The European whitefish, Coregonus lavaretus (L.), under conditions of technogenic pollution in the Kostomuksha tailing pond

The population structure and biological parameters of the European whitefish, Coregonus lavaretus (L.), have been analyzed in a technogenically polluted water body. The biochemical state of the whitefish and the fauna and morphology of helminths parasitizing them have been assessed. It is shown that the species composition of the fish, plankton, benthos, and parasite faunas of this water body are depleted and the morphological parameters of common fish parasites are altered. It is noted that, in addition to adaptive rearrangements in biochemical metabolism, the whitefish from the transformed water body are characterized by a reduction in the level of protein synthesis in muscles and the rate of aerobic energy metabolism in the liver and muscles.     

Benthic community structure and biomarker responses of the clam Scrobicularia plana in a shallow tidal creek affected by fish farm effluents (Rio San Pedro,SW Spain)

The effects of solid organic wastes from a marine fish farm on sediments were tested using benthic community as ecological indicators and biomarkers in native clam (Scrobicularia plana) as biochemical indicators. The benthic fauna and clam samples were collected in the intertidal sediment in October 2010 from five sites of the Rio San Pedro (RSP) creek, following a gradient of contamination from the aquaculture effluent to the control site. Numbers of species, abundance, richness and Shannon diversity were the biodiversity indicators measured in benthic fauna. Morphological and reproduction status of clams were assessed using the condition factor and gonado-somatic index, respectively. Phase I and Phase II detoxification enzymatic activities (ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST)), antioxidant enzymatic activities (glutathione peroxidase (GPX), glutathione reductase (GR)) and oxidative stress parameters (Lipid Peroxidation (LPO) and DNA strand breaks) were measured in clams' digestive gland tissues. In parallel, temperature and salinity in the adjacent water, redox potential, pH and organic matter in sediment, and dissolved oxygen in the interstitial water were measured. The results suggested that RSP showed a spatial gradient characterised by hypoxia/anoxia, reduced potential, acidic conditions and high organic enrichment in sediments at the most contaminated sites. Significant (p < 0.05) decrease of biodiversity indicators were observed in the areas impacted by the aquaculture discharges. Biomarkers did not show a clear pattern and of all biochemical responses tested, GPX, DNA damage and LPO were the most sensitive ones and showed significant (p < 0.05) increase in the polluted sites. Benthic biodiversity indicators were significantly (p < 0.05) positively correlated with pH, redox potential and dissolved oxygen and negatively correlated with organic matter. On the contrary, antioxidant enzymatic responses (GPX) and oxidative stress parameters were significantly (p < 0.05) negatively correlated with those physico-chemical parameters. It has been demonstrated that effluents from fish aquaculture activities in Río San Pedro creek may produce an alteration of physico-chemical characteristics of seabed and induce oxidative stress and DNA damage in soft-sediment species which may lead to changes of the benthic population structure and health status of the exposed organisms.     

Ecological and faunistic characteristics of the leech fauna in the Bukhtarma Reservoir,Eastern Kazakhstan

The taxonomic diversity of the Hirudinea fauna and its dependence on the ecological conditions in the Bukhtarma Reservoir (Eastern Kazakhstan) have been studied. The morphological analysis has shown that these leeches belong to two orders and three families: Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and Arhynchobdellida (family Erpobdellidae). On the whole, eight leech species from five genera (Alboglossiphonia, Helobdella, Theromyzon, Piscicola, and Erpobdella) have been identified. Among them, there are three glossiphoniid species (A. heteroclite, H. stagnalis, and T. tessulatum), two species of piscicolids (Piscicola geometra and Piscicola sp.), and three species of predatory leeches (E. octoculata, E. vilnensis, and Erpobdella sp.). Possible effects of hydrochemical parameters of the aquatic environment on the species diversity have been analyzed. Correlation has been revealed between the abundance of species and the physical and chemical characteristics of the environment.     

