Forensic reconstruction of Ictalurus punctatus invasion routes using on-line fishermen records

In this work, the presence of the channel catfish Ictalurus punctatus in the Portuguese section of the Guadiana drainage (Iberian Peninsula) is confirmed based on morphological and molecular species identification. The spatial and temporal dispersal of this non-native catfish was also reconstructed for the Guadiana drainage, based mostly on online fishermen records with minor contributions from the few scientific reports available. The obtained records (mainly from angling fora) span the period since the species\u27 first reported presence in Iberia (1980s) up to the present, and support a westward invasion pattern of non-native fish (NNF) reported for the Iberian fish invasion hotspot. The invasion pathway is driven mainly by natural dispersal downstream at a rate between 8 and 42 km per year. Yet, at least four introduction events within the Guadiana drainage can unambiguously be assigned to human translocations after the initial human-mediated introduction. The present study reinforces the usefulness and relevance of using validated on-line fishermen records, provides a more complete and updated distribution range of NNF species and enables assessment of their dispersal patterns. This is of particular importance because it allows near real-time monitoring of NNF dispersal, including first occurrences of NNF, at minimal cost

Patterns and drivers of aquarium pet discharge in the wild

Aquarium pets release is an important vector for invasive species establishment in freshwater ecosystems. Here the perceptions and risk behaviors associated to this vector were evaluated using a survey. Portuguese aquarium hobbyists were interviewed through an on-line survey (Google forms) publicized in 9 web sites connected to this hobby (Facebook pages and internet forums). A Pet Propagule Pressure index (PPP), congregating information regarding pet’s popularity and electivity for discharge, was developed and applied in this study, so that relative comparisons can be made among different pet types (taxa). Additionally, non-metric Multidimensional Scaling (nMDS) was applied to pet owner’s data to identify indicator factors associated with risk behaviors and impacts’ awareness. Results indicated that aquarium pet owners usually only have one pet type, most commonly fish or turtles. Only 8% of the owners admit having discharged pets, being more commonly reported the release of only one pet. This risk behavior is connected mainly to the excessive growth of the pet and consequently lack of space in the aquariums. Pet’s discharge occurs until 100 km of distance from owner’s homes, being very common at distances lower than 1 km. The PPP index developed in this study, indicates the pet types with higher risk of discharge were the turtles and the fishes. Pet owner’s awareness regarding the pet discharges impacts in the environment seems to be lower than other risk groups connected to biological invasions in freshwaters, namely anglers. Pet owners most aware of these impacts were associated to higher education levels and higher experience on this hobby. Our study highlights the needs for more environmental education on particular social groups within aquarium pets’ owners, namely those that have started this activity or have lower education levels, to decrease the biological invasion risks associated to this hobby. Additionally, our findings regarding the patterns and drivers of discharge action itself are useful to model risk invasion, as well as for detection, management and control of these species

