Zooplankton of two arms in the Morava River floodplain in Slovakia

The species composition, seasonal dynamic of biomass and density of zooplankton were studied in two arms with a different hydrological regime. The samples were collected in two hydrologically different years — extremely wet in 2002 and extremely dry in 2003. In the first arm the mean annual chlorophyll-a concentration was 31.6 μg L⁻¹ (2002) and relatively high 64.7 μg L⁻¹ during 2003. Mean seasonal zooplankton wet biomass was low and varied: 11.6 g m⁻³ (2002) and 2.93 g m⁻³ (2003). Total zooplankton density was high (7,370 N L⁻¹) in 2002, when rotifers predominated in an open water zone and contributed up to 81% of the total zooplankton biomass and 83% of the total zooplankton density. In medial and littoral zone, in total, 22 cladoceran and 15 copepod species were identified. In the second arm the mean annual concentration of chlorophyll-a was high: 74.8 μg L⁻¹ (2002) and 61.4 μg L⁻¹ (2003). Mean seasonal zooplankton wet biomass varied from 92.5 g m⁻³ (2002) and 44.10 g m⁻³ (2003). In 2002 the planktonic crustaceans predominated; their mean biomass was 87.1 g m⁻³ and B. longirostris formed more than 91% of this value. In 2003, the zooplankton density was high (15,687 N L⁻¹), when rotifers contributed up to 94% of this value. The boom of rotifers (58,740 N L⁻¹) was recorded in June 2003. In total, 45 cladoceran and 14 copepod species were recorded in the medial and littoral zones. During observation we concluded that the structure of zooplankton, particularly species composition, abundance, biomass and seasonal dynamics are affected by the fluctuation of water levels in the arms of the rivers’ inundation areas. This unstable hydrological regime prevented the development of planktonic crustaceans.     

The Colonization Response of Lotic Chironomid Larvae to Substrate Size and Heterogeneity

The colonization patterns of larval chironomid midges were studied on clean sieved sediments (range 0.25-4.0 mm; pure and mixed) placed in a third order stream in NW Pennsylvania, USA. Chironomid abundance and species richness were significantly different among four sites for homogeneous and mixed sediments. Species richness increased with sediment particle size. Fourteen of the 18 most common species had significant substrate preferences. The interpretation of two cluster analyses of sediment samples indicated two assemblages of chironomid species, each of which appeared to correlate with particular sediments, indicating some assemblage level sediment preference. Sediment size, but not heterogeneity, appears to be a strong factor in the species richness pattern of the community, and in the microhabitat choices of individual chironomid species, in this sandy environment.     

Purification and properties of ferrochelatase from Chironomidae larvae

Ferrochelatase with an M_r of 42,700 Da and a pI of 7.35 has been purified to homogeneity from chironomidae larvae. The activity of the enzyme reached maximum at pH 7.8 and decreased with the increase of pH. The enzyme activity varied with temperature and showed maximum activity around 37°C. The purified enzyme was active towards protoporphyrin but inactive towards other porphyrins. The specific enzyme activity of ferrochelatase from chironomidae is about 10-fold higher than that of the rat. Electrophoresis of the purified fractions shows that the enzyme contains only one single polypeptide. The soluble ferrochelatase contained one mole of iron in each mole of the enzyme. The N-terminal sequence analysis of the enzyme shows a high percentage of conserved regions of the enzyme among other species. The enzyme properties are similar to those of the mammalian ferrochelatases except with slightly higher specific activity. Chironomidae ferrochelatase appeared to be more heat resistant and less susceptible than its mammalian equivalent to inhibition by lead.     

Chironomid microdistribution in gravel of an English chalk river

1. The study aimed to determine the relative importance of certain environmental variables to the distribution of instars of chironomid species in mid-stream gravels of the River Pang. 2. Core samples of gravel substrata were collected over 1 year. Water depth, current, particle size distribution, substratum porosity and detritus were recorded for each sample. The four principal components from a linear ordination of the environmental variables were used to constrain the ordination of chironomid data using the program CANOCO. 3. Microdistribution was principally related to a temporal gradient of water depth, current and substratum heterogeneity. There was significant spatial separation of instars along a gradient of fine detritus, silt and substratum porosity. The distributions of early instars of three taxa were also significantly related to particle size. There was a significant relationship between the size distribution of larvae and the spatial distribution of fine sediments and detritus. This relationship was strengthened when restricted to larvae classified as scrapers.     

