Browsing by Author "Reis, Joaquim"
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- Ecology of southern European pearl mussels (Margaritifera margaritifera): first record of two new populations on the rivers Terva and Beça (Portugal)Publication . Varandas, Simone; Lopes-Lima, Manuel; Teixeira, Amílcar; Hinzmann, Mariana; Reis, Joaquim; Cortes, Rui M.V.; Machado, Jorge; Sousa, RonaldoSouthern European populations of Margaritifera margaritifera (L., 1758) are under-studied. From 1986 to 2001 this species was considered extinct in Portugal but between 2001 and 2002 six northern populations were found, five of which were previously unknown. 2. This study comprises a comparative study of the ecology and habitat requirements of two new populations in the rivers Beça and Terva (tributaries of the River Tâmega, northern Portugal) with non-Iberian populations. 3. Surveys were conducted in 2010/2011 to characterize ecological status and propose possible conservation measures. Both rivers were in good environmental condition, but the River Beça had higher biological, physicochemical and hydromorphological quality. 4. Both populations are highly susceptible to extirpation – in particular the River Terva population, given the very low number of specimens found and no sign of recent recruitment. The low number of juveniles and the existence of several threats in both rivers (e.g. fragmentation and loss of habitat caused by the presence of physical obstacles, organic pollution and bank erosion due to fires) imply the need for urgent, effective, conservation measures. 5. Southern European M. margaritifera populations have similar ecological and habitat requirements compared with those of northern and central Europe. However, functional populations may endure higher phosphate content, pH and temperature values. As expected they present faster growth rates and reduced life spans.
- A roadmap for the conservation of freshwater mussels in EuropePublication . Sousa, Ronaldo; Zając, Tadeusz; Halabowski, Dariusz; Aksenova, Olga V.; Bespalaya, Yulia V.; Carvalho, Francisco; Castro, Paulo S.; Douda, Karel; Silva, Janine P.; Ferreira-Rodríguez, Noé; Geist, Juergen; Gumpinger, Clemens; Labecka, Anna M.; Lajtner, Jasna; Lewin, Iga; Lopes-Lima, Manuel; Meira, Alexandra; Nakamura, Keiko; Nogueira, Joana Garrido; Ondina, Paz; Ożgo, Małgorzata; Reis, Joaquim; Riccardi, Nicoletta; Shumka, Spase; Son, Mikhail O.; Teixeira, Amílcar; Thielen, Frankie; Urbańska, Maria; Varandas, Simone; Wengström, Niklas; Zajac, Katarzyna; Zieritz, Alexandra; Aldridge, David C.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 groups remain largely off the public and scientific radar. Freshwater mussels (Bivalvia, Unionida) are an alarming example of this conservation bias and here we point out six conceptual areas that need immediate and long-term attention: knowledge, threats, socioeconomics, conservation, governance and education. The proposed roadmap aims to advance research, policy and education by identifying the most pressing priorities for the short- and long-term conservation of freshwater mussels across Europe.
- Setting the stage for new ecological indicator species: a holistic case study on the Iberian dolphin freshwater mussel Unio delphinus Spengler, 1793Publication . Lopes-Lima, Manuel; Hinzmann, Mariana; Varandas, Simone; Froufe, Elsa; Reis, Joaquim; Moreira, Cláudia; Araújo, Sandra; Miranda, Fernando Jorge Veloso; Gonçalves, Duarte V.; Beja, Pedro; Sousa, Ronaldo; Teixeira, AmílcarDue to their sensitivity and dramatic declines, freshwater mussels are prime targets for conservation and environmental monitoring. For this, however, information is needed on life history and ecological traits, which is lacking in many taxa, including threatened species. Species recently described or recognized as valid are of particular concern, due to the shortage of even basic knowledge. A case in point is the recently recognized and Near Threatened dolphin freshwater mussel Unio delphinus Spengler, 1793, which is endemic to the western Iberian Peninsula and has suffered marked population declines. To overcome information gaps for U. delphinus, we carried out a holistic biological study across the species range, aiming to: i) estimate the area of occupancy (AOO) and extent of occurrence (EOO) based on updated distribution data taken from the literature and recent surveys; ii) estimate growth patterns from biometrical (shell dimensions and growth annuli) measurements taken on specimens from seven populations; iii) estimate sex ratios from gonad tissue biopsies collected on specimens from eight populations; iv) estimate gametogenesis and sex ratio through histological examination of gonad and gill tissues collected monthly for a year, from a single population; and v) determine host species from infestation trials of glochidia with co-occurring fish species. We estimated an EOO of 706 km2 and an AOO of 61 km2, which together with data on declines assigns the species to the Endangered category using IUCN criteria. Unio delphinus was found to grow faster and to be shorter-lived (up to 11 years, maturity at around 2 years old) than other European freshwater mussels. Growth and life span are similar across the range in lotic habitats, but different from that in lentic habitats. The larvae of U. delphinus may attach to most co-occurring fish species, but only native species were effective hosts. Native cyprinids, especially those from the genus Squalius, seem to be the primary hosts. Overall, the information provided contributes to a better conservation status assessment, selection of conservation and rehabilitation areas, guidance for the establishment of propagation programs and better timing for specimens’ manipulation including monitoring and possible translocations. The framework presented here highlights the importance of basic biological studies to define good ecological and physiological status.
