Dynamics of wood fall colonization in relation to sulfide concentration in a mangrove swamp

• Colonization dynamics of immersed woods were studied in a mangrove swamp.
• Autonomous sensors were used for in situ sulfide monitoring.
• Rapid and sustained sulfide increase was monitored on wood surface.
• Sunken wood host sulfophilic organisms including chemoautotrophic symbioses.
• Wood borers are excluded from the first stage of colonization.

Wood debris are an important component of mangrove marine environments. Current knowledge of the ecological role of wood falls is limited by the absence of information on metazoan colonization processes over time. The aim of this study was to provide insights to their temporal dynamics of wood eukaryotic colonization from a shallow water experiment in a mangrove swamp. Combined in situ chemical monitoring and biological surveys revealed that the succession of colonizers in the mangrove swamp relates with the rapid evolution of sulfide concentration on the wood surface. Sulfide-tolerant species are among the first colonizers and dominate over several weeks when the sulfide content is at its maximum, followed by less tolerant opportunistic species when sulfide decreases. This study supports the idea that woody debris can sustain chemosynthetic symbioses over short time-scale in tropical shallow waters.