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In this study, we investigated for the first time anthropogenic microparticles in the franciscana dolphin Pontoporia blainvillei, the most endangered cetacean of the Southwest Atlantic Ocean. The intestinal content of the proximal and distal sections, and wall tissues of the proximal section of ten female dolphins collected during 2013-2023 were analyzed. All samples contained anthropogenic particles (%FO = 100). Fibers were the most abundant shape (99 %). Micro-Raman and micro-FTIR spectroscopies revealed the presence of polyester, polypropylene, acrylic, polyethylene, and semi-synthetic cotton polymers. Manufactured pigments such as reactive blue 238, Indigo 3600, and diarylide azo pigment (yellow 152) were also detected. We observed variations in the color and types of polymers present in the different sections of the intestine and within the wall tissue, suggesting a differential microplastic absorption. These findings confirm both the presence and absorption of microplastics in the intestines from franciscana dolphins., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: The importance of knowing the impact of work on people's health has increased after the COVID-19 pandemic. Burn Out (BO) syndrome arises from the tension emerging from the conflictive interaction between the worker and his or her employment. The objective was to describe the prevalence and frequency of diagnosis of BO in the health human resources of critical services of the Bahía Blanca Municipal Hospital in the context of the COVID-19 pandemic.Methods: Descriptive, cross-sectional study. The study population was the medical and nursing staff of the Intensive Care (IT), Emergency Medicine (SMU) and Clinic services who worked with COVID-19 during 2021. The Maslach Burnout Inventory (MBI) questionnaire was used and complementary closed questions to identify, among these cases, those that were diagnosed and treated by the institution.Results: Of the 219 workers, 55.3% (121/219) were nurses. In the SMU, 25% (24/96) of respondents had BO, followed by 20.4% (11/54) in Clinic and 8.7% (6/69) in IT (p value=0.004). Only 5.5% (12/219) of the total were diagnosed with BO by the institution and of this group, two people (0.9%) had previously consulted for characteristic symptoms.Discussion: A high prevalence of BO and a marked underdiagnosis were evident at the institutional level during the pandemic. Although the IT Service had the highest demand for attention, it was the one that presented the lowest BO values in relation to other services., (Universidad Nacional de Córdoba)

Wildfire activity is increasing globally. The resulting smoke plumes can travel hundreds to thousands of kilometers, reflecting or scattering sunlight and depositing particles within ecosystems. Several key physical, chemical, and biological processes in lakes are controlled by factors affected by smoke. The spatial and temporal scales of lake exposure to smoke are extensive and under-recognized. We introduce the concept of the lake smoke-day, or the number of days any given lake is exposed to smoke in any given fire season, and quantify the total lake smoke-day exposure in North America from 2019 to 2021. Because smoke can be transported at continental to intercontinental scales, even regions that may not typically experience direct burning of landscapes by wildfire are at risk of smoke exposure. We found that 99.3% of North America was covered by smoke, affecting a total of 1,333,687 lakes ≥10 ha. An incredible 98.9% of lakes experienced at least 10 smoke-days a year, with 89.6% of lakes receiving over 30 lake smoke-days, and lakes in some regions experiencing up to 4 months of cumulative smoke-days. Herein we review the mechanisms through which smoke and ash can affect lakes by altering the amount and spectral composition of incoming solar radiation and depositing carbon, nutrients, or toxic compounds that could alter chemical conditions and impact biota. We develop a conceptual framework that synthesizes known and theoretical impacts of smoke on lakes to guide future research. Finally, we identify emerging research priorities that can help us better understand how lakes will be affected by smoke as wildfire activity increases due to climate change and other anthropogenic activities., (© 2024 Oak Ridge National Laboratory and The Author(s). Global Change Biology published by John Wiley & Sons Ltd.)

