European Streams Research Articles

FDI in Africa: potential implications of Brexit on South Africa’s financial sector

Purpose This paper aims to investigate whether any potential weakening of the UK’s financial sector, as a result of Brexit, will have a negative impact on South Africa’s financial sector given the close ties between the countries’ financial systems. This paper seeks to also argue that Brexit may provide an opportunity for South Africa to pursue new trade linkages with other countries in Africa and Asia. Design/methodology/approach This paper is a review of relevant sources from foreign direct investment (FDI) and international economic literature. It analyses comparative and cross-disciplinary research and examines the current trends in the legal and economic climate in South Africa – within the context of economic growth and FDI inflows patterns. Findings This paper finds that Brexit does not pose a systemic risk to South Africa’s financial system. This paper also finds that South Africa’s recent policy changes may serve as obstacles to South Africa attracting new FDI. Research limitations/implications The implications of Brexit on the investment in the economy of African countries are under-researched, and this paper provides an additional contribution to the euro-centric discussion of the ramifications of Brexit on the economic developments in the financial sector after Britain’s exit. Originality/value This paper argues for an enhanced FDI system for South Africa and its policy proposals can be used to further the independence of African countries from European investment streams.

Invasive brook trout disrupt the diel activity and aggregation patterns of native brown trout

In European streams, native brown trout (Salmo trutta) feed primarily on aquatic prey but consume a higher proportion of terrestrial prey in sympatry with non-native brook trout (Salvelinus fontinalis). This is a rare example of diet convergence that may be associated with changes in diel activity or aggregation pattern by brown trout in sympatry. We recorded the activity and positions of brown trout from two origins and in two competition modes (allopatry versus sympatry, four combinations) placed in replicated stream enclosures for 29 days to test these hypotheses. Brown trout originating from or placed in sympatry were more diurnal and aggregated than those originating from or placed in allopatry. Changes in the diel activity of brown trout placed in a novel competition mode occurred progressively throughout the study. Thus, brown trout show strong behavioral flexibility in response to the non-native competitor and can revert to allopatric behavior when brook trout is removed from the system. These behavioral adjustments may have unsuspected effects on food webs and ecosystem functioning, which deserve further attention.

Depth and vertical hydrodynamics constrain the size structure of a lowland streambed community.

Abundance-body mass (N-M) relationships are prominent macroecological patterns and provide an integrated measurement of the structure and energy flow through natural communities. However, little is known about how N-M relationships are constrained by local environmental conditions. Here, we quantify how sediment depth and direction of surface-groundwater exchange (vertical hydrodynamics), two major drivers of the streambed ecology, determine N-M scaling in a sandy lowland European stream. Streambed assemblages included flagellates, ciliates, meiofauna and macroinvertebrates, and spanned five orders of magnitude in body mass. We detected a significant interaction of body mass with depth and vertical hydrodynamics with a sharp reduction in N-M slopes in the hyporheic zone and under upwelling conditions. These results revealed that streambed assemblages become more size-structured as environmental constraints increase with direct implications for the metabolic capacity and functioning of the system.

Distribution and ecological preferences of the species of the family Athericidae in three hydrobiological ecoregions of Central Europe

From the family Athericidae, only three species (Atherix ibis, Ibisia marginata, Atrichops crassipes) are widespread in Central and Western Europe. Although predatory larvae of these species are an important component of many benthic communities, little is known about their distribution and ecological preferences. Aiming to fill these gaps, the distribution and ecological preferences of these species were studied in three ecoregions of central Europe (Central highlands, The Carpathians, Hungarian lowlands). We found that A. ibis was present in the most streams in all of the studied ecoregions. I marginata clearly preferred the streams of the Carpathians ecoregion, whilst A. crassipes was more frequent in the Central highlands and Hungarian lowlands and it occasionally inhabited streams in the Carpathian ecoregion. The occurrence of the species was explained by the physico-chemical parameters of water (explained variability = 18.6%), site characteristics (3.8%), as well as catchment characteristics (3.3%). Four environmental variables (temperature, conductivity, percentage of agricultural land, catchment area) from three defined groups represented significant gradients, which explained species distribution in running waters of Central Europe. For the Central European streams, a correction of the saprobic index of the species was made, and the altitudinal, temperature, current and pH preferences for each species were also calculated. These values can be used for completion of the “freshwaterecology.info” database, which includes several biological and ecological traits of most European benthic species.