A fossil hominid frontal from Velika Pećina (Croatia) and a consideration of Upper Pleistocene hominids from Yugoslavia

Fossil hominid remains dating to the Upper Pleistocene in Yugoslavia are reviewed. Particular emphasis is placed on the assessment of a hominid frontal from the site of Velika Pe?ina in northwestern Croatia. This specimen represents the earliest absolutely-dated hominid associated with the Upper Paleolithic in Europe. Also the hominid material from the site of Veternica is discussed, and data are presented on the new remains from ?andalja. It is concluded that no Neandertal remains, except for Krapina, have been found in Yugoslavia.     

Littoral Chironomid Communities of Alpine Lakes in Relation to Environmental Factors

The results of a study of littoral chironomid communities from 89 lakes in the Alps are presented. The lakes are located on the northern and southern sides of the Alps from the western Bernese to the eastern Julian Alps. Due to the different origins of the data set here considered, different sampling years and sampling methodologies were adopted. All of the lakes were sampled during the ice-free season, but 79/89 lakes were sampled mainly in autumn 2000, while for a few of them the sample dated back to 1996 or the early 90s. Samples were taken by kicking the different substrata or a stretch of lakeshore (10–30 m) for at least 2–5 min with a standard net and were then preserved in alcohol. Larvae and pupal exuviae were sampled by skimming the lake surface with the same net, to extend identification to species level. Notwithstanding the large altitudinal gradient, almost all of the lakes are situated above the timberline, and show a wide range of morphological (depth, watershed and lake area) and chemical characteristics. Chironomids were the most abundant insects represented in these lakes, with highest abundances at pH between 6.0 and 7.5. In particular, Orthocladiinae and Chironominae were the two subfamilies with the widest distribution. Altitude and temperature played an important role in determining their distribution, the higher altitudes were dominated by the former, whereas the latter were more numerous in lower lakes. The prevalence of Orthocladiinae and Tanytarsini at high altitudes was regarded as a general pattern of taxonomic composition in harsh climatic areas. A reverse condition occurred only in the Julian Alps, where Tanytarsini dominate, followed by Tanypodinae and rare Orthocladiinae. Although our results demonstrated that the composition of chironomid assemblages was also determined by pH, the pattern was unbalanced. Due to the fact that no cases of strong water acidification were present, taxa restricted to very low pH were poorly represented (only three taxa—Limnophyes, Endochironomus and Orthocladius (O.) spp.) compared with circumneutral (8) and alkaline (14) taxa, which occurred in slightly acid and non-acidified soft water lakes. As regard conductivity and altitude, we found that almost all the taxa present at higher pH were contemporary present at conductivity higher than 100 μeq l⁻¹ and altitude lower than 2100 m a.s.l. At species level, Pseudodiamesa branickii, Corynoneura arctica, Heterotrissocladius marcidus and Paratanytarsus austriacus resulted to be the most ubiquitous and abundant species in the Alps. When the west to east distribution of taxa was taken into account, Chironomini (particularly the genera Chironomus and Dicrotendipes) and Tanypodinae (Larsia and Paramerina) were more typical of the eastern lakes (JA). They may be better indicators of more alkaline waters. Assembling all the existing data and presenting a comprehensive panorama of lake-littoral chironomid taxa of the Alps was one of the aims of this paper. Further monitoring, but also harmonization of the sampling methodologies and taxonomical identification including inter-calibration exercises among laboratories are recommended, to provide reliable basis and more knowledge for future studies of comparative biogeography, and to preserve these environments where global climatic changes may cause abrupt shifts in the faunal assemblages with a loss of taxa typical of these mountainous areas.     