Water monitoring faces challenges that are driven by the infrastructure, protection, financial resources, science and innovation policies, among others. A modular, low-cost, fully open-source and small-sized Unmanned Surface Vessel (USV) called EMAC-USV (EMAC: Estación de Monitoreo Ambiental Costero), is proposed for monitoring bathymetry and water quality parameters (i.e. temperature, suspended solids concentration and hydrocarbon concentration) in complex water scenarios. A detailed description of each part of the platform as well as all electronic connections and functioning is presented.The field works were carried out in two small waste stabilization ponds and in a portion of the main tidal channel of the Bahía Blanca port. The EMAC-USV is the result of a cautious design, regarding the balancing performance, communications, payload capacity, among others., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

The accuracy assessment of three different Normalized Difference Water indices (NDWIs) was performed in La Salada, a typical lake in the Pampean region. Data were gathered during April 2019, a period in which floods occurred in a large area in the Southwest of the Buenos Aires Province (Argentina). The accuracy of the estimations using spaceborne medium-resolution multi-spectral imaging and the reliability of three NDWIs to highlight shallow water features in satellite images were evaluated using a high-resolution airbone imagery as ground truth. We show that these indices computed using Landsat-8 and Sentinel-2 imagery are only loosely correlated to the actual flooded area in shallow waters. Indeed, NDWI values vary significantly depending on the satellite mission used and the type of index computed.

Plastic debris is thought to be widespread in freshwater ecosystems globally 1 . However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging 2,3 . Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 μm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris 4 . Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: In recent decades, invasive quagga mussels have expanded to the Western United States from the Great Lakes region of North America. Most studies that evaluate the invasion potential of quagga mussels in western water bodies have utilized physiological and life history information from zebra mussels, a related taxon. Few studies have assessed the potential for invasion using specific information from quagga mussel life history or experiments that test for their survival in the fresh and saline waters of the western United States., Methods: We investigated quagga mussel survival, growth, and reproduction using semi-natural experiments under temperature and light controlled conditions across a gradient of water salinity (fresh to brackish) and pH (8.4-11). Water from Lake Mead was used as a positive control in our experiment, and water from Pyramid Lake and the Truckee River was used as brackish and freshwater treatments, respectively. The mussels used in the experiments were collected from Lake Mead., Results: After 12 h in brackish water (4 ppt, pH 9.3), we observed 100% mortality of adult mussels. The swelling and disintegration of body tissues and high mortality rates indicated that high potassium, sodium, and chloride concentrations were the likely causes of death in brackish water treatments. In contrast, mussels were able to survive, grow, and reach sexual maturity in freshwater (0.1 ppt) with a low calcium concentration (17 mg L -1 ) after 57 days. Mussels died after 2 days at pH 11 and after 12 days at pH 10; during the 14-day monitoring period, no mortality was detected at pH 9.0, 9.3, or 9.5 and mussels did not exhibit any visual indications of stress. Understanding quagga mussel physiological and environmental tolerances appears to be essential for assessing their invasion potential in aquatic habitats., Competing Interests: The authors declare that they have no competing interests., (© 2023 Seitz et al.)

