Marine Coastal Areas Research Articles

Nonlinear Hydrophysical Disturbance Infragravity Sea Waves

An analysis of the behavior of the infra-gravitational sea wave revealed nonlinear hydrophysical disturbance of the “rogue waves” type. This disturbance is associated with transformation of sea waves when they move along a coastal marine area of decreasing depth, and with interaction with wind waves. These conclusions are confirmed through analysis of in situ data of the laser interference pressure meter of the hydrosphere in this paper and previous works. Full-scale data were obtained on the shelf of the Sea of Japan. During processing of in situ data, we focused on sea waves with periods ranging from 1 to 10 min.

Spatial and seasonal fluctuations in fresh submarine groundwater discharge revealed by marine continuous resistivity profiling

Submarine Groundwater Discharge (SGD) is a major pathway for the discharge of fresh and saline groundwater and associated dissolved compounds into marine environments. However, assessing SGD processes in coastal aquifers is challenging due to inaccessibility, dynamic conditions, complex subsurface geology, and the need for long-term monitoring to capture temporal and spatial variations in SGD rates accurately. This study employs marine continuous resistivity profiling (MCRP) as a main method to assess the presence of freshwater or brackish SGD offshore and to examine its potential seasonal variations. The method has been applied in the coastal alluvial aquifer of Maresme (Spain) and validated with other methods to trace SGD, including salinity profiles, Ra isotopes, and piezometric levels. Several MCRP transects of 700 m long, perpendicular to the coastline, were performed in a coastal marine area to obtain electrical resistivity data of the seabed covering an area of 3 km2. The data was acquired in two field campaigns with contrasting hydrological conditions (dry and wet seasons). The MCRP results allow the identification of areas of fresh SGD in marine sediments, with a clear seasonal variability that indicates a higher discharge of fresh groundwater in the wet season.

Coastal marine habitats deterioration according to users’ perception: the case of Cap de Creus Marine Protected Area (NE Spain)

Assessing how different users of a Marine Protected Area perceive environmental changes can contribute to design management strategies. We assess how locals and tourists perceive environmental changes in the Cap de Creus protected area (NW Mediterranean, Spain). To identify locally perceived changes, we first conducted semi-structured interviews with locals (n = 38). Reported environmental changes were then used to construct a survey applied to locals and tourists (n = 427). In semi-structured interviews, environmental changes were the least reported changes compared to economic and social changes; reports of negative environmental changes dominated over reports of positive environmental changes. Overall, all survey participants reported a decline of the health status of the local environment, with locals displaying higher levels of agreement with statements referring to coastal environmental deterioration than tourists. The predominance of responses reporting economic versus environmental changes can be explained by the recent radical transformation of the area towards tourism. Reports of coastal marine area deterioration are in line with available instrumental data. Higher levels of agreement with statements referring to environmental deterioration among locals than among tourists highlight the importance of people’s connection with nature to assess change. Considering that Cap de Creus has been protected for more than two decades, our findings raise concerns regarding its ongoing deterioration and underscore the importance of monitoring the effectiveness of marine protection to modulate management strategies.

A GIS-MCDA approach to map environmental suitability of Posidonia oceanica meadows as blue nature-based solutions in the Mediterranean eco-region

The growing environmental risks induced by interacting climate and human-induced pressures threaten the survival and growth of marine coastal ecosystems (MCEs) and the ecosystem services they provide. Nature-based solutions (NBS), consisting of ecosystem-based approaches, have emerged as vital tools for climate adaptation and mitigation facing biodiversity loss and societal challenges. Identifying suitable environmental conditions for implementing Blue-NBS in marine coastal areas is a key priority to drive robust and cost-effective nature-based adaptation pathways. This study developed a suitability model for Blue-NBS, with a specific focus on Posidonia oceanica meadows in the Mediterranean Sea under a baseline scenario. GIS-based Multiple Criteria Decision Analysis (MCDA) was applied for data integration and prioritization of different environmental variables in geomorphological (e.g., depth), water quality (WQ) (e.g., salinity), and climatic (e.g., thermal stress) sub-groups. Suitability classes and scores for each variable were determined using statistical distributions, ensuring a data-driven approach to defining environmental suitability. Variables' weights were derived from the Analytic Hierarchy Process (AHP) based on expert judgment and then combined with scores to generate suitability maps for managing Blue-NBS on seagrasses. Depth was found to be the most dominant environmental variable, with shallow areas (e.g., Northern Adriatic, Gulf of Gabés) showing higher suitability. The southern part of the Mediterranean (e.g., Egypt) reported relatively low scores for both climate and WQ, while the Northern Adriatic had the lowest WQ scores. This study represents the first attempt to evaluate Blue-NBS suitability for seagrass meadows at the eco-regional scale with geomorphologic, WQ, and climatic variables, providing decision support for the selection and allocation of Blue-NBS in different environmental settings. The resulting environmental suitability maps represent a basis for the integration of socio-economic and governance-related indicators into a more complex, multi-tier approach to support NBS mainstreaming.

