Freshwater Ecosystem

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

Significance The salinity of freshwater ecosystems is increasing worldwide. Given that most freshwater organisms have no recent evolutionary history with high salinity, we expect them to have a low tolerance to elevated salinity caused by road deicing salts, agricultural practices, mining operations, and climate change. Leveraging the results from a network of experiments conducted across North America and Europe, we showed that salt pollution triggers a massive loss of important zooplankton taxa, which led to increased phytoplankton biomass at many study sites. We conclude that current water quality guidelines established by governments in North America and Europe do not adequately protect lake food webs, indicating an immediate need to establish guidelines where they do not exist and to reassess existing guidelines.

The present short communication describes a technique to customise the decision system MOIRA-PLUS for applications to the marine environment. MOIRA-PLUS was originally designed to predict the behaviour of 137 Cs and 90 Sr in freshwater ecosystems and to evaluate the environmental, social and economic impacts of selected countermeasures aimed at restoring the polluted environment and at reducing the doses to man. An example of application for predicting the concentration of radiocaesium of Chernobyl origin in the Mediterranean Sea is described and discussed. The technique allows the user to easily integrate existing state-of-the-art box models of sea water circulation into the MOIRA-PLUS decision system.

Cast net fishery of a tropical lotic freshwater ecosystem (Cross river at Afikpo, Nigeria) was investigated from December 2004 to November 2005. Thirty two (32) species of finfishes belonging to 23 genera and 16 families and one decapod crustacean – Macrobrachium volenhovenii were collected. Alestes baremoze was the dominant of the five species of the Characidae identified. The Cichlidae (4 species) had the highest weight (1887.77 kg) representing 75.39 % of the total catch and 1,175 (64.41%) abundance. The Bagriidae (3 species) had abundance value of 84(4.53%) and weight of 4.026 kg (3.46%). The Mochokidae (4 species) had abundance value of 44 (2.37 %) and 2.23 kg (1.91%) weight. The Notopteridae, Osteoglossidae, Schilbidae and Cyprinidae had one species each. Two species of the Carangidae; Decapterus rhonchus and Trachinotus teraia which are brackish water dwellers constituted 0.27 % and 0.03 % of the total abundance and weight respectively of the catch. The Cichlidae had the highest frequency followed by the Characidae. The Cichlidae had the highest Simpson’s and Shannon Wienner diversity of 0.116 and 0.488 respectively. Simpson’s and Shannon Wienner diversity of 0.861 and 0.988 were recorded for all the species. The monthly variation of the catch during the study showed double peak maxima in April/May and October/November. The mesh size of the cast nets used by the fishers varied from 3.25 cm to 3.85 cm with a mean size of 3.5 cm. Only 2(11%) of the 18 canoes used by the fishers were dugout types. The remaining 16 (89%) of the canoes were plank boats.

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

River ecosystems, mainly those draining tropical dry forests, are among the most endangered tropical ecosystems and a major conservation priority in South America, as elsewhere. In this study, we assessed the influence of environmental factors (e.g., precipitation) and riparian vegetation on Trichoptera larval assemblages colonizing four substrates (rock, gravel, sand, and litter) in the Venadillo and Opia watersheds (Tolima, Colombia). In each river, five 20m reaches nested into two 100m segments (one at -550 and another at -250masl), were surveyed for benthic invertebrates in the above mentioned substrates. In addition, water samples were collected for physicochemical analyses and the QBR index ("qualitat del bosc de ribera" or riparian forest quality) was applied in both rivers. A total of 6,282 larvae were collected, belonging to 11 families and 22 genera, representing 73.30% and 43.13% of the Trichoptera fauna reported to Colombia, respectively. The most abundant fami...

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

Significance The salinity of freshwater ecosystems is increasing worldwide. Given that most freshwater organisms have no recent evolutionary history with high salinity, we expect them to have a low tolerance to elevated salinity caused by road deicing salts, agricultural practices, mining operations, and climate change. Leveraging the results from a network of experiments conducted across North America and Europe, we showed that salt pollution triggers a massive loss of important zooplankton taxa, which led to increased phytoplankton biomass at many study sites. We conclude that current water quality guidelines established by governments in North America and Europe do not adequately protect lake food webs, indicating an immediate need to establish guidelines where they do not exist and to reassess existing guidelines.

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species in North America. Little is known regarding this species' impacts on freshwater ecosystems. It is believed that population densities can be high, yet no population estimates have been reported. We utilized a mark-recapture approach to generate a population estimate for Chinese mystery snail in Wild Plum Lake, a 6.47-ha reservoir in southeast Nebraska. We calculated, using bias-adjusted Lincoln-Petersen estimation, that there were approximately 664 adult snails within a 127 m 2 transect (5.2 snails/m 2 ). If this density was consistent throughout the littoral zone (<3 m in depth) of the reservoir, then the total adult population in this impoundment is estimated to be 253,570 snails, and the total Chinese mystery snail wet biomass is estimated to be 3,119 kg (643 kg/ha). If this density is confined to the depth sampled in this study (1.46 m), then the adult population is estimated to be 169,400 snails, and wet biomass is estimated to be 2,084 kg (643 kg/ha). Additional research is warranted to further test the utility of mark-recapture methods for aquatic snails and to better understand Chinese mystery snail distributions within reservoirs.

Un système biologique riche et productif La prolifération de la perche du Nil (Lates niloticus) dans le lac Victoria a fortement intrigué les écologistes. Cette espèce est en effet présente dans tous les milieux aquatiques de l'Afrique sahélo-soudanienne où elle cohabite avec les autres espèces, sans poser de problèmes particuliers. Rechercher les causes de la prolifération de la perche du Nil, nécessite de s'intéresser au fonctionnement du système écologique luimême, afin de tenter d'identifier les facteurs qui pourraient être à l'origine de cette prolifération.