This study evaluated the occurrence and distribution of largely known pollutants (Ag, Cd, Cu, Cr, Hg, Ni, Pb, Pd, and Zn), as well as emerging ones (Li, and V) in the water dissolved fraction, suspended particulate matter, and surface sediments from the lower course of the Negro River, Argentina. There are scarce preceding data on inorganic pollution in the entire watershed and, in the case of the emerging pollutants, there are almost no studies performed worldwide. Sampling was conducted in 2019 at six sampling sites, three of them mostly river dominated and the rest under marine domain. The samples were subjected to an acid digestion in a microwave digester, and analyzed using an Inductively Coupled Plasma Atomic Emission Spectrometer. Results: revealed that Cu, Li, V, and Zn were always on the top four of the highest average metal concentrations in water and sediment fractions. The pollution assessment indicated that the watershed might be exposed to anthropogenic pollution, as over 60% of Cu and Zn, and over 85% of Hg in water dissolved samples from the marine dominated sites were above the maximum recommended values from guidelines. The multivariate analyses characterized the watershed into two clusters, with metals in the sediment fraction mainly contributing to the uppermost sites. Indeed, sedimentary Cu and Zn background enrichment indices pointed out a moderate pollution of the river dominated sites. This study highlights the relevance of an integrative approach in metal pollution evaluation, as the results denoted a progressive deterioration of the watershed, affecting the water quality of the lower course of the Negro River and its adjacent coastal zone. Overall, these results contribute to a more complete evaluation of the potential to fulfill the Sustainable Development Goals, with implications for future treatment strategies to enhance the environmental quality of the area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This study explores the effect of different wind events (direction and duration) on the surf zone zooplankton community in a temperate sandy beach. Samplings were realized on the surf zone of Pehuen Co sandy beach during 17 wind events from May 17th, 2017, to July 19th, 2019. Biological samples were taken before and after the events. The identification of the events was realized using recorded high-frequency wind speed data. General Linear Model (LM) and Generalized linear models (GLM) were employed to compare physical and biological variables. We observed that the wind direction unequally altered the ecosystem along with its duration, modifying the composition and abundance of zooplankton communities. Short-duration wind events were associated with an increment in the zooplankton abundances, being Acartia tonsa and Paracalanus parvus dominant. Within the short-duration cases, winds from the W sector were identified with the inner continental shelf species' presence, such as Ctenocalanus vanus and Euterpina acutifrons, and to a lesser extent, Calanoides carinatus, and Labidocera fluviatilis, together with surf zone copepods. Long-duration cases were associated with a significant decrease in the zooplankton abundance. Within this group, SE-SW wind events were identified with adventitious fraction taxa. Considering that the occurrence of extreme events is growing because of climate change, affecting the frequency and intensity of storm surges, the knowledge of the responses of biological communities to these events is necessary. This work provides quantitative evidence on a short-time scale of the implications of the physical-biological interaction during different strong wind cases in surf zone waters of sandy beaches., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The increasing landscape alterations due to anthropogenic activities is of global concern since it affects aquatic ecosystems, often resulting in compromise of the ecological integrity and the water quality. In this sense, the evaluation, monitoring, and prediction of the aquatic ecosystem quality becomes an important research subject. This study presents the first integrated water quality assessment of the Sauce Grande River Basin, in Argentina, based on the spatial distribution of the phytoplankton community, the physicochemical parameters, and the metal concentrations (Cd, Cu, Cr, Fe, Mn, Ni, Pb, and Zn) found in the particulate fraction. According to the trophic indices and the phytoplankton abundance, composition, and diversity, the water quality showed significant deterioration in the lower basin after the Sauce Grande lake. The trophic state index indicated that water was oligotrophic in over 75% of the sampling sites, increasing downstream, where two sites were characterized as mesotrophic, and one described as hypertrophic. The phytoplankton community was dominated by diatoms in zones with low anthropogenic impact and conductivity, whereas high densities of Euglenophyta, Chlorophyta, and Cyanobacteria were found in the middle-lower basin, associated with higher organic matter and eutrophication. The conductivity, turbidity, and most metal concentrations also increased towards the downstream area, even exceeding recommended levels for the metals Cu, Cr, Mn, and Pb in the middle and lower reaches of the basin (Cu: 3.5 µg L -1 ; Cr: 2.4 µg L -1 ; Pb: 1.2 µg L -1 ; Mn 170 µg L -1 ). This study generates a database for the water quality of the Sauce Grande River Basin and sets an example of how the water quality varies along a basin that crosses different topographic environments, land covers, and anthropogenic influences., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There is a need to make substantial advances in the taxonomic, systematic, and distribution knowledge of plants, and find better ways of transmission of this information to society to surpass the general pattern described as "plant blindness." The diversity of the plant family Solanaceae reaches its peak in South America; however, many of its species are threatened due to the expansion of the human footprint. Here, we examine the diversity patterns of the family in southern South America (Argentina and Chile) by means of species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE). We also evaluated conservation gaps in relation to protected areas and the human footprint as a proxy for potential impacts on this biodiversity. Results show two richness centers in NW and NE Argentina, with a high degree of overlap with protected areas, which, on the other side, show a relative high index of human footprint. Comparatively, coastal Atacama (Chile) shows lower richness values, but outstanding CWE and WE values. The coast of Atacama harbors high values due the presence of species of the genus Nolana with restricted distributions. Protected areas in this tight coastal strip are sparse, and the human footprint is also relatively high. The degree of protection based on these parameters is then unbalanced, highlighting the need for a geographically explicit strategy for the conservation of the family at subcontinental scale. In doing so, it is likely that other representatives of these unique centers of richness and endemism will benefit., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Moreira-Muñoz, Palchetti, Morales-Fierro, Duval, Allesch-Villalobos and González-Orozco.)

