Hydrobiology

The fish stock of a deep temperate, mesotrophic lake was sampled at different depths using a fixedframe fry trawl, during two nights in mid-September 2009. Additionally, horizontal and vertical hydroacoustics were used simultaneously to evaluate fish abundance and biomass estimates obtained by the trawl. Roach Rutilus rutilus and smelt Osmerus eperlanus were the dominant species of young-ofthe-year (YOY) fish in the trawl catches from the surface layers (0-9 m). Bleak Alburnus alburnus dominated the catch of older fish in the upper part of the surface profile (0-6 m). Around the thermocline (9-13 m) smelt dominated the catches of both the YOY and older fish. Beneath the thermocline (13-36 m) vendace Coregonus albula dominated the catch of YOY fish, and smelt was the only species of older fish in the trawl catches. Species composition, abundance and biomass of the YOY and older fish were heterogeneous throughout the depth profiles of the lake, but only abundance differed significantly between the layers. The hydroacoustics gave relatively similar estimates of abundance and biomass to those obtained by the trawl in all the depths sampled. Our results indicate that there is a clear separation of small fish of different species along the vertical profile of a deep temperate lake during the night, and an unequal vertical distribution of fish abundance and biomass. The similarity of the trawl and hydroacoustics estimates of abundances and biomass indicated that the trawl sampling did not cause important avoidance reactions of small fish during the night in this deep temperate lake.

We studied the rotifer fauna of one of the most pristine peat-swamps in the Southern Thai province of Narathiwas, To Daeng peat swamp. The samples yielded a total of sixty-seven rotifer species. Of these, three -Keratella mixta (Oparina-Charitonova), Lecane enowi Segers & Mertens and Monommata dentata Wulfert-are new to the Oriental region and the Thai fauna, one, Keratella taksinensis n. sp., is new to science. The fauna consists mainly of cosmopolitan {sensu lato) species, complemented by some Paleotropical and endemic taxa, and is dominated by littoral-benthonic taxa, especially Lecane and, to a lesser extent, Lepadella.

Efficient management of mass algal cultures requires appreciation of the most important factors governing the light regime of the average cell, i.e. the interrelationships between the intensity of the light source -never the sole factor involved in mass culture productivity -and the optimal cell density affected by the optical path. The latter is a dominant factor in photosynthetic productivity of ultra high cell density cultures (UHDC) cultured in flat plate reactors. Indeed, a very short optical path (5-10 mm) permits a most efficient use of strong light by facilitating ultra-high cell densities (ca. 10-20 g dry cell mass l −1 ), in which the condensed cells are exposed to very high frequency light/dark cycles. Another important feature of dense cultures concerns the very small but highly efficient light dose available to cells under extreme mutual shading. The low productivity of the single cell in the culture is well compensated, in terms of culture productivity, by the high culture cell mass exposed to very high frequency light/dark cycles. The combined effects of all these factors result in high efficiency of strong light-use for photosynthesis. UHDC are associated with growth inhibition which represents a severe production obstacle. Once this aspect is better understood and managed, UHDC in ultra short optical path reactors may become a useful production mode of photoautotrophic cell mass and secondary metabolites.

Changes in water clarity (secchi disc transparency) in relation to the presence/absence of introduced, exotic fish, including rudd (Scardinius erythrophthalmus), tench (Tinca tinca), perch (Perca fluviatilis), brown bullhead catfish (Ameiurus nebulosus), goldfish (Carassius auratus), and koi carp (Cyprinus carpio) were determined for 49 small, North Island, New Zealand lakes. There was a negative association between water clarity and the presence of exotic fish independent of lake depth. Moreover, a 'before-and-after' comparison and examination of case-studies indicated that introductions of exotic fish reduce water clarity. The number of species introduced affected the relationship between lake depth and water clarity but the specific role of each species could not be distinguished because most of the lakes (83%) contained more than one exotic fish species. A model incorporating the known mechanisms by which planktivorous, benthivorous and herbivorous fish can influence water clarity in lakes showed that control over just one species or feeding guild may not result in an improvement in water clarity because of the additive and synergistic effects of different species on lake trophic processes.

In addition to answering Hutchinson's question ''Why are there so many species?'', we need to understand why certain species are found only under certain environmental conditions and not others. Trait-based approaches are being increasingly used in ecology to do just that: explain and predict species distributions along environmental gradients. These approaches can be successful in understanding the diversity and community structure of phytoplankton. Among major traits shaping phytoplankton distributions are resource utilization traits, morphological traits (with size being probably the most influential), grazer resistance traits, and temperature responses. We review these trait-based approaches and give examples of how trait data can explain species distributions in both freshwater and marine systems. We also outline new directions in trait-based approaches applied to phytoplankton such as looking simultaneously at trait and phylogenetic structure of phytoplankton communities and using adaptive dynamics models to predict trait evolution.

Tardigrada is a phylum closely allied with the arthropods. They are usually less than 0.5 mm in length, have four pairs of lobe-like legs and are either carnivorous or feed on plant material. Most of the 900+ described tardigrade species are limnoterrestrial and live in the thin film of water on the surface of moss, lichens, algae, and other plants and depend on water to remain active and complete their life cycle. In this review of 910 tardigrade species, only 62 species representing13 genera are truly aquatic and not found in limnoterrestrial habitats although many other genera contain limnoterrestrial species occasionally found in freshwater.

Due to their boom and bust population dynamics and the enormous biomasses they can attain, jellyfish and ctenophores can have a large influence on the cycling of carbon (C), nitrogen (N) and phosphorus (P). This review initially summarises the biochemical composition of jellyfish, and compares and contrasts the mechanisms by which non-zooxanthellate and zooxanthellate jellyfish acquire and recycle C, N

We conducted a study to assess the impact of peri-urban agricultural
activities of the city of Dschang on the water quality and macroinvertebrate
structure of the Menoua stream. This study covered 3 stations (one reference
station at the upstream of the peri-urban agricultural activities and two
downstream) with a monthly sampling frequency from March 2015 to
February 2016. The physico-chemical analysis were carried out according to
standard protocols while the benthic macro-fauna was harvested using a haze
net of 30 cm side and 400 μm mesh size. Physico-chemical parameters such
as temperature, pH, conductivity, TDS (Total Dissolved Solids), salinity,
turbidity, colour, SS (Suspended Solids), nitrate, ammonium and
orthophosphate were analyzed. The inventory of benthic macroinvertebrates
revealed a taxonomic richness of 42 families and 77 taxa and a gross
abundance of 1833 individuals. Spatio-temporal monitoring of
physicochemical and biological parameters provided the image of relatively
low pollution. Metrics such as total taxonomic richness, richness of ETO
(Ephemeroptera-Trichoptera-Odonata), relative abundance of
Ephemeroptera-Trichoptera-Odonate (% ETO), diversity of Shannon and
Weaver and Pielou's equitability were determined at each of the three
stations. These indices, unlike several other studies, increased downstream of
anthropogenic activities. Low agricultural activity in the watershed has
resulted in habitat diversification and availability of resources for benthic European Scientific Journal September 2017 edition Vol.13, No.27 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431
369
macroinvertebrates, resulting in increased abundance and diversity.