Litter Quality Modulates Effects of Dissolved Nitrogen on Leaf Decomposition by Stream Microbial Communities.

Rates of leaf litter decomposition in streams are strongly influenced both by inorganic nutrients dissolved in stream water and by litter traits such as lignin, nitrogen (N) and phosphorus (P) concentrations. As a result, decomposition rates of different leaf species can show contrasting responses to stream nutrient enrichment resulting from human activities. It is unclear, however, whether the root cause of such discrepancies in field observations is the interspecific variation in either litter nutrient or litter lignin concentrations. To address this question, we conducted a controlled laboratory experiment with a known fungal community to determine decomposition rates of 38 leaf species exhibiting contrasting litter traits (N, P and lignin concentrations), which were exposed to 8 levels of dissolved N concentrations representative of field conditions across European streams (0.07 to 8.96mgNL-1). The effect of N enrichment on decomposition rate was modelled using Monod kinetics to quantify N effects across litter species. Lignin concentration was the most important litter trait determining decomposition rates and their response to N enrichment. In particular, increasing dissolved N supply from 0.1 to 3.0mgNL-1 accelerated the decomposition of lignin-poor litter (e.g. < 10% of lignin, 2.9× increase ± 1.4 SD, n = 14) more strongly than that of litter rich in lignin (e.g. > 15% of lignin, 1.4× increase ± 0.2 SD, n = 9). Litter nutrient concentrations were less important, with a slight positive effect of P on decomposition rates and no effect of litter N. These results indicate that shifts in riparian vegetation towards species characterized by high litter lignin concentrations could alleviate the stimulation of C turnover by stream nutrient enrichment.

Valve teratologies and Chl c in the freshwater diatom Tabellaria flocculosa as biomarkers for metal contamination

Freshwater benthic diatoms, routinely used for bioassessment, are potential metal indicators because of their known capacity to reflect changes in water chemistry. Nevertheless, the effect of metals on benthic freshwater diatoms is still poorly understood. Metals, such as Zn and Cu, are not only essential as micronutrients, but also one of the main anthropogenic pressures in aquatic ecosystems. However, metal stress cannot be detected with the current European standard methods using bioindicators for environmental assessment, so new tools need to be developed. We studied the effects of Zn and Cu on the freshwater diatom Tabellaria flocculosa. This diatom isolated from a Zn and Cu contaminated stream, was exposed to different concentrations of Zn and Cu, and the metal effects were assessed by measuring physiological ((growth, fluorescence, pigments’ content (Chl a, c, carotenoids)) and morphological parameters (teratological forms). We found that at environmental concentrations occurring in European streams, Zn and Cu showed toxic effects on T. flocculosa. Toxic effects induced by Zn were only observed at high concentrations (500 and 1000 µg/L), resulting in fluorescence changes, an increase of Chl c cellular content and an increase of teratological forms (with an increase of more heavily deformed valves with increasing metal concentrations). Increasing Cu exposure induced several changes, such as increasing the cellular content of Chl a and c, while carotenoids’ cellular content decreased. Cu also increased the number of T. flocculosa frustule deformations. Cu did not affect the cellular fluorescence. Our results thus show that the frequency of diatom teratologies could potentially be used to assess metal stress for the studied metals Zn and Cu. Additionally, the analysis of algal pigments could potentially separate the effects of different metals.

