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Fatty acid, triacylglycerol, phospholipid, tocol and sterol compositions of E. maritimum seeds collected from plants grown in ten different Tunisian littoral locations were determined. Constitutes from different locations are significantly different. Seeds presented high oil content, ranging from ca. 22% to 34% on a dry weight basis, and were characterized by a constant fatty acid profile among the growing locations. Gas chromatographic analysis revealed an important level of unsaturated fatty acids (ca. 90% of total fatty acid content), with a prevalence of oleic (ca. 63%) and linoleic (ca. 25%) acids. Results obtained by GC-FID showed that the carbon number (CN) values of the TAGs in all samples were 50 (1.5%), 52 (25.6%) and 54 (73%). Phosphatidylcholine was the most common phospholipid, accounting for more than 60% of the total content, followed by phosphatidic acid (about 30%). Different tocols concentration was reported in seeds with β-tocotrienol as the most abundant one in all samples. Stigmasterol was the most abundant sterol in all seeds, representing nearly 70% of the total content, followed by β-sitosterol and Δ 7 -sitosterol. In all, the findings of this work highlight the valuable levels of minor constituents from Eryngium maritimum storage lipids which can be therefore a prospective source of useful natural bioactive molecules that may replace synthetic antioxidants. [ABSTRACT FROM AUTHOR]

During the past 50 years, wet stormwater ponds have been constructed to reduce negative environmental impacts of urban stormwater discharges on receiving aquatic environments. However, in many jurisdictions there is little information on the current operational status of such ponds and their functioning. This paucity of information prompted a field survey of 25 Swedish municipal stormwater ponds, aged between 3 and 26 years. The pond survey focused on estimating the pond hydraulic loading and efficiency, the state of littoral vegetation, characteristics of bottom sediment in the inlet and outlet zones (sizes and the chemistry), and the overall operational pond status, including the access for maintenance. The hydraulic efficiencies of ponds were estimated for pond footprint shapes and relative locations of the inlets and outlets using literature data. The estimated hydraulic efficiencies correlated well with the pond length-to-width ratios and the ratio of the pond surface area to the impervious area of the runoff contributing catchment (i.e., the hydraulic loading). Littoral vegetation was inspected visually and found to be overgrown at some facilities, which impeded the maintenance access. Benthic sediments in ponds contained silt and clay (<63 μm), sand and gravel fractions, and when compared with the literature data, such sediments appeared relatively coarse. Chemical characteristics of sediments reflected anthropogenic (traffic) activities, but without excessive contamination warranting special disposal requirements. Of the 25 ponds surveyed, four were fenced off and inaccessible to machinery. In fact, the design of these four ponds was such that it made inspection and maintenance very difficult, which may pose potential risks to ponds operation. Fifty-four percent of the investigated ponds were in need of minor maintenance, primarily because of sediment and litter accumulation in their inflow and outflow sections. The fact that the inspection survey revealed relatively few minor issues that could be corrected easily demonstrates the importance of relatively simple regular inspections serving to detect minor problems at an early stage before they would seriously impact pond functioning. The above survey methodology should be helpful for developing similar low-cost surveys in other jurisdictions. [ABSTRACT FROM AUTHOR]

The current study presents the ostracod communities recovered from 26 shallow waterbodies in southern Kenya, combined with an ecological assessment of habitat characteristics. A total of 37 waterbodies were sampled in 2001 and 2003, ranging from small ephemeral pools to large permanent lakes along broad gradients in altitude (700–2 800 m) and salinity (37–67 200 µS cm−1). Between 0 and 12 species were recorded per site. Lack of ostracods was associated with either hypersaline waters, or the presence of fish in fresh waters. Three of the 32 recovered ostracod taxa,Physocypriasp.,Sarscypridopsiscf.elizabethaeandOncocypris mulleri, combined a wide distribution with frequent local dominance. Canonical correspondence analysis on species–environment relationships indicated that littoral vegetation, altitude, surface water temperature and pH best explain the variation in ostracod communities. Presence of fish and water depth also influence species occurrence, with the larger species being more common in shallow waterbodies lacking fish. Based on Chao’s estimator of total regional species richness, this survey recovered about two-thirds (60–68%) of the regional ostracod species pool. Scanning electron micrographs (SEM) of the valve morphology of 14 ostracod taxa are provided, in order to facilitate their application in biodiversity and water-quality assessments and in palaeoenvironmental reconstruction. [ABSTRACT FROM PUBLISHER]