A multi-disciplinary approach based on chemical characterization of foreshore sediments, ecotoxicity assessment and statistical analyses for environmental monitoring of marine-coastal areas

The present work aims at providing a multi-disciplinary approach for environmental monitoring in marine-coastal areas. A monitoring campaign of 13 months (October 2022–October 2023) was carried out on sandy foreshore sediments (SFSs). The SFSs were analysed for potentially toxic elements (PTEs) and rare earth elements (REEs) content determination. In the investigated area, variable contamination trends were assessed through Friedman and Nemenyi tests. Further results also indicated the usefulness of statistical data elaboration in the identification of potential contamination sources. In fact, from Spearman test, significant positive correlations (between 0.650 and 0.981) were observed among PTEs of possible anthropogenic origin (such as Co, Cr, Cu, Pb, V, and Zn). For REEs, La and Nd showed strong correlations with Ce (0.909 and 0.920, respectively). The study also integrated luminescence inhibition (Aliivibrio fischeri), algal growth inhibition (Phaeodactylum tricornutum), and embryotoxicity assessment (Paracentrotus lividus) on sediment elutriates showing varying degrees of toxicity. Also these data were analysed through statistics in order to highlight possible correlations between contaminants and observed ecotoxicological effects on the involved bioindicators. The results outline an approach useful for more comprehensive monitoring of marine areas quality and identification of suitable environmental restoration strategies.

Policy coherence for ecosystem-based management: Implementing EU water and marine policies in the Archipelago Sea

The European Union (EU) Water Framework Directive (WFD) and Marine Strategic Framework Directive (MSFD) call for member states to achieve the good environmental status of coastal waters and marine areas and to create ecosystem-based management plans that cover individual sectors. The Baltic Marine Environment Protection Commission (HELCOM) has listed the Archipelago Sea as an environmental hotspot in the Baltic Sea due to its vulnerability to the impacts of eutrophication. Agricultural runoff is the main source of excess nutrient loading, although aquaculture, tourism, wastewater treatment and internal loading also contribute. In this paper, we focus on the horizontal and vertical policy coherence in the Archipelago Sea region. The research data consist of policy documents and 11 thematic interviews. This paper aims to reveal how European water and marine policies are implemented in the Archipelago Sea and to identify the synergies and coherence challenges exist between policy sectors of agriculture, aquaculture and offshore wind. Evidence from the Archipelago Sea case study shows that a lack of coherence between sectoral policies can create challenges for ecosystem-based management. Moreover, the coherence and synergies in implementing regional and EU marine policy frameworks at the national and local levels can guide sectoral decisions towards strengthening of marine resilience and biodiversity.

Comparative analysis of the microbial plastisphere at three sites along the Sarno river (Italy)

This study investigated microplastics (MP) and their associated microbial plastisphere in the Sarno river (Italy), its estuary and in the nearby coastal area in January 2020. Scanning Electron Microscopy (SEM), High Throughput Sequencing (HTS) and Fourier-Transformed Infrared Spectroscopy (FTIR) were used to characterize the collected MPs and their associated microbes. The three stations sampled differed substantially for MP concentrations and microbial communities, with the estuarine station showing very high MP concentrations (2048.6 MP m-3), highlighting the threat represented by the river for the coastal marine area and its ecosystem. The prokaryotic plastisphere showed differences between the three stations sampled, in terms of community composition, with only 75 Amplicon Sequence Variants (ASV) in common. The Comamonadaceae was the most abundant family in MP-attached and freshwater communities, and this lifestyle seems to be pivotal in the colonization of new habitats while flowing towards the sea. The results highlight the importance of the plastisphere in colonization of new habitats and support the need of correct management and risk mitigation efforts.

