Decay and persistence of empty bivalve shells in temperate riverine systems

Bivalve shells can persist over a geological time, acting as important physical resources to the associated fauna. However, few studies have investigated their relevance as persistent long-term ecological attributes to the ecosystem. As such, it is relevant to investigate the shell decays in riverine systems subjected to different environmental conditions. Towards this end, shells of four bivalve species (Anodonta anatina, Corbicula fluminea, Potomida littoralis and Unio delphinus) were made available individually and in clusters of different sizes. The effects of river flow and seasonality were assessed by recording the decay rates of shells in lentic and lotic habitats throughout the year. Our results evidenced that the decays varied among species and depend on shell size, water flow and season. Thin shelled species (A. anatina and U. delphinus) showed the highest mean percentage of decay per month, 3.17% (lotic) and 2.77% (lotic), respectively, and thick shelled species (C. fluminea and P. littoralis) the lowest, 2.02% (lotic) and 1.83% (lotic), respectively. Size was a relevant variable explaining decays, with the smallest shells presenting the highest values, 1.2–2.0 times higher compared to the other size classes. Also, robustness showed to be the most relevant feature explaining the decays in thick shelled species. River flow was also a relevant descriptor of the decays, with higher decays observed in the lotic compared to the lentic habitats. Furthermore, lower decays were observed mainly during summer (lentic site), and autumn (lotic site) associated to the burial effect of leaves. In summary, shells of the native species A. anatina and U. delphinus are expected to persist and contribute less as habitat engineering species, than shells of the native P. littoralis and invasive C. fluminea species. This is especially valid to lotic habitats where the decays were up to 2.13 times higher than in lentic habitats.This study was supported by the FCT (Foundation for Science and Technology, Portugal) strategic fund UID/Multi/04423/2019

Physical legacy of freshwater bivalves: effects of habitat complexity on the taxonomical and functional diversity of invertebrates

Bivalves may play a major role in structuring aquatic communities. This may be especially relevant in aquatic communities dominated by non-native invasive bivalves, which can contribute to the increase of habitat homogenization. In this study, we assess how habitat homogenization, through the reduction of empty bivalve shells identities, influences the macroinvertebrate assemblages. Towards this end, a manipulative experiment with the empty shells of two native (Potomida littoralis and Unio delphinus) and one non-native (Corbicula fluminea) species was performed. Seven treatments were prepared, three of them consisting of homogeneous substrates using shells of one species, and four of them consisting in heterogeneous substrates using more than one species. The associated fauna colonizing different treatments was analyzed through taxonomic and trait-based approaches. Our results showed that the substrate complexity influenced the density of macroinvertebrates, with the heterogeneous treatments significantly yielding more dense assemblages. Also, the trait patterns differed among the levels of habitat heterogeneity, influencing mainly organisms that feed on microphytes of both small and big sizes, that inhabit areas with slow to moderate water flow, and that have short and long live cycles. Further, the functional diversity was not influenced by the substrate heterogeneity. Therefore, the habitat homogenization, through the accumulation of non-native C. flumineaempty shells in the river bottom, did not affect the functional diversity of the macroinvertebrate assemblages. (C) 2018 Elsevier B.V. All rights reserved.This study was conducted as part of the project FRESCHO: Multiple implications of invasive species on Freshwater Mussel coextinction processes, supported by FCT (contract: PTDC/AGRFOR/1627/2014). M Ilarri is supported by a Post-doc grant (SFRH/BPD/90088/2012) from the Portuguese Foundation for Science and Technology - FCT through POPH/FSE funds

All for One and One for All: Dynamic Injection of Situations in a Generic Context-Aware Application

In a new smart-world, users are getting accustomed to fast-responding applications that make their everyday tasks and daily life easier. In order to meet their expectancies, mobile applications are shifting towards a new era of context awareness. Nonetheless, it seems that context-aware applications are still struggling to provide the user with a real situation understanding. They only consider non-evolving limited scenarios and react to them using only generic services. To address these concerns, we have developed the Long Life Application, a dynamic context-aware situation-based distributed mobile application dedicated to assist end-users in their everyday needs. This application considers the requirements of the users and provides them with the appropriate services according to their current context. In this paper we focus in the way that the user''s context is considered by the application. We propose a hybrid approach that combines both high-level context (top-down approach), by injecting user-related context, and a low-level context (bottom-up approach), by inferring it from sensor data. Peer-review under responsibility of the Conference Program Chairs