Genetic diversity may play an analogous role to species diversity, as it can contribute to ecosystem function and stability, and provision of ecosystem services. In the Baltic Sea, perennial algal beds are often comprised of only Fucus vesiculosus and the amount of genetic variation in fitness-related traits (i.e., the ability of the alga to photosynthesize or withstand stress) will thus determine the alga's local persistence in a changing environment. To study genetic variation in the crucial traits behind persistence we grew replicate vegetative branches that came from the same genotype in common gardens. We quantified osmotic stress tolerance and recovery responses by exposing branches to desiccation, freezing, and hyposalinity regimens. Our results show that genetic variation among genotypes was apparent for some photosynthetic parameters (maximal electron transport rate, saturation irradiance for electron transport, nonphotochemical quenching) and growth. Algae tolerated freezing (1,440 min at −2.5°C) and hyposalinity (1,560 min at 2.5) well, but did not recover from desiccation (70 min at 12°C, causing ~94% water loss). Furthermore, we found very little if any evidence on genetic variation in tolerance to these stressors. Our results suggest that low salinity and cold winters in the northern marginal populations selected for hyposalinity and freezing tolerant genotypes, possibly eroding genetic variation in tolerance, but that tolerance to harsh desiccation has been lost, likely due to relaxed selection. The overall availability of genetic variation in fitness related traits might be supportive for F. vesiculosus during adaptation to gradual changes of its environment. [ABSTRACT FROM AUTHOR]

An integrated approach focused on sedimentology, geochemistry, palynology, C and N isotopes and radiocarbon dating of a sediment core from an herbaceous plain not flooded by tides of the Amapá littoral, near the Amazon River mouth, allowed identification of two phases with marine and terrestrial influences. Mangroves occurred over tidal mud flats with marine influence between > 5610–5470 and 470–310 cal yr BP. The absence of mangrove vegetation since 470–310 cal yr was followed by the transition of brackish water organic matter to terrestrial C 3 plants. Also, the geochemical data indicate a decrease in sea water influence during this last time interval. Likely, the displacement of mangrove forest to lower surfaces was caused by a relative sea-level fall that may be associated with drier conditions with less rainfall during the second part of the last millennium. As suggested by this work, slight relative sea-level fluctuations caused by regional or global climatic change may affect significantly the current mangrove area. [ABSTRACT FROM AUTHOR]

Lake Naivasha is a freshwater lake in the East African Rift Valley. With continued lake level declines between 1980 and 2011, the newly exposed land areas were gradually taken for agricultural use. The resulting chronosequences allow for an analysis of the effects of land use duration on nutrient dynamics and agricultural production. Transects representing land use durations of 0-30 (cropland) and 15-30 years (pasture) were established on soils formed on alluvial deposits and lacustrine sediments. We assessed changes in topsoil nitrogen (N) stocks (t ha−1), ammonium mineralization potential (N-supplying capacity), and plant-available P with increasing durations of land use. An additional greenhouse experiment studied the responses of kikuyu grass ( Cenchrus clandestinus) and maize ( Zea mays) in potted topsoil collected from differnt land-use types and chronosequence positions. With increasing duration of land use we noted a significant decline ( P < 5%) in soil N contents under both pasture and cropland uses, following a model of exponential decay. The N stocks decreased at 84 kg ha−1 a−1 and a decay rate constant of 0.019 a−1 in pasture soil within 15 years, and at 75 kg ha−1 a−1 with a decay rate-constant of 0.013 a−1 in cropland soil within 30 years. While the ammonium-N mineralization potential also decreased with land use duration, the trends were significant only in lacustrine pasture soils. Plant-available P did not show any trends that were related to the duration of land use. Kikuyu grass and maize accumulated less dry matter and N as the duration of use increased. This biomass accumulation was significantly related to soil N. A continued mineralization of soil organic matter has possibly contributed to the observed soil N depletion over time. The continuous agricultural use of the littoral wetland zone of Lake Naivasha is likely to entail declining production potentials for both pastures and food crops. [ABSTRACT FROM AUTHOR]

