Marine Science & Technology
Compostables in Marine Environments
Understanding Compostable Plastics in the Marine Environment
What are Compostable Plastics?
Compostable plastics are materials made from organic elements or plants and can break down into non-toxic, natural elements under certain conditions. To be certified compostable, an item must be tested to completely break down and leave no residues after 90 days in a commercial compost facility. Common compostable plastics include polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT).
The degradation of these plastics in the marine environment is not well known. However, environmental factors have been linked to the time frame of the breakdown of the plastics.
For example, PLA has been found to break down into lactic acid at high temperatures, but it may not do so reliably or quickly in colder conditions
Why use compostable plastics?
Compostable plastics are intended to be a sustainable alternative to conventional plastics, which can pollute the environment if not recycled or disposed of properly.
Biodegradable Materials Vs Compostable Materials
Plastic that is compostable is biodegradable, but not every plastic that is biodegradable is compostable. Compostable is used to describe a product that can disintegrate into non-toxic, natural elements. These products require microorganisms, humidity, and heat to yield a finished compost product. Biodegradable products are those that can be consumed by living microorganisms like fungi or bacteria. This helps to break them down into compounds that are found in nature. The main difference between the two is that biodegradable materials can take an undetermined time to break down.
Reclaiming the Sea from Marine Debris
Plastic pollution, particularly from single-use plastics, constitutes a significant environmental crisis, with about 50% of plastic production being non-properly disposed, leading to the formation of microplastics in oceans. The "Reclaiming the Sea from Marine Debris" Curriculum addresses this issue by combining hands-on learning and STEM education to inform participants about the impact of marine debris emphasizing the need for behavioral change and promoting the Seabin as both a cleaning tool and an educational instrument.
Seaside's efforts
Seaside Sustainability has been partnering with a company to test the biodegradability of their compostable products. Interns conduct monthly compostable testing off the Dunfugin Dock at Gloucester High School. A lobster trap has been placed off the side of the dock containing three compostable products: a straw, a cookie tray, and a piece of film. While at the site, interns take pictures, perform water chemistry tests (pH, salinity, water temperature), record air temperature, and release any marine organisms that got in each. Analysis of the three products consists of recording any decomposition, texture, and growth of the products as well as measuring mass and product size.
Consistent monthly data collection allows interns to test the biodegradability of the compostable products in real-time. The company we partner with will be able to use our data to improve their product design in the future.
Marine Compostability Data
Compostable Marine Debris
Location: Gloucester High School
Testing Monthly
Date | Collector | Salinity | Water Temperature | pH |
|---|---|---|---|---|
06/05/2024 | Grace Topouzoglou | 25 ppt | 70℉ | 6 |
07/22/2024 | Rowan Galanis and Camila Gomez | 35 ppt | 65℉ | 7 |
08/13/2024 | Rowan Galanis and Camila Gomez | 33 ppt | 63℉ | 7 |
09/09/2024 | Bella Levine and Anna Kate Armstorng | 35 ppt | 18.8℃ | 7.09 |
09/30/2024 | Bella Levine and Cassie Fetter | 37 ppt | 18.33℃ | 7.3 |
10/28/2024 | Bella Levine and Cassie Fetter | 40 ppt | 14.33℃ | 7.39 |