Stage‐by‐stage exploration of normal embryonic development in the Arabian killifish, Aphanius dispar

AbstractBackgroundArabian killifish, Aphanius dispar, lives in marine coastal areas of the Middle East, as well as in streams that experience a wide range of salinities and temperatures. It has been used as a mosquito control agent and for studying the toxicities of environmental pollutants. A. dispar's eggshell (chorion) and embryos are highly transparent and are suitable for high resolution microscopic observations, offering excellent visibility of live tissues.ResultsIn this study, the staging of normal embryonic development of A. dispar was described and investigated at different temperatures. Embryonic development was then examined under different thermal environments from 26 to 34°C. Our data suggest that temperature has a significant effect on embryonic development, with accelerated development at higher temperatures.ConclusionA. dispar exhibits broad thermal tolerance and extended independent feeding capabilities, making it a promising model organism for toxicology and pathogenesis studies conducted over an extended period of time (12 days post‐fertilization).

A multibiomarker approach to assess the effects of a BPA analogue-contaminated diet in the crab Carcinus aestuarii

Bisphenol A analogues are largely used plasticisers that are going to replace bisphenol A in many sectors. Due to this replacement, their discharge and presence in the marine coastal areas are increasing, with unknown consequences for organisms and the trophic chain. This study assessed the effects of three different bisphenols (BPAF, BPF and BPS) - alone or as a mixture - provided via food (exposed clams) to the crab Carcinus aestuarii. First, clams were exposed for two weeks to 300 ng/L of each of the three bisphenols and their mixture (100 ng/L of each) to allow the bioaccumulation of the contaminants in bivalves. Then, crabs were fed for two weeks with BPA analogue-exposed clams, while unexposed clams were used to feed control crabs. After 7 and 14 days, haemolymph, gills and hepatopancreas were collected from crabs to measure a battery of biomarkers indicative of cytotoxicity, oxidative stress and damage, neurotoxicity, physiological performance (respiration and excretion rate) and electron transport system activity. Lastly, bioaccumulation of BPA analogues was assessed by UHPLC-HRMS in crabs. Our findings revealed that BPA analogue-exposed clams were able to alter total haemocyte count, haemocyte size and their proliferation. The activity of immune enzymes, such as phosphatases and phenoloxidase was altered. Moreover, we observed an impairment of antioxidant and detoxifying enzymes like SOD, CAT, GST and GPX activities. Alterations of metabolism-involved enzymes and physiological parameters and increased oxidative damage to macromolecules like proteins, lipids, and DNA were also observed in crabs. Among BPA analogues, only bioaccumulation of BPAF, which has the highest Logkow value among the tested bisphenols, was evidenced in crabs. Overall, the obtained results indicated that crabs, under the tested experimental conditions at least, underwent alterations in cellular, biochemical and physiological responses following a diet of bisphenol-exposed clams, suggesting a potential ecotoxicological risk in the marine food chain.

Exploring the response and prediction of phytoplankton to environmental factors in eutrophic marine areas using interpretable machine learning methods

Coastal marine areas are frequently affected by human activities and face ecological and environmental threats, such as algal blooms and climate change. The community structure of phytoplankton—primary producers in marine ecosystems—is highly sensitive to environmental factors, such as temperature, salinity, and nutrients. However, traditional methods for exploring the relationship between phytoplankton communities and environmental factors in eutrophic marine areas are limited by various factors. Therefore, this study employed interpretable machine learning models, integrating high-dimensional data analysis and complex system modeling, to quantitatively and thoroughly analyze the dynamic relationship between phytoplankton communities and environmental variables in high-frequency samples collected over 53 weeks from eutrophic marine areas. The cell abundance of phytoplankton exhibited a distinct “two-peak pattern” variation. Interpretable machine learning model analysis revealed the dynamic contributions of different environmental factors during changes in the phytoplankton community structure. The results showed that temperature was a key environmental factor that affected phytoplankton growth during peak periods. In addition, the contribution of salinity increased during the second peak in phytoplankton abundance, highlighting its central role in the ecological dynamics of this phase. During green tide outbreaks, particularly in Area 01, the contributions of factors such as temperature and salinity increased, whereas those of phosphates and silicates decreased, indicating that green tide outbreaks substantially altered the nutritional dynamics of the ecosystem. Furthermore, different phytoplankton species, such as Skeletonema costatum, Thalassiosira spp., and Nitzschia spp., exhibit varying responses to environmental factors. Hence, the predictions made using random forest and generalized additive models for phytoplankton cell abundance in two marine areas revealed complex nonlinear relationships between environmental factors, such as temperature, salinity, and phytoplankton abundance.