Research on charcoal remains from prehistoric caves located in the south Adriatic-Sea coast reveals the regional palaeovegetation composition and its strong relationship to rapid changes of the eustatic sea level, during the last glacial–interglacial cycle and early Holocene. We intend to characterize biogeographical conditions mechanically disturbed by the glacial–interglacial transgressive eustatic level, which destroyed the trees and shrubs managed by prehistoric Adriatic human populations. Thus it appears that some ligneous taxa, such as deciduous taxa ( Quercus , Prunoideae, etc.) and the genus Pistacia , may be considered markers of the rapid eustatic changes within this littoral environment. [ABSTRACT FROM AUTHOR]

Development of effective methods for assessing the ecological status of lakes based on littoral benthic fauna has been hampered by the lack of quantitative data on the relative impacts of key pressures on the benthic community. We used variance partitioning at 126 sites belonging to 14 natural Mediterranean lakes to analyze the pure and shared effects of eutrophication, morphological alterations, microhabitat type, lake morphometry and geographic position on the littoral macroinvertebrate community. The spatial arrangement of the sampling sites was responsible for 9.1% of the total variance in littoral benthic community composition, lake morphometry accounted for 4.3% of variation, and microhabitat type accounted for 3.9%. Communities appeared to be affected primarily by morphological alterations to lake shorelines, and their impact was 2.5 times as important as that of eutrophication. The structure of littoral benthic communities was governed by processes acting at several spatial scales from region to lake scale. Thus, several pressures and the various spatial scales at which these act should be taken into account when implementing methods of assessing lake ecological condition based on littoral benthic invertebrates. Region-specific methods for subalpine and volcanic lakes might enhance the validity of assessment of results of morphological alterations and improve management of those water resources. [ABSTRACT FROM AUTHOR]

Ecosystem services are typically valued for their immediate material or cultural benefits to human wellbeing, supported by regulating and supporting services. Under climate change, with more frequent stresses and novel shocks, 'climate adaptation services', are defined as the benefits to people from increased social ability to respond to change, provided by the capability of ecosystems to moderate and adapt to climate change and variability. They broaden the ecosystem services framework to assist decision makers in planning for an uncertain future with new choices and options. We present a generic framework for operationalising the adaptation services concept. Four steps guide the identification of intrinsic ecological mechanisms that facilitate the maintenance and emergence of ecosystem services during periods of change, and so materialise as adaptation services. We applied this framework for four contrasted Australian ecosystems. Comparative analyses enabled by the operational framework suggest that adaptation services that emerge during trajectories of ecological change are supported by common mechanisms: vegetation structural diversity, the role of keystone species or functional groups, response diversity and landscape connectivity, which underpin the persistence of function and the reassembly of ecological communities under severe climate change and variability. Such understanding should guide ecosystem management towards adaptation planning. [ABSTRACT FROM AUTHOR]

Here we present a formal description of Biremis panamae Barka, Witkowski et Weisenborn sp. nov., which was isolated from the marine littoral environment of the Pacific Ocean coast of Panama. The description is based on morphology (light and electron microscopy) and the rbcL, psbC and SSU sequences of one clone of this species. The new species is included in Biremis due to its morphological features; i.e. two marginal rows of foramina, chambered striae, and girdle composed of numerous punctate copulae. The new species also possesses a striated valve face which is not seen in most known representatives of marine littoral Biremis species. In this study we also present the relationship of Biremis to other taxa using morphology, DNA sequence data and observations of auxosporulation. Our results based on these three sources point to an evolutionary relationship between Biremis, Neidium and Scoliopleura. The unusual silicified incunabular caps present in them are known otherwise only in Muelleria, which is probably related to the Neidiaceae and Scoliotropidaceae. We also discuss the relationship between Biremis and the recently described Labellicula and Olifantiella. [ABSTRACT FROM AUTHOR]

