Land–Sea Coupling and Global-Driven Forcing: Following Some of Scott Nixon’s Challenges

Abstract

Adjoined watershed–estuary–coastal ecosystems are coupled by biogeochemical and hydrodynamic processes, as Scott Nixon repeatedly argued in his many contributions. Case histories from Waquoit Bay and the Pacific Coast of Panama, supplemented by information from other sites, make evident that the couplings that enable connectivity among spatially separate landscape units, while highly subject to detailed local contingencies, take place in every coastal zone, can be powerfully affected by human activities on land, and by global-scale forcings, as Scott Nixon often reminded us. While the factors that determine the details of land–sea coupling differ significantly from one coastal zone to the next, estuarine systems manage, to different degrees, to furnish ecological services not only as filters or transformers of land-derived inputs but also as exporters of energy-rich subsidies to coastal food webs.