Work

Trait-mediated effects of Macoma balthica (L.) on nitrogen and carbon biogeochemistry in estuarine ecosystems

Year: 2025

Type: article

Abstract: Coastal ecosystems depend on microbially mediated biogeochemical processes for ecosystem functioning, particularly the cycling of carbon and nitrogen across the water-sediment interface supported by benthic invertebrate fauna. Bivalves can significantly influence these cycles by modifying nutrient fluxes through their bioturbation activity. Here, we conducted an 8-week coastal microcosm experiment using Macoma balthica, a common intertidal clam found in Chesapeake Bay. Our primary objective was to assess how the presence of M. balthica could influence nutrient concentrations in both the water column and interstitial water. We also examined how the clam’s traits, such as burial position (surface vs. buried) and shell length influenced nutrient cycling. We monitored concentrations of ammonia (NH3), nitrate and nitrite (NOx) as indicators of nutrient dynamics within the nitrogen cycle, and CDOM at 250 nm (aCDOM 250 m-1) as an indicator of the carbon cycle. Our results showed a significant effect of bivalve presence on nitrogen cycling, with NH3 levels in the water column rising initially before declining, and NOx concentrations increasing exponentially in both water column and interstitial water. M. balthica position influenced NH3 and NOX concentrations in some sampling weeks, and larger individuals were associated with higher NOx levels. aCDOM 250 m-1 values increased over time regardless of bivalve presence. These findings demonstrate that M. balthica influence on N nutrient cycling is shaped by individual traits (size and burial position) and temporal dynamics, leading to functional heterogeneity, with important potential implications for estuarine nutrient fluxes and overall ecosystem functioning.

Source: Marine Environmental Research

DOI: 10.1016/j.marenvres.2025.107621

Authors: Gabriel Pereira, Calli M. Wise, Katrina M. Pagenkopp Lohan, Genevieve L. Noyce, Marta L. Lopes, Luísa Magalhães

Institutions: Centro de Estudos do Ambiente e do Mar, University of Aveiro, Smithsonian Environmental Research Center

Language: English

Topic: Marine Bivalve and Aquaculture Studies

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDG: Life below water

Open Access status: hybrid

Estimated APC paid: $3,440