Harnessing online digital data in biodiversity monitoring.

Online digital data from media platforms have the potential to complement biodiversity monitoring efforts. We propose a strategy for integrating these data into current biodiversity datasets in light of the Kunming-Montreal Global Biodiversity Framework.

High and rising economic costs of biological invasions worldwide.

Biological invasions are responsible for substantial biodiversity declines as well as high economic losses to society and monetary expenditures associated with the management of these invasions1,2. The InvaCost database has enabled the generation of a reliable, comprehensive, standardized and easily updatable synthesis of the monetary costs of biological invasions worldwide3. Here we found that the total reported costs of invasions reached a minimum of US$1.288 trillion (2017 US dollars) over the past few decades (1970-2017), with an annual mean cost of US$26.8 billion. Moreover, we estimate that the annual mean cost could reach US$162.7 billion in 2017. These costs remain strongly underestimated and do not show any sign of slowing down, exhibiting a consistent threefold increase per decade. We show that the documented costs are widely distributed and have strong gaps at regional and taxonomic scales, with damage costs being an order of magnitude higher than management expenditures. Research approaches that document the costs of biological invasions need to be further improved. Nonetheless, our findings call for the implementation of consistent management actions and international policy agreements that aim to reduce the burden of invasive alien species.

Using citizen science data for predicting the timing of ecological phenomena across regions.

The scarcity of long-term observational data has limited the use of statistical or machine-learning techniques for predicting intraannual ecological variation. However, time-stamped citizen-science observation records, supported by media data such as photographs, are increasingly available. In the present article, we present a novel framework based on the concept of relative phenological niche, using machine-learning algorithms to model observation records as a temporal sample of environmental conditions in which the represented ecological phenomenon occurs. Our approach accurately predicts the temporal dynamics of ecological events across large geographical scales and is robust to temporal bias in recording effort. These results highlight the vast potential of citizen-science observation data to predict ecological phenomena across space, including in near real time. The framework is also easily applicable for ecologists and practitioners already using machine-learning and statistics-based predictive approaches.

A protocol for harvesting biodiversity data from Facebook.

The expanding use of community science platforms has led to an exponential increase in biodiversity data in global repositories. Yet, understanding of species distributions remains patchy. Biodiversity data from social media can potentially reduce the global biodiversity knowledge gap. However, practical guidelines and standardized methods for harvesting such data are nonexistent. Following data privacy and protection safeguards, we devised a standardized method for extracting species distribution records from Facebook groups that allow access to their data. It involves 3 steps: group selection, data extraction, and georeferencing the record location. We present how to structure keywords, search for species photographs, and georeference localities for such records. We further highlight some challenges users might face when extracting species distribution data from Facebook and suggest solutions. Following our proposed framework, we present a case study on Bangladesh's biodiversity-a tropical megadiverse South Asian country. We scraped nearly 45,000 unique georeferenced records across 967 species and found a median of 27 records per species. About 12% of the distribution data were for threatened species, representing 27% of all species. We also obtained data for 56 DataDeficient species for Bangladesh. If carefully harvested, social media data can significantly reduce global biodiversity knowledge gaps. Consequently, developing an automated tool to extract and interpret social media biodiversity data is a research priority.

Un protocolo para recolectar datos sobre biodiversidad en Facebook Resumen El uso creciente de plataformas de ciencia comunitaria ha causado un incremento exponencial de los datos sobre biodiversidad en los repositorios mundiales. Sin embargo, el conocimiento sobre la distribución de las especies todavía está incompleto. Los datos sobre biodiversidad obtenidos de las redes sociales tienen el potencial para disminuir el vacío de conocimiento sobre la biodiversidad mundial. No obstante, no existe una guía práctica o un método estandarizado para recolectar dichos datos. Seguimos los protocolos de privacidad y protección de datos para diseñar un método estandarizado para extraer registros de la distribución de especies de grupos en Facebook que permiten el acceso a sus datos. El método consta de tres pasos: selección del grupo, extracción de datos y georreferenciación de la localidad registrada. También planteamos cómo estructurar las palabras clave, buscar fotografías de especies y georreferenciar las localidades de dichos registros. Además, resaltamos algunos retos que los usuarios pueden enfrentar al extraer los datos de distribución de Facebook y sugerimos algunas soluciones. Aplicamos nuestro marco de trabajo propuesto a un estudio de caso de la biodiversidad en Bangladesh, un país tropical megadiverso en el sureste de Asia. Reunimos casi 45,000 registros georreferenciados únicos para 967 especies y encontramos una media de 27 registros por especie. Casi el 12% de los datos de distribución correspondió a especies amenazadas, que representaban el 27% de todas las especies. También obtuvimos datos para 56 especies deficientes de datos en Bangladesh. Si los datos de las redes sociales se recolectan con cuidado, éstos pueden reducir de forma significativa el vacío de conocimiento para la biodiversidad mundial. Como consecuencia, es una prioridad para la investigación el desarrollo de una herramienta automatizada para extraer e interpretar los datos sobre biodiversidad de las redes sociales.

