Persistence

Persistence is the ability of a material to stay in the marine environment without degradation. This can occur by two different mechanisms:

1. The material released with not or very slowly evaporate or dissolve. Such substances will form slicks on the sea surface, which could contaminate birds or finally reach the coast.
2. The substance in the water or on the sea floor will not or very slowly biodegrade.

In both cases, the substance cannot or very slowly be degraded under environmental conditions.

The GESAMP category A2 will indicate whether a substance is biodegradable or not. A substance that is rated NR (not readily biodegradable) is considered persistent.