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Melzner, F.

Publications and source records attributed to Melzner, F..

2 recordsLinked to original sources

A Bayesian overhaul of thermal tolerance landscape models: Predicting ectotherm lethality buildup and survival amid heatwaves

1. In the face of escalating heatwaves, accurately forecasting ectotherm population mortality is a pressing ecological challenge. Current Thermal Tolerance Landscape (TTL) models, while surpassing single-threshold metrics by incorporating individual survival times, are constrained by frequentist regression parametrization reliant on constant-temperature experiments, omitting probabilistic outcomes. 2. This study addresses these limitations by pioneering the application of Approximate Bayesian Computation-Sequential Monte Carlo (ABC-SMC) to analyze survival data from Baltic Mytilus mussels subjected to both microcosm (constant temperature) and mesocosm (dynamic temperature) heatwave regimes. 3. The ABC-SMC yields probabilistic predictions of individual lethality buildup and population survival trajectories, closely aligned with observed survival data across both experimental conditions. Informed by more realistic dynamic data, the TTL model predicts local mussel resilience against the most extreme summer heatwaves projected for this century, albeit with considerations for sublethal impacts and potential recruitment declines. 4. Our approach can enhance the predictive accuracy concerning the sensitivity of key marine populations amidst intensifying heatwaves, addressing the urgent need for accurate modeling tools to inform conservation practices and ecosystem management, ultimately aiding in the preservation of marine biodiversity.

ecology↗

Long-term culture system for deep-sea mussels Gigantidas childressi

The simulation of deep-sea conditions in laboratories is technically challenging but necessary for experiments that aim at a deeper understanding of physiological mechanisms or host-symbiont interactions of deep-sea organisms. In a proof-of-concept study, we designed a recirculating system for long-term culture (>2 years) of deep-sea mussels Gigantidas childressi (previously Bathymodiolus childressi). Mussels were automatically (and safely) supplied with a maximum stable level of ~60 {micro}M methane in seawater using a novel methane-air mixing system. Experimental animals also received daily doses of live microalgae. Condition indices of cultured G. childressi remained high over years, and low shell thickness growth could be detected, which is indicative of positive energy budgets. Using stable isotope data, we demonstrate that G. childressi in our culture system gained energy, both, from digestion of methane oxidizing endosymbionts and from digesting particulate food (microalgae). Limitations of the system, as well as opportunities for future experimental approaches involving deep-sea mussels are discussed.

ecology↗