Coasts

This review synthesizes the literature on the degradation and decomposition of holopelagic Sargassum, with a focus on process dynamics, including microbial contribution, process descriptions, and ecological impacts. Our objective is to consolidate a robust knowledge framework to inform and optimize management strategies in affected areas. Overall, we observed that the current literature relies primarily on isolated field ecological descriptions rather than a coherent, unified research line; mechanistic studies, including bacterial pathways and factors controlling degradation, remain scarce. At the fine scale, microbial community shifts during decomposition are strongly linked to the sequential utilization of distinct organic substrates, thereby favoring the proliferation of microorganisms capable of degrading complex organic molecules and of bacterial groups involved in sulfur respiration, methanogenesis, and nutrient recycling. In the case of sulfur respiration, groups such as Desulfobacterales and Desulfovibrionales may be responsible for the reported H₂S emissions, which pose significant public health concerns. At a broad scale, degradation occurs both on beaches during emersion and in the water column during immersion, particularly during massive accumulations. The initial stages are characterized by the release of organic exudates and leachates. Experimental and observational studies confirm a strong early-stage release of H₂S until the substrate is largely depleted. Depending on environmental conditions, a significant amount of biomass can be lost; however, this loss is highly variable, with notable consequences for contamination studies. Leachates may also contain low but ecologically significant amounts of arsenic, posing a potential contamination risk. Decomposition contributes to water-quality deterioration and oxygen depletion, with impacts at the individual, population, and ecosystem levels, yet many remain imprecisely attributed. Although evidence of nutrient enrichment in the water column is limited, studies indicate biological nutrient uptake. Achieving a comprehensive understanding of degradation and decomposition, including temporal and spatial dynamics, microbiome interactions, by means of directed research, is critical for effective coastal management, improved mitigation strategies, industrial valorization, and accurate modeling of biogeochemical cycles.

Incidental capture (bycatch) is a major threat to all seven marine turtle species worldwide. This systematic review assessed (i) research trends over the past 20 years; (ii) relationships between fishery types, gear, and species caught; (iii) post-capture outcomes; and (iv) challenges in bycatch mitigation. A systematic search of Web of Science and Scopus up to April 2024 identified 236 studies, comprising 336,616 global bycatch records. Publications on turtle bycatch increased significantly (p < 0.001), peaking in 2020. Reported captures also rose (ρ = 0.45; p = 0.026), with Caretta caretta most frequently documented (74.8%). Methodology influenced outcomes: aerial monitoring and direct observation underestimated captures of Chelonia mydas, Lepidochelys kempii, and Eretmochelys imbricata compared with mixed methods; interviews only affected the latter. Regarding fishery interactions, Dermochelys coriacea was more susceptible to hook-and-line fishing (p = 0.0079), while C. mydas was more associated with small-scale fisheries (p = 0.0115). Most turtles were released after capture (60.6%), with no significant temporal variation in outcomes (p > 0.05). Despite growing monitoring, knowledge gaps remain in standardized reporting, regional and species coverage, and methodological integration. Addressing these issues is essential to guide effective, collaborative conservation strategies.

The study focuses on the impact of climate change and spatial planning policies on coastal landscape dynamics. We examine the present and future coastal land use/land cover (LULC) change for southwestern Ghana under the coastal resilience (CR) scenario and coastal planning (CP) scenario. It employs an integrated approach of a review of literature and satellite imagery analysis to map coastal land use/land cover (LULC) change, from 2010 to 2020, to predict future landscape transitions under a coastal resilience approach and then contrast it with a scenario where development of the coast continues. The results show a continual decline in wetlands, from 1882.43 ha in 2010 to 1743.49 ha in 2020. Increased development would dominate the landscape under a scenario where coastal planning continues to expand, whereas cultivated, agricultural lands and vegetation are likely to increase under a coastal resilience scenario in 2035 and 2057. This study recommends that government and other stakeholders should consider coastal landscape restoration plans and programmes towards landscape sustainability for Sustainable Development Goals (SDG) 11 and 13.