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Sustainable remediation is a new way of thinking and acting in the management of contaminated sites. This research aims to identify and structure the state-of-the-art of sustainable remediation from the risk management and stakeholder involvement perspective. A systematic and bibliometric study of scientific production was performed on scientific papers indexed in the Scopus and Web of Science databases with the objectives: 1) to select a bibliographic portfolio that is aligned with the perception of the researchers in regard to theme, 2) to perform a bibliometric analysis of the selected bibliographic portfolio, and 3) to conduct a thematic synthesis and identify the integration of sustainable remediation from the risk management and stakeholder involvement perspective. The results indicated that although sustainable remediation is a recent theme it presents a promising field for development worldwide, verified by the growing number of publications in recent years. A change is observed in the way risk management is considered with the rise of sustainable remediation, demonstrated by different approaches in publications. Likewise, the involvement of stakeholders is widely discussed, and the importance of their participation in decision-making processes in the field of sustainable remediation is identified. This research brings several and new contributions as it provides with a detailed overview and guidance about the main characteristics and peculiarities as well as what already exists, the form to approach, the advances and what still needs to be improved so that the perception of stakeholders and risk management are better understood within the context of sustainable remediation.

Lead poisoning, through the ingestion of spent lead gunshot, is an established cause of morbidity and mortality in waterbirds globally, but the thresholds at which blood levels begin to affect the physiology of birds in the wild are less well known. Here we determine the prevalence of lead exposure in whooper swans and, for the first time, identify the level of blood lead associated with initial reductions in body condition. Blood lead elevated above background levels (i.e. >20 μg dL⁻¹) was found in 41.7% (125/300) of swans tested. Blood lead was significantly negatively associated with winter body condition when levels were ≥44 μg dL⁻¹ (27/260 = 10%). Our findings indicating that sub-lethal impacts of lead on body condition occur at the lower end of previously established clinical thresholds and that a relatively high proportion of individuals in this population may be affected, reaffirm the importance of reducing contamination of the environment with lead shot.

The impacts of iron oxide nanoparticles (γ-Fe2O3 NPs) and ferric ions (Fe³⁺) on plant growth and molecular responses associated with the transformation and transport of Fe²⁺ were poorly understood. This study comprehensively compared and evaluated the physiological and molecular changes of Citrus maxima plants as affected by different levels of γ-Fe2O3 NPs and Fe³⁺. We found that γ-Fe2O3 NPs could enter plant roots but no translocation from roots to shoots was observed. 20 mg/L γ-Fe2O3 NPs had no impact on plant growth. 50 mg/L γ-Fe2O3 NPs significantly enhanced chlorophyll content by 23.2% and root activity by 23.8% as compared with control. However, 100 mg/L γ-Fe2O3 NPs notably increased MDA formation, decreased chlorophyll content and root activity. Although Fe³⁺ ions could be used by plants and promoted the synthesis of chlorophyll, they appeared to be more toxic than γ-Fe2O3 NPs, especially for 100 mg/L Fe³⁺. The impacts caused by γ-Fe2O3 NPs and Fe³⁺ were concentration-dependent. Physiological results showed that γ-Fe2O3 NPs at proper concentrations had the potential to be an effective iron nanofertilizer for plant growth. RT-PCR analysis showed that γ-Fe2O3 NPs had no impact on AHA gene expression. 50 mg/L γ-Fe2O3 NPs and Fe³⁺ significantly increased expression levels of FRO2 gene and correspondingly had a higher ferric reductase activity compared to both control and Fe(II)-EDTA exposure, thus promoting the iron transformation and enhancing the tolerance of plants to iron deficiency. Relative levels of Nramp3 gene expression exposed to γ-Fe2O3 NPs and Fe³⁺ were significantly lower than control, indicating that all γ-Fe2O3 NPs and Fe³⁺ treatments could supply iron to C. maxima seedlings. Overall, plants can modify the speciation and transport of γ-Fe2O3 NPs or Fe³⁺ for self-protection and development by activating many physiological and molecular processes.

Mangrove tidal wetland habitats are recognised as highly vulnerable to large and chronic oil spills. This review of current literature and public databases covers the last 6 decades, summarising global data on oil spill incidents affecting, or likely to have affected, mangrove habitat. Over this period, there have been at least 238 notable oil spills along mangrove shorelines worldwide. In total, at least 5.5milliontonnes of oil has been released into mangrove-lined, coastal waters, oiling possibly up to around 1.94millionha of mangrove habitat, and killing at least 126,000ha of mangrove vegetation since 1958. However, there were assessment limitations with incomplete and unavailable data, as well as unequal coverage across world regions. To redress the gaps described here in reporting on oil spill impacts on mangroves and their recovery worldwide, a number of recommendations and suggestions are made for refreshing and updating standard operational procedures for responders, managers and researchers alike.