Changes in the structure of ichthyofauna in water bodies of Kaluga oblast over the past few decades

The structure of the ichthyofauna in water bodies of Kaluga oblast has undergone significant rearrangements over the past 20 years. The abundance of some species has increased, while that of other species has decreased; spontaneous dispersal of some fishes is underway. Synchronous fluctuations of fish abundance (“waves of life”) take place simultaneously in the Western Dvina, Dnieper, and Volga basins. These processes differ in intensity depending on fish species and are conditioned by a number of factors, including changes in hydrological regimes of rivers, improvement of the ecological state of small rivers, and increased poaching pressure. The results of monitoring the ichthyofauna fauna of small rivers are used as an example to trace the routes of fish dispersal and discuss changes in the composition of fish communities.     

Faunal diversity and dynamics of species richness and dominance of parasite communities in age series of the perch (<Emphasis Type="Italic">Perca fluviatilis</Emphasis>)

Changes in parameters of species richness and dominance in parasite communities of perch have been analyzed in the age series of hosts from two water bodies, Lake Gusinoe and Chivyrkui Bay (Lake Baikal), at the levels of a host individual (infracommunity) and a host age group (set of infracommunities). The species richness of parasite infracommunities has been found to increase in both age series due to decreasing proportions of fish affected by no more than three to four parasite species and increasing proportion of fish parasitized by more than four to five species.     

Residues of organochlorine pesticides in fish from the Egyptian delta lakes

The distribution and residue levels of BHC, Lindane, Endrin, o,p′-DDT, p,p′-DDE, and p,p′-DDD in Mugil and Tilapia species collected from Egyptian Delta lakes were evaluated. Residues of BHC and p,p′-DDT were found in most fish samples obtained from El-Manzala, El-Burullus, Edku, and Maryut lakes. Fish samples from Lake Edku showed the highest residue levels of the studied compounds. Residues of BHC and p,p′-DDT in Mugil and Tilapia species are within the range found in fish from the northwest Atlantic but lower than the levels reported for other fish species the United States. Mugil and Tilapia species could be used as indicator organisms for monitoring the residue levels of organochlorine pesticides and their distribution.     

Changes in the Species Composition of Parasites in European Perch, <Emphasis Type="Italic">Perca fluviatilis</Emphasis>, in Lake Gusinoye (Lake Baikal Basin) during Depression and Subsequent Recovery of Host Abundance

Changes in the species composition of parasite fauna in the European perch in Lake Gusinoye (the Lake Baikal basin) were analyzed in the periods before and during depression of host abundance (the early and late 1970s) and in the years of its recovery to a stable level (the mid-2010s). The period of depression was associated with a significant decrease in the species richness of parasite fauna. Subsequent recovery of perch abundance to a stable level resulted in an increase in the parasite species richness, but it remained lower than before the depression of host abundance.     

Measured elemental transfer factors for boreal hunter/gatherer scenarios: fish, game and berries

The environmental assessment of long-term nuclear waste management requires data to estimate food chain transfers for radionuclides in various environmental settings. For key elements such as iodine (I) and chlorine (Cl), there is a paucity of transfer factor data, particularly outside of agricultural food chains. This study dealt with transfers of I, Cl and 28 other elements to foods that would be typical of boreal hunter/gatherer lifestyles, as well as being common foods for modern recreational and subsistence hunters. Food/substrate concentration ratios (CRs) and related transfer factors for eight species of widely distributed fish, whitetail deer (Odocoileus virginianus), Canada geese (Branta canadensis) and wild blueberries (Vaccinium myrtilloides) were measured and compared to the literature. Limited data were obtained for caribou (Rangifer tarandus), elk (Cervus elaphus) and moose (Alces americanus). Freshwater sediment Kd values and CRs for a ubiquitous freshwater macrophyte were also obtained. The CRs for I in fish were 29 L kg⁻¹ in edible muscle (fillets) of large-bodied species and 85 L kg⁻¹ for whole, small-bodied fish. The log CRs for fish and macrophytes were correlated across elements. For several elements, the Kds for sediments in deep water were ∼4-fold higher than for littoral samples. The elemental transfers to wild animals for some elements were notably different than the literature indicates for domestic animals. It is argued that the transfer data obtained using indigenous elements from real environmental settings, as opposed to contaminant elements in experimental or impacted environments, are especially relevant to assessment of long-term impacts.     

