Ronaldo Sousa

• PhD
• Professor at University of Minho

Resource pulses are episodes of low frequency, large magnitude and short duration that result in increased resource availability in space and time, with consequences for food web dynamics. Studies assessing the importance of resource pulses by invasive alien species in the interface between terrestrial and aquatic ecosystems are rare, especially th...

Study of the impacts of biological invasions, a pervasive component of global change, has generated remarkable understanding of the mechanisms and consequences of the spread of introduced populations. The growing field of invasion science, poised at a crossroads where ecology, social sciences, resource management, and public perception meet, is inc...

Several non-indigenous bivalve species have been colonising aquatic ecosystems worldwide, in some cases with great ecological and economic impacts. In this paper, we focus on the ecosystem engineering attributes of non-indigenous invasive bivalves (i.e., the capacities of these organisms to directly or indirectly affect the availability of resource...

This study evaluates the potential of brown trout (Salmo trutta) as a biological control of a recently established signal crayfish (Pacifastacus leniusculus) population in a protected area (Baceiro River, Montesinho Natural Park, Portugal). Five sampling sites were monitored over an entire year. Results indicated that brown trout was able to predat...

Individual variation assessments are essential to better understand population and community dynamics, as well ecosystem functioning. Although researchers have long recognized this aspect, only recently has evidence accumulated about the ecological importance of variation within species. The incorporation of individual variation provides an even mo...

Biological invasions and human migrations have increased globally due to socio-economic drivers and environmental factors that have enhanced cultural, economic, and geographic connectivity. Both processes involve the movement, establishment, and spread of species, yet unfold within fundamentally different philosophical, social and biological contex...

The non-native signal crayfish (Pacifastacus leniusculus) may alter ecosystems and affect local biota by changing the availability of chemical elements that accumulate and may act as contaminants. This elemental availability may change spatially. In this study, we investigate the differences in elemental exposure in signal crayfish in the Rabaçal R...

Molluscs represent the second most diverse phylum on Earth and are among the most prevalent in freshwater ecosystems, exhibiting both high species richness and abundance/biomass. In addition, molluscs are one of the taxonomic groups with the highest number of non-native species in freshwater ecosystems. Many of these have significant ecological and...

Invasion science addresses interconnected ecological, economic, and social challenges posed by the introduction of non-native species. Hence, invasion scientists have to consider and reconcile interdisciplinary needs while addressing potential implications of their findings. Navigating diverse disciplines, including environmental sciences, ecology,...

Invasive species have been drivers of biodiversity loss and functional changes in aquatic ecosystems, including in protected areas. Therefore, monitoring population invasion dynamics and biological traits is fundamental to better understand their ecological and economic impacts and for management actions development. We followed signal crayfish (Pa...

Technological advances have boosted the ability to obtain large and high-quality ecological data. These new technological tools have the potential to rapidly develop knowledge on how species behave and interact in ecosystems at relevant spatial and temporal scales. Comprehensive time-series datasets on the in situ behaviour and dispersal of wild or...

This study highlights the conservation problems faced by the tiny freshwater bivalves of the family Sphaeriidae, also known as pea, pill, or fingernail clams (or mussels) in Europe. Despite their global distribution, assumed ecological importance, and potential uses, basic knowledge about their taxonomy, biology, and ecology is very limited and muc...

The loss of lateral hydrological connectivity (LLHC) in freshwater ecosystems is increasingly threatening biodiversity; however, studies reporting this situation are limited, especially those assessing multi-measure biodiversity features at large spatial scales. Here, and using one the most threatened taxonomic groups in freshwater ecosystems, we e...

Here, we present a synthesis of the available knowledge on the Giant Freshwater Pearl Mussel Pseudunio auricularius (= Margaritifera auricularia) (Spengler, 1793). We also identify critical knowledge gaps that require attention for effective conservation guidance and species recovery. Pseudunio auricularius is one of Europe’s most endangered invert...

Biological invasions cause biodiversity erosion on a global scale. Invasive species spreading beyond their natural range compete with native fauna for food and space, push native species to suboptimal habitats, impairing their behaviour and thus limiting their occurrence. Freshwater ecosystems are especially vulnerable to biological invasions and t...