Chironomid pupal exuviae and larvae of two storage reservoirs in The Netherlands

For three years chironomid larvae were collected bimonthly with a grab sampler in two deep storage reservoirs in The Netherlands. Chironomid pupal exuviae were collected monthly, from April to November, with a handnet. Net samples yielded more taxa than grab samples. The taxa found in net samples originated from more habitats, than taxa found in grab samples. The relative contribution of Orthocladiinae was much larger in net samples. Based on the results obtained in the two reservoirs, some advantages and disadvantages of both sampling methods are discussed.     

Fouling Communities of Mussel Aquaculture Installations in the White Sea

We have classified fouling communities developing on artificial substrates of mussel mariculture plants in Kandalakshskii Bay of the White Sea. Several major types of fouling have been distinguished: mussel fouling; fouling similar to the epifauna of the benthos biocenosis of Laminaria saccharinadominated by the ascidian Styela rusticaor sponges Halichondria paniceaand Halisarca dujardini; young fouling developed by algae and the ascidians of the genus Molgula; and ecotone communities in-between these types of fouling. The characteristics of the distinguished communities are provided.     

Longitudinal organisation of the mollusc species in a theoretical French river

An analysis of mollusc communities collected at 272 stations was carried out, using multivariate statistical methods. The stations ranged from the sources to the lower reaches of large rivers. Nine malacotypes succeeded each other along this upstream-downstream gradient; comments are given regarding the composition of their communities. The organisation of the 52 mollusc species included corresponds to that of a theoretical river, representative of the French hydrographic system. The reduction of the abundance and of species richness in the lower reaches of large rivers is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Chironomid community structure deduced from larvae and pupal exuviae of a chalk stream

Species abundances of Chironomidae (Insecta: Diptera) have often been excluded from studies of benthic river communities because of difficulties associated with sampling and identifying larvae. Chironomid pupal exuviae are easier to collect and identify and could be used to determine community structure if shown to be representative of local larval assemblages. Larvae were sampled along a 20 m chain secured over mid-channel gravels, upstream of two collection points for pupal exuviae. Proportional taxa abundances of pupal exuviae and larvae sampled from 130 m of stream were directly compared by a ² test of independence and also separately fitted to four models of species abundance distribution. Observed proportions of taxa were not independent of the life stage sampled. The greatest discrepancies occurred with species of pupal exuviae that were absent as larvae from the gravel. The log series model provided the best fit with both pupal and larval data. Collections of pupal exuviae had greater species richness and evenness than samples of larvae. This was considered to be a consequence of sampling larvae from the gravel habitat alone.     

The distribution of Chironomid larvae in relation to Chloride concentration in a brackish water region of the Netherlands

Drainage ditches are a familiar and common habitat in the Netherlands. Until recently however they have been the focus of few ecological studies. Extensive studies on Walcheren, a brackish water region of The Netherlands, have shown that chironomid larvae form a major component of the animal communities in the mud. The spatial distribution of some of these species can be correlated with the chloride concentration of the water. Biometric data are included for the speciesChironomus salinarius, C. halophilus andC. plumosus. Communication nr. 151 of the Delta Institute for Hydrobiological Research     

Structural Compositions of Pelagic Communities in the River Warnow and their Changes

The phytoplankton and heterotrophic microbial communities from the Oberwarnow and Unterwarnow were analyzed from November 1987 to May 1988. The production potential of the microorganisms was quantified in laboratory experiments. On the average, phytoplankton accounted for 73 % of the total biomass in the Oberwarnow and 59 % in the Unterwarnow. The corresponding figures for bacterial biomass were 24 % and 33 %, respectively. If the nutrient supply is unlimited and phytoplankton biomass predominates, the development of primary producers in eutrophic to polytrophic waters is not regulated by metazooplankton. Top-down regulation is possible only if prevailing conditions limit the growth of the dominant phytoplankton species.     

Communities of Coral Reefs of Central Vietnam

Communities of macrobenthos on fringing reefs of central Vietnam were studied by the hydrobiological method using scuba diving. The species composition (more than 600 species), population densities of common species of the macrobenthos, and the degree of coverage of the substrate by corals and macrophytes were examined. Bottom communities classified on the basis of these data are indicative of the similarity of the investigated reefs with those of southern and northern Vietnam.     