Using social media records to inform conservation planning.

Citizen science plays a crucial role in helping monitor biodiversity and inform conservation. With the widespread use of smartphones, many people share biodiversity information on social media, but this information is still not widely used in conservation. Focusing on Bangladesh, a tropical megadiverse and mega-populated country, we examined the importance of social media records in conservation decision-making. We collated species distribution records for birds and butterflies from Facebook and Global Biodiversity Information Facility (GBIF), grouped them into GBIF-only and combined GBIF and Facebook data, and investigated the differences in identifying critical conservation areas. Adding Facebook data to GBIF data improved the accuracy of systematic conservation planning assessments by identifying additional important conservation areas in the northwest, southeast, and central parts of Bangladesh, extending priority conservation areas by 4,000-10,000 km2 . Community efforts are needed to drive the implementation of the ambitious Kunming-Montreal Global Biodiversity Framework targets, especially in megadiverse tropical countries with a lack of reliable and up-to-date species distribution data. We highlight that conservation planning can be enhanced by including available data gathered from social media platforms.

Registros de las redes sociales para guiar la planeación de la conservación Resumen La ciencia ciudadana es importante para monitorear la biodiversidad e informar la conservación. Con el creciente uso de los teléfonos inteligentes, muchas personas comparten información de la biodiversidad en redes sociales, pero todavía no se usa ampliamente en la conservación. Analizamos la importancia de los registros de las redes sociales para las decisiones de conservación enfocados en Bangladesh, un país tropical megadiverso y mega poblado. Cotejamos los registros de distribución de especies de aves y mariposas en Facebook y Global Biodiversity Information Facility (GBIF), las agrupamos en datos sólo de GBIF o datos combinados de Facebook y GBIF e investigamos las diferencias en la identificación de las áreas de conservación críticas. La combinación de los datos de Facebook con los de GBIF mejoró la precisión de las evaluaciones de la planeación de la conservación sistemática al identificar otras áreas importantes de conservación en el noroeste, sureste y centro de Bangladesh, extendiendo así las áreas prioritarias de conservación en unos 4,000-10,000 km2 . Se requieren esfuerzos comunitarios para impulsar la implementación de los objetivos ambiciosos del Marco Global de Biodiversidad Kunming-Montreal, especialmente en países tropicales que carecen de datos confiables y actuales sobre la distribución de las especies. Destacamos que la planeación de la conservación puede mejorarse si se incluye información tomada de las redes sociales.

Dating first cases of COVID-19.

Questions persist as to the origin of the COVID-19 pandemic. Evidence is building that its origin as a zoonotic spillover occurred prior to the officially accepted timing of early December, 2019. Here we provide novel methods to date the origin of COVID-19 cases. We show that six countries had exceptionally early cases, unlikely to represent part of their main case series. The model suggests a likely timing of the first case of COVID-19 in China as November 17 (95% CI October 4). Origination dates are discussed for the first five countries outside China and each continent. Results infer that SARS-CoV-2 emerged in China in early October to mid-November, and by January, had spread globally. This suggests an earlier and more rapid timeline of spread. Our study provides new approaches for estimating dates of the arrival of infectious diseases based on small samples that can be applied to many epidemiological situations.

Expanding conservation culturomics and iEcology from terrestrial to aquatic realms.

The ongoing digital revolution in the age of big data is opening new research opportunities. Culturomics and iEcology, two emerging research areas based on the analysis of online data resources, can provide novel scientific insights and inform conservation and management efforts. To date, culturomics and iEcology have been applied primarily in the terrestrial realm. Here, we advocate for expanding such applications to the aquatic realm by providing a brief overview of these new approaches and outlining key areas in which culturomics and iEcology are likely to have the highest impact, including the management of protected areas; fisheries; flagship species identification; detection and distribution of threatened, rare, and alien species; assessment of ecosystem status and anthropogenic impacts; and social impact assessment. When deployed in the right context with awareness of potential biases, culturomics and iEcology are ripe for rapid development as low-cost research approaches based on data available from digital sources, with increasingly diverse applications for aquatic ecosystems.

