Sunlight fades with depth following the Beer–Lambert law, and the kelp canopy's photosynthesis rate saturates with light the way real photosynthesis–irradiance (P–I) curves do. Free-swimming dinoflagellate-like plankton flash when the local shear from a passing fish or strong current exceeds a mechanical threshold — real mechanoluminescence, the mechanism behind glowing wakes in the ocean at night.
I(z) = I₀·exp(-k·z) light at depth z, clarity sets k
P(I) = Pmax·I / (Ksat + I) Michaelis–Menten P–I saturation curve
disturbance = Σ v_fish / d² + current·turbulence
flash when disturbance > threshold(sensitivity)
- Clearer water lowers the attenuation coefficient k, letting far more light reach the canopy at any given depth — try Water clarity against Viewing depth together.
- Photosynthesis rate saturates rather than growing linearly with light: past a point extra light barely raises it further, matching real P–I curves for kelp (Laminaria/Macrocystis).
- Each fish carries a shrinking disturbance field; a plankton flash fires once local disturbance crosses the sensitivity threshold, then that particle cools down before it can flash again.