ask participants to survey four random sections, called transects. Your class will complete at least four transects of your survey site, but depending on your class size and how you have assigned tasks, it may make sense to do more than four. Each transect is 5 meters across and runs all the way from the back barrier (e.g., rocks, dunes, or vegetation along the back of the beach) to the water’s edge. There are 20 possible transects within each 100-meter site. Transects are numbered according to which 5-meter increments along the 100-meter site they begin (0, 5, 10, 15, 20, etc., for an example, see Diagram 2 in the Shoreline Survey Guide, page 8). The survey design requires a truly random set of four (or more) transects for each survey.  

Teacher Tip: Many MDMAP volunteers work in groups that are likely smaller than a class size or student group. Here we have highlighted a few notes on what can be adapted for a larger group and what must be consistent to ensure comparable data across MDMAP: 
  • The survey needs to be 100 meters long.
  • The transects need to be 5 meters across.
  • There should be one or two students surveying per transect. There cannot be more than two.
  • There can be as many transects as you need for the class!
Cross-Curricular Concept: Why doesn’t the number of transects impact the survey data? MDMAP survey data is calculated based on the average amount of debris found across the randomly selected transects at your site, rather than the aggregate (or total) amount of debris found. Because of this, you can survey as many transects as you need and not impact the survey data! This could be a great opportunity to discuss mean, median, mode and other statistical analysis strategies. 
Cross-Curricular Concept: Why does it matter that we survey a random section of the site at each survey? Random transects help avoid bias - humans need help to be random, we cannot just pick four transects without underlying bias. Left to our own devices, people can easily influence where and how data are collected so that the results tell a story that meets their hopes or expectations. This even happens unconsciously.
For example, a person who is very concerned with demonstrating the problem of marine debris might focus only on transects that appear to have a high amount of debris in them. A person who is interested in showing how clean the beach is might focus on relatively cleaner areas. Neither approach will paint an accurate picture of the area as a whole. Surveying random transects within each site avoids these potential biases and provides an average snapshot of the whole area over time.

Here are a few ways to select random transects for each survey: 

  • Email the NOAA MDMAP team at md.monitoring@noaa.gov to request a lifetime supply of random transect numbers.
  • Use a smartphone or internet application to get a random number between 0 and 19, then multiply that by five. Do that four times - these numbers will indicate the beginning of the four transect sites. 
  • Roll a 20-sided die. Roll the die, subtract one, multiply by five, and repeat three more times. 
  • Note: If you have more than four student pairs for your survey, you will need to select more random numbers. There can be as many transects as you need for your class, but there cannot be more than two surveyors per transect. 
Teacher Tip: One teacher participant in MDMAP shared an engaging idea for selecting random transects with students: Use a collection of bottle caps from previous cleanups - especially caps that have different languages or colors - and label each one with transect starts. When it’s time to select transects, mix them up in a bag and have students choose!

Once you’ve selected the transect locations, record the numbers on your Transect Survey forms. That will be where each transect begins! See Diagram 2 in the Shoreline Survey Guide, page 8, for examples of four transects across the whole 100-meter site.

Ready to Go? Final Steps Before Every Survey:

  • Gather and double check that all supplies are packed.
  • Check the weather.
  • Revisit safety tips.
Last updated Wed, 03/06/2024 - 18:48