Use of seasonally flooded rice fields by fish and crayfish in a Mediterranean wetland

Rice fields constitute a significant proportion of the existing wetlands in the Mediterranean basin and are important areas for the conservation of different vertebrate species, especially birds. However, little is known on how fish and crayfish use rice fields in Mediterranean areas. In this work we analyze fish communities and crayfish populations occupying rice fields and their associated irrigation network (inflow and outflow channels) in the Ebro Delta (NE Spain). We set fyke nets in 104 sites and captured almost 23,000 fish belonging to 19 species, 9 of which were found to occupy rice fields, as well as over 3000 red swamp crayfish (. Procambarus clarkii). Stone moroko (Pseudorasbora parva), common carp (Cyprinus carpio), dojo loach (Misgurnus anguillicaudatus) and Eastern mosquitofish (Gambusia holbrooki) were the most common fish found in rice fields. More than 95% of the fish individuals captured belonged to non-native species. Dojo loach, a recently introduced species well adapted to rice cultivation cycles in its native range, used rice fields as reproduction ground. Outflow channels seemed to be a more important source of fish colonizing rice fields than inflow channels. Colonization was the main limitation for the establishment of fish populations in rice fields and fish tended to be more abundant in rice fields than in channels for any given frequency of occurrence. The importance of fish as trophic resource for natural predators and the possible interactions between fish occupying rice fields and rice yield, largely unexplored in the Mediterranean areas, could be managed by modulating connectivity between rice fields and irrigation channels. Rice fields, however, are not important areas for the conservation of native fish biodiversity, being largely occupied by non-native fishes. Moreover, the influence of low-conductivity water diverted for rice cultivation on natural wetlands favors the establishment and expansion of different non-native fish species.Peer Reviewe

The ecology of sexual dimorphism in size and shape of the freshwater blenny Salaria fluviatilis.

Sexual selection is considered the major cause of sexual dimorphism, but recent observations suggest that natural selection may play a more important role in the evolution of sex differentiation than previously recognized. Therefore, studying the trade-offs between natural selection and sexual selection is crucial to a better understanding of the ecology underlying the evolution of sexual dimorphism. The freshwater blenny Salaria fluviatilis, a fish inhabiting lakes and rivers around the Mediterranean Sea, displays strong sexual dimorphism in size, shape, and behavior (i.e., larger body and head size for males and higher swimming requirements for females during the reproductive period). We tested for differences in sexual dimorphism in size and shape between the populations from lake and river habitats with the goal of identifying the trade-offs between natural and sexual selection that underlie variations in sexual dimorphism in this species. Our results show i) differences in sexual size dimorphism (SSizeD) in accordance to Rensch's rule (i.e., larger individuals in rivers associated with higher SSizeD), and ii) a decrease in shape differentiation between males and females in lake populations. Together, this suggests that the different environmental conditions between lake and river habitats (e.g., resource limitations, predation pressure, water velocity) affect the relative importance of sexual selection in the display of sexual dimorphism within the species. This study highlights the importance of considering the environmental conditions to which populations are exposed to better understand the ecology underlying the evolution of sexual dimorphism

RECOMENDAÇÕES ESTRATÉGICAS PARA A GESTÃO TRANSNACIONAL DE LAGOSTINS E CARANGUEJOS EXÓTICOS INVASORES NAS ÁGUAS INTERIORES DA PENÍNSULA IBÉRICA

Um objetivo importante do LIFE INVASAQUA é desenvolver ferramentas que melhorem a gestão e aumentem a eficácia no Alerta Precoce e Resposta Rápida para Espécies Exóticas Invasoras (EEI) na Península Ibérica. Desenvolvemos um processo participativo com especialistas para obter recomendações estratégicas para a gestão transnacional de lagostins e caranguejos exóticos invasores em águas continentais de Espanha e Portugal. As recomendações foram concebidas para servir de instrumento orientador para identificar uma direção estratégica seguindo a governação espanhola e portuguesa que já está a ser desenvolvida. As recomendações resultantes são uma ferramenta importante para apoiar a implementação do Regulamento EEI da UE. Em última análise, as informações incluídas podem ser utilizadas para atingir a meta da Estratégia de Biodiversidade da UE para 2030 de combate às espécies exóticas invasoras, e também para a implementação de outras políticas da UE com requisitos relativos a espécies exóticas, como as Diretiva Aves e Habitats, Diretiva-Quadro da Estatégia Marinha (DQEM) e Diretiva-Quadro da Água (DQA)