... N. Iwasaki Æ DS Sprague Ecosystem Informatics Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba ... 2005 and are listed in Table 1. We surveyed the presence of fish species using a D-flame net ... 3 Sympetrum darwinianum (Selys) SDA 36 ...

Alburnus alburnus alborella is a fish species native to northern Italy. It has suffered a very sharp decrease in population over the last 20 years due to human impact. Therefore, it was selected for reintroduction projects. In this research project, support vector machines (SVM) were tested as possible tools for building reliable models of presence/absence of the species. A system of 198 sites located along the rivers of Piedmont in NorthWestern Italy was investigated. At each site, 19 physical-chemical and environmental variables were measured. We verified that performances did not improve after feature selection but, instead, they slightly decreased (from Correctly Classified Instances [CCI] = 84.34 and Cohen's k [k] = 0.69 to CCI = 82.81 and k = 0.66). However, feature selection is crucial in identifying the relevant features for the presence/absence of the species. We then compared SVMs performances with decision trees (DTs) and artificial neural networks (ANNs) built using the same dataset. SVMs outperformed DTs (CCI = 81.39 and k = 0.63) but not ANNs (CCI = 83.03 and k = 0.66), showing that SVMs and ANNs are the best performing models, proving that their application in freshwater management is more promising than traditional and other machine-learning techniques.

Pollutants in aquatic environment tends to alter the community composition and activities of biofilm cells. The stress induced by these pollutants leads to the production of excessive reactive oxygen species (ROS) which play a key role in the degradation of pollutants in aquatic environment. This mini-review is aimed at forecasting the efficiency of the use of natural freshwater microalgae biofilm in the treatment of water resulting from mining activities. Moreover, it summarises the concept of mining by concisely stating the stages involved in mining and how the pollutants produced during mining can cause deleterious effects to aquatic flora and fauna. Environmental issues resulting from mining activities and how they hindered the progress of biodiversity were concisely discussed. Freshwater microalgae play an important role in the mitigation of the impact of pollution resulting from mining activities. The process of pollutants removal in freshwater by microalgae biofilm is by degradation and biosorption. However, it is an unestablished fact that the extracellular polymeric substances (EPS) were responsible for the biosorption of heavy metals from mining wastewater. It is also important to know the kinetic model that best explains the chemical and physical reactions of heavy metal absorption by the surface of microalgae biofilm.

The present study focus on some aspects of zooplankton structure in the Alcantara River (Sicily, Italy), in relation to environmental factors. Zooplankton samplings were performed in spring in four sites, located from up-to downstream along the river course. Four low-flow velocity station points were chosen along a transversal river section in each site. Samples were taken from all station points in the four sites by two different mesh sizes (55 and 100 mm) rectangular nets. Rotifer abundances were an order of magnitude higher in 55 mm mesh size samples than in 100 mm mesh size ones. The two communities also resulted significantly different (ANOSIM test, r = 0.212; P = 0.1%). Generally, low abundances (from 3470 ¡ 5133 to 422 ¡ 474 ind.m x3 ) were explained by low chlorophyll a concentration and the highflow regime of this river. Rotifer dominated the zooplankton community. Cladocerans, copepods and nauplii occurred with considerably lower abundances than rotifers. However, the relative contributions of these taxa to total abundances depended on the mesh sizes used. Euchlanis and Adineta genera exhibited the highest abundances in the rotifer assemblage. Conductivity alone or in association with temperature and dissolved oxygen was the most important environmental factor affecting rotifer community distribution. Cephalodella sp., Lepadella sp. and Trichotria pocillum showed a high positive relation to pico-plankton, showing this fraction as a possible rotifer food item. This paper demonstrated a higher efficiency of the finest net to characterize riverine zooplankton community that increases from up to downstream in terms of abundances and diversity.

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.) gill, kidney and liver due to this complex water pollution. Eels were caged and plunged at five different PF sites (A-E) for 48 h. A reference site (R) was also selected at the river spring where no industrial contamination should be detected. Lipid peroxidation (LPO), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and reduced glutathione (GSH) were the oxidative stress biomarkers studied. In gill, site A exposure induced a significant GST activity increase and site B exposure induced CAT activity increase when compared to R. Site C exposure showed a significant CAT and GPX activity increase. Data concerning site D exposure were not determined due to cage disappearance. Site E exposure displayed a significant CAT and GST activity increase. In kidney, site A exposure induced a significant CAT and GPX decrease as well as a GST increase. Site B exposure showed a significant decrease in GPX activity and GSH content. However, site C exposure demonstrated a significant increase in CAT and a decrease in GPX. Site E exposure showed a significant decrease in GPX and increase in GST. In liver, site A exposure showed a significant GST activity decrease as well as GSH content increase. Site B exposure showed a significant CAT, GST and LPO decrease. Site C exposure showed only GST activity decrease, while site E exposure induced a significant increase in GPX. These investigation findings provide a rational use of oxidative stress biomarkers in freshwater ecosystem pollution biomonitoring using caged fish, and the first attempt reported in Portugal as a study of this particular watercourse under the previous conditions. The presence of pollutants in the PF water was denunciated even without a clear relation to the main pollution source distance. The organ specificity was evident for each parameter but without a clear pattern. (I. Ahmad), mpacheco@bio. ua.pt (M. Pacheco), [email protected] (M.A. Santos). www.elsevier.com/locate/chemosphere Chemosphere 65 (2006) 952-962

... of changes in fish body size have been investigated as a significant index of aquatic ecosystem function (Heessen &amp; Daan 1996; Millner &amp; ... Conover &amp; Munch (2002) illustrated experimentally that artificial size-dependent selection changes the body size of fish within a few ...