Emerging threat of marine microplastics: Cigarette butt contamination on Yellow Sea beaches and the potential toxicity risks to rotifer growth and reproduction

Cigarette butts have become one of the most common and persistent forms of debris in marine coastal areas, where they pose significant toxicity risks. This study investigated cigarette butt pollution along beaches of the Yellow Sea and used laboratory experiments to assess the toxicity of their leachate and fibers on the euryhaline rotifer Brachionus plicatilis. A pollution index confirmed pollution by this debris across all eight beaches surveyed, where the density of cigarette butts averaged 0.23 butts/m2. In controlled laboratory experiments, both the fibers and leachates from cigarette butts exhibited negative impacts on the development, reproduction, and population growth of rotifers. Unique abnormalities observed under different exposure treatments indicated toxicity specific to certain chemicals and particles. Continuous exposure to cigarette butts initially reduced rotifer fecundity, but this effect diminished over successive generations. However, the exposure induced transgenerational reproductive toxicity in the rotifers. Adaptive responses in rotifers after repeated exposure led to relative reduction in reproductive inhibition in the F3 and F4 generations. Furthermore, rotifers were capable of ingesting and accumulating cigarette butts, and maternal transfer emerged as an alternative pathway for uptake of this material in the offspring. These results increase our understanding of the ecological risks posed by cigarette butts in aquatic environments.

Three-Dimensional Hydrodynamic and CFD Modeling of a Tidal Barrage Power Plant without Sluicing in Buenaventura, Colombia

Recent research revealed the potential of tidal energy in the central coastal region of the Colombian Pacific. Buenaventura City, located in the Valle del Cauca department in Colombia, has an important opportunity to develop tidal power technologies near its marine coastal areas. This research implemented a 3D hydrodynamic model for simulating the hydrodynamics of the Buenaventura Bay to provide data as input for evaluating the hydraulics of a tidal barrage without sluicing through CFD modeling. According to the results, the velocities across the gates during Syzygy (April 2021) showed impressive velocities between 9 and 11 m/s, which suggest a high possibility of producing electricity through tidal turbines. The mean behavior of velocities in the gates pointed to values of 3 and 5 m/s in most of the cases. The results during the Stoa condition were interesting because flow velocities higher than 1 m/s were not expected. This is promising because the plant might produce electricity even during the Stoa condition. For the first time, the results of this research suggest that there exists a high possibility of implementing tidal barrage plants in Buenaventura City, Colombia.

Геоэкологические методы оценки динамики береговой линии на Черноморском побережье Кавказа

