The Mathematics of a Beach Cleanup

One day we went on a dinghy exploration and ended up on a clean looking beach. But when we took a walk looking for trash we found bits and pieces of trash everywhere. To learn more about this adventure keep on reading.

The beach we cleaned is between Elizabeth Island and Stocking Cay, near Georgetown, Great Exuma Island in the Bahamas. There are a lot of beaches and even more boats around Georgetown. We estimate that there are about 200 cruising boats in the area. It’s fun because many of the boats have kids aboard! The beach area we cleaned was 1/3 of a nautical mile long and about 40 feet wide. This is equal to 972,000 square inches! Click below to see the location of the beach we cleaned!

At first we didn’t think there was much trash for us to cleanup. But after just an hour of work we had collected more than two garbage bags full! When we were done cleaning, we put all the trash in our dinghy and brought it to the beach right next to Sargo. Then we sorted the trash into categories and arrange them into a large rectangle so we could grid them. This helped us estimate how much and what types of trash we collected. In just an hour, the four of us collected 5,892 square inches of beach trash. That means we collected 98 square inches of trash per minute! The beach we cleaned we only 0.6% covered in trash - which doesn’t seem like much - but look how much we found anyway!

Not surprisingly 98% was plastic. Part of this is because plastic floats unlike glass or metal. Even with that in mind we still found some weird things. For example, we found two light bulbs a hair comb and four pairs of shoes. The chart below shows the persentage of different types of beach trash we found.

We picked up 5,892 square inches of trash off a protected clean looking beach. If we had gone to a different beach that is less protected we could have got 15 trash bags of beach trash instead of two. We went to a clean looking beach but you don’t have to. You can chose the windiest yuckiest beach in your area and clean it. This dosen’t only make the beach look nicer it also helps the ocean and all the life in it.