Communities of oligochaetes in mountain streams of Poland

This study compares the structure of oligochaete communities in mountain streams of Poland. These streams can be divided into three groups. First, those dominated by the Enchytraeidae (Mesenchytraeus armatus), second where the Naididae, Nais bretscheri, Nais alpina, Nais communis or Nais variabilis prevail and third, where the Lumbriculidae, represented by Stylodrilus heringianus, and in one case by Stylodrilus parvus, are dominant. The nature of the stream bottom is the main factor determining the structure of the community, but geographic location is also important.     

High Organic Carbon Export Precludes Eutrophication Responses in Experimental Rocky Shore Communities

We studied the effect of nutrient inputs on the carbon (C) budget of rocky shore communities using a set of eight large experimental mesocosms. The mesocosms received a range of inorganic nitrogen (N) and phosphorus (P) additions, at an N:P ratio of 16. These additions were designed to elevate the background concentration, relative to that in eutrophic Oslofjord (Norway) waters, by 1, 2, 4, 8, 16, 32 μmol dissolved inorganic nitrogen (DIN)l⁻¹ (and the corresponding P increase). Two unamended mesocosms were used as controls. The nutrients were added continuously for 27 months before gross primary production (GPP), respiration (R), net community production (NCP), and dissolved organic carbon (DOC) production were assessed for the dominant algal species (Fucus serratus) and for the whole experimental ecosystem. Inputs and outputs of DOC and particulate organic carbon (POC) from the mesocosms were also quantified. The F. serratus communities were generally autotrophic (average P/R ratio = 1.33 ± 0.12), with the GPP independent of the nutrient inputs to the mesocosms, and maintained a high net DOC production during both day (0.026 ± 0.008 g C m⁻² h⁻¹) and night (0.015 ± 0.004 g C m⁻² h⁻¹). All the experimental rocky shore ecosystems were autotrophic (P/R ratio = 2.04 ± 0.28), and neither macroalgal biomass nor production varied significantly with increasing nutrient inputs. Most of the excess production from these autotrophic ecosystems was exported from the systems as DOC, which accounted for 69% and 58% of the NCP of the dominant community and the experimental ecosystem, respectively, the rest being lost as POC. High DOC release and subsequent export from the highly energetic environments occupied by rocky shore communities may prevent the development of eutrophication symptoms and render these communities resistant to eutrophication. Received 10 October 2001; accepted 18 July 2002.     

Bottom Communities of Nyivo Lagoon (Northeastern Sakhalin)

Clasterization of benthic stations by biomass of common species using an index of coenotic similarities allowed us to distinguish three communities of macrophytobenthos (Zostera marina + Z. japonica, Zostera japonica, and Potamogeton pectinatus) and eight macrozoobenthos communities (Macoma balthica, Limnodrilus hoffmeisteri + Anisogammarus tiuschovi, Spio filicornis + Archaeomysis grebnitzkii, Kamaka kuthae, Glyptotendipesparipes, Neomysisawatschensis + Dolielinotusmoskvitini, Neomysismirabilis, andAnisogammarustiuschovi + Littorinasitkana + Crangonseptemspinosa). The bulk of the bottom surface is occupied by a community of Zostera marina + Macoma balthica with the mean biomass of the dominating species reaching 0.3–1386.6 and 573.9 g/m², respectively. Specific geomorphologic and hydrologic features, as well as the presence of many estuarine areas in Nyivo Lagoon, provide conditions for numerous different fresh-and brackish water communities and variations of them. However, bottom communities cannot be clearly separated into mostly freshwater and mostly brackish communities, which is the case for Pil'tun Lagoon, a well studied lagoon in eastern Sakhalin. Several decades of timber rafting in the Tym' River has had a significant effect on bottom biota and the communities of Nyivo Lagoon. Considering the well-known negative effects of phenol and its derivatives on benthic biota and communities derived during timber decomposition, the sources of pollution of the natural environment in the lagoons of eastern Sakhalin must be evaluated and differentiated.     

