Marsh construction techniques influence net plant carbon capture by emergent and submerged vegetation in a brackish marsh in the northwestern Gulf of Mexico

► Carbon capture by emergent and submerged vegetation was similar in constructed and reference areas. ► Submerged vegetation captured less carbon than emergent vegetation. ► Constructed areas contained less emergent vegetation than the reference area. ► The smaller ratio of land to water in constructed areas reduced their annual rate of carbon capture. ► Constructed marsh designs should replicate the ratio of land to water in reference marshes.