Evaluating global interest in biodiversity and conservation.

The first target of the Convention for Biological Diversity (Aichi target 1) was to increase public awareness of the values of biodiversity and actions needed to conserve it-a key prerequisite for other conservation targets. Monitoring success in achieving this target at a global scale has been difficult; however, increased digitization of human life in recent decades has made it easier to measure people's interests at an unprecedented scale and allows for a more comprehensive evaluation of Aichi target 1 than previously attempted. We used Google search volume data for over a thousand search terms related to different aspects of biodiversity and conservation to evaluate global interest in biodiversity and its conservation. We also investigated the correlation of interest in biodiversity and conservation across countries to variables related to biodiversity, economy, demography, research, education, internet use, and presence of environmental organizations. From 2013 to 2020, global searches for biodiversity components increased, driven mostly by searches for charismatic fauna (59% of searches were for mammal species). Searches for conservation actions, driven mostly by searches for national parks, decreased since 2019, likely due to the COVID-19 pandemic. Economic inequality was negatively correlated with interest in biodiversity and conservation, whereas purchasing power was indirectly positively correlated with higher levels of education and research. Our results suggest partial success toward achieving Aichi target 1 in that interest in biodiversity increased widely, but not for conservation. We suggest that increased outreach and education efforts aimed at neglected aspects of biodiversity and conservation are still needed. Popular topics in biodiversity and conservation could be leveraged to increase awareness of other topics with attention to local socioeconomic contexts.

Evaluación del interés mundial en la biodiversidad y la conservación Resumen La primera meta del Convenio sobre la Diversidad Biológica (Meta 1 de Aichi) era aumentar la conciencia pública sobre los valores de la biodiversidad y las acciones necesarias para conservarla, un requisito previo clave para otras metas de conservación. Ha sido difícil monitorear el éxito en la obtención de esta meta a escala mundial; sin embargo, la creciente digitalización de la vida humana en las últimas décadas ha facilitado la medición de los intereses de la gente a una escala sin precedentes y permite una evaluación más exhaustiva de la Meta 1 de Aichi que la que se había intentado previamente. Utilizamos datos sobre el volumen de búsquedas en Google de más de mil términos relacionados con distintos aspectos de la biodiversidad y la conservación para evaluar el interés mundial en la biodiversidad y su conservación. También investigamos la correlación del interés por la biodiversidad y la conservación en los distintos países con variables relacionadas a la biodiversidad, la economía, la demografía, la investigación, la educación, el uso del internet y la presencia de organizaciones ambientalistas. Las búsquedas mundiales sobre los componentes de la biodiversidad aumentaron de 2013 a 2020, impulsadas sobre todo por búsquedas de especies carismática (el 59% de las búsquedas correspondían a especies de mamíferos). Las búsquedas de acciones de conservación, impulsadas principalmente por búsquedas de parques nacionales, han disminuido desde 2019, probablemente debido a la pandemia de COVID-19. La desigualdad económica se correlacionó negativamente con el interés en la biodiversidad y la conservación, mientras que el poder adquisitivo se correlacionó indirectamente de manera positiva con niveles más altos de educación e investigación. Nuestros resultados sugieren un éxito parcial en la obtención de la Meta 1 de Aichi en el sentido de que aumentó ampliamente el interés por la biodiversidad, pero no por la conservación. Sugerimos que se necesitan mayores esfuerzos de divulgación y educación dirigidos a aspectos desatendidos de la biodiversidad y la conservación. Los temas populares de biodiversidad y conservación podrían aprovecharse para aumentar la conciencia sobre otros temas si se presta atención a los contextos socioeconómicos locales.

Statistical inference of earlier origins for the first flaked stone technologies.

