Integration and Automation in Selective Bi-Directional Fish Passage: How Do You Sort an Assortment of Things?

The evolution of single–stream recycling (SSR) can inform development and expectations for selective bi-directional fish passage in the Great Lakes. Single-stream recycling evolved over 25y from curbside manual pre-sorting of individual components to tri-sort (i.e., newspaper and cardboard, glass, and metals and plastics), finally to SSR (all materials combined) with integrated automated post-sorting. Our objectives were to: (1) identify challenges and innovative solutions in the evolution of SSR; (2) use lessons learned via SSR to develop a conceptual framework for selective fish passage. Although technologies used to achieve sorting in post-consumer recycling and fish passage differ dramatically, the problem is the same—how do you automatically sort an assortment of things? The incremental integration of new automated component (i.e., species) specific sorting technologies was the key innovation in SSR evolution. The following conceptual framework may help fishery biologists and engineers approach the problem of selective fish passage: (1) identify biological and ecological characteristics of the species targeted for sorting; (2) acquire detailed knowledge of their life histories; (3) identify which characteristics can be targeted for sorting; (4) identify technologies specific to the sortable characteristics; and (5) determine how technologies can be integrated to automatically sort desirable from non-desirable species.