Nutrient discharge into rivers and estuaries and the factors that control it need to be further understood to decrease the risk of harmful algae blooms on these ecosystems. Preliminary seasonal physicochemical parameters at six stations along the Negro River Estuary (Argentina) were studied during 2019 (Austral summer, winter, and spring) with high- and low-frequency data. Three of the stations were mainly estuarine-influenced and three were marine-influenced ones. The concentration of phosphate (P), river discharge, meteorological conditions, seasonality, and physicochemical variables were analyzed. Total phosphorus (TP) showed seasonal variations and was higher than previously reported for the upper watershed in all stations in the warmer months, except for the marine control one. Orthophosphate values were also high compared to previous watershed data and changed independently of TP fluctuations. Changing turbidity, water temperature, pH, and conductivity did not appear to have an essential role in phosphorus variations. An unexplained high TP spike in the late spring sample shows the need for further research in the area, while the seawater mixing with P-rich river water could be acting as a dilution agent at the mouth of the river., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Evidence shows that the majority of aquatic field microplastics (MPs) could be microfibers (MFs) which can be originated directly from massive sources such as textile production and shedding from garments, agricultural textiles and clothes washing. In addition, wear and tear of tyres (TRWPs) emerges as a stealthy major source of micro and nanoplastics, commonly under-sampled/detected in the field. In order to compile the current knowledge in regards to these two major MPs sources, concentrations of concern in aquatic environments, their distribution, bulk emission rates and water mitigation strategies were systematically reviewed. Most of the aquatic field studies presented MFs values above 50%. MPs concentrations varied from 0.3 to 8925 particles m -3 in lakes, from 0.69 to 8.7 × 10 6 particles m -3 in streams and rivers, from 0.16 to 192000 particles m -3 estuaries, and from 0 to 4600 particles m -3 in the ocean. Textiles at every stage of production, use and disposal are the major source of synthetic MFs to water. Laundry estimates showed an averaged release up to 279972 tons year -1 (high washing frequency) from which 123000 tons would annually flow through untreated effluents to rivers, streams, lakes or directly to the ocean. TRWPs in the aquatic environments showed concentrations up to 179 mg L -1 (SPM) in runoff river sediments and up to 480 mg g -1 in highway runoff sediments. Even though average TRWR emission is of 0.95 kg year -1 per capita (10 nm- 500 μm) there is a general scarcity of information about their aquatic environmental levels probably due to no-availability or inadequate methods of detection. The revision of strategies to mitigate the delivering of MFs and TRWP into water streams illustrated the importance of domestic laundry retention devices, Waste Water Treatment Plants (WWTP) with at least a secondary treatment and stormwater and road-runoff collectors quality improvement devices., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The worldwide spread of the SARS-CoV-2 caused an unprecedented lockdown measures in most countries with consequences on the world society, economy, and sanitary systems. This situation provided an opportunity to identify the effects of human confinement on natural environments, like touristic sandy beaches, which are stressed due to anthropogenic pressures. Based on previous articles about heavy metals sources and levels in these ecosystems, this paper discusses the dynamic of these pollutants and a regulatory scenario associated with COVID-19 sanitation policies. The main findings suggest that 39% of the studies were on Asian sandy beaches, 16% from Europe, while America and Africa with 23% each. Also Co, Cd, Cu, Cr, Zn, Pb, Ni, Fe and Mn were the most frequently analyzed metals in sediments and in several cases their concentrations exceed international guidelines assessment. Finally, even though beaches are under several metals inputs, tourism plays a key role in these ecosystems quality. After analyzing the potential indirect effect of COVID-19 measures on metals dynamics, we propose some key recommendations and management strategies to mitigate heavy metal pollution on sandy tourist beaches. These proposals are useful for decision-makers and stakeholders to improve sandy beach management, mainly those beaches not addressed from a management perspective; and their implementation should be adapted according to the regulations and legislation of each country., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Microplastics (MPs) are ubiquitous contaminants of great concern for the environment. MPs' presence and concentration in the air, soil, marine, and freshwater environments have been reported as a matter of priority in recent years. This review addresses the current knowledge of the main pathways of MPs in air, soil, and freshwater reservoirs in order to provide an integrated understanding of their behaviors in the continental environment. Therefore, MPs' occurrence (as particle counts), sources, and how their features as shape, size, polymer composition, and density could influence their transport and final sink were discussed. Wind resuspension and atmospheric fallout, groundwater migration, runoff from catchments, and water flow from rivers and effluents were pointed as the principal pathways. MPs' size, shape, polymer composition, and density interact with environmental variables as soil structure and composition, precipitation, wind, relative humidity, water temperature, and salinity. Sampling designs for MPs research should further consider soil characteristics, climate variability and extreme events, time lag and grasshopper effects, morphological and hydrological features of aquatic systems, and water currents, among others. Furthermore, long-term monitoring and lab experiments are still needed to understand MPs' behavior in the environment. This information will provide a unified understanding of the continental MPs pathways, including the key main findings, knowledge gaps, and future challenges to understand this emerging contaminant., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Plastic use and production have dramatically increased globally over the past 65 years with the improvement of life quality by the daily use of plastic products. Still, around 50% of the plastic produced is disposable products that generate substantial waste. Several reports pointed out the adverse effects of plastic litter in coastal environments in recent years, emphasizing single-use plastics (SUP). In this manner, Latin America and the Caribbean (LAC) coastal environments are highly vulnerable due to wastewater treatment facilities scarcity and poor plastic waste management strategies. Since COVID-19 pandemic, the single-use plastic waste/person rate is expected to rise due to the use of personal protective equipment and SUP as health care measures. Based on literature research and the review of plastic waste regulations, this paper will assess the main COVID-19 plastic pollution threats and LAC beaches' regulations to suggest possible measures to abate this problem. The main findings suggest that unifying the ongoing fragmented and overlapped policies is key to abate plastic pollution, including plastic industry regulations and circular economies. In addition, increasing public risk perception about plastic pollution is critical to reducing plastic waste generation. Research advances in the adverse effects of plastic debris could improve the public's perception of plastic pollution risk, pushing forward global marine plastic governance., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Elsevier Ltd. All rights reserved.)