In the present study a character data set suitable for cladistic analysis at the family level was developed. A data matrix consisting of 50 morphological characters from 15 families of tardigrades was analyzed by maximum parsimony. Kinorhynchs, loriciferans, and gastrotrichs were used as outgroups. The results agree with the currently accepted hypothesis that Eutardigrada and Heterotardigrada are distinct monophyletic groups. Among the eutardigrades, Eohypsibiidae was found to be a sister group to Macrobioti-dae+Hypsibiidae, while Milnesiidae was the basal eutardigrade family. The basal heterotardigrade family was found to be Oreellidae. Echiniscoideans grouped with some traditional Arthrotardigrada (Renaudarctidae, Coronarctidae+Batillipedidae) suggesting that the arthrotardigrades are not monophyletic. The 18S rRNA gene sequence of Batillipes mirus Richters, 1909 and Calohypsibius schusteri Nelson & McGlothlin, 1996 were obtained and their addition to a previously published dataset supports the monophyly of Heterotardigrada and of Parachela versus Apochela within the Eutardigrada.

1. The in situ abundance, biomass and mean cell volume of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic German mining lake (Lake 111; pH 2.65), were determined over three consecutive years (spring to autumn, 2001-03). 2. Actinophrys sol exhibited pronounced temporal and vertical patterns in abundance, biomass and mean cell volume. Increasing from very low spring densities, maxima in abundance and biomass were observed in late June/early July and September. The highest mean abundance recorded during the study was 7 • 10 3 Heliozoa L)1. Heliozoan abundance and biomass were higher in the epilimnion than in the hypolimnion. Actinophrys sol cells from this acidic lake were smaller than individuals of the same species found in other aquatic systems. 3. We determined the growth rate of A. sol using all potential prey items available in, and isolated and cultured from, Lake 111. Prey items included: single-celled and filamentous bacteria of unknown taxonomic affinity, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp. and the rotifers Elosa worallii and Cephalodella hoodi. Actinophrys sol fed over a wide-size spectrum from bacteria to metazoans. Positive growth was not supported by all naturally available prey. Actinophrys sol neither increased in cell number (k) nor biomass (k b) when starved, with low concentrations of single-celled bacteria or with the alga Ochromonas sp. Positive growth was achieved with single-celled bacteria (k ¼ 0.22 ± 0.02 d)1 ; k b ¼)0.06 ± 0.02 d)1) and filamentous bacteria (k ¼ 0.52 ± <0.01 d)1 ; k b ¼ 0.66 d)1) at concentrations greater than observed in situ, and the alga C. acidophila (up to k ¼ 0.43 ± 0.03 d)1 ; k b ¼ 0.44 ± 0.04 d)1), the ciliate Oxytricha sp. (k ¼ 0.34 ± 0.01 d)1) and in mixed cultures containing rotifers and C. acidophila (k ¼ 0.23 ± 0.02-0.32 ± 0.02 d)1 ; maximum k b ¼ 0.42 ± 0.05 d)1). The individual-and biomass-based growth of A. sol was highest when filamentous bacteria were provided. 4. Existing quantitative carbon flux models for the Lake 111 food web can be updated in light of our results. Actinophrys sol are omnivorous predators supported by a mixed diet of filamentous bacteria and C. acidophila in the epilimnion. Heliozoa are important components in the planktonic food webs of 'extreme' environments.

On basis of recent developments in phytoplankton ecology an assemblage index, Q, was developed to assess ecological status of different lake types established by the Water Framework Directive (WFD). Since 5 ≥ Q ≥ 0, the developed index can provide 5-grade qualification required by WFD. Case studies from very different lake types support the usefulness of the developed index. Straights and weaknesses of the Q index for monitoring purposes are discussed. Without arguing for the superiority of the assemblage index in comparison with any other measures of ecological status of lakes, we aim to open a discussion about its possible applications.

Larvae of almost all of the 5,680 species of the insect order Odonata (dragonflies and damselflies) are dependent on freshwater habitats. Both larvae and adults are predators. The order is relatively well studied, and the actual number of species may be close to 7,000. Many species have small distributional ranges, and are habitat specialists, including inhabitants of alpine mountain bogs, seepage areas in tropical rain forests, and waterfalls. They are often successfully used as indicators for environmental health and conservation management. The highest diversity is found in flowing waters in rain forests of the tropics, the Oriental and Neotropical regions being the most speciose. This paper discusses diversity, summarises the biogeography of dragonflies in the different biogeographical regions and gives the total number of species and genera per family per biogeographical region. Examples are given of areas of particular diversity, in terms of areas of endemism, presence of ancient lineages or remarkable recent radiations but no well-based review of areas with high endemism of dragonflies is available so far. The conservation status of dragonflies is briefly discussed. Species confined to small remnants of forest in the tropics are most under threat of extinction by human activities.

The effects of fish kill and different fish stocks on the phytoplankton and zooplankton dynamics were studied in a shallow hypertrophic reservoir system. When fish stock was below 100 kg ha-1, nutrient availability was not the main limiting factor for growth of phytoplankton. Consequently top-down forces controlled phytoplankton. In the years with high fish stock (>100 kg ha-1) the bottom-up forces dominated as nutrient availability was the main limiting factor for growth of phytoplankton. We can conclude that significant water quality improvement can be achieved in the reservoir system by decreasing fish stock below 100 kg ha-1. Although clear-water phase could be stabilised temporary by macrophytes, stabilisation of good water quality requires continuous regulation of fish community. (

1. Urbanisation is an important cause of eutrophication in waters draining urban areas. We determined whether benthic algal biomass in small streams draining urban areas was explained primarily by small-scale factors (benthic light, substratum type and nutrient concentrations) within a stream, or by catchment-scale variables that incorporate the interacting multiple impacts of urbanisation (i.e. variables that describe urban density and the intensity of drainage or septic tank systems). 2. Benthic algal biomass was assessed as chlorophyll a density (chl a) in 16 streams spanning a rural-urban gradient, with both a wide range of urban density and of piped stormwater infrastructure intensity on the eastern fringe of metropolitan Melbourne, Australia. The gradient of urban density among streams was broadly correlated with catchment imperviousness, drainage connection (proportion of impervious areas connected to streams by stormwater pipes), altitude, longitude and median phosphorus concentration. Catchment area, septic tank density, median nitrogen concentration, benthic light (photosynthetically active radiation) and substratum type were not strongly correlated with the urban gradient. 3. Variation in benthic light and substratum type within streams explained a relatively small amount of variation in log chl a (3-11 and 1-13%, respectively) compared with between-site variation (39-54%). 4. Median chl a was positively correlated with catchment urbanisation, with a large proportion of variance explained jointly (as determined by hierarchical partitioning) by those variables correlated with urban density. Independent of this correlation, the contributions of drainage connection and altitude to the explained variance in chl a were significant. 5. The direct connection of impervious surfaces to streams by stormwater pipes is hypothesised as the main determinant of algal biomass in these streams through its effect on the supply of phosphorus, possibly in interaction with stormwater-related impacts on grazing fauna. Management of benthic algal biomass in streams of urbanised catchments is likely to be most effective through the application of stormwater management approaches that reduce drainage connection.