The rapid rate of habitat loss in Madagascar urges a comprehensive assessment of the threats that its fauna faces by living in fragmented, secondary and/or exotic forests. The role of habitat disturbance in determining potential boosts of parasite infections in lemurs, for instance, has been only recently investigated. Here, we conducted a preliminary assessment of prevalence and intensity of gastrointestinal parasite infections in two populations of endangered red-collared brown lemurs,Eulemur collaris(Geoffroy, 1812) (Mammalia: Lemuridae), living in two littoral forest fragments of southeastern Madagascar. We collected faecal samples from 45 lemurs. The samples were stored in 70% alcohol, and we used a modified McMaster technique to analyze egg shedding. The analysis revealed only nematode infections. We found a higher prevalence of infection in the more disturbed fragment, while no differences were revealed in terms of infection intensity. Prevalence of infection was found to be sex-biased in the less degraded area, being higher in females. We hypothesize that this might have been caused by female immune suppression due to increased energetic costs during pregnancy and/or to avoid possible harm to the foetus. Since red-collared brown lemurs are the largest seed dispersers in the littoral forest and only small populations survive in a few fragments, the implications of our results should be considered in future conservation plans for this habitat. [ABSTRACT FROM AUTHOR]

We explored δ15N compound-specific amino acid isotope data (CSI-AA) in filter-feeding intertidal mussels (Mytilus californianus) as a new approach to construct integrated isoscapes of coastal primary production. We examined spatial δ15N gradients in the California Upwelling Ecosystem (CUE), determining bulk δ15N values of mussel tissue from 28 sites between Port Orford, Oregon and La Jolla, California, and applying CSI-AA at selected sites to decouple trophic effects from isotopic values at the base of the food web. Bulk δ15N values showed a strong linear trend with latitude, increasing from North to South (from ∼7‰ to ∼12‰, R2 = 0.759). In contrast, CSI-AA trophic position estimates showed no correlation with latitude. The δ15N trend is therefore most consistent with a baseline δ15N gradient, likely due to the mixing of two source waters: low δ15N nitrate from the southward flowing surface California Current, and the northward transport of the California Undercurrent (CUC), with15N-enriched nitrate. This interpretation is strongly supported by a similar linear gradient in δ15N values of phenylalanine (δ15NPhe), the best AA proxy for baseline δ15N values. We hypothesize δ15NPhe values in intertidal mussels can approximate annual integrated δ15N values of coastal phytoplankton primary production. We therefore used δ15NPhe values to generate the first compound-specific nitrogen isoscape for the coastal Northeast Pacific, which indicates a remarkably linear gradient in coastal primary production δ15N values. We propose that δ15NPhe isoscapes derived from filter feeders can directly characterize baseline δ15N values across major biochemical provinces, with potential applications for understanding migratory and feeding patterns of top predators, monitoring effects of climate change, and study of paleo- archives. [ABSTRACT FROM AUTHOR]

Aim Our aim was to document African rain forest tree diversity patterns to test whether they support one of the following hypotheses: the structure of tree species diversity is at equilibrium and mostly driven by neutral processes (H0); the structure of tree species diversity results from Pleistocene forest cover dynamics (H1); or the structure of tree species diversity results from ecological sorting along environmental gradients (H2). Location West Central Africa: the hilly region of Gabon, a putative Pleistocene forest refuge, and the adjacent flat littoral region, putatively colonized by forests from the hilly region after the last glaciation. Methods We used 103 standardized 0.1-ha tree plots distributed among five landscapes in the two regions. We partitioned the tree diversity within and among plots at a local and regional scale using the Hurlbert effective number of species framework. The explanatory power of geographical and elevational distances on species turnover was tested. At the landscape scale, we partitioned the beta diversity into nestedness and turnover components. Results Mean alpha and gamma diversities were much higher in the hilly region, where differences in elevation explained a significant part of species turnover. Substantial species turnover correlated with geographical distance also occurred in the littoral region despite its low elevational heterogeneity. Floristic turnover between plots from different regions remained stable whatever the elevational/geographical distances. At the regional scale, species replacement remained the main contributor to beta diversity (low nestedness values). Main conclusions The heterogeneous distribution of alpha and gamma diversity, similar levels of species turnover among plots and the low contribution of the nestedness component to beta diversity between hilly and littoral landscapes do not support hypotheses H0 and H1. The combined impacts of limited dispersal and ecological sorting along environmental gradients (H2) can explain patterns within regions. The marked floristic discontinuity between regions could reflect contrasting histories (two distinct refugia) although the role of contrasting environments cannot be discounted. [ABSTRACT FROM AUTHOR]