As a result of the COVID-19 pandemic, there is an evident decrease in economic activity, especially in the tourism sector. On the southwest coast of the Buenos Aires Province (Argentina), coastal cities base their economy on 3S tourism. In this context, the analysis of social views is crucial for participatory coastal management. As well as the forecast of beach use areas in semi-diurnal mesotidal and low-slope beach conditions, wherein few hours the available beach can double or disappear. Therefore, our objective was to determine the beach's optimal use according to its tides, socio-environmental characteristics, and the perception of the interested parties about the 2020/2021 summer season in the pandemic context in Pehuén Co Beach. We employed camera images (January 2019 and 2020) to obtain the behaviour of normal, spring and neap tides, beach geomorphology, and daily and hourly beach use curves. Online surveys were also conducted with residents, second homeowners, and Pehuén Co visitors about their perception for the 2020/2021 summer season. With this analysis, we were able to divide the beach into four areas according to its potential carrying capacity. During low tide, users' maximum capacity on the beach, respecting sanitary distances, may be 6400 people. Meanwhile, at low tide, this number may rise to 34,000. This information is essential for coastal management after the COVID-19 irruption to ensure maximum efficiency in using the beach maintaining a safe social distance., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Elsevier Ltd. All rights reserved.)

Microplastics (MPs) on lakes have been reported mainly from Europe, Asia, and North America. Then, this study aimed to address the quantification and identification of MPs in nine lakes from the Argentine Patagonian Region. Blue colored fibers were dominant, with a size range between 0.2 and <0.4 mm. The mean MPs concentration was 0.9 ± 0.6 MPs m -3 , suggesting a low pollution state when compared to other worldwide lakes. Raman microscopy analysis showed a predominance of Indigo Blue Polyethylene terephthalate (PET) particles. The upper-gradient runoff from urban settlements, textiles, and fisheries were identified as the main MPs sources and levels positively correlated with the higher area, shallower depth, and with an end-position in the watershed. These findings fill a gap in the geographical distribution knowledge, setting a baseline that emphasizes the need for better treatment of urban and fisheries wastes in continental lakes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The amount and type of municipal solid waste (MSW) in Bahía Blanca (Argentina) were assessed and correlated with population socioeconomic level. In this sense, seven areas with different quality of life were selected. In addition, a parallel study on a control area was performed and validated for obtaining a representative result to provide analogous conclusions for the whole city. From this study, a combination of sorting methodologies is proposed in order to reduce the actual amount of waste sent to landfill. If these methodologies are implemented in Bahia Blanca city, MSW in landfill could be reduced at least 80%. The proposed strategy is to combine waste sorting at source and at destination. An alternative separation at source could be proposed as follows: packaging (including plastic, cans and Tetra Pak), other plastics, paper and glass. The rest of MSW could be included in a container which would be collected daily or three times a week without changing inhabitants' habits and promoting their collaboration. Then, it could be separated at destination for waste-to-energy, composting, and biogas obtaining. Residuals from incinerators and biogas/composting plants would be sent to landfill. On the other hand, regarding the relationship between the proposed strategy and population quality of life, obtained results from this study could be useful to size and to efficiently locate disposal bins/containers for source separation as well as to redesign routes of municipal solid waste collection. Also, this strategy allows to add value to different components of MSW, improving working conditions of waste workers and creating new jobs in Bahia Blanca city., (© 2020 The Authors. Published by Elsevier Ltd.)