1. We studied the effects of increased water temperatures (0–4.5 °C) and nutrient enrichment on the stoichiometric composition of different primary producers (macrophytes, epiphytes, seston and sediment biofilm) and invertebrate consumers in 24 mesocosm ecosystems created to mimic shallow pond environments. The nutrient ratios of primary producers were used as indicative of relative nitrogen (N) or phosphorus (P) limitation. We further used carbon stable isotopic composition (δ13C) of the different primary producers to elucidate differences in the degree of CO2 limitation.2. Epiphytes were the only primary producer with significantly higher δ13C in the enriched mesocosms. No temperature effects were observed in δ13C composition of any primary producer. Independently of the treatment effects, the four primary producers had different δ13C signatures indicative of differences in CO2 limitation. Seston had signatures indicating negligible or low CO2 limitation, followed by epiphytes and sediment biofilm, with moderate CO2 limitation, while macrophytes showed the strongest CO2 limitation. CO2 together with biomass of epiphytes were the key variables explaining between 50 and 70% of the variability in δ13C of the different primary producers, suggesting that epiphytes play an important role in carbon flow of temperate shallow lakes.3. The ratio of carbon to chlorophyll a decreased with increasing temperature and enrichment in both epiphytes and seston. The effects of temperature were mainly attributed to changes in algal Chl a content, while the decrease with enrichment was probably a result of a higher proportion of algae in the seston and epiphytes.4. Macrophytes, epiphytes and seston decreased their C : N with enrichment, probably as an adaptation to the different N availability levels. The C : N of epiphytes and Elodea canadensis decreased with increasing temperature in the control mesocosms. Sediment biofilm was the only primary producer with lower C : P and N : P with enrichment, probably as a result of higher P accumulation in the sediment.5. Independently of nutrient level and increased temperature effects the four primary producers had significantly different stoichiometric compositions. Macrophytes had higher C : N and C : P and, together with epiphytes, also the highest N : P. Seston had no N or P limitation, while macrophytes and epiphytes may have been P limited in a few mesocosms. Sediment biofilm indicated strong N deficiency.6. Consumers had strongly homeostatic stoichiometric compositions in comparison to primary producers, with weak or no significant treatment effects in any of the groups (insects, leeches, molluscs and crustaceans). Among consumers, predators had significantly higher N content and lower C : N than grazers.

1. We investigated the effect of moderate eutrophication on leaf litter decomposition and associated invertebrates in five reference and five eutrophied streams in central Portugal. Fungal parameters and litter N and P dynamics were followed in one pair of streams. Benthic invertebrate parameters that are considered useful in bioassessment were estimated in all streams. Finally, we evaluated the utility of decomposition as a tool to assess stream ecosystem functional integrity.2. Decomposition of alder and oak leaves in coarse mesh bags was on average 2.3–2.7× faster in eutrophied than in reference streams. This was attributed to stimulation of fungal activity (fungal biomass accrual and sporulation of aquatic hyphomycetes) by dissolved nutrients. These effects were more pronounced for oak litter (lower quality substrate) than alder. N content of leaf litter did not differ between stream types, while P accrual was higher in the eutrophied than in the reference stream. Total invertebrate abundances and richness associated with oak litter, but not with alder, were higher in eutrophied streams.3. We found only positive correlations between stream nutrients (DIN and SRP) and leaf litter decomposition rates in both fine and coarse mesh bags, associated sporulation rates of aquatic hyphomycetes and, in some cases, total invertebrate abundances and richness.4. Some metrics based on benthic invertebrate community data (e.g. % shredders, % shredder taxa) were significantly lower in eutrophied than in reference streams, whereas the IBMWP index that is specifically designed for the Iberian peninsula classified all 10 streams in the highest possible class as having ‘very good’ ecological conditions.5. Leaf litter decomposition was sufficiently sensitive to respond to low levels of eutrophication and could be a useful functional measure to complement assessment programmes based on structural parameters.

Drought in Atpadi Tehsil is having serious ecological and economic consequences and assuring adequate safe and sustainable drinking water and sanitation to all is a challenge. The data collected from 60 villages in Atpadi Tehsil (2010-2012). The data reveal that high temperature, less rainfall, decrease ground water level in various dams, tanks and wells causes’ water and fodder scarcity, low agriculture production, less productivity, unemployment and finally migration.
Key words: Atpadi Tehsil, Drought, Water crisis.

1. Waterbirds are considered to import large quantities of nutrients to freshwater bodies but quantification of these loadings remains problematic. We developed two general models to calculate such allochthonous nutrient inputs considering food intake, foraging behaviour and digestive performance of waterbirds feeding in terrestrial habitats: an intake model (IM), mainly based on an allometric relationship for energy requirements and a dropping model (DM), based on allometric relationships for defaecation.2. Reviewed data of nitrogen (N) and phosphorus (P) content of herbivorous food varied according to diet type (foliage, seeds and roots), season and fertilization. For model parameterization average foliage diet contained 38.20 mg N g−1 and 3.21 mg P g−1 (dry weight), whereas mean faeces composition was 45.02 mg N g−1 and 6.18 mg P g−1.3. Daily allochthonous nutrient input increased with body mass ranging from 0.29 g N and 0.03 g P in teals Anas crecca to 5.69 g N and 0.57 g P in mute swans Cygnus olor. Results from IM differed from those of DM from ducks to swans by 63–108% for N and by −4 to 23% for P. Model uncertainty was lowest for the IM and mainly caused by variation in estimates of food retention time (RT). In DM food RT and dropping mass determined model uncertainty in similar extent.4. Exemplarily applying the models to Dutch wetlands resulted in mean annual contribution of herbivorous waterbirds to allochthonous nutrient loading of 382.8 ± 167.1 tonnes N a−1and 34.7 ± 2.3 tonnes P a−1, respectively, which corresponds to annual surface-water loadings of 1.07 kg N ha−1 and 0.10 kg P ha−1.5. There was a distinct seasonal pattern with peak loadings in January, when bird abundances were highest. Lowest inputs were in August, when bird abundance and nutrient content in food was low and birds foraged less in terrestrial habitats. Three-quarters of all nutrient input was contributed by greater white-fronted goose Anser albifrons, greylag goose Anser anser, wigeon Anas penelope and barnacle goose Branta leucopsis alone.6. We provide general, easy to use calculation methods for the estimation of allochthonous nutrient inputs by waterbirds, which are applicable to a range of waterbird species, a variety of potential diets and feeding behaviours, and across spatial scales. Such tools may greatly assist in the planning and execution of management actions for wetland nutrient budgets.