Residential development on lake shores is regularly associated with the conversion of natural littoral habitats to riprap, sheet piles, beaches, parks, or marinas. The subsequent loss of littoral vegetation induces a decline of structural diversity and impacts littoral fish communities. These impacts may be shaped by lake morphology. Using boosted regression trees (BRT) to relate fish abundance data from 57 north-east German lowland lakes to various factors characterizing trophic state, lake morphology, and shoreline development, we investigated the response of 11 fish species to shoreline development. The analyses revealed that mean depth followed by trophic level and shoreline length (SL) contributed most in explaining littoral fish abundance. BRT models built for deep and shallow lakes separately confirmed that primarily trophic level and SL influenced fish abundance but that littoral vegetation was relatively more important in deep compared to shallow lakes, indicating that the effects of shoreline development may be more pronounced in deep lakes where the littoral makes up a smaller proportion of the lake area as compared to shallow lakes. The BRT further demonstrated species-specific responses to shoreline degradation, indicating that the reliability of ecological quality assessments of lakes can be improved by applying separate metrics for individual species. [ABSTRACT FROM AUTHOR]

Phragmites australis and Glyceria maxima are fast-growing littoral grasses often competing for similar wetland habitats. Eutrophication affects their competitiveness, but the outcome is not generally predictable due to the complexity of interrelated factors. We hypotheses that pore water N:P and NH:NO modify their growth and metabolic responses to the trophic status of the habitat. The hypothesis was tested under standardized conditions of long-term sand cultures. Application of N + P up to extreme levels in combination with N:P < 10 and NH:NO < 1 triggered positive growth response in both species. In contrast, similar N levels applied in N:P > 90 and NH:NO = 4 caused lower productivity, changes in resource allocation, morphology and metabolic relations (e.g. high shoot density, low shoot diameters and heights, reduced root and rhizome growth). Observed signs of stress resembled the factors associated with the reed retreat at the die-back sites. Unbalanced N levels obviously alter plant susceptibility to stresses (altering, e.g. ventilation efficiency, plant anchorage or below-ground storage capacity). The positive effect of sufficient P supply was pronounced in Glyceria. It might therefore favour Glyceria in competition with Phragmites at highly fertile habitats rich in P. [ABSTRACT FROM AUTHOR]

Abstract: To compare the performance of two common methods for surveying boreal lake aquatic macrophyte communities (the transect survey and the phytolittoral inventory) in lake bioassessment, we studied five small humic lakes with both methods. In addition to this pairwise comparison, we contrasted available independent sets of reference lake data of either methodological origin. Specifically, we compared the observed species richness and a number of ecological quality (community) metrics and their variability both between the methods and within them in relation to sampling effort and operator. With the phytolittoral inventory, more taxa (mean 38.8±s.d. 12.1) were observed than with transect survey (29.8±6.5) in a shorter time. Ecological quality metrics relying on taxonomic composition were sensitive to variation both between (reference lake data: t-test, p <0.001) and within methods (metric values varied with sample size), whereas a trophy-specific metric based on indicator species was more robust in this respect (ref. lakes: t-test, p =0.788; minor variation with sample size). The two methods did not differ in among-observer variation (CV of community metrics 5.0–8.7), which was, as indicated by an NMDS ordination, relatively low compared to among-lake variation. Overall, the results highlight the importance of establishing reference conditions using unified methods, which are also consistent with those used in the macrophyte-based ecological assessments. Even though the more cost efficient phytolittoral inventory method is more suitable for biodiversity surveys focusing on the overall species richness and rare species, we suggest that the transect survey better meets the requirements of ecological status assessment, as it produces information also on the zonation of the littoral vegetation. [Copyright &y& Elsevier]

The main differences between the linear and areal types of littoral habitats are in their shape, structure and the hydro- and litho-dynamic, salinity and ecological gradients between terrestrial and aquatic environments. Understanding the nature of linear littoral habitats is important for interpreting the 'coastal squeeze' effect. The aim of this study is to analyse and compare the integrity of the key linear littoral habitats adjacent to two European lagoons-Lesina Lagoon on the Adriatic Sea and the Curonian Lagoon on the Baltic Sea. Among the four linear habitats selected for this study, we found that the glasswort ( Salicornia spp.) swards showed the highest level of integrity, while the reed beds showed the lowest level of integrity. The linear littoral habitats rely on the dynamic equilibrium conditions. Hence, the strip of glasswort swards and the freshwater dune slack ponds of Bosco Isola di Lesina both depend upon climatic conditions that determine the shape of the salinity gradient. This gradient runs perpendicular to the coast and is based on a transition from fresh groundwater to saline water. The chain of shifting coastal dunes and the reed beds of the Curonian Spit depend upon the long-shore hydro- and litho-dynamic flow conditions. [ABSTRACT FROM AUTHOR]