Identifying when hominins first produced Lomekwian, Oldowan, and Acheulean technologies is vital to multiple avenues of human origins research. Yet, like most archaeological endeavors, our understanding is currently only as accurate as the artifacts recovered and the sites identified. Here we use optimal linear estimation (OLE) modelling to identify the portion of the archaeological record not yet discovered, and statistically infer the date of origin of the earliest flaked stone technologies. These models provide the most accurate framework yet for understanding when hominins first produced these tool types. Our results estimate the Oldowan to have originated 2.617 to 2.644 Ma, 36,000 to 63,000 years earlier than current evidence. The Acheulean's origin is pushed back further through OLE, by at least 55,000 years to 1.815 to 1.823 Ma. We were unable to infer the Lomekwian's date of origin using OLE, but an upper bound of 5.1 million years can be inferred using alternative nonparametric techniques. These dates provide a new chronological foundation from which to understand the emergence of the first flaked stone technologies, alongside their behavioral and evolutionary implications. Moreover, they suggest there to be substantial portions of the artifact record yet to be discovered.

The paradoxical extinction of the most charismatic animals.

A widespread opinion is that conservation efforts disproportionately benefit charismatic species. However, this doesn't mean that they are not threatened, and which species are "charismatic" remains unclear. Here, we identify the 10 most charismatic animals and show that they are at high risk of imminent extinction in the wild. We also find that the public ignores these animals' predicament and we suggest it could be due to the observed biased perception of their abundance, based more on their profusion in our culture than on their natural populations. We hypothesize that this biased perception impairs conservation efforts because people are unaware that the animals they cherish face imminent extinction and do not perceive their urgent need for conservation. By freely using the image of rare and threatened species in their product marketing, many companies may participate in creating this biased perception, with unintended detrimental effects on conservation efforts, which should be compensated by channeling part of the associated profits to conservation. According to our hypothesis, this biased perception would be likely to last as long as the massive cultural and commercial presence of charismatic species is not accompanied by adequate information campaigns about the imminent threats they face.

Digital data sources and methods for conservation culturomics.

Ongoing loss of biological diversity is primarily the result of unsustainable human behavior. Thus, the long-term success of biodiversity conservation depends on a thorough understanding of human-nature interactions. Such interactions are ubiquitous but vary greatly in time and space and are difficult to monitor efficiently at large spatial scales. However, the Information Age also provides new opportunities to better understand human-nature interactions because many aspects of daily life are recorded in a variety of digital formats. The emerging field of conservation culturomics aims to take advantage of digital data sources and methods to study human-nature interactions and thus to provide new tools for studying conservation at relevant temporal and spatial scales. Nevertheless, technical challenges associated with the identification, access, and analysis of relevant data hamper the wider adoption of culturomics methods. To help overcome these barriers, we propose a conservation culturomics research framework that addresses data acquisition, analysis, and inherent biases. The main sources of culturomic data include web pages, social media, and other digital platforms from which metrics of content and engagement can be obtained. Obtaining raw data from these platforms is usually desirable but requires careful consideration of how to access, store, and prepare the data for analysis. Methods for data analysis include network approaches to explore connections between topics, time-series analysis for temporal data, and spatial modeling to highlight spatial patterns. Outstanding challenges associated with culturomics research include issues of interdisciplinarity, ethics, data biases, and validation. The practical guidance we offer will help conservation researchers and practitioners identify and obtain the necessary data and carry out appropriate analyses for their specific questions, thus facilitating the wider adoption of culturomics approaches for conservation applications.

Fuentes de Información Digital y Métodos para la Culturomia de la Conservación Resumen La continua pérdida de biodiversidad es el resultado principal del comportamiento humano insostenible. Por esto, el éxito a largo plazo de la conservación de la biodiversidad depende de una comprensión exhaustiva de las interacciones humano-naturaleza. Dichas interacciones son ubicuas pero varían enormemente en el tiempo y el espacio, lo que dificulta su monitoreo eficiente a escalas espaciales amplias. Sin embargo, la Era de la Información también nos proporciona nuevas oportunidades para comprender de mejor manera las interacciones humano-naturaleza pues muchos aspectos de la vida diaria quedan registrados en una variedad de formatos digitales. El campo emergente de la culturomia de la conservación busca aprovechar los recursos y los métodos digitales para estudiar las interacciones humano-naturaleza y así proporcionar nuevas herramientas para el estudio de la conservación a escalas temporales y espaciales relevantes. No obstante, las dificultades técnicas asociadas con la identificación, acceso y análisis de la información relevante obstaculizan la adopción más amplia de los métodos de la culturomia. Para ayudar a superar estas barreras proponemos un marco de trabajo de investigación de culturomia de la conservación que aborde la obtención de datos, el análisis y los sesgos inherentes. Entre las principales fuentes de datos sobre culturomia se incluyen las páginas web, las redes sociales y otras plataformas digitales a partir de las cuales se pueden obtener medidas del contenido y la participación. Normalmente se busca obtener datos crudos a partir de este tipo de plataformas, pero esto requiere que se tengan en consideración las vías de acceso, el almacenaje y la preparación de la información para su posterior análisis. Los métodos para el análisis de datos incluyen analísis de redes para explorar las conexiones entre los temas, el análisis de series de tiempo para los datos temporales y el modelado espacial para resaltar los patrones espaciales. Los desafíos sobresalientes asociados a la investigación en culturomia incluyen temas de interdisciplinariedad, ética, sesgos de datos y validación. La orientación práctica que ofrecemos ayudará a los investigadores y practicantes de la conservación a identificar y obtener los datos necesarios. También les ayudará a realizar análisis apropiados para responder a sus preguntas específicas, facilitando así la adopción más amplia de las estrategias de culturomia para su aplicación en la conservación.

