Warwick Academy students opted to clean up two beaches and survey the sands for debris and tar instead of having an end-of-year picnic.
The year 12 pupils worked with Greenrock and Keep Bermuda Beautiful on the project, which will go towards their International Baccalaureate (IB) qualifications.
KBB executive director Anne Hyde said: "We needed to get beaches surveyed this summer but didn't have the manpower lined up so it was sheer luck that a call from one of Warwick Academy's students provided the solution.
"I want to thank all the year 12 IB students who volunteered for the project. We were able to complete three tasks — a tar survey to look for tar balls, a marine debris survey to measure the quantity of plastic and other debris washing up on our shores and a litter cleanup of the entire beach area.
"This was done at Grape Bay Beach and John Smith's Bay. The data collected is very important research shared locally and globally for the Sargasso Sea Project."
Ms Hyde said tar was found but none from the recent Gulf oil spill.
Paula Wight, head of year 12 at Warwick, said: "The beach survey and analysis of washed up trash was incredibly interesting.
"The students were interested in hearing how their data would help establish a baseline for any future changes in the tar that may possibly affect Bermuda from the Gulf oil spill.
"It made them realise how interconnected these global events are and how they can affect a small place like Bermuda. It was an incredibly hot June day and I was very proud of how diligently they worked."
The project was organised by students Julia Scully and Erin Gillespie.