The main aim of this study, which is based on cover-abundance values of 20 species of floatingleaved and submersed macrophytes collected in 18 lakes located within the River Po catchment basin (Italy), is to investigate the relationships between lake-scale environmental features (including morphology, hydrology, trophic state and water quality variables) and the changes in species composition and species richness in macrophyte communities. The findings reveal that the main changes in community composition of the pondweed communities, identified by principal component analysis, could be effectively explained by a newly introduced morpho-hydrological parameter (the theoretical laminar water renewal rate -R L ) and by the trophic state of the lakes, expressed as Carlson's trophic state index (TSI). The results of the multivariate analyses performed also show that the grouping of species is strictly related to growth-form traits. In particular, floating-leaved and submerged macrophytes appeared mutually exclusive in dominating different habitat types defined on the basis of the R L -TSI framework. An increasing trend in species richness was also observed in relation to R L . The possibility of using the bivariate R L -TSI framework for the identification of habitat utilisation patterns by single species was also investigated, and cover-abundance prediction maps based on the R L -TSI framework were produced for several macrophyte species. Observations in another system characterised by high spatial heterogeneity for hydrological and trophic conditions, support the predictions in terms of growth-form prevalence, species richness and single species cover-abundance (where available), and also suggest a more refined application of the proposed approach. Gaertn.; NLUT -Nuphar luteum L. Sibth & Sm; NALB -Nymphaaea alba L.; NPEL -Nymphoides peltata; PAMP -Polygonum amphybium L.; PCRI -Potamogeton crispus L.; PLUC -Potamogeton lucens L.; PPEC -Potamogeton pectinatus L.; PPER -Potamogeton perfoliatus L.; PPUS -Potamogeton pusillus L.; RTRI -Ranunculus trichophyllus Chaix;TNAT -Trapa natans L.; VSPI -Vallisneria spiralis L.; ZPAL -Zannichellia palustris L.

Generalized additive models are proposed for a better understanding of the underlying mechanisms for anchovy variations in abundance. Environmental variables derived from satellite imagery (surface chlorophyll, sea surface temperature and wind-mixing index), river discharge (Rhône River and Ebre River) and anchovy landings (landings per unit of effort) as proxy for abundance were used, and three fishing zones were defined along the Catalan Coast. A time shift among wind index mixing, sea surface temperature and chlorophyll was observed for these variables to be significantly correlated with anchovy. Results pointed out to processes that appear to greatly influence species abundance and affect different life stages of anchovy (conditions preceding reproduction, larvae growth and survival and recruits growth). A high proportion of anchovy LPUE variability could be explained by environmental variables. Thus, some univariate models explained deviance are more than 50%, even up to around 70% of anchovy variability. In several cases the deviance explained by a given variable was even higher at the longer time-lags. Among all univariate and bivariate models fitted, the model that best explained anchovy LPUE variability, 79% of total deviance, was a model proposed for the central zone, based on the additive effect of surface chlorophyll and Rhône River discharge, considering time lags of 15 and 18 months, respectively, for each variable.

Over the past few years, there has been growing interest among the sponge community in the phylogenetic position of the Homoscleromorpha (i.e. within or outside the class Demospongiae). Recent molecular analyses clearly show that the Homoscleromorpha forms a distinct clade separated from the Demospongiae and is composed of two families, Oscarellidae and Plakinidae. Within the currently more widely accepted hypothesis of a monophyletic Porifera, we formally propose here to raise Homoscleromorpha to the class rank (the fourth one). We, therefore, provide a definition and a formal diagnosis. In the supplementary materials, we also present an alternative classification of the Homoscleromorpha, following the PhyloCode.

An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.

Ujani Dam also known as Bhima Dam or Bhima irrigation project is the major freshwater aquatic ecosystem constructed on the Bhima river located near Ujani village of Madha tehsil in Solapur district, Maharashtra state. The Bhima river basin has about 14 tributaries having total drainage area of 48,631 Km2, it spreads over the Maharashtra (75%) and Karnataka (25%) states. The Ujani Dam and its large reservoir provide multipurpose benefits including irrigation, drinking, hydroelectric power generation, Industrial water supply and fisheries. Present study was undertaken from Nov.2014 to Sept.2016 with respect to bimonthly seasonal variations in physico-chemical parameters. The selected sites are Ujani Dam, Bhima River (Down-stream), Shirala, Kandhar and Chikhalthan. Most of the selected sampling sites are very close to human population and agricultural land; hence their physico-chemical properties are greatly influenced by anthropogenic activities.

During low water levels, habitats in river-floodplain systems are isolated from each other and from the main river. Oppositely, floods tend to connect water bodies with distinct hydrological characteristics and, as a result, ecological processes and biological communities tend to be more similar among the distinct habitats that comprise a river-floodplain system. Based on a literature review and also using unpublished data obtained in tropical floodplains, the aim of this paper is to highlight the effects of floods as a process that reduce spatial variability. The usual negative relationship between the coefficient of variation of any ecological indicator (e.g., chlorophyll-a or total phosphorus) and water level is the main result demonstrating a reduction in spatial variability due to floods. Considering physical, chemical or biotic data gathered in distinct habitats within the floodplain, this pattern was found in temperate and tropical regions, subjected to distinct levels of anthropogenic impacts, and at different spatial extents. The main mechanism that accounts for this pattern may be stated as follow. During low water level, the biological communities of each habitat in the floodplain (e.g., lagoons, backwater, streams) follow distinct temporal trajectories due to the effects of local driving forces (e.g., an efficient predator trapped in a lagoon but not in another). Management plans and biodiversity conservation in river floodplain systems will benefit by considering the effects of flood homogenization and increased connectivity peculiar to these unique ecosystems.

