Amphibians are currently suffering severe worldwide declines caused by chytridiomycosis, an emerging infectious disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). So far, disease mitigation strategies have taken a host-level approach, in which only the host-pathogen interactions have been considered. However, recent results have shown that disease dynamics can be affected by pathogen-environment interactions and underscored the importance of the host-pathogen-environment interplay. Indeed, in the field and laboratory, freshwater zooplankton was found to trigger Bd infection in two amphibian species by directly consuming Bd zoospores. This study raises the hope that chytridiomycosis outbreaks could be controlled in nature by natural augmentation of zooplankton. The project FreeMi aims at developing a safe and effective mitigation strategy targeting Bd at the habitat level. To achieve this aim, I will first identify whether amphibians are protected by the species richness, the overall abundance and/or a few key zooplankton organisms able to consume a high number of Bd zoospores. The samples will be collected from two regions: the Pyrenees and Germany. Then, I will identify the local species that are the most efficient at consuming zoospores. I will isolate these species and establish self-maintaining cultures in outdoor microcosms. Finally, I will test the efficiency of the cultures, in single as well as community trials, under biologically relevant conditions. Compared to other approaches, this highly innovative approach lacks the downsides associated with introducing non-native biocontrol agents (such as antifungal chemicals or non-native skin bacteria) in the environment. Moreover, it would allow to treat all amphibian individuals present at a site, of all species and from larvae to adults directly in the field, and therefore would be more cost-effective than individual treatment strategies.

The global biodiversity and climate crises cannot be solved in isolation or by merely ramping up what is already being done. Urgent and ambitious transformative changes are needed in our economies and societies. Through inclusive deliberation TRANSPATH identifies leverage points and interventions for triggering transformative changes at consumer, producer and organisational levels. It seeks whole-of-society opportunities for achieving climate-neutrality whilst simultaneously allowing local communities and nature to flourish. TRANSPATH draws on diverse contexts in Eastern and Western Europe, Africa and Latin America, to engage with those who affect and are affected by trade regimes and associated ‘greening’ mechanisms. Through deliberation on alternative visions, values, actions, and their systemic interactions across scales and over time, TRANSPATH identifies leverage points that can trigger positive cascading biodiversity changes. Policy packages and other interventions are designed, to enable the emergence of leverage points at different scales of action in ways that changes the choice architecture underlying daily decisions. These interventions consider the synergies and trade-offs of actions across multiple people and places, and the role of incentives and political barriers to implementation. TRANSPATH delivers a suite of Transformative Pathways with a Toolbox of Transformative Interventions for triggering and enabling these pathways. A Transformative Navigation Toolkit guides practitioners on how to enable and navigate pathways, acknowledging that arriving at what constitutes a ‘transformative pathway' is also a product of an iterative and adaptive process that emerges and evolves over time. To implement these, TRANSPATH develops a multi-scalar network of activated agents of change, who can foster inclusive and legitimate decisions, and build capacity and willingness among their actor networks to collectively move forward on transformative pathways.