Sentiment analysis as a measure of conservation culture in scientific literature.

Culturomics is emerging as an important field within science, as a way to measure attitudes and beliefs and their dynamics across time and space via quantitative analysis of digitized data from literature, news, film, social media, and more. Sentiment analysis is a culturomics tool that, within the last decade, has provided a means to quantify the polarity of attitudes expressed within various media. Conservation science is a crisis discipline; therefore, accurate and effective communication are paramount. We investigated how conservation scientists communicate their findings through scientific journal articles. We analyzed 15,001 abstracts from articles published from 1998 to 2017 in 6 conservation-focused journals selected based on indexing in scientific databases. Articles were categorized by year, focal taxa, and the conservation status of the focal species. We calculated mean sentiment score for each abstract (mean adjusted z score) based on 4 lexicons (Jockers-Rinker, National Research Council, Bing, and AFINN). We found a significant positive annual trend in the sentiment scores of articles. We also observed a significant trend toward increasing negativity along the spectrum of conservation status categories (i.e., from least concern to extinct). There were some clear differences in the sentiments with which research on different taxa was reported, however. For example, abstracts mentioning lobe finned fishes tended to have high sentiment scores, which could be related to the rediscovery of the coelacanth driving a positive narrative. Contrastingly, abstracts mentioning elasmobranchs had low scores, possibly reflecting the negative sentiment score associated with the word shark. Sentiment analysis has applications in science, especially as it pertains to conservation psychology, and we suggest a new science-based lexicon be developed specifically for the field of conservation.

El Análisis de Opinión como Medida de la Cultura de Conservación en la Literatura Científica Lennox et al. Resumen La culturomía está emergiendo como un campo importante dentro de la ciencia pues es una manera de medir las actitudes, creencias y sus dinámicas a través del tiempo y el espacio por medio de un análisis cuantitativo de datos digitalizados a partir de la literatura, las noticias, las películas, las redes sociales y otros medios. El análisis de opinión es una herramienta de la culturomía que, en la última década, ha proporcionado los medios para cuantificar la polaridad de las actitudes expresadas en varios medios. La ciencia de la conservación es una disciplina de crisis; por lo tanto, la comunicación certera y efectiva es de suma importancia. Investigamos cómo los científicos de la conservación comunican sus hallazgos por medio de los artículos en las revistas científicas. Analizamos 15,001 resúmenes de artículos publicados entre 1998 y 2017 en seis revistas enfocadas en la conservación que fueron seleccionados con base en los índices de las bases de datos científicos. Categorizamos los artículos por año, taxón de enfoque y el estado de conservación de la especie focal. Calculamos la opinión promedio para cada resumen (puntaje z ajustado a la media) con base en cuatro lexicones (Jockers-Rinker, National Research Council, Bing y AFINN). Encontramos una significativa tendencia positiva anual en los puntajes de opinión de los artículos. También observamos una tendencia significativa hacia el incremento en la negatividad a lo largo del espectro de categorías de estado de conservación (es decir, de aquellas de menos preocupación a aquellas en peligro crítico o extintas). Sin embargo, hubo algunas diferencias claras en las opiniones con las cuales se reportaron las investigaciones sobre los diferentes taxones. Por ejemplo, los resúmenes que mencionaron a los peces de aletas lobuladas tendieron hacia los puntajes altos de opinión, lo que podría relacionarse con el redescubrimiento del celacanto como causa de una narrativa positiva. En contraste, los resúmenes que mencionaron a los elasmobranquios tuvieron puntajes bajos, lo que refleja el puntaje de opinión negativa asociado con la palabra tiburón. El análisis de opinión tiene aplicaciones en la ciencia, especialmente como parte de la psicología de la conservación, y sugerimos que se desarrolle un nuevo lexicón basado en la ciencia específicamente para el campo de la conservación.