Potential impacts of the invasive species Corbicula fluminea on the survival of glochidia

Freshwater mussels (Bivalvia, Unionida) are one of the most imperilled faunal groups globally, being the introduction of invasive species a possible major mechanism of threat. The Asian clam Corbicula fluminea is a problematic invasive species in aquatic ecosystems and can impair the survival of parasitic larvae (glochidia) of native freshwater mussels. However, this possible mechanism of threat remains speculative and to date very few studies addressed quantitatively this issue. In order to cover this gap, we have performed a series of manipulative laboratory studies to assess how distinct densities of C. fluminea can affect the survival of glochidia after 6, 12, 24 and 48 h of exposure, using larvae of the native freshwater mussel Anodonta anatina. Our results suggest an increase in mortality of A. anatina glochidia with an increase in density of C. fluminea. Two main mechanisms may possibly explain our results: 1) the high filtration capacity of C. fluminea that can contribute to the mortality of glochidia due to the mechanical damage of their fragile shells when passing by siphons and/or digestive tract of C. fluminea and 2) the high excretion capacity of C. fluminea that can lead to mortality of glochidia due to increase in ammonia concentration. Mortality of glochidia was also time dependent with higher values registered after 48 h. This work is one of the first showing the influence of C. fluminea density on the survival of glochidia, being filtration (and consequent passage in the digestive tract) and biodeposition the main potential mechanisms explaining overall mortality. These results also suggest that sites with high densities of C. fluminea may be highly detrimental for the conservation of freshwater mussels, potentially impairing the survival of glochidia and negatively affecting the recruitment of juveniles.VM, MLL and PC were supported by doctoral grants (SFRH/BD/108298/2015), (SFRH/BD/115728/2016) and (SFRH/BD/131814/2017) from the Portuguese Foundation for Science and Technology - FCT through POPH/FSE funds. This study was conducted within the project FRESHCO - Multiple implications of invasive species on Freshwater Mussel coextinction processes, supported by FCT and COMPETE funds (contract: PTDC/AGRFOR/1627/2014). This study was also supported by the FCT project UID/Multi/04423/2019. We thank Allan Souza, Francisco Arenas, Jacinto Cunha and Lucia Guilhermino for their help in the design of the experiment. We also thank the editor and three anonymous referees for valuable suggestions

Palatability of the Asian clam Corbicula fluminea (Müller 1774) in an invaded system

Biotic interactions such as predation may influence the success of invasive alien species (IAS). Although the Asian clam Corbicula fluminea is recognized as one of the most problematic aquatic IAS, few studies have investigated its use as a food resource. In this study, we aimed to investigate (i) the palatability of C. fluminea under natural (Minho River) and laboratory conditions and (ii) if C. fluminea submitted to different conditions (individuals from Lima and Minho Rivers) vary in palatability. Soft tissues from different Corbicula populations, plus soft tissues from a native clam, tuna and Corbicula shell powder were offered to consumers. Field assays were performed seasonally and laboratory assays only in summer; both assays also tested possible differences during distinct periods of the day. Overall, in natural conditions, the treatments containing C. fluminea had a low palatability. In laboratory assays, higher consumption (almost two times) was observed for Cyprinus carpio and Anguilla anguilla. Also, C. fluminea palatability was different between populations, with the treatment Corbicula Lima being more consumed than Corbicula Minho. Despite the low values of consumption in the field, laboratory results suggest that C. fluminea soft tissues can be a food resource to some species.This study was conducted as part of the project FRESCHO: Multiple implications of invasive species on Freshwater Mussel coextinction processes, supported by FCT (contract: PTDC/AGRFOR/1627/2014). MI is supported by a Post-doc grant (SFRH/BPD/90088/2012) from the Portuguese Foundation for Science and Technology—FCT through POPH/FSE funds. RS also acknowledge the support of the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER007569) funded by national funds through the FCT I.P and by the ERDF through the COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)

Differences in the macrozoobenthic fauna colonising empty bivalve shells before and after invasion by Corbicula fluminea

