Liang Duan

Although blue carbon ecosystems (BCEs) have received widespread attention for their potential to mitigate climate change, the degradation of BCEs has not been effectively addressed, posing a direct threat to global climate goals. Here, the current degradation status of BCEs and proposed countermeasures from a global perspective were clarified. Before carrying out BCE conservation and restoration, the driving factors of degradation were identified, including climate-mediated environmental stress and direct human interference. The implementation of the BC project cannot be achieved without standardized guidance. This review constructs a full-process standardized roadmap for BCE conservation and restoration, including initial investigation and assessment, project design and planning, project implementation, and long-term evaluation and carbon verification. Further, expansion and globalization pathways were proposed to support large-scale, sustainable BC projects. This review delivers a standardized process and a technical roadmap to combat global BCE degradation and promote sustainable BC governance.

Medium-chain fatty acids (MCFAs) offer a sustainable route for valorizing waste-activated sludge (WAS) into higher-value products, yet their bioproduction is constrained by the rigid extracellular polymeric substance (EPS) barrier and inefficient chain elongation (CE). Here, we develop a synergistic pretreatment strategy employing 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim][OTf], a representative ionic liquid) and sodium percarbonate (SPC) to sequentially enhance sludge solubilization and targeted MCFA production. The maximum MCFA yield reaches 5910 mg COD/L in the combined group, 1.3-, 1.1-, and 0.7-fold higher than the control (2537 mg COD/L), [Emim][OTf] alone (2888 mg COD/L), and SPC alone (3409 mg COD/L) groups, respectively. Mechanistically, SPC acted as the primary oxidant to disrupt EPS and cell membranes, while [Emim][OTf] synergistically amplified this effect, as evidenced by enhanced protein solubilization and the progressive mineralization of organic nitrogen to ammonium. The combined pretreatment enriched acidogens (e.g., Proteiniclasticum, 96.8-fold increase), CE-associated Bacillota and Petrimonas (1.1- and 24-fold increases), and MCFA release-associated thioesterase-encoding genes (e.g., fluoroacetyl-CoA thioesterase, 0.5-fold increase). These findings demonstrate that [Emim][OTf] not only activates SPC-mediated sludge disintegration but also facilitates CE, as evidenced by a 1.7-fold increase in MCFA selectivity in model substrate tests, offering a dual-functional strategy for the efficient recovery of MCFA from WAS.

This study investigated the community structure and interaction mechanisms of algae and macrobenthos in the Tuojiang River Basin using environmental DNA (eDNA) metabarcoding with 18S ribosomal RNA (rRNA) and cytochrome c oxidase subunit I (COI) markers. Water samples from 10 sites across 8 rivers were analyzed through high-throughput sequencing and multivariate statistics. The upper mainstream exhibited clean-water communities dominated by Chrysophyceae, Gastropoda, and Porifera, while the middle-lower reaches and tributaries formed pollution-tolerant communities dominated by Cryptophyceae and Bivalvia under organic pollution and hypoxia stress. Three key biological interaction mechanisms were identified: Cryptophyceae and Bivalvia formed a pollution-tolerant functional symbiosis via positive feedback; Chrysophyceae exerted trophic cascade inhibition on Bivalvia through chemical interactions; and Clitellata enhanced benthic diversity through bioturbation-mediated microhabitat modification. These findings reveal that community assembly is jointly driven by environmental filtering and biological interactions, challenging the conventional abiotic-dominant view. This study provides a scientific basis for ecological health assessment and restoration in the Tuojiang River Basin.