Susceptibility of European freshwater fish to climate change: Species profiling based on life-history and environmental characteristics.

Climate change is expected to strongly affect freshwater fish communities. Combined with other anthropogenic drivers, the impacts may alter species spatio-temporal distributions and contribute to population declines and local extinctions. To provide timely management and conservation of fishes, it is relevant to identify species that will be most impacted by climate change and those that will be resilient. Species traits are considered a promising source of information on characteristics that influence resilience to various environmental conditions and impacts. To this end, we collated life-history traits and climatic niches of 443 European freshwater fish species and compared those identified as susceptible to climate change to those that are considered to be resilient. Significant differences were observed between the two groups in their distribution, life history, and climatic niche, with climate-change-susceptible species being distributed within the Mediterranean region, and being characterized by greater threat levels, lesser commercial relevance, lower vulnerability to fishing, smaller body and range size, and warmer thermal envelopes. Based on our results, we establish a list of species of highest priority for further research and monitoring regarding climate-change susceptibility within Europe. The presented approach represents a promising tool to efficiently assess large groups of species regarding their susceptibility to climate change and other threats, and to identify research and management priorities.

Boom-bust dynamics in biological invasions: towards an improved application of the concept.

Boom-bust dynamics - the rise of a population to outbreak levels, followed by a dramatic decline - have been associated with biological invasions and offered as a reason not to manage troublesome invaders. However, boom-bust dynamics rarely have been critically defined, analyzed, or interpreted. Here, we define boom-bust dynamics and provide specific suggestions for improving the application of the boom-bust concept. Boom-bust dynamics can arise from many causes, some closely associated with invasions, but others occurring across a wide range of ecological settings, especially when environmental conditions are changing rapidly. As a result, it is difficult to infer cause or predict future trajectories merely by observing the dynamic. We use tests with simulated data to show that a common metric for detecting and describing boom-bust dynamics, decline from an observed peak to a subsequent trough, tends to severely overestimate the frequency and severity of busts, and should be used cautiously if at all. We review and test other metrics that are better suited to describe boom-bust dynamics. Understanding the frequency and importance of boom-bust dynamics requires empirical studies of large, representative, long-term data sets that use clear definitions of boom-bust, appropriate analytical methods, and careful interpretations.

On the functional extinction of the Passenger Pigeon.

The Passenger Pigeon (Ectopistes migratorius) was a social breeder, and it has been suggested that the species experienced functional extinction, defined as a total reproductive failure, prior to its actual extinction in the early years of the 20th century. We applied a novel randomization test based on the relative times of the most recent egg- and skin-specimen sightings (i.e., recorded date of specimen collection) to test for functional extinction. For a total of 6 eggs and 27 skins, the observed significance level was 0.38, which indicated that the species did not become functionally extinct. Thus, proposals to reverse its rapid decline in the late 19th century could have been successful.

Use of histopathology and elemental accumulation in different organs of two benthophagous fish species as indicators of river pollution.

The bottom feeding fish species have a good potential to be used for assessments of pollution, as they are under pressure from pollutants from both water and sediments. In this study, the level of similarity of histopathological responses to pollution in gills and liver between barbel (Barbus barbus) and sterlet (Acipenser ruthenus) from the Danube River was assessed, and compared with elemental concentrations in their gills, liver, and muscle. Results indicate that the detected metal concentrations were likely cause of different tissue responses in gills and liver of the two investigated fish species. Statistical analysis indicated a clear differentiation of the two species based on elemental concentrations and the level of histopathological changes in gills and liver. Metal concentrations exceeded maximum acceptable concentrations in a number of analyzed specimens, which indicates the importance of this type of monitoring. Results indicate that barbel is a better indicator for specific, rather narrow sites, whereas sterlet is a better indicator of larger (longer) water current segments. Obtained information could be of importance for both scientists and fishery and water management authorities working on the development of water monitoring programs.