The introduction of invasive species has become an increasing environmental problem in freshwater ecosystems due to the high economic and ecological impacts it has generated. This systematic review covers publications from 2010 to 2020, focusing on non-native invasive freshwater bivalves, a particularly relevant and widespread introduced taxonomic...

Invasion scientists need to focus on the population level, not the species level, if aiming to unravel the complexities of invasion dynamics at meaningful spatial and temporal scales and contribute to a more comprehensive understanding of how invasive non-native species interact with and impact ecosystems.

Biological invasions cause biodiversity erosion on a global scale. Invasive species spreading beyond their natural range compete with native fauna for food and space, push native species to suboptimal habitats, impairing their behaviour and thus limiting their occurrence. Freshwater ecosystems are especially vulnerable to biological invasions and t...

Non-native invasive species threaten freshwater biodiversity and ecosystem services (ES), which are critical for environmental health and possess noteworthy socioeconomic and cultural importance. This research specifically delves into the impact of the signal crayfish (Pacifastacus leniusculus) in a protected area (Montesinho Natural Park, Portugal...

Global technological advances have boosted the discovery of new tools that have increased the ability to obtain large and high-quality ecological data with the potential to rapidly develop knowledge on how species behave and interact in ecosystems. Comprehensive time-series datasets on the in situ behaviour and dispersal of wild organisms are essen...

Freshwater mussels (Bivalvia, Unionida) play essential roles in the well-functioning of ecosystems, even providing essential services to humans. However, these bivalves face numerous threats (e.g. habitat loss and fragmentation, pollution, introduction of invasive species, and climate change) which have already led to the extinction of many populat...

Predation is a dominant structuring force in ecological communities. In aquatic environments, predation on bivalves has long been an important focal interaction for ecological study because bivalves have central roles as ecosystem engineers, basal components of food webs, and commercial commodities. Studies of bivalves are common, not only because...

Mollusca is the second largest phylum on Earth comprising more than 90,000 species. Molluscs are responsible for key functions and services in aquatic and terrestrial ecosystems. Despite their diversity and ecological and economic importance, several knowledge gaps exist concerning their basic biology. In this mini-review, I succinctly propose a ne...

Individual variation assessments are essential to better understand population and community dynamics, and ecosystem functioning. Although researchers have long recognized this aspect only recently has evidence accumulated about the ecological importance of variation within species. The incorporation of individual variation provides a more complete...

EuropaBON EBV workflow templates The information provided here represents the EBV workflow templates collected during the EuropaBON online workshop on Essential Biodiversity Variable (EBV) workflows from 22–24 February 2023. The templates were designed to capture comprehensive descriptions about the three workflow components (data collection and s...

The information represents the EBV workflow templates collected during the EuropaBON online workshop on Essential Biodiversity Variable (EBV) workflows from 22–24 February 2023. The templates were designed to capture comprehensive descriptions about the three workflow components (data collection and sampling, data integration, and modelling) that...

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. R...

Organism features, such as size, weight, sex and age, among others, can influence the success of parasitism. For species that depend on a host to complete their life cycle, such as freshwater mussels (Bivalvia, Unionida), understanding how these traits influence parasitism can help guide management actions aimed at improving their reproductive succ...

Climate change may lead to range shifts, and barriers to such displacements may result in extirpations from previously suitable habitats. This may be particularly important in freshwater ecosystems that are highly fragmented by anthropogenic obstacles, such as dams and other smaller in-stream barriers. Conservation planning in freshwaters should co...

In the context of the European Union (EU) Drinking Water Directive, freshwater mussels (Order Unionoida: Bivalvia) can help us face the challenges of safe drinking water provisions for all citizens in the EU. Specifically, the implementation of high frequency noninvasive (HFNI) valvometers allows the early detection of eventual pollution events in...

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relat...

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relat...

Freshwater mussels are one of the most threatened animal groups in the world. In the European Union, threatened and protected mussel species are not adequately monitored, while species considered to be common and widespread receive even less attention. This is particularly worrying in the Mediterranean region, where species endemism is high and fre...

