It's important that information about the litter collected on beaches can be used to understand how we can all reduce waste. So it's really useful if you can download and use the Ocean Conservancy's monitoring forms on the right of this page. These forms are available in English, Spanish, French and Portuguese. By filling in the forms on the day and then sending them off to the Ocean Conservancy, you will be adding to a huge, worldwide survey.
The easiest way to weigh your litter is to use scales you would usually find in a bathroom and then have the beach clean coordinator hold the bag of rubbish and subtract their own weight. Alternatively you could use luggage weighing scales.