Temperature variability regulates the interactive effects of warming and pharmaceutical on aquatic ecosystem dynamics

Area of Science:

• Ecology
• Environmental Science
• Aquatic Ecosystems

Background:

• Climate warming and pharmaceutical contaminants significantly impact aquatic ecosystems.
• The interactive effects of these stressors on population dynamics and community structure are poorly understood.
• Pharmaceuticals can alter species' boldness, influencing ecological interactions.

Purpose of the Study:

• To investigate the interactive effects of climate warming and pharmaceutical-induced boldness changes on aquatic food-chain models.
• To analyze how daily mean temperature (DMT) and diurnal temperature range (DTR) modulate these interactions.
• To understand the combined impacts on aquatic community stability and population dynamics.

Main Methods:

• Utilized an empirically informed food-chain model with a size-structured fish consumer, zooplankton prey, and a fish predator.
• Incorporated climate warming variables: daily mean temperature (DMT) and diurnal temperature range (DTR).
• Simulated pharmaceutical-induced changes in species' boldness.

Main Results:

• Daily mean temperature (DMT) and high species boldness were identified as primary drivers of community instability.
• Interactive effects led to diverse outcomes, including predator collapse and cyclical population dynamics.
• Daily temperature variability (DTR) significantly modulated interactive effects; moderate DTR stabilized communities, while large DTR destabilized them.

Conclusions:

• Climate warming and pharmaceutical contaminants interact synergistically to affect aquatic ecosystems.
• Daily temperature range is a critical factor mediating the stability of aquatic communities under combined stressors.
• Further research is crucial to quantify cumulative impacts of multiple environmental stressors on aquatic ecosystems.