Distribución de pescadores en la cuenca del río Santa Cruz

Abstract

Steelhead ecotype (Oncorhynchus mykiss) and Chinook salmon (Oncorhynchus tshawytscha) have promoted a recreational fishery in the Santa Cruz River, the last large free-flowing river of Patagonia. However, two dams are being built upstream in the middle course potentially affecting the life cycle of these anadromous salmonids. The study describes the dynamics of the recreational fishery of the Santa Cruz River around Piedrabuna town and anglers perceptions, discussing its trends according to possible river connectivity scenarios. The fishery was assessed through a monthly year-round field sampling from April 2018 to April 2019, developing instantaneous angler counts, discriminating fishing methods, effort, and catch per unit effort; also, in situ interviews were used to collect information on anglers´ motivations and perceptions. In addition, information on fishing tournaments was used. Three fishing zones (FZ) were identified near Piedrabuena city : FZ-1, located downstream where anglers used baited hook and line to catch the native marine Patagonian blenny (Eleginops maclovinus); FZ-2, located in the town where baited hook and line, spinning, and fly cast are used to catch Patagonian blenny and salmonids; FZ-3 located upstream the town, where fishing effort was mainly directed to salmonids employing spinning and fly cast. Fishing effort showed a seasonal pattern with high values from March to May and September to October, agreeing with Steelhead and Chinook salmon runs, respectively. The most relevant motivations for anglers were non-oriented catch variables. Anglers preferred the capture of salmonids over native species, considering dams a major fishery threat. Although a post-damming scenario could allow the adult salmonids to migrate upstream, the current reproduction grounds of Steelhead will be flooded, and juveniles and adults of both species will be hindered in their downstream migration to sea. These aspects seem to compromise the future of these unique fisheries seriously.