Although Elton and Leopold identified trophic cascades in
primarily terrestrial systems, such as the Kaibab Plateau and northern Mexico, today the majority have been observed in aquatic systems.
They refer frequently to their «design
system», Echoes (Environmentally Controlled Human Operational Enclosed / External Space), that appears
primarily to be a set of vague or obscure guidelines such as this, which appears under the puzzling heading «Lines of sight for healthy living buildings»: «The building spot must be geologically undisturbed... ascertain that there is no disturbance of cosmic and
terrestrial influence on the human life form (DNA)... take care of harmonic measures, properties and forms».