Restructuring and Health in Canadian Coastal Communities

Environmental and socioeconomic restructuring has had profound consequences for coastal communities in Canada. The decline of traditional resource-based industries—fisheries, forestry, and mining—and the emergence of new economic activities, such as tourism and aquaculture, compounded by concurrent shifts in social programs, have affected the health of environments, communities, and people. Drawing on research conducted as part of the interdisciplinary major collaborative research initiative Coasts Under Stress, we examined the implications of interactive restructuring for the health of people and communities on Canada’s east and west coasts. The research is guided by a socioecological framework that identifies the pathways from interactive restructuring through health determinants to health risks and health outcomes. The utility of the proposed framework is exemplified by a specific place-based example in Prince Rupert, British Columbia, and a case-based example from coastal communities in Newfoundland and Labrador. A focus on interactive restructuring draws our attention to the many challenges associated with promoting health in a context of rapid and often accelerating environmental and institutional change that is relevant to other areas and contexts.     

Sentinel Human Health Indicators: A Model for Assessing Human Health Status of Vulnerable Communities

The presence of toxic substances in the Great Lakes (GL) continues to be a significant concern. Eleven of the most persistent and ubiquitous substances were identified as “critical Great Lakes pollutants” by the International Joint Commission (IJC). In some areas of the GL these toxic substances bioaccumulate in sediment and organisms, biomagnify in food webs, and persist at high levels. The Agency for Toxic Substances and Disease Registry (ATSDR) Great Lakes Human Health Effects Research Program (GLHHERP) characterizes contaminant exposures via GL fish consumption and investigates the potential for short- and long-term adverse health effects. The program has identified a set of eight indicators to determine risk. The GLHHERP findings indicate: (1) vulnerable populations are still being exposed to persistent toxic substances (2) body burden levels are two to four times higher than in the general U.S. population, (3) women and minorities are less knowledgeable about fish advisories than other segments of the population, (4) the presence of neurodevelopmental deficits in newborns, and cognitive deficits in children and adults, and (5) disturbances in reproductive parameters have been demonstrated in adults. The public health implications of these findings and the need for intervention strategies are discussed.     

Chironomid (Diptera) larvae of the Butoniga reservoir,Istria, Croatia,and its feeder rivers

After the formation of a drinking water reservoir at Butoniga, Istria, research on the fauna of the Chironomidae larvae was undertaken in the feeder waters and the reservoir itself. Forty eight species were identified, belonging to the subfamilies Chironominae, Orthocladiinae, Diamesinae and Tanypodinae. Chironomidae colonized the reservoir waters relatively more quickly than other groups of macroscopic invertebrates. The similarity quotient (QS) of Chironomidae of the feeder waters and the reservoir is only 37.8%, which points to the formation of new communities in the reservoir. There were qualitative and quantitative changes in the composition of Chironomidae fauna in the river Mirna and in the river Butoniga downstream from the dam after water was released from the reservoir for the purpose of testing the dam. The Chironomid composition of the feeder waters places them in quality grade II. In the Butoniga reservoir the bottom water was assigned to grade II–III, because of the decomposition of the remains of surface fauna.     

Fouling Communities of Hydrotechnical Constructions in Nakhodka Bay (Sea of Japan)

The fouling of mooring facilities in Nakhodka Bay, Sea of Japan, has been studied. The main fouling communities have been distinguished dominated by green algae Enteromorpha linza and Ulva fenestrata, brown algae Laminaria japonica and Costaria costata, a hydroid Obelia longissima, a polychaete Pseudopotamilla occelata, cirripede barnacles Balanus crenatus and Semibalanus cariosus, a bivalve mollusk Mytilus trossulus, and an ascidian Halocynthia aurantium. The naturalization of some species-invaders in the fouling of mooring facilities in Nakhodka Bay has been registered, namely hydroids Laomedea flexuosa and Clytia languida, a polychaete Pseudopotamilla occelata, and a bryozoan Bowerbankia gracilis.