Human dispersal of freshwater invasive fauna

The main goal of this thesis was to improve the knowledge on the mechanisms involved on Human dispersal of freshwater invasive fauna, contributing for the management of these problematic species. Several vectors were investigated, both accidental and intentional, from a freshwater invaders list that included some of the worse species. It was found that the red swamp crayfish and the signal crayfish presented desiccation survival capacities compatible with long-distance human-mediated dispersal. Off-road vehicles constituted a viable accidental vector for invasive macroinvertebrates, like the red swamp crayfish and the bladder snail. Live bait capture using dip nets and crayfish trapping constitute viable vectors for invasive freshwater macrofauna dispersal. The former is more related with accidental transport of small invasive organisms, and the latter is mostly related with intentional transport of invasive fish species. The importance of the angling web forums as a useful tool to help detection of non-native fish species was demonstrated with the first record of European Perch, a non-native fish in continental Portugal. Freshwater anglers from Portugal and Spain presented preference for invasive fish species, similar mobility, low incidence of live bait use and similar perception of biological freshwater invasions processes and impacts. Differences among countries were found for angler's activity patterns throughout the year and motivations for introductions. Zebra mussel larvae desiccation survival is compatible with long-distance overland dispersal. Its transport by natural vectors, like ducks, or human vectors like fishing tackle, such as waders and keep nets is viable. Yet, when comparing both types of vectors, fishing tackle presented a higher propensity to spread zebra mussel larvae than ducks; Dispersão de fauna invasiva dulçaquícola pelo Homem Resumo: O principal objetivo desta tese foi melhorar o conhecimento dos mecanismos envolvidos na dispersão de fauna dulçaquícola invasiva pelo homem, contribuindo assim para a gestão destas espécies problemáticas. Investigaram-se vários vetores, quer acidentais quer intencionais de uma lista de invasores dulçaquícolas que incluem algumas das piores espécies. Verificou-se que o lagostim vermelho e o lagostim sinal possuem uma capacidade de sobrevivência à dessecação compatível com a sua dispersão a longa distância pelo Homem. Os veículos todo-o-terreno constituem um vetor viável para macroinvertebrados invasivos como o lagostim vermelho e o caracol aquático. A captura de isco vivo com recurso a camaroeiro e o uso de armadilhas para a captura de lagostim constituem vetores viáveis de dispersão para a macrofauna dulçaquícola, sendo que o primeiro está relacionado com o transporte acidental de pequenos organismos invasores e o segundo com transporte intencional de peixes invasores. Através do primeiro registo em Portugal Continental de Perca-europeia, uma espécie não-nativa, demostrou-se a importância de fóruns on-line de pesca desportiva como uma ferramenta útil para a deteção de peixes não-nativos. Os pescadores dulçaquícolas de Portugal e Espanha apresentam preferência por espécies de peixes invasores, similar mobilidade, baixa incidência no uso de isco vivo e similar perceção dos processos e impactos das invasões biológicas dulçaquícolas. Detetaram-se diferenças entre países nos padrões de atividade dos pescadores durante o ano e na motivação para as introduções. A sobrevivência à dessecação de larvas de mexilhão-zebra é compatível com o seu transporte a longas distâncias fora de água, sendo viável o seu transporte quer por vetores naturais, como patos, quer humanos como equipamento de pesca, como botas altas e redes de retenção. No entanto, quando se comparam ambos os tipos de vetores, o equipamento de pesca apresenta maior propensão que os patos para dispersar larvas de mexilhão-zebra

Non-native freshwater fauna in Portugal: a review

We present the most updated list of non-native freshwater fauna established in Portugal, including the Azores and Madeira archipelagos. This list includes 67 species at national level but corresponds to 84 species records, of which 53 are in the mainland, 23 in the Azores and 8 in Madeira archipelagos. We also discuss the progression of the cumulative number of introductions since 1800 and identify the most probable vectors of introduction, main taxonomic groups and their regions of origin. Furthermore, we review the existing knowledge about ecological and economic impacts, invasion risk and potential distribution of invaders, under present and future climatic conditions, and the applied management actions, including the production of legislation. Along the 20th century the number of successful introductions increased at an approximate rate of two new species per decade until the beginning of 1970s. Since then, this rate increased to about 14 new species per decade. These introductions were mainly a result of fisheries, as contaminants or for ornamental purposes. Fish and mollusks are the taxonomic groups with more established species, representing more than half of the total. Most species (>70%) are native from other regions of Europe and North America. Studies about ecological or socioeconomic impacts are more common for fish, crustaceans and mollusks. Impacts for most amphibians, reptiles and mammals are not thoroughly studied. A few studies on the impacts and management actions of health-threatening mosquitoes are also available. The potential distribution in the Portuguese territory was modelled for 26 species. Only a minority of these models provides projections of distributions under scenarios of future climate change. A comparison of the Portuguese and EU legislation shows large discrepancies in the invasive species lists. Using the EU list and a ranking procedure for the national context, we identify freshwater species of high national concern for which actions are urgently needed.This work was supported by the FRISK Project (Ref. PTDC/AAG-MAA/0350/2014) to F. Ribeiro and by the strategic plan of MARE - Marine and Environmental Sciences Centre (UID/MAR/04292/2013) to F. Banha with a short term post-doc grant on the University of Evora and a small project. A. F. Filipe was supported by the FRESHING project funded by FCT and COMPETE (PTDC/AAG-MAA/2261/2014 - POCI-01-0145-FEDER-356 016824). R. Sousa was supported by FRESHCO project (contract: PTDC/AGRFOR/1627/2014) funded by FCT

Population dynamics and expansion of Crangonyx pseudogracilis, a potentially invasive amphipod.

