OCEAN HEALTH
Microplastic Density (MPD)
Plastic-particle concentration in surface water, sampled heavily at the gyre stations where currents concentrate debris.
Threshold Bands
| Band | Range | State |
|---|---|---|
| Low | < 1 | OK |
| Elevated | 1–10 | WARN |
| Garbage-patch | > 10 | CRIT |
Formula
Manta-trawl count, size-classified, normalised to filtered volume.