By: Kimberly Ovitz and Tyler Gagne
I am walking downstream after a long day sight fishing, I’ve thrown large dry mouse patterns at Golden Dorado weighing over 8kg all day. I’ve seen countless fish today, jammed in this tiny clear river in cascading pools and riffles. I look downstream a few meters and see one of my collaborators and fishing partners float a mouse pattern through a deep pool, just below a small waterfall. BOOM, with an incredible turning of water and smash at the surface I see a Dorado take the fly with a mid-air strike and run with an incredible fight. The violence, the intent, and the incredible power of their strike; these fish have consistently awed me. We bring this fish in quickly after the fight to waters edge, take a small non-lethal blood sample and release it quickly. It climbs back upstream with vigor. As I watch the Dorado swim with power upstream, I continue to have a hard time believing our team is fortunate enough to be studying this sharp-toothed, regal, golden, and incredible species.
This May, our team of University of Massachusetts researchers, lead by Patagonia Ambassador and Professor Andy Danylchuk, departed on a two-month conservation research mission in the northwest province of Salta, Argentina. The Juramento and Dorado rivers winding through Salta’s arid valleys, provide extensive habitat for Golden Dorado and integral resources for regional fishers, farmers, and Gaucho cattle ranchers alike.
As a result of their unique features and remote and rugged habitat, Dorado have become an increasingly popular species to catch on the fly. However, a rapidly changing landscape, poor handling, and limited enforcement of conservation regulations, pose measurable threats to this minimally studied fish species.
As UMass researchers we worked closely alongside resident guides and international anglers, to conduct the first study examining preferred catch-and-release angling practices for Golden Dorado. We relied heavily on the ecological knowledge of Alejandro Haro, his family and the experienced guides of Juramento Fly Fishing. Coupling extensive regional knowledge with ecological research allowed for a comprehensive analysis of both physiological stress and socio ecological implications of this growing catch-and-release fishery.
Our team analyzed non-lethal blood samples to understand Dorado stress physiology and relied on radio-telemetry to assess post release movement. Furthermore, we compiled angler responses to socio ecological surveys to understand anglers’ preferred management strategies.
Our findings indicate that a careful set of scientifically backed best practices and increased conservation awareness at the community and management levels will encourage this fishery to recover from anthropogenic stressors. Dorado have come to symbolize conservation for Argentina’s river systems; calling our attention to the ways that we, as fishers, impact the ecosystems in which we fish. Through continued community awareness and greater accountability, we as anglers and stakeholders can ensure a more sustainable future for the Dorado fishery.
Keep paying attention for more updates as this project is only the first step to better understanding this incredible species and the rivers they inhabit.