Seagrasses that are distributed over a large area of the Swan Lake, Weihai, China, support a productive ecosystem. In recent years, however, frequent macroalgal blooms have changed the ecosystem structure and threatened the seagrasses. To understand the bloom-forming macroalgae we conducted a yearly field survey of Swan Lake. Results indicated that the macroalgae Chaetomorpha linum and Ulva pertusa both exhibited a much higher productivity and attained a greater maximum biomass (of 1712±780gDWm−2 and 1511±555gDWm−2, respectively) than was the case for the seagrasses. The mean annual atomic ratios of C/N, C/P and N/P in C. linum were 14.31±4.45, 402.82±130.25, and 28.12±2.08, respectively. The δ15N values (11.09±0.91‰ for C. linum; 9.27±2.83‰ for U. pertusa) indicated a land-based source of N enrichment to the macroalgal blooms. High concentrations of nitrogen and phosphorus in the lagoon, particularly near the river mouth, supported the blooms.

Physical and biological seabed impacts can persist long after the cessation of marine aggregate dredging. Whilst small-scale experimental studies have shown that it may be possible to mitigate such impacts, it is unclear whether the costs of restoration are justified on an industrial scale. Here we explore this question using a case study off the Thames Estuary, UK. By understanding the nature and scale of persistent impacts, we identify possible techniques to restore the physical properties of the seabed, and the costs and the likelihood of success. An analysis of the ecosystem services and goods/benefits produced by the site is used to determine whether intervention is justified. Whilst a comparison of costs and benefits at this site suggests restoration would not be warranted, the analysis is site-specific. We emphasise the need to better define what is, and is not, an acceptable seabed condition post-dredging.

The continued rise in atmospheric carbon dioxide (CO2) levels is driving climate change and temperature shifts at a global scale. CO2 Capture and Storage (CCS) technologies have been suggested as a feasible option for reducing CO2 emissions and mitigating their effects. However, before CCS can be employed at an industrial scale, any environmental risks associated with this activity should be identified and quantified. Significant leakage of CO2 from CCS reservoirs and pipelines is considered to be unlikely, however direct and/or indirect effects of CO2 leakage on marine life and ecosystem functioning must be assessed, with particular consideration given to spatial (e.g. distance from the source) and temporal (e.g. duration) scales at which leakage impacts could occur. In the current mesocosm experiment we tested the potential effects of CO2 leakage on macrobenthic assemblages by exposing infaunal sediment communities to different levels of CO2 concentration (400, 1000, 2000, 10,000 and 20,000 ppm CO2), simulating a gradient of distance from a hypothetic leakage, over short-term (a few weeks) and medium-term (several months). A significant impact on community structure, abundance and species richness of macrofauna was observed in the short-term exposure. Individual taxa showed idiosyncratic responses to acidification. We conclude that the main impact of CO2 leakage on macrofaunal assemblages occurs almost exclusively at the higher CO2 concentration and over short time periods, tending to fade and disappear at increasing distance and exposure time. Although under the cautious perspective required by the possible context-dependency of the present findings, this study contributes to the cost-benefit analysis (environmental risk versus the achievement of the intended objectives) of CCS strategies.

Despite over 21,000ha of mangrove forests being removed per year in Brazil, ecological changes following mangrove deforestation have been overlooked. Here we evaluated changes in benthic macrofaunal assemblages and food-webs at a mangrove removal and natural sites in a tropical estuary in Eastern Brazil. The impacted site had coarser sediment particle sizes suggesting significant changes in sedimentation processes after forest clearing. Spatial differences in macrofaunal abundance, biomass and diversity were not directly associated with the removal of mangrove forests, supporting recolonization of impacted areas by estuarine fauna. However, benthic assemblage composition, infaunal δ13C signatures and food-web diversity markedly differed at the impacted site being strongly related to sedimentary changes. The loss of infaunal trophic diversity that followed mangrove removal suggests that large-scale forest clearing may impact estuarine food webs, with potential consequences to nearby coastal ecosystems given the high clearing rate of mangrove forests in Brazil.

Benthic octopuses have been widely documented in artificial shelters for decades, and this use is apparently increasing. Despite any possible positive effects, the use of litter as shelter could have negative implications. In this work, we aimed to elucidate the interactions of octopuses with marine litter, identifying types of interactions and affected species and regions. To achieve this, we obtained 261 underwater images from ‘citizen science’ records, and identified 8 genera and 24 species of benthic octopuses interacting with litter. Glass objects were present in 41.6% of interactions, and plastic in 24.7%. Asia presented the highest number of images, and most records were from 2018 to 2021. Citizen science provided important evidence on octopus/marine litter interactions, highlighting its value and the need for more investigations on the subject. This information is fundamental to help prevent and mitigate the impacts of litter on octopuses, and identify knowledge gaps that require attention.