Global declines in biodiversity, together with widespread degradation of ecosystem services, have led to urgent calls to safeguard. Humans maintain plants around their houses to increase their quality of life. In the present study, 90 and 30 plots of 50 m2 each were studied in urbanised and rural areas in Cameroon. In each plot, vascular plant species were identified and their coefficient of abundance-dominance was determined. Different diversity indices were calculated to compare the flora of urbanised and rural areas as well as the distribution of plants. A total of 119 species belonging to 95 genera and 45 families were sampled. Shannon-Weaver diversity index, Pielou and Sheldon values vary when taking into account not only erected or wooded plants, but also herbs and erected or wooded plants. Plots near houses in urban areas comprised weeds, ornamentals and fruits, whereas in rural areas medicinal or edible plants dominated. Based upon the results, we conclude that the use of plants as food, medicinal resources or for other purposes, might be helpful for biodiversity conservation, ecosystem services, the management of resources and to fight poverty. However, the composition of the flora is likely to change as urbanisation proceeds. [ABSTRACT FROM AUTHOR]

Hydropolyps inhabiting temperate ecosystems exhibit marked seasonality, and undergo regression as a normal part of their life cycle. In the campanulariid species Clytia gracilis, both hydroids and medusae are decidedly seasonal in occurrence. Epizoic colonies of C. gracilis, growing on colonies of Ectopleura crocea, were collected monthly in the intertidal zone at Mar del Plata, Argentina (38°08′S–57°37′W) during low tide from February 2000 to January 2001. Abundance, seasonality and reproductive periods were analysed. The hydroid reached peak abundance during the summer, yet reproductive structures were scarce and observed in only a few colonies. A remarkable regression period was evident in the cold season. During that period, hydroids of the species had few functional polyps, and the colonies were largely reduced to dormant tissue in the coenosarc of hydrocauli and stolons. Hydranths of C. gracilis regenerated during summer and produced a profuse asexual growth by stolonization. Asexual propagation is proposed as the prime mechanism in maintaining these hydroid populations. In comparisons of intertidal and subtidal populations of C. gracilis, available hydroid colonies of Amphisbetia operculata and Plumularia setacea collected from neighboring rocky outcrops (38°10′S–57°30′W), at depths of 18–20 m, during both warm and cold seasons were analysed. As in the intertidal populations, these colonies showed marked stolonal growth at the end of summer. [ABSTRACT FROM AUTHOR]

Abstract: A level with fern stumps was discovered in the Aptian Douiret Formation, South-Tunisia. These stumps are preserved as external moulds or casts, without any preservation of anatomical structures. These stumps are considered to be affiliated with the numerous fossil plants assigned to the fern genera Alstaettia and Piazopteris that are widely distributed in coeval strata from the same region, either as leaf imprints or as permineralized remains. The record of in situ fossil forests for the Southern Hemisphere reveals that their systematic components are different, i.e. mainly corystosperms and/or conifers, and rarely under tidal influence. The way this fern grove settled in a margino-littoral environment is discussed. [Copyright &y& Elsevier]

Coastal zooplankton have been investigated since 1984 at a Long Term Ecological Research station MC (LTER-MC) in the inner Gulf of Naples (Tyrrhenian Sea, Western Mediterranean). The sampling site, located between the littoral and the open sea systems, has very active hydrography that affects plankton communities. The present work was aimed at establishing whether, in such a dynamic and variable environment, species associations and homogeneous periods could be identified as characteristic and stable features of the mesozooplankton over the period 1984–2006. Hierarchical clustering was applied to assess species associations based on a matrix of similarities between species (R-mode), and homogeneous periods based on a matrix of similarities between observations (Q-mode). The Indicator Value index [IndVal, Dufrene and Legendre (1997) Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol. Monogr., 67, 345–366] was calculated to identify species characterizing each period. Five taxonomic groups with well-defined composition and abundance were identified as robust associations that likely reflect different modes of community functioning. The temporal course of these associations was largely shaped by strong seasonal forcing comprising both physical and biological (e.g. trophic) signals. These associations persisted over the long term, thus indicating some stable characters in the Naples zooplankton time-series, providing evidence of resilience in communities in highly variable coastal conditions. [ABSTRACT FROM AUTHOR]

