Explain why the biodegradation of plastic might be more hazardous to the environment than the presence of plastic as marine debris

It’s a fact that biodegradation of plastic is more hazardous to the environment than the presence of plastic as marine debris. Although the latter may entangle marine organisms or could cause immediate ingestion, it’s the former which is more harmful. Plastic degradation is a slow process and if biodegradation is not done properly (with all important factors to consider), greenhouse gas like methane may be emitted during the process - creating a bigger problem for the environment.