Strategic Recommendations for the Transnational Management of Invasive Alien Crayfish and Crabs in Iberian Inland Waters

An important goal of LIFE INVASAQUA is to develop tools that will improve management and increase the efficiency of the Early Warning and Rapid Response framework for Invasive Alien Species (IAS) in the Iberian Peninsula. We developed a participative process with experts in order to obtain Strategic Recommendations for the transnational management of invasive alien crayfish and crabs in inland waters of Spain and Portugal. They promote the coordinated management between Spain and Portugal, in order to facilitate implementation of international commitments and best practices and to support development of policies and targets on IAS management at Iberian scale. They were designed to serve as a guiding tool seeking to identify a strategic direction for the Spanish and Portuguese governance that is already being developed. The resulting Strategic Recommendations are important tools supporting the implementation of the IAS EU Regulation. Ultimately, the information included can be used for achieving the target of the EU Biodiversity Strategy to 2030 for combatting IAS, and also for implementing of other EU policies with requirements on alien species, such as the Birds and Habitats Directives, and the Marine Strategy and Water Framework Directives

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one

Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula.

Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula

Guía de las especies Exóticas e Invasoras de los Ríos, Lagos y Estuarios de la Península Ibérica.

Guía de las especies Exóticas e Invasoras de los Ríos, Lagos y Estuarios de la Península Ibérica

Guia das Espécies Exóticas e Invasoras dos Rios, Lagos e Estuários da Península Ibérica.

Guia das Espécies Exóticas e Invasoras dos Rios, Lagos e Estuários da Península Ibérica

LISTA NEGRA Y LISTA DE ALERTA DE ESPECIES EXÓTICAS INVASORAS ACUÁTICAS DE LA PENÍNSULA IBÉRICA - Ejercicio de exploración del horizonte transnacional centrado en las especies exóticas invasoras acuáticas de alto riesgo para las aguas interiores ibéricas.

Un objetivo importante de LIFE INVASAQUA es desarrollar herramientas que mejoren la gestión y sean más eficientes en el marco de Alerta Temprana y Respuesta Rápida (EWRR) para las Especies Exóticas Invasoras (EEI) en la Península Ibérica. La exploración del horizonte para las EEI de alto riesgo es básica para aplicar medidas que reduzcan las nuevas invasiones y para centrar los esfuerzos en las especies ya registradas. Desarrollamos un ejercicio transnacional de exploración del horizonte centrado en las aguas interiores de España y Portugal con el fin de proporcionar una lista negra de las EEI acuáticas actualmente establecidas y una lista de alerta de las EEI acuáticas potenciales que pueden suponer una amenaza para los ecosistemas acuáticos y los sectores socioeconómicos en el futuro. Para la exploración del horizonte seguimos un enfoque estructurado de 5 pasos que combinaba las pruebas existentes sobre las EEI con una puntuación de expertos de los taxones priorizados. En la lista negra final se priorizaron 126 EEI, que representan el 41,2% de los taxones exóticos registrados en las aguas continentales ibéricas. Las 24 primeras especies tenían un riesgo de impacto muy alto porque obtuvieron los valores máximos en el proceso de puntuación de la evaluación de riesgos. Además, la lista de alerta incluía 89 EEI con un riesgo significativo de invasión en la Península Ibérica en el futuro, estando 11 taxones en cabeza con un riesgo muy alto de invasión

Biology and habitat use of three-spined stickleback (Gasterosteus aculeatus) in intermittent Mediterranean streams

We present the first data on three-spined stickleback (Gasterosteus aculeatus) life history and habitat use in seasonal Mediterranean streams, analysing populations from NE Iberian Peninsula. Stickleback populations were strictly annual, with reproduction events involving exclusively 1+ fish. Somatic growth was concentrated in two periods, one in spring and early summer, and another in autumn and winter. During summer there was a clear stop in the somatic growth, coupled with low values of somatic condition. This growth pattern contrasts both with that of other Mediterranean stream fish species and that of stickleback in other European locations. Stickleback populations occupied mainly intermediate locations along fluvial gradients. The presence of abundant aquatic vegetation was identified as one of the main factors related with both stickleback presence and the abundance of its populations, while the latter was also negatively related with that of invasive fish and crayfish species. Stickleback tended to occur in native-dominated fish communities, being almost absent from lower stream reaches, which bear high abundances of invasive fish species.Peer reviewe