Dataset: Accretion rates of low intertidal salt marshes in the Pacific Northwest

Mean accretion rate over all sites was 3.6 mm yr -1 (95% CI = 2.4 to 4.8 mm yr -1 ), which exceeded present mean sea-level-rise rate (1.3 mm yr -1 ; sd = 0.6). However, a mean rise rate of 5.5 mm yr -1 (sd = 1.9) predicted by a moderate sea-level-change scenario to occur by the year 2050 exceeds mean accretion rate.

Marshes with adequate sediment input seemed to have the capacity to keep pace with an increased sea-level-rise rate. Lowest accretion rates were recorded at sites with the least sediment supply. Accretion rate showed a weak negative correlation with sediment organic matter (measured as volatile solids) and marsh standing stock.