One of the main drivers of biodiversity loss is the introduction of exotic invasive species. In 2011, an abundant population of Crangonyx pseudogracilis, a freshwater amphipod native to North America, was detected in Portugal. This study allowed us to better understand its biology, analysing the population dynamics in a temporary river and a small lake for one year, and to follow its expansion. Our results showed that this species reproduces in the temporary river during most of the year, but in the lake only from March to July. Amphipod density decreases from May to October and increases from November to April. As usual, females were larger than males, but the proportion of females was higher than males at both sampling locations. Finally, we noticed a great increase in C. pseudogracilis distribution area in relation to what was observed in 2014, with a diffusion coefficient of 2495.27 km2/year and a spread rate of 26 km/year. However, no overlap was yet detected between native and exotic amphipod species

Can birds enhance the dispersal of freshwater macrocrustaceans?

The freshwater crustaceans, Crangonyx pseudogracilis, Atyaephyra desmaresti and Procambarus clarkii (hereby referred to as FCs) are non-native in several areas of their distribution range presumably due to human-mediated introductions. Here we test dispersal by waterbirds as a complementary mechanism of dispersal of these 3 species. For P. clarkii, we studied the transport of recently hatched juveniles while, for the other two species, adults were used. In an initial experiment, we evaluated the effect of environmental conditions and size on FCs desiccation survival time. Next, we performed a set of experiments to evaluate the likelihood of FCs taking a bird transport vector. This was quantified using a freshly dead mallard (Anas platyrhynchos) or mallard’s feet under still or moving conditions. A third set of experiments evaluated FCs survival probability during transport by birds. For that purpose we released, at several distances, pigeons carrying FCs on a small mesh bag. In addition, we also used a freshly dead mallard mounted on the top of a moving vehicle and carrying FCs on its feathers. All 3 species were capable of clinging to mallard’s feathers and to mallard’s feet resulting in successful transport. A value of the probability of taking the transport vector was obtained for each species under each set of experimental conditions. This probability depends on the water depth, on the resting time of the vector and on the stillness or movement of the vector. The time lengths for 50% or 90% mortality (LT50 and LT90) of the FCs when removed from the water and also when transported by birds show that they are capable of surviving overland bird transport. We found that some P. clarkii juveniles survived distances up to 150 km outside a moving vehicle simulating bird flight and up to 62 km when transported by birds. Nevertheless, the majority of the FCs was only capable of surviving much smaller distances. Our results have shown that FCs ectozoochory is possible and that, distance, size and environmental conditions can significantly affect the likelihood of survival of FCs during bird flight

o caso da rua das pedras negras n.os 21-28

UID/HIS/04666/2013Uma extensa escavação decorreu entre 1991 e 1998 em três edifícios contíguos na Rua das Pedras Negras, em Lisboa, cujos dados permanecem no essencial inéditos. Tendo o tema sido antes aflorado em data recente (Silva et al., no prelo), os autores publicam e descrevem o conjunto ali colectado das cerâmicas medievais importadas entre os finais do século XIII e o século XIV, que incluem produções valencianas, sevilhanas, granadinas, de Saintonge (polícroma, lisa e “mosqueada”), Norte da França, flamengas (Bruges e Antuérpia?), inglesas (Londres) e, eventualmente, dos Países Baixos. O seu conjunto a amostragem mostra um predomínio marcado das elaborações oleiras comerciadas a partir dos portos de Bordéus e La Rochele sobre todas as restantes origens, sendo sintomático quer da capacidade aquisitiva dos lisboetas atingida entre os reinados de D. Afonso III e D. Pedro I, como do papel preponderante desempenhado pela cidade de Lisboa no quadro das teias de relações comerciais marítimas então estabelecidas por Portugal com o norte atlântico europeu. An extensive archaeological excavation occurred between 1991 and 198 in Rua das Pedras Negras, Lisbon, but data remains mainly unpublished. The authors publish and describe the assemblage of medieval imported pottery dating from late 13th to 14th centuries, turning back to the theme already previously treated (Silva et al., forthcoming). Productions include fabrics originated in Valencia, Seville and Granada, Saintonge («polychrome», «highly decorated», plain and «mottled»), North French («highly decorated»), Flemish (from Bruges and perhaps Antwerp), English (London) and, eventually, the Low Countries. The overall assemblage demonstrates that ceramic productions exported through Bordeaux and La Rochelle harbours are predominant over the remaining, and quantity and diversity are symptomatic of high acquisition capacity verified by Lisboners between the reigns of Afonso III and Pedro I, as well as of the chief role played by Lisbon in the network of commercial maritime relations then established between Portugal and the north Atlantic European façade.publishersversionpublishe

A potential threat to amphibians in the European Natura 2000 network: Forecasting the distribution of the American bullfrog Lithobates catesbeianus.

