Theory 14/Deep scattering layer/Threshold lens
Layers Form on Predator Density
The claim
A coherent scattering layer forms above a threshold in predator density, so sparse populations disperse rather than aggregate.
01Mechanism
Aggregation is favoured when the risk of remaining dispersed exceeds the competition cost of crowding; the threshold is where those balance.
02Prediction
Layer formation should track density.
03Refutation
Formation tracking biomass would remove the predation term.