Quantifying Biomass of Microphytobenthos in sediments of Mangroves in the east coast of Qatar

Mangroves, Avicennia marina, are highly productive coastal ecosystems with capacity to store carbon within plants and in sediments. Micropytobenthos (MPB) in the sediments also fix carbon and play a significant role in carbon burial. However, there is paucity of information on the role of MPB in coastal carbon budget. We quantified the biomass of MPB as an important carbon pool in the mangrove of Al Thakhira, located at the east coast of Qatar. Sediments at different tidal levels namely, supratidal, intertidal, and subtidal were collected and analyzed for grain size, chlorophyll (a), total carbon, and inorganic carbon contents. Results indicated that sand was the dominant species (60%), followed by silt (39%) and clay (1%) at all tidal levels. While the supratidal level had significantly higher silty sand content, silt dominated the intertidal levels. Moreover, chlorophyll (a) was significantly influenced by tidal levels with highest levels in the subtidal level sediments, where mangroves grow extensively. Results also demonstrated that as we move towards the intertidal zone, the total carbon content in sediments gets higher. Finally, chlorophyll (a) and TOC% were positively associated (r=0.643) in all tidal zones. As we move towards the mangrove subtidal growth area, the total carbon content in sediments gets higher. This work recommends that mangrove forests in Qatar be protected by special sanctuaries and law-enforcement to maintain this natural and dynamic blue carbon ecosystem.