Examining differences in colour plasticity between closely-related species in relation to the heterogeneity of background colours found in their respective habitats may offer important insight into how cryptic colour change evolves in natural populations. In the present study, we examined whether nonbreeding dorsal body coloration has diverged between sympatric species of stickleback along with changes in habitat-specific background colours. The small, limnetic species primarily occupies the pelagic zone and the large, benthic species inhabits the littoral zone. We placed benthic and limnetic sticklebacks against extremes of habitat background colours and measured their degree of background matching and colour plasticity. Benthics matched the littoral background colour more closely than did the limnetics, although there was no difference between species in their resemblance to the pelagic background colour. Benthics were able to resemble both background colours by exhibiting greater directional colour plasticity in their dorsal body coloration than limnetics, which may be an adaptive response to the greater spectral heterogeneity of the littoral zone. The present study highlights how habitat-specific spectral characteristics may shape cryptic coloration differences between stickleback species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, , 902-914. [ABSTRACT FROM AUTHOR]

Primates deal with fluctuations of the thermal environment by both physiological and behavioral mechanisms of thermoregulation. In this article we focus on nonhibernating lemurs, which are hypometabolic and have to cope with a seasonal environment. Behavioral thermoregulation has received little attention compared with specific physiological adaptations to seasonality, i.e., hibernation and torpor, which characterize a number of lemurs. We investigated the role of seasonality and dietary-related factors in determining frequencies of resting, social and postural thermoregulation, and microhabitat selection in collared lemurs, Eulemur collaris. We observed two groups of collared lemurs over a 14-month period in the littoral forest of Sainte Luce, Southern Madagascar. Frequencies of total resting and time spent in huddling, prone, and curled postures were collected via 5-min instantaneous sampling. Microhabitat selection was evaluated as the proportion of time spent in the upper canopy as compared with other layers. Climatic variables were recorded by automatic data loggers, while dietary variables were derived from phenological data and nutritional analyses of the ingested food items. We weighted the combined effects of climatic and dietary variables on the different types of behavioral thermoregulation by means of canonical correlation analysis. The model with the strongest canonical correlation included a first root representing mainly feeding time, day length, and ambient temperature and a second root representing diet quality and height of feeding trees. The output indicated that collared lemurs adapt to thermal and dietary-related metabolic stress by adjusting resting time, social, and postural thermoregulation. Am J Phys Anthropol, 2011. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Inocybe tauensis is described as a new species from the island of Ta’u, American Samoa. The species occurs in native littoral forest and is associated with the ectomycorrhizal tree Pisonia grandis. Based on an analysis of nLSU, RPB1, and RPB2 sequence data, I. tauensis appears to be derived from ancestors with a Paleotropical biogeographical distribution. Alternative explanations for the unexpected presence of an Inocybe species in the Samoan Archipelago are discussed. [Copyright &y& Elsevier]

Mangroves occur in coastal areas and are therefore vulnerable to anthropogenic disturbance and exhibit high rates of deforestation. Mexico is among the countries with the highest degree of mangrove deforestation in America; however, precise data on national mangrove coverage in Mexico is incomplete, making it impossible to accurately ascertain the rate of mangrove loss over time. Precise information is necessary to assess changes at local and regional scales to detect the magnitude, trends, and drivers of the transformation. This study aimed to estimate the loss of mangrove cover in the area of Mahahual-Xcalak (Quintana Roo, Mexico) between 1995 and 2007, to calculate the annual deforestation rate and to identify the drivers of deforestation. Landsat TM and ETM+ images from 1995 and 2007 were used to estimate the loss of mangrove cover using a multitemporal analysis. Semi-structured interviews with local residents of Mahahual and Xcalak were undertaken to identify and validate the drivers of deforestation. The image analysis for the 12-year period showed that 1070 ha of mangrove forest have been lost, with an annual deforestation rate of 0.85%—a relatively high value compared with other mangrove regions in Mexico. The main factor that has triggered the reduction of mangrove coverage is the expansion of anthropogenic land uses (e.g., settlements and roads). This study concludes that conservation and rehabilitation programs need to be implemented so that the Mahahual-Xcalak mangrove environment can continue to provide key ecosystem services. [ABSTRACT FROM AUTHOR]

