Role of abiotic factors in enhancing the capacity of mangroves in reducing ocean acidification

Ecotoxicology. 2022 Sep;31(7):1169-1188. doi: 10.1007/s10646-022-02566-y. Epub 2022 Jul 28.

Abstract

The present study investigated the effects of rising carbon dioxide levels in nature and the carbon sequestration potential of dominant mangrove species for reducing the toxic effects of ocean acidification. The study was conducted on the east coast of Odisha, in the western Bay of Bengal. To determine the effect of these ambient parameters on the absorption of carbon dioxide by the mangroves, water temperature, salinity, pH levels of seawater along with soil texture and pH, salinity expressed in electrical conductivity, compactness expressed in bulk density, and soil organic carbon were simultaneously monitored. The aboveground biomass and carbon of the selected species were studied for 2 consecutive years at 10 designated stations. The total carbon calculated for the study area varied from 242.50 ± 49.00 to 1321.29 ± 445.52 tons with a mean of 626.68 ± 174.81 tons for Bhitarkanika and Mahanadi mangrove chunks. This is equivalent to 2299.92 ± 641.55 tons of CO2 absorbed from the atmosphere. A total of 27 equations were selected as the best fit models for the study area. The equations between mangrove biomass and carbon along with aquatic and edaphic factors governing the pH of water and soil strongly support the positive influence of mangrove photosynthetic activity in shifting the equilibrium toward alkalinity. This calls for conservation of mangrove ecosystem to minimize the pace of acidification of estuarine water. The results indicate that Excoecariaagallocha and Avicennia marina as are the most capable species for combatting maximum carbon dioxide toxicity from the atmosphere; which will be helpful in REDD + programs and carbon-based payments for ecosystem services (PES).

Keywords: Aquatic and sediment pH; Mangrove biomass and carbon; Ocean acidification; Soil organic carbon.

MeSH terms

  • Carbon
  • Carbon Dioxide
  • Ecosystem*
  • Hydrogen-Ion Concentration
  • Oceans and Seas
  • Seawater
  • Soil
  • Water
  • Wetlands*

Substances

  • Soil
  • Water
  • Carbon Dioxide
  • Carbon