Bivalve shells can potentially alter the structure of aquatic benthic communities. However, little is known about the effect that different shell morphologies have on their associated fauna. This study aimed to understand how empty shells, from four different freshwater bivalve species, affect macrozoobenthic communities, using the River Minho (Iberian Peninsula) as a study area. Three native (Anodonta anatina, Potomida littoralis, Unio delphinus) and one non-indigenous (Corbicula fluminea) species were used for this research. Comparisons among species and between scenarios (i.e. before and after invasion by C. fluminea) were performed. Our results suggest that macrozoobenthic community structure did not vary among treatments, with the exception of species richness, which was higher on shells of native species. Furthermore, little difference was detected when comparing scenarios with and without C. fluminea shells, despite dissimilarities in size and morphology between species. The empty shells of C. fluminea partially (in terms of density and biomass, but not in species richness) replaced the role of empty shells of native species as a physical substratum for the associated macrozoobenthic community.Martina Ilarri is supported by a Post-doc grant (SFRH/BPD/90088/2012) from the Portuguese Foundation for Science and Technology – FCT through POPH/FSE funds. This study was conducted within the scope of the project ECO-IAS: Ecosystem-level impacts of an invasive alien species, supported by FCT and COMPETE funds (contract: PTDC/AAC-AMB/116685/2010) and was also partially supported by the European Regional Development Fund (ERDF) through COMPETE funds (PEst-C/MAR/LA0015/2011) and by FCT/MEC through Portuguese funds (PIDDAC – PEst-OE/BIA/UI4050/2014).info:eu-repo/semantics/publishedVersio

Environmental Assessment of Microplastic Pollution Induced by Solid Waste Landfills in the Akmola Region (North Kazakhstan)

[EN] This paper presents the outcomes derived from an environmental assessment of microplastic pollution resulting from solid waste landfills in the Akmola Region, situated in North Kazakhstan. This research represents a pioneering investigation conducted on microplastics within this specific region. This study encompasses a comprehensive examination of plastic waste disposal sites across the Akmola region, with a particular emphasis on evaluating the status of the municipal solid waste management system. To characterize the plastic content within the waste present at the landfill sites, quantitative techniques were employed. Through experimental means, the composition and fractionation of plastics within the municipal solid waste (MSW) at the landfills were determined. These data were subjected to a comparative analysis, aligning them with official statistics and previously published scientific data from both Kazakhstan and other regions globally. The methodologies employed focused on the ¿soft¿ removal of organic substances through the use of oxidants which do not damage plastics, and were tested using a water-bath therapeutic treatment. Furthermore, an analysis of soil samples taken from the landfills unveiled the ultimate retention of microplastic particles, attributed to leachate and rainwater runoff. Extracts were obtained from the subsoil samples using a density-based separation process, involving a three-step extraction followed by subsequent filtration of the resulting supernatants. In addition, the soil samples underwent examination through dry-phase particle fractional separation. The particles were meticulously enumerated and classified, and their dimensions were measured employing microscopic techniques coupled with photographic documentation. The outcomes stemming from these diverse tests will serve as fundamental input for the forthcoming numerical modeling endeavor, which aims to simulate the behavior of microplastics within both soil and water. This endeavor represents a continuation of the research project, the preliminary findings of which are expounded upon in this paper.This research was funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan through the research project entitled ¿Health Risk Modelling Based on the Identification of Microplastics in Water Systems and the Reasoning About Actions to Manage the Water Resources Quality¿ (Grant No. AP14869081).Salikova, NS.; Rodrigo-Ilarri, J.; Rodrigo-Clavero, M.; Urazbayeva, SE.; Askarova, AZ.; Magzhanov, KM. (2023). Environmental Assessment of Microplastic Pollution Induced by Solid Waste Landfills in the Akmola Region (North Kazakhstan). Water. 15(16). https://doi.org/10.3390/w15162889151

Relevance of Environmental Surveys on the Design of a New Municipal Waste Management System on the City of Kokshetau (Kazakhstan)

[EN] The increasing amount of municipal solid waste is one of the most urgent problems for many countries in the world, including Kazakhstan. In 2021, a new environmental code was adopted in the country. In accordance with this code, some types of garbage (such as plastic, paper, cardboard or glass) are not accepted at sanitary landfills. Besides this, a separate collection system of municipal solid waste in Kokshetau is practically absent, and only a few points for the collection of secondary raw materials are currently available. The state bodies are faced with the task of introducing dual waste collection technology. This work shows the results obtained by a sociological online survey performed among the residents of the city in order to identify their attitudes with respect to the separation and classification of waste. This survey allowed us to study the level of environmental awareness and interest in solving waste-related issues in the population of Kokshetau. The results show that the majority of the population is concerned about the problem of municipal waste management and is ready to cooperate on the classification of waste at the original source. Additionally, it was revealed that the survey participants have weak environmental knowledge, so it is necessary to conduct environmental education activities for the population. The existence of a statistically significant relationship between the variables under consideration in terms of the Pearson Chi-squared criterion was observed.This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan, grant number IRN: AP09259015 included in the grant financing of scientific and scientific and technical projects for 2021-2023 with a period of implementation of 36 months. Project topic: Development of technology for the efficient processing of organic waste using the thermophilic fermentation method to produce biological fertilizers.Bayazitova, ZE.; Rodrigo-Ilarri, J.; Rodrigo-Clavero, M.; Kurmanbayeva, AS.; Safronova, NM.; Belgibayeva, AS.; Zhaparova, SB.... (2022). Relevance of Environmental Surveys on the Design of a New Municipal Waste Management System on the City of Kokshetau (Kazakhstan). Sustainability. 14(21):1-16. https://doi.org/10.3390/su142114368116142

