Earth and Environmental Sciences

As the world’s largest archipelagic state, Indonesia is increasingly exposed to microplastic contamination across its aquatic environments. This review synthesizes evidence from 497 publications reporting microplastic occurrence in environmental matrices across the Indonesian archipelago, including freshwater and marine waters, sediments, and aquatic biota. The analysis examines reported abundance levels, dominant polymer types, spatial patterns of contamination, and methodological approaches used in microplastic research conducted in Indonesia. The literature reveals a pronounced geographic imbalance in research coverage. More than 60% of studies were conducted in western Indonesia, with a strong concentration on Java Island, whereas large parts of eastern Indonesia remain poorly documented. Reported concentrations vary widely among environmental matrices and sampling designs, reflecting differences in both environmental conditions and analytical practices. Notably, studies that did not apply rigorous quality assurance procedures or confirm polymer composition using spectroscopic techniques tended to report markedly higher concentrations, suggesting that methodological limitations may contribute to inflated contamination estimates. To place these observations into a comparable framework, risk band thresholds were derived from the abundance dataset using a quantile-based statistical approach. Overall, this review provides an integrated baseline of microplastic contamination across Indonesian environments and identifies critical geographic and methodological gaps that should guide future monitoring strategies and environmental risk assessments.

Abstract This piece concludes the Focused Issue on Just Transitions in the Global South intended to make up for the limited studies of dynamics of just transitions in the Global South with its unique colonial history, structural constraints, development challenges, and weak governance systems. A careful reading of the contributions from this collection reveals three interrelated themes: (a) just transition as contestation of development visions; (b) the on-set of green extractivism; and (c) a gradual movement towards shifted responsibility where developing countries are subtly shifting the burden of global clean transition to countries and communities that are least responsible for climate change and least equipped to bear the cost. The findings suggest that a broader and more nuanced understanding of just transitions is required, one that accounts for national contexts, realities, and priorities, global connectivity, and the need of the most vulnerable and affected communities. The most important question for the next decade for climate politics may not be how quickly the world transitions but whether the transition itself becomes another mechanisms through which historical injustices are reproduced.

This study presents U-Pb ages together with newly obtained systematic Hf isotopic data from detrital zircons of the Middle Ordovician Miboshan Formation in the eastern Hexi Corridor (northwestern China), aiming to constrain its provenance characteristics and the relationship of the Alxa Block with the North China Craton. Four major age groups are identified: 500–650 Ma, 750–1200 Ma, 1500–2000 Ma, and 2400–3000 Ma. Comparison with the ages of basement rocks from adjacent tectonic units and their Hf isotopic features indicates that the Miboshan Formation has multiple provenances: the central-northern Qilian Orogenic Belt contributed the Late Neoproterozoic to Early Paleozoic zircons, while the 750–1200 Ma zircons were primarily sourced from both the central-northern QOB and the Alxa Block. The 1500–2000 Ma zircons mainly originated from the Alxa Block, and the 2400–3000 Ma zircons are related to recycled materials from the Alxa Block and the central-northern QOB. In conjunction with detrital zircon data from regional Paleozoic strata, this study proposes that the Alxa Block was independent of the North China Craton before the Middle Ordovician, and that the two blocks began to approach each other in the Late Ordovician, with their final amalgamation possibly occurring no earlier than the Late Devonian.

Sound is crucial in marine ecosystems, serving as the primary conduit for information transfer for many organisms. The effects of anthropogenic noise on marine organisms vary from behavioral changes to physical harm. The Gulf of Tribugá has diverse ecosystems and species of high ecological and economic value. This research aimed to characterize three sites in the Gulf of Tribugá using acoustic indices, distinguishing between conditions with and without boat noise across different years. Since 2018, 1518 recordings from passive acoustic monitoring at three sites in the Gulf have been analyzed, categorized as having boat noise present or not. A descriptive analysis of acoustic indices was conducted (1) across space and time, (2) between times with and without boat noise, and (3) between two frequency ranges. Passive acoustic monitoring at three Colombian sites (2018 -2022) used EAR and SNAP recorders deployed at ~16 -25 m, recording 10 min every 20 min at 15,625 or 48,000 Hz. Eight 10_min files daily were manually annotated for sound sources and boat presence. Acoustic indices (ACI, ADI, AEI) and SPL were computed in R and MANTA. Statistical comparisons assessed temporal/spatial differences with/without boat noise. All sites had significantly different Acoustic Complexity Index values based on boat noise presence, which were dependent on the frequency range examined. The absolute values of the acoustic indices varied over time, as significant differences were found across an annual time span for the Acoustic Evenness Index and Acoustic Diversity Index when comparing recordings with and without boat noise. Furthermore, a difference in sound pressure levels of 10 dB re 1 µPa over the full bandwidth was found before compared to after COVID-19. These results could serve as a guide for other studies and continued monitoring in the area, but they are not comparable with other sites, as changes may depend on different factors, or the indices may not be suitable for other cases.