Behind the Scenes: Mechanisms Regulating Climatic Patterns of Dissolved Organic Carbon Uptake in Headwater Streams

AbstractLarge variability in dissolved organic carbon (DOC) uptake rates has been reported for headwater streams, but the causes of this variability are still not well understood. Here we assessed acetate uptake rates across 11 European streams comprising different ecoregions by using whole‐reach pulse acetate additions. We evaluated the main climatic and biogeochemical drivers of acetate uptake during two seasonal periods. Our results show a minor influence of sampling periods but a strong effect of climate and dissolved organic matter (DOM) composition on acetate uptake. In particular, mean annual precipitation explained half of the variability of the acetate uptake velocities (VfAcetate) across streams. Temperate streams presented the lowestVfAcetate, together with humic‐like DOM and the highest stream respiration rates. In contrast, higherVfAcetatewere found in semiarid streams, with protein‐like DOM, indicating a dominance of reactive, labile compounds. This, together with lower stream respiration rates and molar ratios of DOC to nitrate, suggests a strong C limitation in semiarid streams, likely due to reduced inputs from the catchment. Overall, this study highlights the interplay of climate and DOM composition and its relevance to understand the biogeochemical mechanisms controlling DOC uptake in streams.

European Streams of Protection for Right to Privacy and Right to Protection of Personal Data, and Their Connection in the EU Gonzales Case and Beyond

Protections of the to privacy concerning publications have a relatively long history in Europe. The first part of the article explores comparatively and historically, the mechanisms of such protections originated in the XIXth century Germany and synthesized brilliantly by Brandeis and Warren in the US. This part includes a brief overview of European supranational protection of the to privacy, as framed in article 8 of the European Convention of Human Rights and, more recently, in article 7 of the EU Charter of Fundamental Rights. The protections of the to personal data in digital processing is a more recent occurrence in Europe. Few national constitutions or international instruments recognize such rights, and even fewer jurisdictional remedies are associated with it. There are some significant exceptions, mainly at the supranational level, such as the EU Data Protection Directive (recently replaced by the EU General Data Protection Regulation) and Article 8 of the EU Charter of Fundamental Rights. The second part of the article briefly explores these protections, their inherent logic, and the implementing mechanisms as clearly different from those characterizing the protections of the to privacy. The third part examines the articulation between the two protection mechanisms, as reflected by the reasoning of the European Union Court of Justice on the famous Gonzales case. The decision implemented a of de-listing as right to be forgotten on the Internet, by the search engines. We propose a new reading for the reasoning of the Court, which underlines the essential role of protections of the to privacy in grounding and circumscribing the data protection mechanisms of the EU Data Protection Directive within the decision. Last but not least, the article asses that the newly adopted EU General Data Protection Regulation will not affect the precedent created by the Gonzales and the adequate remedies it implemented.

The abundance and distribution of guilds of riparian woody plants change in response to land use and flow regulation

Abstract Many riparian ecosystems in Mediterranean Europe are affected by land use and flow alteration by dams. We focused on understanding how these stressors and their components affect riparian forests in the region. We asked the following questions: (1) Are there well‐defined, responsive riparian guilds? (2) Do dam‐induced streamflows determine abundance and distribution of riparian guilds? (3) What are the main drivers governing composition and cover of riparian guilds in regulated rivers? We inventoried the cover of riparian woody species in free‐flowing rivers and downstream of dams. We performed a cluster analysis and ordination to derive riparian guilds, using abundance data from 66 riparian woody species and 26 functional plant traits. We used a reduced set of principal components for the environment, land use and hydrology, and general linear modelling to explore the effect of these factors (separately and combined) on riparian guilds. We found that: (1) four dominant guilds are responsive to disturbance in southwestern European streams, namely the obligate riparian, water‐stress tolerant, deciduous competitive and Mediterranean evergreen guilds; (2) a set of land use and hydrological variables differentially affect the diverse co‐occurring riparian guilds; (3) frequency and duration of high flow pulses and the low‐flow conditions were major drivers of change in landscapes dominated by intensive agriculture and forestry; (4) storage reservoirs reduced the cover of obligate riparian and Mediterranean evergreen guilds, and increased the abundance of water‐stress tolerant and deciduous competitive guilds, while run‐of‐river dams, having limited water storage, reduced both obligate and deciduous competitive guilds. Synthesis and applications. Future research in southwestern Europe should address the resilience of riparian guilds and the effects of interacting landscape factors and stressors on guild distribution. Streamflow regulations downstream of reservoirs should focus on specific flow components, namely the magnitude of flows, and frequency and duration of extreme flow events. For successful mitigation of the dam‐induced effects on riparian vegetation, river management plans must incorporate the environmental and land use site‐specific contexts.