Freshwater biodiversity is declining at an accelerated pace. Climate change and associated global warming and changes in precipitation patterns, combined with the expansion of generalist -invasive species are two of the main threats. Niche-based models (NBMs) are becoming inevitable tools in invasive species risk assessment and in conservation decision-making. Lithobates catesbeianus is an invasive species globally known for its adverse ecological impacts on native amphibians and biodiversity. To assess species current and future climatic suitable areas at the global and European scales we used an ensemble forecasting approach. We considered six climatic variables, three timeframes (current, 2050, and 2070), and two CO2 emission scenarios. Temperature seasonality, minimum temperature of the coldest month, maximum temperature of the warmest month, and precipitation in the driest month were the most important variables predicting bullfrog occurrence. Globally currently 3.8% of land area is suitable for bullfrog and an increase of up to 5.2% in 2070 is expected. Increase in suitable areas is expected at higher latitudes, especially in North America and central Europe. Currently, 3.45% of total Natura 2000 area is suitable, and a predicted range gain of up to 355.93% (12.28%) is expected in the highest concentration scenarios predictions. This can indicate that the 64 native amphibian species present in the Natura 2000 network could be at increased risk. The choice of Natura 2000 for a geographic detailed analysis of the possible effects on native amphibians is due to its importance for habitats and wildlife conservation. Identification of its invasion-susceptible areas will allow resource and management practices optimization

Evaluating the range expansion of recreational non-native fishes in Portuguese freshwaters using scientific and citizen science data.

Updating information on the distribution of recently introduced and other poorly known non-natives is essential to prevent and control their spread and better address biological invasions. Here, we combine scientific and citizen science data to update the distribution of five recently arrived (i.e., < 25 years), non-native fish species (Alburnus alburnus, Ameiurus melas, Rutilus rutilus, Sander lucioperca and Silurus glanis) and one rare, longer established (i.e., > 50 years), non-native (Esox lucius) in Portugal. These species have been increasingly targeted by recreational fishermen, thus likely expanding their distribution. Specifically, we obtained distribution maps for each species, based on data gathered through a comprehensive search for records in 1) scientific literature, 2) unpublished reports of research projects, and 3) citizen science databases. We gathered 443 valid records, of which 64% were from citizen science data, mainly provided by recreational fishermen. Data highlighted that all species have expanded their distribution in the last 20 years, with high numbers of new records for A. alburnus, S. lucioperca and S. glanis, mostly located in the Tagus, Guadiana and Douro river basins. Changes in species distributions reflected dispersal within invaded basins and colonisation of previously unoccupied drainages. Integrating citizen science with scientific data provides an effective framework to understand non-native species introduction and spread, stressing the need for increasingly encourage and engage recreational fishermen in information sharing

Patterns of Distribution of Bivalve Populations in a Mediterranean Temporary River.

In the south of the Iberian Peninsula, many rivers are intermittent, a state most likely to be exacerbated by climate change, strongly affecting river biota. An additional challenge for native biota in this area is the arrival of new species, frequently aided by humans, and bivalves are particularly at risk. Here we assessed whether the native (Unio delphinus) and invasive (Corbicula fluminea) bivalves differed in habitat use. To address this question, we sampled populations of both species in six isolated permanent pools in the same river during summer in three consecutive years. U. delphinus occurred in all pools, while C. fluminea occurred only in the two most downstream pools. U. delphinus, but not C. fluminea, was found preferentially in patches under riparian vegetation cover. Both species were found in similar sediment types (coarse and fine gravel respectively). Although U. delphinus was present in all pools, recruitment was detected only in 2016, in one pool. We concluded that both species have the potential to compete for space, but a well-developed riparian vegetation cover may provide U. delphinus some advantage against C. fluminea