https://www.nedo.go.jp/news/press/AA5_101850.html

We have discovered that commercially available fishing lines, which were previously thought to be indegradable, can biodegrade in the ocean. As “ghost gear”, they remain in the ocean or on the seabed for a long time, causing adverse effects on ecosystems due to entanglement with wildlife such as waterfowl and sea turtles, and marine pollution due to microplasticization

The team discovered that among commercially available nylon fishing lines, which were thought to be non-biodegradable, there are several whose strength significantly decreased over time and whose surfaces showed signs of decomposition. This completely overturns the descriptions in textbooks that have treated nylon as a non-biodegradable polymer, as well as the common knowledge in the polymer and fisheries fields.

These findings will lead to the development of other non-biodegradable fishing lines and help to curb the spread of marine pollution caused by fishing lines and the ghost gear problem.