Mayfly (Ephemeroptera) assemblages of a Pannonian lowland mountain, with first records of the parasite Symbiocladius rhithrogenae (Zavrel, 1924) (Diptera: Chironomidae)

Despite increasing numbers of studies on aquatic insects in South-East European streams, there are still gaps in the knowledge about their distribution and assemblage composition in many regions. As one of the most abundant and sensitive aquatic insects, mayflies are widely used as bioindicator taxa. With the main goal of improving the knowledge of South-East European mayflies, a study was conducted of 15 streams along a Pannonian lowland mountain, in spring and summer 2017. A total of 18 mayfly taxa were recorded, where Ephemera danica Müller, 1764 and Baetis rhodani (Pictet, 1843) were the most widespread. All sites were characterized with the domination of rhithral elements, with similar shares of grazers/scrapers and detritivores. Nevertheless, sites at lower altitudes generally had a higher share of potamal and littoral elements, and a higher share of detritivores than at higher altitudes. NMDS analysis separated sites mainly based on sampling period. Although Heptageniidae nymphs were recorded in all streams, the parasitic chironomid Symbiocladius rhithrogenae (Zavrel, 1924) was recorded attached to three nymphs of Rhithrogena group semicolorata, each in a different stream. These records represent the first report of this species for Croatia. The current study contributes significantly to our knowledge of mayfly assemblages and species distribution in South-East Europe. Moreover, with a newly recorded species, this study indicates that the knowledge of the Croatian chironomid fauna is still growing.

Living with an engineer: fish metacommunities in dynamic patchy environments

Different environmental preferences and dispersal abilities allow fish to coexist in local communities. In the present study we analysed the effects of engineering species on the community structure based on the example of the European beaver (Castor fiber) and mountainous European stream fish. We hypothesised that the creation of beaver impoundments increases environmental heterogeneity and causes a strong spatial and temporal variation in fish species composition and size structure. Finally, we placed these results in the context of the metacommunity theory. Our research was conducted over a large spatial scale, and over a relatively long (5-year) temporal scale. Data analysis revealed strong environmental gradients associated with stream size and increased environmental heterogeneity associated with the creation of beaver impoundments. The results also indicated strong spatial and temporal variation in fish species composition and size structure associated with this environmental heterogeneity. Although local communities changed over time, the main metacommunity characteristics remained constant. Fish must move and follow environmental changes for their populations and communities to persist in streams inhabited by beavers. Gaining a deeper understanding of the effects of the engineering species on fish community structure may help inform management and the conservation of stream ecosystems.

Effects of changing climate on European stream invertebrate communities: A long-term data analysis

Long-term observations on riverine benthic invertebrate communities enable assessments of the potential impacts of global change on stream ecosystems. Besides increasing average temperatures, many studies predict greater temperature extremes and intense precipitation events as a consequence of climate change. In this study we examined long-term observation data (10–32years) of 26 streams and rivers from four ecoregions in the European Long-Term Ecological Research (LTER) network, to investigate invertebrate community responses to changing climatic conditions. We used functional trait and multi-taxonomic analyses and combined examinations of general long-term changes in communities with detailed analyses of the impact of different climatic drivers (i.e., various temperature and precipitation variables) by focusing on the response of communities to climatic conditions of the previous year. Taxa and ecoregions differed substantially in their response to climate change conditions. We did not observe any trend of changes in total taxonomic richness or overall abundance over time or with increasing temperatures, which reflects a compensatory turnover in the composition of communities; sensitive Plecoptera decreased in response to warmer years and Ephemeroptera increased in northern regions. Invasive species increased with an increasing number of extreme days which also caused an apparent upstream community movement. The observed changes in functional feeding group diversity indicate that climate change may be associated with changes in trophic interactions within aquatic food webs. These findings highlight the vulnerability of riverine ecosystems to climate change and emphasize the need to further explore the interactive effects of climate change variables with other local stressors to develop appropriate conservation measures.

Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers

AbstractBiogeochemical cycling of elements largely occurs in dissolved state, but many elements may also be bound to natural nanoparticles (NNP, 1–100 nm) and fine colloids (100–450 nm). We examined the hypothesis that the size and composition of stream water NNP and colloids vary systematically across Europe. To test this hypothesis, 96 stream water samples were simultaneously collected in 26 forested headwater catchments along two transects across Europe. Three size fractions (~1–20 nm, &gt;20–60 nm, and &gt;60 nm) of NNP and fine colloids were identified with Field Flow Fractionation coupled to inductively coupled plasma mass spectrometry and an organic carbon detector. The results showed that NNP and fine colloids constituted between 2 ± 5% (Si) and 53 ± 21% (Fe; mean ± SD) of total element concentrations, indicating a substantial contribution of particles to element transport in these European streams, especially for P and Fe. The particulate contents of Fe, Al, and organic C were correlated to their total element concentrations, but those of particulate Si, Mn, P, and Ca were not. The fine colloidal fractions &gt;60 nm were dominated by clay minerals across all sites. The resulting element patterns of NNP &lt;60 nm changed from North to South Europe from Fe‐ to Ca‐dominated particles, along with associated changes in acidity, forest type, and dominant lithology.

Using streamflow observations to estimate the impact of hydrological regimes and anthropogenic water use on European stream macroinvertebrate occurrences

AbstractUnderstanding the drivers of stream macroinvertebrate distribution patterns—the most diverse animal group in freshwater ecosystems—is a major goal in freshwater biogeography. Climate and topography have been shown to explain species' distributions at continental scales, but the contribution of natural and anthropogenically altered streamflow is often omitted in large‐scale analyses due to the lack of appropriate data. We test how macroinvertebrate occurrences can be linked to streamflow observations and evaluate the relative importance of streamflow regimes and water use for macroinvertebrate occurrences from 19 orders across Europe. We first paired species sampling locations with hydrological gauging stations considering 5 combinations of the geographic distance and difference in flow accumulation (upstream contributing area). We then used Generalized Linear Models to assess the influence of the streamflow regime, simulated water use, and climate and topography on the occurrence of macroinvertebrates. The pairing method that assigned species records to the closest gauging station in terms of both distance and flow accumulation performed best. Most of the species studied occurred preferentially in river habitats with low mean annual streamflow and streamflow variability, high winter streamflow, and low levels of water withdrawals for irrigation or manufacturing. We conclude that flow accumulation is a useful proxy to evaluate the proximity of species records to gauging stations, omitting species records that do not belong to a given stream reach. The strong contribution of streamflow and water use indicators on macroinvertebrate occurrences underline their importance for yielding robust occurrence estimates.