Effect of anthropogenic pollution on oxidative processes in the liver of fish from the Rybinsk Reservoir

The levels of total lipids, peroxidation products, and antioxidant activity in the liver were studied in fish species living in unequally polluted areas of the Rybinsk Reservoir and differing in their ecology and taxonomic position: the bream (Abramis brama L.), roach (Rutilus rutilus L.), burbot (Lota lota L.), and zander (Stizostedion lucioperca L.). The fish from polluted water areas were characterized by higher levels of total lipids and malonic dialdehyde and a deficiency of antioxidants. It is shown that the test parameters depend on the type of feeding and mode of life of the fish species.     

Artisanal fisheries of the Itaparica reservoir,São Francisco River,Brazil: socioeconomic profile,environmental dynamics,and management recommendations

Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.     

TCDD distribution in the Spring River,Southwestern Missouri

The waste management practices of a now defunct chemical company created several disposal sites containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminated materials. A sampling survey of the Spring River, which drains the disposal sites, was conducted to determine if TCDD contamination of this river had occurred. TCDD was found in fish at concentrations of 0.8 to 55 ng/kg (whole fish) and 1.4 to 18. ng/kg (fillet). In addition, TCDD was present in the fish at least as far as 69 mi (111 km) downstream of the disposal sites. The detection limits were generally not sufficient to determine the sediment TCDD concentration in the river. TCDD was only found in the sediments immediately downstream of the former manufacturing facility, at 12 ng/kg.     

Anomalous behavior of trace element magnesium in fish tissues

Six fish species were collected: summer trout (Salmo alar), rock fish (Roccus lineatus), pink snapper (Lutianus ava), croaker (Stellifer lancelatus), sheepshead (Diplodus holbrooki) and spanish mackeral (Scomberomorus maculatus). Seven trace elements were determined by flame atomic absorption spectrophotometry. The results indicate that the trace elements iron, copper, zinc, mercury, chromium, and nickel show higher levels in the livers than in the flesh of all the six fish species. Surprisingly, magnesium concentration levels were consistently higher in flesh than in the livers of all six fish species.     

Radionuclide transfer to freshwater biota species: review of Russian language studies

Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for ²⁴¹Am (bivalve molluscs, gastropods and pelagic fish), ⁶⁰Co (gastropods, benthic fish and insect larvae), ⁹⁰Sr and ¹³⁷Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species.     

Most Interesting Findings from Remnants of Chironomid (Insecta: Diptera: Chironomidae) Larvae in Layers of a 200-Year-Old Stratum of Lake Oron Bottom Sediments

The remnants of chironomid larvae from layers of the 10-cm-thick bottom sediment in Lake Oron have been studied. Six taxons unknown in the current chironomid fauna of the lake have been identified: Abiskomyia rivalis, Corynoneura arctica-type, Mesocricotopus thienemanni, Metriocnemus eurynotus-type, Nanocladius rectinervis-type, and Robackia pilicauda. The most probable reasons for the disappearance of these species from the Oron fauna, which are related to environmental changes caused by global climate changes, are considered.     

Morphophysiological Rearrangements in Fish in Response to Pollution (in the Light of S.S. Shvarts' Theory)

The results of a study on morphophysiological variation in fish inhabiting a subarctic lake exposed to chronic industrial pollution are described using an example of cisco, Coregonus lavaretus. It is shown that indices of the heart, liver, kidneys, gills, and fatness in these fish are increased significantly and have retained increased values for the past 20 years. The observed changes are analyzed on the basis of biochemical data. The results of studies on the dynamics of hematological parameters in fish are used for characterizing the development of toxicosis. Adaptive rearrangements associated with an increase in the metabolic rate and the activation of protective systems in the fish are explained in the context of S.S. Schvarts' concept. The idea is proposed that the additional energy cost of detoxification may be responsible for morphophysiological variation in fish under conditions of water pollution.     