The present study deals with the analysis of physico-chemical parameters of the Song River at
Dehradun (U.K.). In the present study various physico-chemical characteristics of Song River
viz Temperature, pH, Turbidity, TS, TDS, TSS, DO, BOD, COD, FreeCO2, Acidity, Alkalinity,
Hardness, Calcium, Magnesium and Chloride were done. During the course of study only
minor differences in physical and chemical parameters of study area were observed.

The present study was done to assess status and threats for Ujani wetlands like Palasdev, Dalaj, Kumbhargaon, Diksal, Kondhar Chincholi, Rajegaon (Bhigwan) and Khanota. These wetlands are rich in biodiversity but day by day they are facing challenges like unplanned tourism, sand lifting, over fishing, uncontrolled siltation and weed infestation, encroachment like agricultural expansion resulting in shrinkage of wetland area. Figures: 10 References: 18 Table: 01

1. The effect of total nitrogen (TN) and phosphorus (TP) loading on trophic structure and water clarity was studied during summer in 24 field enclosures fixed in, and kept open to, the sediment in a shallow lake. The experiment involved a control treatment and five treatments to which nutrients were added: (i) high phosphorus, (ii) moderate nitrogen, (iii) high nitrogen, (iv) high phosphorus and moderate nitrogen and (v) high phosphorus and high nitrogen. To reduce zooplankton grazers, 1 + fish (Perca fluviatilis L.) were stocked in all enclosures at a density of 3.7 individuals m )2 . 2. With the addition of phosphorus, chlorophyll a and the total biovolume of phytoplankton rose significantly at moderate and high nitrogen. Cyanobacteria or chlorophytes dominated in all enclosures to which we added phosphorus as well as in the high nitrogen treatment, while cryptophytes dominated in the moderate nitrogen enclosures and the controls. 3. At the end of the experiment, the biomass of the submerged macrophytes Elodea canadensis and Potamogeton sp. was significantly lower in the dual treatments (TN, TP) than in single nutrient treatments and controls and the water clarity declined. The shift to a turbid state with low plant coverage occurred at TN >2 mg N L )1 and TP >0.13-0.2 mg P L )1 . These results concur with a survey of Danish shallow lakes, showing that high macrophyte coverage occurred only when summer mean TN was below 2 mg N L )1 , irrespective of the concentration of TP, which ranged between 0.03 and 1.2 mg P L )1 . 4. Zooplankton biomass and the zooplankton : phytoplankton biomass ratio, and probably also the grazing pressure on phytoplankton, remained overall low in all treatments, reflecting the high fish abundance chosen for the experiment. We saw no response to nutrition addition in total zooplankton biomass, indicating that the loss of plants and a shift to the turbid state did not result from changes in zooplankton grazing. Shading by phytoplankton and periphyton was probably the key factor. 5. Nitrogen may play a far more important role than previously appreciated in the loss of submerged macrophytes at increased nutrient loading and for the delay in the reestablishment of the nutrient loading reduction. We cannot yet specify, however, a

1. We conducted a statistical reassessment of data previously reported in the lake total phosphorus (TP) input/output literature (n ¼ 305) to determine which lake characteristics are most strongly associated with lake phosphorus concentration and retention. We tested five different hypotheses for predicting lake TP concentrations and phosphorus retention. 2. The Vollenweider phosphorus mass loading model can be expressed as: TP out ¼ TP in / (1 + rs w), where TP in is the flow-weighted input TP concentration, s w is the lake hydraulic retention time and r is a first-order rate constant for phosphorus loss. 3. The inflow-weighted TP input concentration is a moderately strong predictor (r 2 ¼ 0.71) of lake phosphorus concentrations when using log-log transformed data. Lake TP retention is negatively correlated with lake hydraulic retention time (r 2 ¼ 0.35). 4. Of the approaches tested, the best fit to observed data was obtained by estimating r as an inverse function of the lake's hydraulic retention time. Although this mass balance approach explained 84% of the variability in log-log transformed data, the prediction error for individual lakes was quite high. 5. Estimating r as the ratio of a putative particle settling velocity to the mean lake depth yielded poorer predictions of lake TP (r 2 ¼ 0.77) than the approach described above, and in fact did not improve model performance compared with simply assuming that r is a constant for all lakes. 6. Our results also demonstrate that changing the flow-weighted input concentration should always have a directly proportionate impact on lake phosphorus concentrations, provided the type of phosphorus loaded (e.g. dissolved or particulate) does not vary.

The marbled lungfish, Protopterus aethiopicus, a recent introduction into Lake Baringo, Kenya is now an important commercial species there. Because little is known about its behaviour, we used ultrasonic telemetry to investigate its movements and use of habitat as part of a broader biological study. Twelve marbled lungfish were implanted with ultrasonic tags and tracked for variable periods between September 2001 and 2002. Two individuals were tracked for most of the study period. Daily movement ranged from little or none to 5.2 km. Mean hourly rates of movement for three fish located twice a day (morning and late afternoon) over several days suggested that individuals were active throughout the diel period. Maximum lake depth was about 3 m and fish utilized all depths greater than 1 m. Six home ranges described for four lungfish varied in size from 5.8 to 19.8 km 2 and were occupied for between 2 and 4.5 months. Use of habitat and the movement of marbled lungfish in Lake Baringo appeared to be influenced more by biotic than abiotic factors.

Australia is a land of salt lakes and despite low human population density, many lakes are adversely impacted by a range of factors. Secondary salinisation is the most pernicious force degrading lakes, especially in south-west Western Australia where up to 30% of the landscape is predicted to be affected. Mining also impinges on many salt lakes in this state, mainly through the dewatering of saline groundwater. Exploitation of groundwater for irrigation caused some lakes in Victoria, Australia, to dry, especially the significant Red Rock Complex. Global climate change will result in new water balances in endorheic lakes, with most having less water, particularly the seasonal lakes of southern Australia. This has already happened in Lake Corangamite, Victoria, but the prime reason is diversion of inflowing floodwater. Consequently, the lake has retreated and become salinised compromising its status as a Ramsar site. Various other lakes suffer from enhanced sedimentation, have introduced biota or their catchments are being disturbed to their detriment. Enlightened management should be able to maintain some important lakes in an acceptable condition, but, for most others, the future is bleak. Hydrobiologia (2005) 552:1-15

The basis of this study were 132 adult Allis Shad and 150 Twaite Shad collected as bycatches from salmon stake nets in Scotland on the north side of the Solway Firth. Most (60%) of the Allis Shad were immature fish 2–3 years of age (mean length 305 mm). Mature males were younger (3–5 years) and smaller (mean length 421 mm) than females (4–6 years and 481 mm mean length). The largest Allis Shad was a female of 515 mm and 2183 g. In contrast, almost all the Twaite Shad were mature, the males younger (3–5 years) and smaller (mean length 341 mm) than the females (4–6 years and 364 mm mean length). The largest Twaite Shad was a female of 400 mm and 1213 g. The food of Allis Shad consisted mainly of small zooplankton with some fish and larger Crustacea. Fine vegetable fragments were common in the stomachs and attributed to filter feeding. The food of Twaite Shad was mainly small fish with some Crustacea. Mature Allis Shad of both sexes with large gonads (maximum female GSI: 20.63) were found throughout the spring and summer but no definite evidence of local spawning was obtained. Mature Twaite Shad of both sexes with large gonads (maximum female GSI: 23.32) were found until early July, thereafter most of the fish were spent. It appears that Twaite Shad spawn locally in June. Some hybrids between the two species were found.