The securitization of residential rental revenue streams in Europe

PurposeThe purpose of this paper is to analyze the securitization of rental streams, a new investment and finance product introduced in the USA in 2013 that enables fundraising from large residential portfolios owned by major investment funds and investment banking. The securities are made up of non-performance loans as well as real estate portfolios of financial entities.Design/methodology/approachAn academic analysis of the European securitization market is performed, as well as a broad overview of the state of the art of the rental housing market and investment property market. Moreover, a market study of Real Estate Owned (hereinafter, REOs) and Real Estate Debts is carried out to determine both the present framework and future trends. Various financial entities and real estate management companies are examined through interviews and data collection to assess the reality of distressed assets and residential portfolios owned by major investors. It introduced the Broker’s Price Opinion concept, de loan-to-value concept and the London Interbank Offered Rate.FindingsREO-to-rental securitization is a step forward toward the democratization of finance through the globalization of the residential market, improving risk sharing for major and retail investors. The securitization of rental streams in Europe has not taken off, despite several issuances in the USA since 2013 with significant success where first tranches obtained a credit qualification of triple-A from the majority of the main rating agencies.Originality/valueAt the end of 2013, a global investment firm launched an innovative finance and investment vehicle that securitized the cash flows originating from leased residential properties. That issue resulted in considerable success and in the development of a new alternative and innovative financing source for real estate activity. Taking into account that housing is a primary need of our society, there is a strong motivation for improving the residential market, and thus, REO-to-rental securitization could help take a step forward in making the housing market more efficient.

Novel Approach for Characterizing pH-Dependent Uptake of Ionizable Chemicals in Aquatic Organisms.

Here, we present and evaluate a combined experimental and modeling approach for characterizing the uptake of ionizable chemicals from water and sediments into aquatic organisms under different pH conditions. We illustrate and evaluate the approach for two pharmaceuticals (diclofenac and fluoxetine) and one personal care product ingredient (triclosan) for the oligochaete Lumbriculus variegatus. Initially, experimental data on the uptake of the three chemicals at two pH values were fitted using a toxicokinetic model to derive uptake and depuration constants for the neutral and ionized species of each molecule. The derived constants were then used to predict uptake from water and sediment for other pH conditions. Evaluation of predictions against corresponding experimental data showed good predictions of uptake for all test chemicals from water for different pH conditions and reasonable predictions of uptake of fluoxetine and diclofenac from a sediment. Predictions demonstrated that the level of uptake of the study chemicals, across pH ranges in European streams, could differ by up to a factor of 3035. Overall, the approach could be extremely useful for assessing internal exposure of aquatic organisms across landscapes with differing pH. This could help support better characterization of the risks of ionizable chemicals in the aquatic environment.

Cyanobacterial Contribution to Travertine Deposition in the Hoyoux River System, Belgium.

Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate precipitation is a complex relationship between biogenic and abiotic causative agents, involving adapted microbial assemblages but also requiring high levels of carbonate saturation, spontaneous degassing of carbon dioxide and slightly alkaline pH. We have analysed calcareous crusts and water chemistry from four sampling sites along the Hoyoux River and its Triffoy tributary (Belgium) in winter, spring, summer and autumn 2014. Different surface textures of travertine deposits correlated with particular microenvironments and were influenced by the local water flow. In all microenvironments, we have identified the cyanobacterium Phormidium incrustatum (Nägeli) Gomont as the organism primarily responsible for carbonate precipitation and travertine fabric by combining morphological analysis with molecular sequencing (16S rRNA gene and ITS, the Internal Transcribed Spacer fragments), targeting both field populations and cultures to exclude opportunistic microorganisms responding favourably to culture conditions. Several closely related cyanobacterial strains were cultured; however, only one proved identical with the sequences obtained from the field population by direct PCR. This strain was the dominant primary producer in the calcareous deposits under study and in similar streams in Europe. The dominance of one organism that had a demonstrated association with carbonate precipitation presented a valuable opportunity to study its function in construction, preservation and fossilisation potential of ambient temperature travertine deposits. These relationships were examined using scanning electron microscopy and Raman microspectroscopy.