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relat...

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relat...

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relat...

1. Clams from the Corbicula species complex of Asian origin are invasive all over the world, currently extending their distribution to waters of the natural thermal regime in Central European areas. Features linking the clams to their habitats in newly invaded areas have not been fully examined. These include substratum preferences and mobility, wh...

Corbicula fluminea is a widespread and problematic invasive bivalve species in many freshwater ecosystems. Here, a systematic literature review was performed to synthesise what is presently known about C. fluminea in relation to its biology, ecology, and management. Of the total 1156 studies analysed, most were conducted in North America and Europe...

The Asian clam Corbicula fluminea has been widely introduced into aquatic ecosystems and may impact the physiological condition and survival of native freshwater mussels. However, very few studies have evaluated this issue quantitatively. To fill this gap, manipulative field experiments were performed to assess two possible mechanisms of impact on...

Climate change is becoming the leading driver of biodiversity loss. The Mediterranean region, particularly southwestern Europe, is already confronting the consequences of ongoing global warming. Unprecedented biodiversity declines have been recorded, particularly within freshwater ecosystems. Freshwater mussels contribute to essential ecosystem ser...

Freshwater biodiversity is under threat, but long-term quantitative studies showing major demographic declines in invertebrate species are still scarce. Here we focus on a long-term study (2004 to 2019) using four native freshwater mussel species (Order Unionida) colonizing two canals of the Ebro River (Spain). Special attention was given to Pseudu...

Freshwater mussels (FMs) are useful bioindicators to detect environmental disturbances. However, studies that evaluate FMs suitability for monitoring the hydrodynamic stressors impact are lacking. Since future climatic scenarios predict an increase in frequency and intensity of extreme events, understanding how flood conditions affect freshwater or...

Aim Freshwater mussels are among the most threatened taxa in the world, partially due to the dependence on fish hosts to complete their life cycle. Knowledge about the role of environmental and biotic drivers in determining mussels' distribution is currently lacking. We aimed to assess the role of environmental and biotic drivers in determining the...

Currently, the parasitic and endosymbiontic fauna of Corbicula clams remain poorly studied throughout their range. Here, using samples from the Mekong basin, we describe two Symbiocloeon species new to science: Symbiocloeon corbiculinus sp. nov. and Symbiocloeon laoensis sp. nov. Our results and a review of available published data indicate that fr...

Information about biotic interactions (e.g. competition, predation, parasitism, diseases, mutualism, allelopathy) is fundamental to better understand species distribution and abundance, ecosystem functioning, and ultimately guide conservation efforts. However, conservation planning often overlooks these important interactions. Here, we aim to demon...

We identified 14 emerging and poorly understood threats and opportunities for addressing the global conservation of freshwater mussels over the next decade. A panel of 17 researchers and stakeholders from six continents submitted a total of 56 topics that were ranked and prioritized using a consensus-building Delphi technique. Our 14 priority topic...

Europe has a long history of human pressure on freshwater ecosystems. As pressure continues to grow and new threats emerge, there is an urgent need for conservation of freshwater biodiversity and its ecosystem services. However, whilst some taxonomic groups, mainly vertebrates, have received a disproportionate amount of attention and funds, other g...

In this correspondence, we show for the first time that mayflies, chironomids, and fishes can use the Corbicula clams as host for their larval development. These examples were collected within the native range of Corbicula in East and Southeast Asia (Thailand, Laos, and South Korea). Supplementary information is available on figshare: https://doi.o...

Pseudunio auricularius (Spengler, 1793) is one of the most threatened unionid species worldwide. Translocation is considered one of the ultimate actions that can save this species from extinction in the Iberian Peninsula. Since 2013, massive mortalities have been recorded in the Canal Imperial de Aragón (CIA), an anthropogenic habitat where the hig...

The armed conflict in Ukraine is the first in Europe after decades of peace and is currently taking thousands of human lives while reshaping global geopolitical dynamics. On top of its humanitarian and economic consequences, we cannot ignore the widespread environmental impacts of an armed conflict at this scale.