Bu çalışmada Karadeniz havzasında seçilen 14 lokasyondan toplanan Alburnoides bipunctatus (Bloch, 1782)'un popülasyon içi ve popülasyonlar arası varyasyonları, tür içindeki farklılıkların açıklanması amacıyla morfometrik karakterler kullanılarak çalışılmıştır. Metrik karakterler üzerine uygulanan ayırma fonksiyonu analizi (DFA) ve kümeleme analizi (CA), Karadeniz havzasının Batı, Doğu ve Orta bölgelerindeki örnekleri morfolojik açıdan farklı üç popülasyon olarak sınıflandırmıştır. Morfometrik karakterler ve çok değişkenli analizler, Doğu Karadeniz havzasındaki popülasyonların Alburnoides fasciatus'a yakın olduğunu göstermiştir. Ayrıca Orta Karadeniz Bölgesi'ni temsil eden Bafra bölgesindeki popülasyonun diğer bölgelerden farklılık gösterdiği belirlenmiştir. /
In this study, inter and intra-population variations of cyprinid fish Alburnoides bipunctatus (Bloch, 1782) collected from selected 14 localities in Black Sea basin, Turkey, were studied by using morphometric characters for explaining differentiation within the species. Discriminant function analysis (DFA) and cluster analysis (CA) applied on metric characters, indicated that samples from Western, Eastern and Middle regions of Black Sea basin were classified into three morphologically distinct populations. Morphometric characters and multivariate analyses showed that the Eastern Black Sea basin populations are similar to Alburnoides fasciatus. Also population from Bafra region that represents Middle Black Sea region is well differentiated from other regions.

Several hundred vascular plants taxa reported for Albania by foreign and Albanian botanists were not included in the guide flora "Flora of Albania", although some of them are referred in the guide "Flora of Europe" and many other in different databases of the European or Mediterranean flora. Only during the last two decades have been reported or confirmed about 440 new vascular plants species and subspecie for Albania.
In this paper is presented a list of 180 species and 79 subspecie reported or referred by various authors for Albania until 1990, but not included in the main guide of the flora of Albania (except some of them with red) and not confirmed after its publication. About 49 species and 18 subspecies are endemic, sub-endemic or Balkan species, of which 8 species and 1 subspecies are endemic to Albania, while 7 species and 3 subspecies are alien.

The European list of aquatic macro-invertebrate taxa, and its associated ecological database, originated within the context of the AQEM project and have been extended during the STAR project. The AQEM/STAR taxalist is a product of co-operation between applied freshwater ecologists and scientists from different zoological fields, applied partners and the administration. The basic idea is that a sound understanding of benthic invertebrate ecology is a prerequisite for the implementation of a biological approach to aquatic ecosystem management in Europe. The database has been generated under the management of BOKU (University of Natural Resources and Applied Life Sciences, Vienna) and UDE (University of Duisburg-Essen) and provides an important means of standardisation and unification of ecological classifications in Europe. This paper outlines the aims for setting up the AQEM/STAR macro-invertebrate taxalist and autecological database and provides a current summary of the numbers of aquatic orders, families, species, and species occurrences in 14 European countries. The number of available and applicable assignments of taxa to each ecological parameter is summarised and examples are given for different parameters and taxonomic groups. Gaps in the autecological information are identified and discussed. Besides its ecological relevance, the operational character of this database is underlined by the fact that it provides the associated taxon codes for each of five different European assessment systems for nearly 10,000 European macro-invertebrate taxa.

We determine the composition of invertebrate community in the
permanent spring areas in the Blanice river and Zlaty stream catchments.
The samples of macroinvertebrates from 83 spring areas were taken. Number
of individuals in the samples weried from 6 to 533 individuals. Considerable
differences in taxonomical group distribution were recorded. The most abundant
taxonomic groups were Plecoptera and Pisidium sp. In total, 16 000 individuals
were determined. The most common type of spring area was helocrene (more
than 50%). Pea clams are very abundant in the spring areas, especially in
helocrenes. They represents tiny clams, whose ecological requirements are
not well known up to now; hence they are described in detail in this paper.