Over the past few decades, the degradetion of coastal marine areas has become an acute problem for the Black Sea coast of the Caucasus. The negetive effects of climete change are more pronounced in the subtropics, where sea levels rise and the frequency and intensity of storms increase. In addition, insufficient efforts to mitigete anthropogenic impact have accelereted the degradetion of bio resources. The work is devoted to the issues of increasing the reliability of coastline forecasting by improving the methods of using GIS technologies. Meterials and methods. Radar topographic mission (SRTM) deta were used to creete a digital elevetion map. In addition, archival remote sensing images of the earth (taken by setellites: Corona, Spot-1, Sentinel 2, Landset 8–9), as well as images from the Google Earth detabase, were digitized. The SAGA geo-informetion system was used to process the images, and three-dimensional spline interpoletion in the Gnuplot software was used for subsequent processing of the obtained elevetion deta. Results. The article presents the results of absolute values of coastline displacements of the Sochi Black Sea region reletive to the basic reference points (1985), as well as the values of the coastline displacement rete in the study area (109 km) for the period from 1985 to 2021. It was found thet coastal erosion of the Black Sea increases nonlinearly, while the maximum value of its average displacements (in the 109 km section) over 36 years was about 24.2 m. The abrasion rete for the entire time period is about 0.67 m/year. The total displacement of reference points of the coastline in the local section no. (8–9) over 36 years of observetions can exceed the average value for the entire 109-meter study area by more than 50 % (1.04 versus 0.67 m/year). This allows us to estimete the degree of development of abrasion processes of the coastline over a period of 36 years, which will allow us to predict future changes in the coastal environment and prevent negetive consequences. Conclusion. The results of the study provide a comprehensive understanding of the evolution of the coastline along the entire length of Greeter Sochi, including the rete of abrasion/accretion processes, the spetial position of segments with different degrees of degradetion of the coastal environment and temporal varietions in the processes under study. The results prove the non-linear neture of coastal processes, demonstreting changes in areas more susceptible to erosion over time and the impact on coastal ecosystems. The study uses remote sensing images and GIS technology to creete a comprehensive coastal zone detabase, with Greeter Sochi as an example. This detabase will contribute to improving the quality of future coastal protection projects, as part of the master plan for the resort city of Sochi, providing a more informed and effective approach to coastal zone management. Resume. As a result, it was found thet coastal erosion in the studied section of the Black Sea coast increases nonlinearly, while the average displacement of the 109 km long coastline over 36 years is 24.2 m, and the abrasion rete for the entire time period is about 0.67 m/year. As economic development expands from Sochi to Lazarevskoye, the load on the coastal environment is expected to increase. Therefore, if appropriete measures are not taken in the identified degradetion zones, these territories may face complete unsuitability for the integreted reproduction of tourist resources.

Air Composition over the Russian Arctic–4: Atmospheric Aerosols

This work presents the analysis of the spatial distribution of number concentration, size distribution, and chemical composition of aerosol particles measured for the first time over the seas of the Russian Arctic. Various types of vertical distribution of the number concentration were recorded, characteristic of both coastal marine and continental areas. Most of them turned out to be of the continental type. Attention is also drawn to the almost complete absence of coarse particles above 2–3 km over all seas. The chemical composition of the Arctic aerosol at altitudes of both 200 m and 5000 m contains ions that can be referred to as both marine and continental. The identifiable carbon- and salt-free elemental part of the aerosol over the Arctic is 3–4 times larger than that of ions. Over all seas and at both altitudes, the Arctic aerosols mainly contain elements of terrigenous origin – Al, Cu, Fe, and Si. Over almost all seas, except the Barents Sea, Si is dominant in the elemental composition of the aerosol, its contribution over the Chukchi Sea reaching 85%. The analysis of backward trajectories showed that in all cases considered, whether the aerosol was formed over the continent or sea, air trajectories passed both over sea and over land. In this case, the formed particles could be enriched with additional ions and elements along their pathway. This work completes a cycle of the papers, devoted to studying air composition, which was carried out over the seas of the Russian Arctic in September 2020. Our results can be used to model the atmospheric processes occurring in the Arctic under the conditions of changing climate.

Irrigation Practices and Their Effects on Soil Quality and Soil Characteristics in Arid Lands: A Comprehensive Geomatic Analysis

Comprehension of the long-term effects of irrigation on basic soil characteristics and quality is essential for sustainable land management and agricultural production, particularly in arid regions where water availability is limited. This study aimed to investigate long-term irrigation effects on soil quality, soil organic carbon (SOC), and nitrogen (N) stocks in the arid lands of Egypt. Seventy soil samples were collected and analyzed to determine various soil properties. A soil quality index (SQI), SOC, and N stocks were computed. ANOVA and PCA analyses were used to identify significant differences between alluvial soils in the southwest part of the investigated area and coastal marine soils in the northeast of the study area. The results demonstrated that most of the studied soil parameters had significantly greater values in alluvial compared to coastal marine soils. Long-term irrigation led to an 8.00% increase in SOC and 7.22% increase in N stocks compared to coastal marine soils production. Furthermore, a 39.53% increase was found in the SQI upon long-term irrigation practice. These results suggest that shifting from rain-fed in coastal marine areas to irrigated production systems in alluvial fields can improve soil quality, SOC, and N stocks. Therefore, further studies are required to investigate the impact of additional factors, such as irrigation method and salinity status of sub-surface soil layers, to enhance agricultural productivity and sustainable land use.