The species Cyanocyclas brasiliana (Deshayes, 1854) is endemic to South America and occurs in northern Brazil, in the state of Amazonas, Pará and Piauí. The present study was carried out in the Parnaíba River estuary, Piauí, Brazil. The objective of this study was to verify the tolerance limit and survival of the freshwater bivalve Cyanocyclas bras...

Climate change is expected to alter impacts of invasive alien species (IAS). As omnivores and ectotherms, invasive crayfish species (ICS) can be particularly influenced by altered thermal regimes with possible impacts on native species and key ecosystem processes, such as leaf-litter breakdown. We performed a controlled study using a multi-trophic...

Identification of ecosystem services, i.e. the contributions that ecosystems make to human well-being, has proven instrumental in galvanising public and political support for safeguarding biodiversity and its benefits to people. Here we synthe-sise the global evidence on ecosystem services provided and disrupted by freshwater bivalves, a heterogeno...

Taxonomic and aesthetic biases permeate biodiversity conservation. We used the LIFE program-the European Union's funding scheme for the environment-to explore the economic dimension of biases in species-and habitat-level conservation. Between 1992 and 2020, animal species received three times more funding than plants. Within plants, species at nort...

The freshwater pearl mussel Margaritifera margaritifera has been suffering major population declines in Europe. This endangered species is a host specialist and exclusively requires salmonid species ( Salmo trutta and Salmo salar ) to complete its life cycle. In theory, obligatory biotic interactions should deserve special conservation attention, b...

Invasive alien species (IAS) are leading to the homogenisation of taxonomic and functional biodiversity, with negative consequences for key ecosystem processes in fresh water. Invasive signal crayfish ( Pacifastacus leniusculus ) is expected to disrupt detritus‐based food webs by affecting leaf breakdown and/or by decreasing invertebrate density an...

The X Iberian Symposium on the Hydrographic Minho River Basin, organized by the Aquamuseu do Rio Minho/Câmara Municipal de Vila Nova de Cerveira and co-organized by the Interdisciplinary Centre of Marine and Environmental Research (CIIMAR) - University of Porto, in a multidisciplinary context, addressed themes that covered areas from the geochemist...

O X Simpósio Ibérico Sobre a Bacia Hidrográfica do Rio Minho, organizado pelo Aquamuseu do Rio Minho/Câmara Municipal de Vila Nova de Cerveira e co-organizado pelo Centro Interdisciplinar de Investigação Marinha e Ambiental – Universidade do Porto, num contexto multidisciplinar, abordou temas que abrangeram áreas desde a geoquímica de sedimentos e...

Climate change is expected to alter impacts of invasive alien species (IAS). As omnivorous and ectotherms, invasive crayfish species (ICS) can be particularly influenced by altered thermal regimes with possible impacts on native species and key ecosystem processes, such as leaf-litter breakdown. We performed a controlled study using a multi-trophic...

1. Pseudunio marocanus (Pallary, 1918) is an endemic species of Morocco and is considered one of the world's 100 most threatened species. The life cycle of this critically endangered freshwater mussel remains unknown. However, knowledge about the discharge period of its larvae and its ecological fish hosts is crucial to adopt more effective conserv...

Corbicula fluminea is a known aquatic invasive species responsible for several ecological and economic impacts. In Portugal, it is found in all major watersheds, although to varying degrees of invasion (regarding density, biomass and spatial distribution). The aim of this study was to evaluate the spatio-temporal differences in condition indices (C...

The Asian clam (Corbicula spp.) was first detected in 2004 in the Ebro River (Aragón, Spain). In 2006, it was also found in the Canal Imperial de Aragón (CIA) and in 2007 in the Canal de Tauste (CT). Both artificial canals held large populations of native freshwater mussels and are the main habitat of Pseudunio auricularius (Spengler 1793). However...

Theidentification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species...

Pseudunio auricularius is one of the most threatened freshwater mussel species worldwide and is classified as Critically Endangered in the IUCN Red List. The artificial Canal Imperial de Aragón (CIA) in the Ebro basin (Aragón-Spain) presents the largest census colony in the world (around 6000 tagged specimens), but since 2013 it has suffered a shar...