Tel. 274 54 30; Faks. 2784161 Mob. 8-620 48 958 [email protected] 3 VYKDYTOJAI: prof. habil. dr. Jūratė Balevičienė mob. 8-650 76160 dr. Aušrys Balevičius mob. 8-652 94118 8-620 48 958 dr. Egidijus Bukelskis mob. 8-687 92656 dr. Antanas Ciūnys mob. 8-614 23913 dr. Vitas Stanevičius mob. 8-614 75887 dr. Gediminas Vaitkus mob. 8-699 99940 dr. Gintaras Valiuškevičius mob. 8-685 08934 dokt. Daiva Kalytytė mob. 8-686 02238 ekonomistė mgr. Rasa Ūselytė mob. 8-686 23939 asist. Kristina Šalčiūnienė mob. 8-655 45355 RESTAURAVIMO PRIEMONIŲ PARINKIMAS RESTAURUOTIEMS EŽERAMS, JŲ EKOLOGINĖS NAUDOS, OPTIMALAUS MASTO IR EFEKTYVUMO ĮVERTINIMAS 7 IR 8 VEIKLOS Šioje ataskaitos dalyje aptariamos konkrečių restauruotinų ežerų b ūklės problemos bei j ų priežastys, pateikiami šiems e ž erams sudaryti restauravimo bei b ū klės pagerinimo kompleksinių priemonių planai, prognozuojama priemonių ekologinė nauda, apskaičiuoti preliminarūs kaštai. Pirminė nuostata, prieš imantis bet kurio vandens telkinio tvarkymo ar valymo, yra taršos ir biogeninių medžiagų prietakos į telkinį sustabdymas. Kitu atveju bet kokios tvarkymo priemonės praranda prasmę. Antroji nuostata -ežero tvarkymas ar valymas jokiu būdu neturi pakenkti ar destabilizuoti telkinio hidrocheminės ir ekologinės būklės. Trečia -tvarkant ar valant vandens telkinį, b ūtina i šsaugoti tai, kas gali b ūti panaudota mezotrofinės ekosistemos kūrimui bei struktūriniam -funkciniam subalansavimui po ežero išvalymo (pvz., nendrynai, kurie gali b ū ti panaudoti kaip natūralus makrofitų biofiltras; keletas uždaresnių eutrofinių įlankų, kuriose valymo darbų metu prieglobstį rastų kuo didesnė ežero hidrobiontų įvairovėšie organizmai po valymo darbų kolonizuos i š valytus plotus, prisidės prie e ž ero ekosistemos funkcionavimo ir gerokai atpigins ekosistemos komponentų struktūrinį -funkcinį subalansavimą). 7 1. VALYTINŲ EŽERŲ RESTAURAVIMO PRIEMONĖS 1.1. Alovės ežeras Alovės ežeras yra Alytaus r., apie 12 km į pietryčius nuo Alytaus miesto, apie 2 km į rytus nuo magistralinio kelio Alytus -Merkinė. Šiaurinėje pusėje įsikūręs Alovės miestelis, aplink ežerą išsidėstę Janapolio, Akalyčių kaimų sodybos (1.1.1 pav.). Ežero plotas siekia 73,7 ha, ilgis -apie 1550 m, vidutinis plotis -450 m, didžiausias plotis ~800 m. Vandens paviršiaus altitudė 132,8 m. Ežeras susidaręs ledo luisto guolyje, todėl jo kranto linija silpnai vingiuota. Krantai žemi, kai kur pelkėti. Į Alovės ežerą įteka 2 bevardžiai upeliai, išteka Alovės upelis, kuris yra Nemuno intakas. 1.1.1 pav. Alovės ežero geografinė vieta Atlikus Corine žemėnaudos (2005-06 m.) analizę, apskaičiuota, kad Alovės ežero baseine 0-250 m spinduliu vyrauja žemės ūkis (93,4 %) ir gyvenvietės (6,6 %), visame baseine žemės ūkis užima 65,3 %, natūralūs biotopai -33,5 %, gyvenvietės -1,2 %. Ežerą supa dirbami laukai, tik vakarinės pusės krante auga miškas. Dalis ežero pakrančių užpelkėjusios, beveik visos pakrantės gausiai apaugusios 8 helofitų juostomis ir lapuočiais medžiais bei krūmais, tai ypatingai išreikšta šiaurinje ir pietinėje ežero dalyse. Atabradas palyginti siauras, apaugęs vešlia nendrynų, monažolynų bei papartuolinių nendrynų juosta, o papelkėjusiose vietose -švendrynų bei viksvynų juostomis (1.1.2 pav.), tuo tarpu povandeninių augalų -limneidų augimą riboja visą vegetacijos sezoną besitęsiantis vandens žydėjimas, kuris drastiškai sumažina vandens skaidrumą (0,7-1,3 m pagal Secchi). Ežero krantai apaugę lapuočiais medžiais, krūmais, kurių nuokritos dar labiau padidina organinių medžiagų kiekį ežero ekosistemoje. 1.1.2. pav. Alovės ežero pakraščiai apaugę makrofitais, o pakrantės lapuočiais medžiais 2009 metų kovo mėnesį Alovės ežere atlikti uždumblėjimo žvalgomieji tyrimai, pelkiniu zondu padaryti 7 gręžiniai (1.1.3. pav.). Pagal gręžinius nubraižytas išilginis ežero geologinis pjūvis (1.1.1. brėžinys). Nustatyta, kad ežero vidutinis vandens gylis yra 2,51 m, maksimalus -4,4 m. Charakteringa, kad visame ežere, išskyrus vieną gilesnę vietą, vandens gylis yra beveik vienodas 2 -2,8 m. Ežere susikaupę dideli dumblo kiekiai: vidutinis sluoksnio storis -4,44 m, maksimalus -8,8 m (3 gręžinyje). Ežere susikaupęs juodas arba rudas vidutiniškai mineralizuotas dumblas, turintis 41,6 % organinės medžiagos. Dumble yra nemažas kiekis azoto (21665 mg/kg), fosforo ir kalio jame nedaug (atitinkamai 1025 mg/kg ir 7025 mg/kg). E ž ero dugną asluoja minkštai plastiškas priemolis. Apskaičiuota, kad ežere susikaupę apie 3,3 mln. m 3 dumblo. 9 1 2 3 6 4 5 7 1.1.3 pav. Alovės ežero tyrimo schema ir mėginių ėmimo vietos Ežeras įrašytas į rizikos vandens telkinių sąrašą, jame kasmet stebimi ilgi ir stiprūs vandens "žydėjimai". Nors ežeras yra pratakus, dėl didelio organinės medžiagos kiekio čia nereti žieminiai žuvų dusimai, dėl to Alovės ež. yra įrašytas į dūstančių ežerų sąrašą. Alovės ežere numatoma vystyti aplinkos Valomas 74 ha ežero plotas Krūmųšalinimas Pakrančių valymas ekskavatoriumi ir užpylimas smėliniu gruntu 1.1.4 pav. Alovės ežero išvalymo ir sutvarkymo planas 11 Atlikus floros tyrimus, nustatyta, kad ežere maža augalų rūšių įvairovė, geriausiai išreikšta helofitų (nendrių, vietomis -siauralapių švendrų) juosta. Lūgnių juosta menka, jos plotis retai kur siekia daugiau, kaip 10 m. Limneidų beveik nėra dėl pastoviai mažo vandens skaidrumo, pasitaiko pavieniai nerties egzemplioriai. Alovės ežere ir apyežeryje saugomų augalų rūšių neinventorizuota. Pagrindinės ežero faunos rūšys peri ežero užpelkėjusios pakrantės ruožuose. Pagrindinę masę sudaro vadinamos nendrynų žvirblinių paukščių rūšys: nendrinukės (ežerinė nendrinukė (Acrocephalus schoenobaenus), didžioji ir mažoji krakšlės (A. arundinaceus ir A. scirpaceus)), iš žiogelių -nendrinis žiogelis (Locustella luscinioides), o iš startų -nendrinė starta (Emberiza schoeniclus). Tai įprastos foninės rūšys. Iš vandens paukščių apyežerio užpelkėjusioje dalyje lizdus susikrauna didžiosios antys (Anas platyrhynchos). Kartais peri pavienės ausuotųjų kragų ar laukių poros. Vandens paukščių fauna labai skurdi, iš dalies dėl prastos mitybinės bazės (trukdo vandens žydėjimas) ir prastų perėjimo sąlygų. Ežere peri gulbių nebylių pora. Perėjimo buveinės netenkina daugelio rūšių dėl siauro atbrado bei dėl medžių (juodalksnių) ir krūmų (šaltekšnių ir karklų) įsigalėjimo apyežerio pelkėse. LRK ir ES PD I rūšių nėra. Ežero valymo nauda bet kuriuo atveju atsvertų galimą žalą faunai (nors pastarąją sunku įsivaizduoti). Norint praturtinti paukščių fauną reikėtų pasirinktinai pašalinti šiaurinės pakrantės užpelkėjusios dalies užgožusius medžius ir krūmus, ir išsaugoti atbrade augančius nendrynus. Jei būtų sukurta mezotrofiniam ežerui artima ekosistema padidėtų augalų rūšių įvairovė, labai pagerėtų paukščių mitybinė bazė. Galėtų formuotis nelizdinės paukščių sankaupos.