Population genetic aspects of susceptibility of the Colorado potato beetle to mycopathogens in the Republic of Bashkortostan

Susceptibility of the Colorado potato beetle to entomopathogenic fungal infection has been studied for the first time in the Republic of Bashkortostan and shown to be associated with other population genetic characteristics of the species in this region. A new strain of Beauveria bassiana, Ufa-2, has been isolated and tested for virulence in comparison to B. bassiana strains isolated from other insect species and maintained in the collection of the Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences.     

Determination of concentration factors for Cs-137 and Ra-226 in the mullet species Chelon labrosus (Mugilidae) from the South Adriatic Sea

Concentration factors for Cs-137 and Ra-226 transfer from seawater, and dried sediment or mud with detritus, have been determined for whole, fresh weight, Chelon labrosus individuals and selected organs. Cesium was detected in 5 of 22 fish individuals, and its activity ranged from 1.0 to 1.6 Bq kg⁻¹. Radium was detected in all fish, and ranged from 0.4 to 2.1 Bq kg⁻¹, with an arithmetic mean of 1.0 Bq kg⁻¹. In regards to fish organs, cesium activity concentration was highest in muscles (maximum - 3.7 Bq kg⁻¹), while radium was highest in skeletons (maximum - 25 Bq kg⁻¹). Among cesium concentration factors, those for muscles were the highest (from seawater - an average of 47, from sediment - an average of 3.3, from mud with detritus - an average of 0.8). Radium concentration factors were the highest for skeleton (from seawater - an average of 130, from sediment - an average of 1.8, from mud with detritus - an average of 1.5). Additionally, annual intake of cesium and radium by human adults consuming muscles of this fish species has been estimated to provide, in aggregate, an effective dose of about 4.1 μSv y⁻¹.     

Occurrence of DNA methylation in Daphnia magna and influence of multigeneration Cd exposure

Most of the research on the epigenetic phenomenon of DNA methylation has been performed with vertebrates and plants. Knowledge on DNA methylation in Daphnia magna, a key test organism in aquatic toxicology, is completely lacking. Through epigenetic inheritance, effects of transient chemical exposure could be transferred to non-exposed generations, which could have a major impact on ecological risk assessment procedures. In this study, we determined if CpG methylation occurs in D. magna and if this can be influenced by exposure to toxic substances. Homologs of human DNA methyltransferases DNMT1, DNMT2 and DNMT3A were found in the partially available D. magna genome. Using an optimized “Amplification of Intermethylated Sites (AIMS)” technique, two methylated fragments were discovered in D. magna DNA. No homology was found for these sequences. The methylation and the D. magna origin of the fragments were confirmed with Southern analysis. This optimized AIMS technique was then applied to DNA of D. magna which were exposed to 180 µg/L Cd for two generations. Exposure resulted in a significant decrease in reproduction. The same methylated fragments with the same band intensity were observed in DNA of both non-exposed and exposed daphnids. As such, it could not be demonstrated that Cd exposure altered DNA methylation. However, the presence of DNA methylation in D. magna shows that potentially epigenetic effects may occur in this species.     

Spatial population structure in forest voles of the genus <Emphasis Type="Italic">Clethrionomys</Emphasis> in the southern taiga of the Middle Irtysh region

A comparative analysis of spatial population structure in the northern red-backed vole (Clethrionomys rutilus Pall.) and large-toothed red-backed vole (Cl. rufocanus Sund.) has been performed in the middle taiga zone of the Middle Irtysh region (Omsk oblast). Populations of these species are represented by sets of territorial groups whose numbers and spatial distribution change from year to year depending on the ratio of these species in a biotope and their population density. There is no significant interspecific competition between cohabitant Cl. rutilus and Cl. rufocanus. In particular, this follows from the fact that the population density and distribution pattern of one species are independent of those of the other species. It has been found that the size of home ranges in Cl. rutilus inversely depends on its population density, with that in Cl. rufocanus remaining approximately the same at different population densities, and that the structure of the resident part of the population in both species changes during the season, as voles from neighboring habitats or dispersing voles settle in the study area.