Urbanization Consequences to Diadromous Fish Production: Lateral and Vertical Hardening of Watersheds

Declines in diadromous fishes are generally driven by a triumvirate of overfishing, habitat loss, and pollution.  Drawing on a number of studies, I will make the case that much of habitat loss is due to urbanization of watersheds in terms of surface hardening.  “Lateral hardening” is the development that leads to loss of open land, with subsequent impacts on surface waters.  “Vertical hardening” refers to damming, which disrupts connectivity of species and ecosystem processes.   Recognition of these connections to marine production can help shine a light on why watershed-ocean linkages are “broken,” however, how to address redress this will require some serious societal re-prioritization.