Low-Dose H₂O₂ Priming Improves Performance Under Simulated Marine Heatwave Conditions in a Coastal Bivalve

Area of Science:

• Marine biology
• Climate change adaptation
• Bivalve physiology

Background:

• Marine heatwaves pose significant threats to marine ecosystems.
• Priming, a process of prior exposure, enhances tolerance to environmental variability.
• Chemical priming in animals, particularly bivalves, is largely unexplored.

Purpose of the Study:

• To investigate if hydrogen peroxide (H2O2) priming can modulate the response of Manila clams to simulated marine heatwaves.
• To assess the efficacy and tolerability of H2O2 as a priming agent in bivalves.

Main Methods:

• Manila clams were subjected to chemical (H2O2), thermal, or combined priming treatments.
• Primed clams were subsequently exposed to a controlled marine heatwave simulation.
• Transcriptomic and microbiota analyses were performed.
• A long-term field trial assessed effects under natural conditions.

Main Results:

• H2O2 priming was well-tolerated and enhanced clam burrowing behavior during heatwaves.
• Primed clams showed minimal transcriptomic changes.
• Microbiota analysis revealed transient shifts and reduced opportunistic taxa.
• Long-term field trials showed no adverse effects.

Conclusions:

• Low-dose H2O2 priming is a potential strategy to enhance the resilience of marine bivalves to climate change-induced heatwaves.
• This approach offers a novel method for managing stress responses in commercially important species like the Manila clam.