4.4.2—Plastic debris accumulation

Plastic control works best upstream: prevent input first, then intercept or recover material already in rivers and seas.

Currents concentrate floating debris in oceanic gyres; UV and abrasion fragment many polymers rather than biologically recycling them. Large pieces entangle or are ingested. Microplastics enter food chains, can accumulate and magnify through trophic transfer, and can transport additives or toxins adsorbed to their surfaces.

A river boom can catch bottles, but reuse, collection and producer responsibility prevent the next load and lost fishing gear.

It removes escaped material but leaves upstream production, litter and gear-loss pathways unchanged.

Fragmentation is not disappearance; smaller particles can be harder to remove and easier to ingest.