ALBERT

Description: Highlights: • MPA is the most widely employed marine management tools. • Five potential habitats selected for MPA declaration in Bangladesh. • These habitats cover 7% of total maritime area of Bangladesh. • Local community involvement is required for a successful implementation of MPA. Abstract: Marine protected areas (MPAs) have become one of the most widely employed marine management tools worldwide for conserving species and habitats, maintaining ecosystem functioning, and ensuring sustainable use of marine resources. In this study, we adopted a science-based, stakeholder-driven and ecosystem based approach to identify coastal and marine habitats for potential MPA declaration towards achieving Aichi target 11. In addition, we also proposed an integrated management approach for MPA management in Bangladesh. Primary data were collected through stakeholder consultations from the three coastal zones of Bangladesh and secondary data were collected from an extensive literature review. We developed a priority index to select the most important habitats for MPA declaration. Our analysis suggests five potential habitats within the maritime boundary of Bangladesh for MPA declaration. These habitats cover an area of 8838 km2 which is about 7.5% of the total maritime area of Bangladesh. Declaration of the MPAs will contribute to conserve the nursing and breeding habitats of fishes, crabs and seabirds, and thus will protect the marine biodiversity. To achieve this goal, local community involvement is required. This study will serve as a baseline for declaring MPAs in a solid scientific way through community engagement.

Description: The unique flavor of Pixian douban (PXDB) is widely acknowledged to be associated with its maturation process. However, there is limited knowledge about the non-volatile metabolites that contribute to this flavor. To bridge this gap, this study employed a metabolomics approach and a feature-based molecular network (FBMN) analysis to investigate the non-volatile metabolite fingerprints of PXDB during its two-year maturation process. Specifically, the FBMN tool was utilized to annotate the flavonoid, amide derivatives, and lipid components of PXDB for the first time. Subsequently, the MolNetEnhancer tool was employed to complement the FBMN annotation and identify eight substructural components. Finally, metabolomics analysis was carried out to identify 45 key metabolites involved in flavor formation across 10 major metabolic pathways (p 〈 0.05). Overall, the findings of this study have significantly expanded our understanding of the non-volatile metabolite fingerprinting and flavor formation mechanisms.

Description: The impact of submarine groundwater discharge (SGD) on coastal sea biogeochemistry has been demonstrated in many recent studies. However, only a few studies have integrated biogeochemical and microbiological analyses, especially at sites with pockmarks of different degrees of groundwater influence. This study investigated biogeochemical processes and microbial community structure in sediment cores from three pockmarks in Hanko, Finland, in the northern Baltic Sea. Pockmark data were supplemented by groundwater and seawater measurements. Two active pockmarks showed SGD rates of 0.02 cm d−1 and 0.31 cm d−1, respectively, based on porewater Cl− profiles, while a third pockmark had no SGD influence. Reactive transport modelling (RTM) established that the porewater systems of these active pockmarks are dominated by advection, resulting in the focusing of biogeochemical reactions and the microbial community into a thin zone at the sediment surface. The advection further reduces the accumulation of organic matter in the surface sediments, resulting in the absence of a sulfate-methane transition zone (SMTZ) at these pockmarks. Furthermore, the RTM estimated low rates of consumption of SO42−, and low rates of production of CH4, NH4+, DIC at the active pockmarks. Archaeal communities in the active pockmarks were dominated by ammonia-oxidizing archaea of predominantly groundwater origin. In contrast, at the inactive pockmark, the lack of SGD has permitted rapid deposition of organic-rich mud. The porewater system in the inactive pockmark is dominated by diffusion, leading to orders of magnitude higher metabolite concentrations at depth compared to the active pockmarks. The biogeochemical environment in the inactive pockmark resembles typical organic-rich mud seafloor in the area, with sulphate reduction and methanogenesis dominating organic matter remineralization. Accordingly, methanogens dominate the archaeal community, whereas sulfate reducers dominate the bacterial community. RTM results suggest that sulfate-mediated anaerobic oxidation of methane (S-AOM) also occurs at this site. Although depth-integrated fluxes of SO42−, CH4, NH4, DIC at the inactive pockmark are orders of magnitude higher compared to the active pockmarks, processes at the inactive pockmark represent internal recycling in the coastal sea. Fluxes observed at the active pockmarks, although comparatively small in magnitude, are partly influenced by external inputs to the sea through SGD. Hence, effluxes across the sediment–water interface at these sites partly represent direct external fluxes to the marine environment, in addition to diagenetic recycling at the benthic interface. The study highlights that SGD can result in significant spatial heterogeneity of biogeochemical processes and microbial community structure in the coastal zone, and that the overall effects of SGD and associated solute fluxes at an SGD site are a function of the number of pockmarks, the rate of SGD, and the ratio of active to inactive pockmarks.