Droughts can change the distribution and alter the behaviour, phenology and physiology of many species, leading in extreme cases to high mortalities or even extirpation. In this study, a before/after comparison was performed in two Portuguese river basins (Rabaçal and Tuela) to assess the possible effects of an extreme drought on the abundance and...

Populations of the critically endangered freshwater mussel Pseudunio auricularius (Spengler, 1793) have been suffering sharp declines, particularly in the Ebro basin (Iberian Peninsula). Among other factors, pollution could be responsible for these declines. We conducted, for the first time, acute toxicological tests (96 h) with heavy metals and am...

Molluscs are among the most diverse and widespread animal groups in freshwater habitats. Unfortunately, like most freshwater taxa, they are decreasing dramatically and are now among the most threatened animals on Earth, with many species already extinct or on the brink of extinction. Here, we review our current knowledge on the biodiversity and con...

• 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...

Anthropogenic freshwater habitats may provide undervalued prospects for long‐term conservation as part of species conservation planning. This fundamental, but overlooked, issue requires attention considering the pace that humans have been altering natural freshwater ecosystems and the accelerated levels of biodiversity decline in recent decades. We...

The morphological plasticity of bivalve species may impair their correct identification. Pisidium species (Sphaeriidae) are difficult to distinguish, notably the common pea clam, Pisidium ca-sertanum (Poli, 1791), which is a polymorphic species, often misidentified and confused with other Pisidium species. This is especially true since this species...

• Freshwater ecosystems are essential to human well‐being and most have high biodiversity. However, this biodiversity has been suffering severe declines owing to the expansion of human activities. Protected areas (PAs) are essential for biodiversity conservation and have proved to be successful in stopping species extirpation if managed properly. U...

Although biodiversity is considered a value to be protected to avoid the degradation of ecosystem functions, conservation practices ignore the role of many species. Species are not protected according to their degree of risk, but according to their degree of attractiveness. The so-called iconic species are used as flag species to convince the publi...

The Unionidae represent an excellent model taxon for unravelling the drivers of freshwater diversity, but, phylogeographic studies on Southeast Asian taxa are hampered by lack of a comprehensive phylogeny and mutation rates for this fauna. We present complete female- (F) and male-type (M) mitogenomes of four genera of the Southeast Asian clade Cont...

Through the Habitats Directive (92/43/EEC) and the financial investments of the LIFE projects, Europe has become an experimental arena for biological conservation. With an estimated annual budget of €20 billion, the EU Biodiversity Strategy for 2030 has set an ambitious goal of classifying 30% of its land and sea territory as Protected Areas and en...

A simple and low-cost method of monitoring and collecting particulate matter detaching from (or interacting with) aquatic animals is described using a novel device based on an airlift pump principle applied to floating cages. The efficiency of the technique in particle collection is demonstrated using polyethylene microspheres interacting with a cy...

The number of non-native freshwater fishes in the Iberian Peninsula has been greatly increasing. In this study, individuals of the genus Phoxinus were detected in 18 out of 138 stream sites sampled across the Douro Basin in 2017 and 2018. A total of 26 individuals were barcoded using partial cytochrome c oxidase subunit I (COI) and cytochrome b (cy...

Through the Habitats Directive (92/43/EEC) and the LIFE projects financial investments, Europe has been the world experimental arena for biological conservation. With an estimated budget of 20 billion euro/year, the EU Biodiversity Strategy for 2030 has set an ambitious goal of reaching 30% Protected Areas and ensure no deterioration in conservatio...

Meiofauna organisms play an important role in ecological, trophic and sedimentary processes in estuarine ecosystems. Recently, the application of environmental DNA (eDNA) for investigating meiofauna in different environments, improved the accessibility to its diversity and composition in a scale, frequency and depth previously unattainable. Neverth...

European freshwater pearl mussel (Margaritifera margaritifera) populations are declining despite a growing effort to conserve them. Here we used a combination of local ecological knowledge (LEK) and field sampling to assess past and current distribution and conservation status of this endangered species in Cávado and Neiva Rivers (Portugal). We per...