Interacciones tierra-mar-tierra, con énfasis en la actividad pesquera en la región norte del Ecosistema Costero Bonaerense, Argentina

[Introduction]: Coastal areas constitute the interface between land and marine environments, connected through multiple natural and socioecological processes that contribute to human well-being. [Objective]: Identify land and marine uses and activities with mutual implications and biophysical processes in the northern region of the Bonaerense Coastal Ecosystem (Argentina), in order to evaluate the degree of compatibility or conflict between these activities, with emphasis on the fishing activity. [Methodology]: The land-sea-land (T-M-T) methodological analysis was applied. Uses and activities (U&A) and biophysical processes of marine and land origin were determined. Interactions between marine-land and biophysical processes T-M-T were identified for further categorization and analysis. [Results]: A total of 121 U&A sea-land-sea (L-S-L) interactions related to fishing were detected. Medium conflicts were mainly caused by competition for space or resources and were associated with the coexistence of U&A (tourism, fishing, and communication activities), both spatially and temporally. Of the total, 68 negative interactions were observed between biophysical processes and U&A L-S-L, which were linked to climatic events and the effects of climate change (variation in sea surface temperature, atmospheric and oceanic circulation, as well as variations in sediment transport and coastal erosion). [Conclusions]: The analysis carried out constitutes an advancement in the study of U&A T-M-T in coastal-marine areas of the Atlantic coast and their interactions, with emphasis on fishing activities, as a contribution to their management with an ecosystemic approach.

The goose barnacle Pollicipes pollicipes as a tool for trace metal biomonitoring and health risk assessment for human consumers in northwestern Atlantic coast of Morocco

The bioaccumulation of trace metals Cd, Cr, Cu, Fe, and Zn in soft tissues of the barnacle Pollicipes pollicipes was investigated seasonally along the Atlantic coast of northwestern Morocco. Average concentrations (μg g−1 dry weight) exhibited a decreasing order: Fe (548.15 ± 132.43) > Zn (430.80 ± 181.68) > Cd (17.46 ± 9.99) > Cu (7.72 ± 1.26) > Cr (3.12 ± 0.80), with the highest levels during wet seasons. The “Metal Pollution Index” and “Individual Multimetal Bioaccumulation Index” revealed a substantial barnacle contamination in industrialized areas. Additionally, Cd and Zn concentrations surpassed permissible guideline limits. While the “Target Hazard Quotient” and “Hazard Index” unveiled no significant health risks associated with barnacle consumption for humans, Cd posed potential risks, particularly for children consuming barnacles from polluted locations. Regarding the “Maximum Safe Consumption”, Cd demonstrated potential harm across all sex and age groups. These findings contribute valuable data on the safety of barnacle consumption, marking the initial assessment of such risks in Morocco. The study offers evidence of metal pollution occurrence and proposes the barnacle species as a reliable biomonitor of trace metal bioavailabilities in marine coastal areas. To our knowledge, this investigation is the first comprehensive report of metal contamination biomonitoring using barnacles from Moroccan Atlantic waters.

Characterization of hypoxic events in Paracas bay (Peru, 13.8°S) through intensity and biological effect indexes