Numerous studies have investigated the ecological impacts of escaped aquaculture fish. Whether people can objectively obtain this information through large language model (LLM) artificial intelligence (AI) systems, which are currently gaining increased traction across the globe, is a question of interest to those engaged in or concerned with aquaculture and aquatic ecology. In this study, the reliability of LLM-based AI systems for assessing the ecological impact of the escape of farmed fish is explored, providing reference data for further research on the application of LLM AI systems in aquaculture and aquatic ecology. The results reveal that the answers provided by the AI systems were largely consistent with the findings from the scientific literature on fish ecological invasion, and they included information regarding resource competition, disease transmission, genetic pollution, water quality deterioration, and disruption of the aquatic ecological structure and function. However, the responses of the AI systems did not mention certain aspects discussed in the literature concerning the ecological risks of the escape of farmed fish, including the difficulty in predicting the potential impact of their escape, the influence of the ecological background information of the receiving water area before the escape, and the potential positive impact of fish already established in the wild. This finding suggests that the responses of the AI systems to the questions posed may have leaned towards more general and widely relevant answers while neglecting more specialized but less-discussed details. Therefore, the reliability of the AI ​​consulting in this study is questionable.

Correction on: Liepina-Leimane I, Jurgensone I, Barda I, Kokorite I and Aigars J (2026) Diverging temporal trends and environmental drivers of dominant cyanobacteria in the Gulf of Riga, 1976-2024. Front. Mar. Sci. 12:1713992. doi: 10.3389/fmars.2025.1713992 There was a mistake in Figure 7 as published. The two bottom rows of the heatmap incorrectly display another set of summer correlation values (DIN/DIP at a specific layer in stations 165, 101A, 119, 121) instead of the intended winter DIN and DIP values. This occurred due to a data mix-up during plot processing in R. The corrected Figure 7 appears below.The original version of this article has been updated.The Figure 5 and Figure 6 were in the wrong order in the PDF and HTML version of this paper (https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1713992/full). This error was flagged by the authors during the proof stage but was not resolved. Note that the captions are in a correct order. The order has now been corrected.The original version of this article has been updated.Reminder: Figures, tables, and images will be published under a Creative Commons CC-BY license and permission must be obtained for use of copyrighted material from other sources (including re-published/adapted/modified/partial figures and images from the internet). It is the responsibility of the authors to acquire the licenses, to follow any citation instructions requested by third-party rights holders, and cover any supplementary charges.Adding/removing text Text insertion in the Introduction. In the second-to-last paragraph of the Introduction, the phrase "odd formatting" has been inserted to replace the correct term "runoff" into the main text: "Moreover, seasonal shifts in riverine odd formating have been observed in recent decades (Käyhkö et al., 2015), altering timing and magnitude of nutrient inflow to coastal areas. This redistribution of river runoff has altered salinity, stratification, and turbidity (Aigars et al., 2024). Consequently, the combined effect on cyanobacterial bloom intensity and species composition in the Gulf of Riga remains unresolved.". This was a comment by authors during proof stage and was meant regarding formatting. It should not have been included by production team in the main text.A correction has been made to the section [Introduction, Paragraph 6, line 180 : "Moreover, seasonal shifts in riverine runoff have been observed in recent decades (Käyhkö et al., 2015), altering timing and magnitude of nutrient inflow to coastal areas. This redistribution of river runoff has altered salinity, stratification, and turbidity (Aigars et al., 2024).Consequently, the combined effect on cyanobacterial bloom intensity and species composition in the Gulf of Riga remains unresolved. [insert corrected paragraph]"The original version of this article has been updated.contact the journal's editorial office.

Recent scholarship on left-behind places shows how uneven spatial development produces affective consequences. Yet discontent and resentment are often treated as near-automatic responses to economic marginalization, obscuring the diversity of left-behind places and their varied emotional and political outcomes. This article argues that left-behindness is temporally constituted: to understand how it is experienced, interpreted, and politicized, we must analyze how places are left behind in time. To do so, the article develops a multi-layered timescape framework linking a macro timescape of global capitalist restructuring, a meso timescape of local change agency, and a micro biographical timescape of lived experience. Interactions across these layers—through timing, sequence, duration, and tempo—shape how left-behindness becomes narratable, meaningful, and contested. Empirically, the article analyzes Northeast China as a case of left-behindness, identifying a distinctive pattern of belated cultural representation and quasi-politicization crystallizing in the city of Shenyang.

Urban AI is increasingly embedded in the governance of security, mobility, and everyday life through sensors, cameras, and algorithmic systems promoted under smart city agendas. While these technologies promise efficiency and protection, their rapid normalisation raises tensions between security, democratic accountability and individual freedom. This commentary critically examines AI-enabled urban surveillance as a contemporary mode of statecraft, arguing that dominant safety narratives often obscure deeper processes of behavioural regulation, data extraction and power consolidation within urban infrastructures. Drawing on examples from both democratic and authoritarian contexts, it shows how AI-driven monitoring can reshape citizenship, amplify inequality through algorithmic bias and erode privacy and autonomy. To address these challenges, the study advances a multi-level analytical framework tracing how smart city paradigms materialise as surveillance infrastructures, generate social consequences, and produce democratic tensions that diverge into care-oriented or control-oriented governance pathways. The commentary concludes that safeguarding urban freedom requires treating urban AI governance as a political project grounded in transparency, participation, civil liberties and democratic oversight, rather than a purely technical exercise.