Buffering fisheries against environmental change: testing the effectiveness of responses to widespread deoxygenation and predator invasions of temperate lakes

Programme

• 10:30 - Accueil
• 11:00 - Séminaire de Peter
• 12:00 - Repas (fourni)
• 13:30 - Visites de la plateforme d'analyse physico-chimique
• Visite des autres plateformes sur le campus Agro à valider selon les inscriptions

INSCRIPTIONS : https://forms.gle/YdmRHgve55S7sVyk6 

Abstract

Presenter: Pete McIntyre, Professor of Natural Resources & the Environment, and Director of the Adirondack Fishery Research Program, Cornell University, USA

Environmental conditions in temperate lakes have shifted dramatically in the last century, yet society generally presumes that fishing opportunities in these ecosystems can be kept unchanged. 
I will describe two classes of management challenges using the Adirondack lake district of New York (USA) as a case study: deoxygenation arising from warming and browning of lake waters, and proliferation of non-native predatory fish species. 

My research team tests the effectiveness of management responses to these challenges using ecosystem-scale experiments, with the goal of safeguarding brook trout fisheries. Across a gradient of lake deoxygenation, we find profound loss of suitable habitat for trout, yet considerable behavioral and physiological flexibility that allows most populations to persist.
Our ongoing stocking experiments suggest that genetic strains of brook trout vary in their performance across this gradient, yet there is no 'super-fish' that performs best across all environments.
To address control of invasive predators, we have removed non-native smallmouth bass from a lake annually for 25 years, yet it remains the dominant nearshore fish species.  This long-term experiment has revealed important ecological benefits of suppressing bass, yet genomic analyses demonstrate that our consistency has had a perverse outcome: evolutionary adaptations to high mortality have made bass even harder to control. 
Both examples underscore the difficulty of satisfying public demands for fishery stability in the face of multiple, rapid environmental changes. We conclude that successfully managing the demography of priority species requires integrating both ecosystem and evolutionary perspectives.

Contact

Thierry Oberdorff : thierry.oberdorff@ird.fr
Peter McIntyre : pmcintyre777@gmail.com