- Streams in the Mediterranean Region are not for mussels: predicting extinctions and range contractions under future climate changePublication . Silva, Janine P.; Sousa, Ronaldo; Goncalves, Duarte Vasconcelos; Miranda, Rafael; Reis, Joaquim; Teixeira, Amílcar; Varandas, Simone; Lopes-Lima, Manuel; Filipe, Ana FilipaClimate change is becoming the leading driver of biodiversity loss. The Mediterranean region, particularly southwest-ern 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 services but are among the most threatened faunal groups on Earth. Their poor conservation status is related to the de-pendence on fish hosts to complete the life cycle, which also makes them particularly vulnerable to climate change. Species Distribution Models (SDMs) are commonly used to predict species distributions, but often disregard the poten-tial effect of biotic interactions. This study investigated the potential impact of future climate on the distribution of freshwater mussel species while considering their obligatory interaction with fish hosts. Specifically, ensemble models were used to forecast the current and future distribution of six mussel species in the Iberian Peninsula, including envi-ronmental conditions and the distribution of fish hosts as predictors. We found that climate change is expected to se-verely impact the future distribution of Iberian mussels. Species with narrow ranges, namely Margaritifera margaritifera and Unio tumidiformis, were predicted to have their suitable habitats nearly lost and could potentially be facing regional and global extinctions, respectively. Anodonta anatina, Potomida littoralis, and particularly Unio delphinus and Unio mancus, are expected to suffer distributional losses but may gain new suitable habitats. A shift in their distribution to new suitable areas is only possible if fish hosts are able to disperse while carrying larvae. We also found that includ-ing the distribution of fish hosts in the mussels' models avoided the underprediction of habitat loss under climate change. This study warns of the imminent loss of mussel species and populations and the urgent need of management actions to reverse current trends and mitigate irreversible damage to species and ecosystems in Mediterranean regions.
- The silent extinction of freshwater mussels in PortugalPublication . Lopes-Lima, Manuel; Reis, Joaquim; Alvarez, Maria G.; Anastácio, Pedro M.; Banha, Filipe; Beja, Pedro; Castro, Paulo S.; Gama, Mafalda; Gil, Maria G.; Gomes-dos-Santos, André; Miranda, Fernando Jorge Veloso; Nogueira, Joana Garrido; Sousa, Ronaldo; Teixeira, Amílcar; Varandas, Simone; Froufe, ElsaFreshwater 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 freshwater habitats are severely affected by water scarcity. In the absence of hard data on population trends, we report here a long-term comparison of freshwater mussel assemblages at 132 sites covering 15 different hydrological basins in Portugal. This study reveals a widespread decline of 60 % in the number of sites and 67 % in the overall abundance of freshwater mussels across Portugal over the last 20 years, indicating that all species are rapidly declining and threatened with extinction. These results show that current legislation and conservation measures are largely ineffective and highlight the importance of updating the Habitats Directive to enforce standard monitoring protocols for threatened species in the European Union and to extend monitoring to other freshwater species thought to be common and widespread. Efficient water management, restrictions on irrigation expansion in important biodiversity areas, mitigation of hydrological changes and loss of aquatic habitat connectivity caused by physical alterations are urgently needed to reverse these declining population trends. For the severely endangered species Margaritifera margaritifera, Potomida littoralis, and Unio tumidiformis, where populations are now critically low, more urgent action is needed, such as ex-situ conservation, protection of remaining populations and large-scale habitat restoration.