The same growth on a submerged surface is worth harvesting, worth recruiting, or worth killing. Which one depends on the surface.
Four signatures. Four responses. One of them was never a problem.
Not against a threshold every coast is supposed to agree on. The mechanism travels between coasts. The numbers stay local.
The hinge. Crop or disposal problem, settled in tissue.
Bathymetry and coastline are cited. The fields drawn over them are generated.
Tide and weather on the map are a synthetic harmonic. These are the gauges the real ones will come from.