Ulva spp. are common in the intertidal zones of the Philippines, but, at certain times, could over-proliferate producing blooms or 'green tide' in some protected bays. In Mactan Island (Cebu), central Philippines, at least two species constitute the Ulva population, either as free-living or attached form. The one referred to in the literature as 'Ulva lactuca' mainly consists of free-living population while the species referred to as Ulva reticulata consists mainly of attached population. Based on morphological and physiological characteristics, 'U. lactuca' differs much from the descriptions of the species from its type locality in Europe in having a crumpled texture of blade, presence of tooth-like protuberances at the margins, thinner thallus (40-50 µm) and more pyrenoids per cell (two to four). The species referred to as 'U. lactuca' in the Philippines therefore is a different species. Two morphotypes consisted the 'U. lactuca' population from Mactan -a thick thallus and a thin thallus type. However, both morphotypes cultured under the same condition in the laboratory could transform into the same thin-thallus type observed in the field. 'Green tide' caused by 'U. lactuca' occur almost regularly in Station 1 of Mactan Island, reaching an average biomass of up to 2.6 kg wet wt m −2 (or 0.5 kg dry wt m −2 ). Ulva reticulata, although was less abundant in the rocky tidal zone at most times, reaching an average biomass of only up to 0.15 kg wet wt m −2 (or 0.03 kg dry wt m −2 ) had caused green tide in Station 2 around February-March. Reproductive structures were not observed in both Ulva species during the survey period suggesting that vegetative fragmentation is the main mode of propagation. Vegetative tissues excised from the thallus can be induced to release biflagellated large and small zooids.

In the present study an investigation has been made on physico-chemical characteristics, primary productivity parameters, nutrient dynamics, plankton diversity and abundance of an urban and peri urban pond, located in Raipur district of Chhattisgarh. The study was conducted during April 2013 to March 2014. The samples were analysed at monthly intervals.
In the urban and peri urban pond, mean value of physico-chemical parameters such as transparency was 47.86 cm and 16.68 cm respectively, pH (7.76 and 8.27 respectively), temperature (24.38°C and 24.52°C respectively), EC (0.46 mS/cm and 0.45 mS/cm respectively), TDS (0.44 ppt and 0.29 ppt respectively), salinity (0.34 ppt both), Free CO2 (1.75 ppm and 0.58 ppm respectively), CO32- (3.33 ppm and 7.33 ppm respectively), HCO3- (156.67 ppm and 180.50 ppm respectively), total alkalinity (160 ppm and 187.83 ppm respectively), total hardness (113 ppm and 76.50 ppm respectively) and DO (4.63 ppm and 5.12 ppm respectively). All the parameters except DO were found within the optimum range recommended for fish culture.
The mean primary productivity values in the urban and peri urban pond such as GPP was 2287.50 mg C/m2/day and 2562.50 mg C/m2/day respectively, NPP (1768.75 mg C/m2/day and 1231.25 mg C/m2/day respectively) and community respiration (518.75 mg C/m2/day and 1331.25 mg C/m2/day respectively). The urban pond was mesotrophic in nature while the peri urban pond is showing signs of progressive eutrophication as evident from the primary productivity values.
The mean value of dissolved nutrients of pond water and soil parameters in the urban and peri urban pond such as NH3-N were 0.09 ppm and 0.12 ppm respectively, NO3-N (0.40 ppm and 0.11 ppm respectively), O-PO4 (0.04 ppm and 0.08 ppm respectively), soil pH (6.84 units both), soil EC (0.44 mS/cm and 0.50 mS/cm respectively), soil available-N (345.85 kg/ha and 381.25 kg/ha), soil available-P (15.13 kg/ha and 12.08 kg/ha respectively), soil available-K (436.16 kg/ha and 468.74 kg/ha respectively) and soil organic carbon (0.56 percent and 1.00 percent respectively). Except soil pH, soil EC and soil available-K, all the nutrient parameters were at sub-optimal levels and need amendment through adoption of soil based fertilisation packages. Nutrient wise, the peri urban pond had greater fertility than the urban pond.
The Menhinik generic diversity index of phytoplankton was higher in the urban pond (1.87 units) than the peri urban pond (0.88 units). The phytoplankton abundance was greater in the peri urban pond (1853500.67 no. of individuals/lit) than its urban counterpart (333174.67 no. of individuals/lit). Similarly, Menhinik generic diversity index as well as abundance of zooplankton was higher in the peri urban pond (6.19 units and 3225 no. of individuals/lit respectively) than its urban counterpart (5.73 units and 1825 no. of individuals/lit). A total of 62 genera of phytoplankton and 21 genera of zooplankton were found in the urban pond. In the peri urban pond, 64 phytoplankton genera and 22 zooplankton genera were noted. Among phytoplankton, members of Chlorophyceae dominated in either of the ponds (40.58 percent and 38.11 percent respectively). Among zooplankton, rotifers dominated in the urban pond (46.69 percent) while copepods dominated in the peri urban pond (46.29 percent). The peri urban pond is better in plankton status as compared to its urban counterpart and can support higher fish yield if managed properly.
Statistically significant positive correlations were observed between EC and salinity, EC and O-PO4, HCO3- and total alkalinity, HCO3- and GPP, HCO3- and soil organic carbon, DO and zooplankton count, NPP and GPP, O-PO4 and soil available-N, soil pH and soil EC while significant negative correlations were found between temperature and NPP, temperature and GPP, temperature and zooplankton count, temperature and Menhinik diversity index of zooplankton, EC and DO, salinity and DO, free CO2 and CO32-, DO and Menhinik diversity index of zooplankton, NPP and Menhinik diversity index of phytoplankton, NH3-N and NO3-N, Phytoplankton count and Menhinik diversity index of phytoplankton, Zooplankton count and Menhinik diversity index of zooplankton.
Most of the limnological parameters reached their peak during the winter months and were within the optimum range for freshwater semi intensive fish culture practices. It was concluded that the present extensive fish culture practices should be upgraded to semi intensive methods in these water bodies based on recommendations.