Over the past decade, there has been a significant increase in low oxygen conditions within marine coastal areas, profoundly impacting ecosystem processes and living coastal resources. Coastal bays in highly productive upwelling regions, where hypoxia occurs naturally, are special areas affected by both local and adjacent shelf-related processes. Paracas Bay (13.8°S) is a traditional shellfish fishing and intense farming area highly influenced by one of the most active upwelling centers of the Peruvian coast. Despite the small dimensions of the bay (35 km2), a key feature is its complex physical dynamics and high environmental variability. Recently, important efforts have been made in the study of both the spatial and temporal oxygen concentration variability, nevertheless, information regarding the ecological and biological impact of hypoxic events is still lacking. In this study, the spatial and temporal distribution of hypoxic events was analyzed across Paracas bay at different depths by means of high-frequency hourly dissolved oxygen records collected by data-loggers deployed across the bay during the periods September 2012 – February 2013 and March 2015 – February 2017. To study the ecological impact of hypoxic events, we developed a hypoxia intensity index, while the biological impact was studied through the development of a hypoxia biological effect index using as model species the Peruvian scallop (Argopecten purpuratus). Our results showed that hypoxic events have an intrinsic variability across the bay. The deeper areas of the bay, towards the northwest and center, were characterized by long, intense, and lethal events, while the southeast and southwest, shallower areas, were characterized by shorter events of low intensity and either sublethal or innocuous. We propose that the observed variability is not only related to the large-scale environmental context in which the events occurred, but also to small-scale variability linked to local circulation, biological activity, and sediment biogeochemistry. We expect that our research will be useful not only for scientific purposes, but also for coastal resource management and aquaculture, underlining the importance of developing high-resolution oxygen monitoring systems in coastal bays.

Defense and Protection of the Marine Coastal Areas and Human Health: A Case Study of Asbestos Cement Contamination (Italy)

Pivotal environmental geology research was carried out in the protected area of Cape Peloro (Messina, NE Sicily, Italy). The main aims were the ascertainment of the presence of Asbestos Cement Materials (ACMs), their mapping, and, consequently, an estimation of the potential risk for human health and marine coastal environments. The beaches surveyed covered 4500 m of coastline. Through high-resolution photographic surveys, over 520 fiber cement fragments were documented on the beaches as well as in beach deposits. The materials, after microscope, SEM-EDS, and FTIR analyses, were found to be composed of Portland cement with chrysotile and crocidolite fibers. Fragments of ACMs showed typical corrugated forms with centimeter-to-decimeter sizes and prevailing well-rounded, platy, and sub-elongate shapes. In a few localities, some fragments were found to be angular or friable. Furthermore, some fragments found on the beach were covered by conspicuous encrustations of marine organisms, testifying to their long staying in shallow-water marine environments. Illicit landfills and abandoned materials were identified in natural sections on the coastal plain. Most of the rounded ACMs were characterized by their surface texture, with mm-size asbestos fibers exposed on the surface due to significant weathering and abrasion. Notably, new fragments appeared after storms. Significant criticisms have been made related to the ACMs, analogously to what was reported for other Italian marine beaches. Possible intervention and reclamation activities cannot limit themselves to removing the fragments on the beach, as fragments are immersed in the coastal sediments at different depths and are also found in the marine deposits. Here, it is underlined that any asbestos removal and reclamation activities, if not designed and based on a multidisciplinary approach and knowledge of local coastal dynamics and the meteo-marine climate, will be very expensive and ineffective.

Evolving blue development discourses and policies: Salmon farming industry and regional making in Chile

As the second biggest producer of salmon after Norway, Chile is one of the leading forces of aquaculture with a long history of being strongly focused on international markets. Based on contributions from critical geography, political ecology and the sociology of globalization, the article analyses the dominant narratives and policies deployed by the Chilean government and the salmon farming industry in successive contexts of boom and crisis of production activity in the archipelago of Chiloé (Los Lagos Region). In a context of a word-wide growing interest in the capabilities of the blue economy, a discourse analysis of governmental, industrial, and public-private institutional documents, together with semi-structured interviews to a broad number of stakeholders contributes to advance the understanding of and learn from the evolution and challenges faced by one the longest world’s salmon aquaculture leaders. The research identifies five discursive and policies phases over more than four decades of development. From an initial narrative that defines the region as “empty” and uses the discourse on salmon farming to justify territorial integration policies (1973–1982); to a second period in which the fostering of the salmon farming in the southern region served as a catalyst of national economic growth interests (1983–1994). It follows a boom phase characterized by the capitalization on the blue revolution discourse (1995–2006), which lasted until the territorial crisis resulting from the ISA virus, and the expansion of the industry towards southern regions (2007–2015). The analysis reveals a fifth phase starting in 2016 and ongoing by 2023, which characterized by the emergency and implementation of a new administrative right over coastal-marine areas to safeguard the traditional uses of indigenous communities, starts to challenge the long-standing hegemony of the salmon farming industry in Chile.