Trophic niche overlap between native freshwater mussels (Order: Unionida) and the invasive Corbicula fluminea

Freshwater mussels (Order Unionida) are highly threatened. Interspecific competition for food sources with invasive alien species is considered to be one of the factors responsible for their decline because successful invaders are expected to have wider trophic niches and more flexible feeding strategies than their native counterparts. In this study, carbon (δ13C: 13C/12C) and nitrogen (δ15N: 15N/14N) stable isotopes were used to investigate the trophic niche overlap between the native freshwater mussel species, Anodonta anatina, Potomida littoralis, and Unio delphinus, and the invasive bivalve Corbicula fluminea living in sympatry in the Tua basin (south-west Europe). The species presenting the widest trophic niches were C. fluminea and A. anatina, which indicate that they have broader diets than U. delphinus and P. littoralis. Nonetheless, all the species assimilated microphytobenthos, sediment organic matter, and detritus derived from vascular plants, although with interspecific variability in the assimilated proportions of each source. The trophic niche of the invasive species overlapped with the trophic niche of all the native species, with the extent varying between sites and according to the species. From the three native species analysed, Potomida littoralis may be at a higher risk for competition for food with C. fluminea in the Tua basin, if food sources become limited, because this native mussel presented the narrowest trophic niche across sites and the highest probability of overlapping with the trophic niche of C. fluminea. Given the global widespread distribution of C. fluminea, the implementation of management measures devoted to the control or even eradication of this invasive alien species should be a conservation priority given its potential for competition with highly threatened native freshwater mussels.V.M. and P.C. were supported by doctoral grants SFRH/BD/108298/2015 and SFRH/BD/131814/2017, respectively, from the Portuguese Foundation for Science and Technology—FCT through POPH/FSE funds. FCT also supported M.L.L. under contract (2020.03608.CEECIND). This study was conducted within the project FRESHCO – Multiple implications of invasive species on Freshwater Mussel coextinction processes, supported by FCT and COMPETE funds (contract: PTDC/AGRFOR/1627/2014). This study was also supported by national funds through FCT – Foundation for Science and Technology within the scope of UIDB/04423/2020 and UIDP/04423/2020. We thank Jacinto Cunha for providing Figure 1.info:eu-repo/semantics/publishedVersio

Massive mortality of invasive bivalves as a potential resource subsidy for the adjacent terrestrial food web

Large-scale mortality of invasive bivalves was observed in the River Danube basin in the autumn of 2011 due to a particularly low water discharge. The aim of this study was to quantify and compare the biomass of invasive and native bivalve die-offs amongst eight different sites and to assess the potential role of invasive bivalve die-offs as a resource subsidy for the adjacent terrestrial food web. Invasive bivalve die-offs dominated half of the study sites and their highest density and biomass were recorded at the warm water effluent. The density and biomass values recorded in this study are amongst the highest values recorded for aquatic ecosystems and show that a habitat affected by heated water can sustain an extremely high biomass of invasive bivalves. These mortalities highlight invasive bivalves as a major resource subsidy, possibly contributing remarkable amounts of nutrients and energy to the adjacent terrestrial ecosystem. Given the widespread occurrence of these invasive bivalves and the predicted increase in the frequency and intensity of extreme climatic events, the ecological impacts generated by their massive mortalities should be taken into account in other geographical areas as well.The authors are grateful to David Strayer for valuable comments on a previous version of the manuscript. Special thanks to the Danube-Ipoly National Park for the help in field work. Ronaldo Sousa was supported by the project "ECOIAS" funded by the Portuguese Foundation for the Science and the Technology and COMPETE funds (contract: PTDC/AAC-AMB/116685/2010)