Ecological food web, computer artwork. This model represents the aquatic ecosystem of the East River Valley, Denver, Colorado, USA. Animal and plant life is represented by the coloured nodes. Red nodes are lowest trophic level organisms such as plants and detritus, orange represents intermediate species and yellow represents top level species and primary predators. Relationships between organisms are shown by the connecting lines. Thick lines connect to predator species and thin lines connect to prey. Food webs are used by biologists to study species interaction and predict ecological outcomes. Model created by Neo Martinez, Pacific Ecoinformatics and Computational Ecology Lab, USA.