This study address for the first time in Argentina and the South American continent the effect of water management on the presence of microplastics (MPs) in a shallow lake, assessing their contribution to the zooplankton fraction. Water samples were collected in the lake and its principal affluent, an irrigation channel, from winter 2018 to summer 2019 with a zooplankton net (47 μm). MPs were present in all analyzed samples, with a dominance of fibers, black color, and ≤ 1000 μm range size. MPs concentration was maximum during summer at the lake (180 MPs m -3 ) while during spring (140 MPs m -3 ) at the channel. Rotifers and cyclopoids dominated the zooplanktonic fraction at both sites which range sizes (< 200 to 600 μm) included most of the size range found for MPs (50-950 μm). According to our results, the MPs found represents a potential risk for the first levels of the food web. In the lake, the concentration of MPs concerning total zooplankton abundance was higher when the channel was closed. Nevertheless, when the channel was open, the higher concentration in summer matches with the increase of tourism and an extraordinary rainfall. Our results suggest that while the runoff of agro-industrial waste regulates the MPs concentration in the channel, its water management, the touristic activities, and the runoff of MPs from nearby urban settlements regulate the concentration of MPs in the lake. These findings emphasize the need for better treatment of urban and agro-industrial waste that develops near continental aquatic systems, mainly in those where tourism activities are frequent and treatment facilities scarce.

The aim of this study was to investigate the temporal dynamics (monthly/tidal) of water temperature, salinity, chlorophyll-a (chlo-a), suspended particulate matter (SPM), particulate organic carbon (POC), and dissolved nutrients in the surf zone of Monte Hermoso sandy beach, Argentina. We also aimed to understand the underlying mechanisms responsible for the observed variability. Sampling was carried out approximately monthly (September 2009-November 2010), and all samples were collected in a fixed station during high and low tide. Water temperature showed a clear seasonal variability (July: 9 °C-December: 26.5 °C) and a thermal amplitude of 17.5 °C. Salinity ranged from 33 to 37, without a pronounced seasonality. SPM (10-223 mg L(-1)) and POC concentrations (399-6445 mg C m(-3)) were high in surf zone waters. Chlo-a (0.05-9.16 μg L(-1)) was low and did not evidence the occurrence of surf diatom accumulations. Dissolved nutrient concentration was quite fluctuating. None of the variables seemed to be affected by tidal stage. The results showed how fluctuating the physico-chemical and biological variables can be in this particular system. The observed variability can be related with local beach conditions but also with regional processes. The study area is highly influenced by a neighbor estuary and as a consequence, could be vulnerable to their seasonal and inter-annual dynamics. All of these characteristics must be considered for further studies and planning of the uses of natural resources and should be taken into account in any environmental monitoring program conducted in a similar beach system.

The aim of this work is to evaluate the applicability of the 3D model obtained through Structure-from-Motion (SFM) from unmanned aerial vehicle (UAV) imagery, in order to characterize bioerosion patterns (i.e., cavities for roosting and nesting) caused by burrowing parrots on a cliff in Bahía Blanca, Argentina. The combined use of SFM-UAV technology was successfully applied for the 3D point cloud model reconstruction. The local point density, obtained by means of a sphere of radius equal to 0.5 m, reached a mean value of 9749, allowing to build a high-resolution model (0.013 m) for resolving fine spatial details in topography. To test the model, we compared it with another point cloud dataset which was created using a low cost do-it-yourself terrestrial laser scanner; the results showed that our georeferenced model had a good accuracy. In addition, an innovative method for the detection of the bioerosion features was implemented, through the processing of data provided by SFM like color and spatial coordinates (particularly the y coordinate). From the 3D model, we also derived topographic calculations such as slope angle and surface roughness, to get associations between the surface topography and bioerosion features.