New tools for the hydromorphological assessment and monitoring of European streams

Hydromorphological stream assessment has significantly expanded over the last years, but a need has emerged from recent reviews for more comprehensive, process-based methods that consider the character and dynamics of the river with greater accuracy. With this as a focus, a series of hydromorphological tools have been developed and/or further extended in Europe within the context of the REFORM (REstoring rivers FOR effective catchment Management) project. The aim of this paper is to present the set of REFORM hydromorphological assessment methods and, based on some examples of their application, to illustrate and discuss their synergic use, specific features, limitations and strengths.This assessment and monitoring includes three tools: the Morphological Quality Index (MQI), the Morphological Quality Index for monitoring (MQIm), and the Geomorphic Units survey and classification System (GUS). These tools constitute the assessment phase of an overall multi-scale, process-based hydromorphological framework developed in REFORM. The MQI is aimed at an assessment, classification and monitoring of the current morphological state; the MQIm aims at monitoring the tendency of morphological conditions (enhancement or deterioration); the GUS provides a characterization, classification and monitoring of geomorphic units.A series of examples are used to illustrate the potential range of application, including: (i) an assessment of morphological conditions; (ii) an assessment of the morphological effects of restoration projects; (iii) an evaluation of the geomorphic impacts of interventions for risk mitigation; and (iv) an integrated use of MQI and GUS to assess and characterise morphological conditions. Finally, some of the main features, strengths and peculiarities of the three hydromorphological tools are discussed with the support of examples of their application.

Flow velocity tolerance of lowland stream caddisfly larvae (Trichoptera)

The process of macroinvertebrate drift in streams is characterized by dislodgement, drift distance and subsequent return to the bottom. While dislodgement is well studied, the fate of drifting organisms is poorly understood, especially concerning Trichoptera. Therefore, the aim of the present study was to determine the ability of six case-building Trichoptera species to return to the stream bottom under different flow velocity conditions in a laboratory flume. The selected species occur in North-West European sandy lowland streams along a gradient from lentic to lotic environments. We determined species specific probability curves for both living and dead (control) specimens to return to the bottom from drift at different flow velocities and established species specific return rates. Species on the lotic end of the gradient had highest return rates at high flow velocity and used active behaviour most efficiently to return to the bottom from drift. The observed gradient of flow velocity tolerance and species specific abilities to settle from drift indicate that, in addition to dislodgement, the process of returning to the bottom is of equal importance in determining flow velocity tolerance of Trichoptera species.

The antidepressant venlafaxine may act as a neurodevelopmental toxicant in cuttlefish (Sepia officinalis)

The Serotonin/Norepinephrine Reuptake Inhibitor (SNRI) antidepressant venlafaxine (VEN, Effexor®) has become one of the most common antidepressants detected in North American and European streams. Mammalian research has established that VEN exposure is associated with a range of structural, neurochemical, and functional alterations of the brain in adults and newborns. However, the neurodevelopmental effects of VEN on non-target organisms have never been investigated. The aim of our research was to decrease this gap in knowledge by characterizing the effects of VEN exposure on a cephalopod mollusk, the common cuttlefish Sepia officinalis. This species inhabits VEN-contaminated waters and possesses an unusually sophisticated brain. These characteristics render it a unique invertebrate species for studying the neurodevelopmental effects of VEN. Cuttlefish were exposed to environmentally-relevant concentrations of VEN (Measured concentrations ≈5 and 100ngL−1) or to filtered natural seawater (control) in a closed-loop system with regular water changes during the first 20days after hatching. We evaluated brain maturation as well as neurochemical changes and behavioral performances during this critical period of development. Our results show that both VEN-exposed groups exhibited a decrease in norepinephrine levels, along with a reduction in the relative number of glutamate NMDA-like receptors binding sites in the group exposed to 5ngL−1 of VEN after 20days of exposure. Brain regional changes in cellular proliferation were observed in VEN-exposed groups in the vertical lobe (i.e. a key structure involved in cognitive processes) and in the optic lobes (i.e. main visual processing centers) in the absence of significant change in their volume. Along with these neurodevelopmental changes, 20days of exposure to 100ngL−1 of VEN was associated with a decrease in camouflage ability. Overall, our study suggests that VEN is a neurodevelopmental toxicant in non-target aquatic organisms at environmentally-relevant concentrations.