Primary producers sustaining macro-invertebrate communities in intertidal mangrove forests

Area of Science:

• Marine Ecology
• Stable Isotope Ecology
• Trophic Ecology

Background:

• Few studies overview primary carbon sources for intertidal mangrove invertebrates.
• Mangrove primary production's trophic significance is well-studied, but invertebrate carbon sources are less clear.

Purpose of the Study:

• To determine the contribution of mangrove leaf litter and other carbon sources to the invertebrate community in Indian mangrove forests.
• To assess carbon utilization patterns in tropical intertidal habitats.

Main Methods:

• Analysis of carbon and nitrogen stable isotope ratios (δ13C, δ15N) in sediments, primary producers, and 22 invertebrate species.
• Comparison of isotope signatures to identify carbon assimilation pathways.

Main Results:

• Sediment organic matter indicated significant contributions from imported phytodetritus, not solely mangrove litter.
• Most invertebrates showed carbon isotope values enriched compared to mangrove leaves, suggesting other sources.
• Limited invertebrate species assimilated mangrove-derived carbon; algal sources were dominant.

Conclusions:

• Local and imported algal sources are major carbon providers for benthic invertebrates in intertidal mangrove forests.
• Mangrove-derived carbon assimilation is restricted to a few species.
• Findings align with temperate salt marsh ecosystems, where local plant production contributes little to intertidal food webs.