We performed a meta-analysis of published studies and long-term monitoring data sets to evaluate the effects of dreissenid mussels (Dreissena polymorpha and D. rostriformis bugensis), two of the world's most problematic biological invaders, on the biogeochemistry, flora, and fauna of lakes and rivers across North America and Eurasia. Dreissenid effects were structured along two distinct energy pathways. For the pelagic-profundal pathway, large mean reductions in phytoplankton (-35% to -78%) and zooplankton (-40% to -77%) biomass occurred and were dependent on habitat type. The largest effects were found in rivers, followed by littoral and pelagic habitats in lakes. In contrast, benthic energy pathways within littoral habitats of lakes and rivers showed dramatic increases in mean benthic algal and macrophyte biomass (+170% to +180%), sediment-associated bacteria (about +2000%), non-dreissenid zoobenthic biomass (+160% to +210%), and total zoobenthic biomass, which includes dreissenid mussel soft tissues (+2000%). Our study quantifies the remarkable ability of these invasive mussels to shift aquatic food webs and energy flow from pelagic-profundal to benthic-littoral energy pathways, and it provides a basis for forecasting their impacts in diverse freshwater ecosystems. Our meta-analysis approach was a powerful tool for moving beyond the idiosyncrasies of individual case studies and may be equally powerful for assessing impacts of other biological invaders. [ABSTRACT FROM AUTHOR]

Abstract: Two hypotheses have been proposed to explain the origin of marine isotope stage (MIS) 11 deposits in small Bermudian caves at +21m above modern sea level: (1) a +21m MIS 11 eustatic sea-level highstand, and (2) a MIS 11 mega-tsunami event. Importantly, the foraminifera reported in these caves have yet to be critically evaluated within a framework of coastal cave environments. After statistically comparing foraminifera in modern Bermudian littoral caves and the MIS 11 Calonectris Pocket A (+21m cave) to the largest available database of Bermudian coastal foraminifera, the assemblages found in modern littoral caves – and Calonectris Pocket A – cannot be statistically differentiated from lagoons. This observation is expected considering littoral caves are simply sheltered extensions of a lagoon environment in the littoral zone, where typical coastal processes (waves, storms) homogenize and rework lagoonal, reefal, and occasional planktic taxa. Fossil protoconchs of the Bermudian cave stygobite Caecum caverna were also associated with the foraminifera. These results indicate that the MIS 11 Bermudian caves are fossil littoral caves (breached flank margin caves), where the total MIS 11 microfossil assemblage is preserving a signature of coeval sea level at +21m. Brackish foraminifera (Polysaccammina, Pseudothurammina) and anchialine gastropods (∼95%, >300 individuals) indicate a brackish anchialine habitat developed in the elevated caves after the prolonged littoral environmental phase. The onset of sea-level regression following the +21m highstand would first lower the ancient brackish Ghyben-Herzberg lens (<0.5m) and flood the cave with brackish water, followed by drainage of the cave to create a permanent vadose environment. These interpretations of the MIS 11 microfossils (considering both taphonomy and paleoecology) are congruent with the micropaleontological, hydrogeological and physical mechanisms influencing modern Bermudian coastal cave environments. In conclusion, we reject the mega-tsunami hypothesis, concur with the +21m MIS 11 eustatic sea-level hypothesis, and reiterate the need to resolve the disparity between global marine isotopic records and the physical geologic evidence for sea level during MIS 11. [Copyright &y& Elsevier]

Herbivory is typically intense in marine littoral environments; thus, macrophytes are expected to evolve defenses against grazing. Although putative defenses of macrophytes are widely studied, there is lack of studies demonstrating the main premises of defense adaptations: the consequences of herbivory to macrophytes, genetic variation of defense traits and the costs and benefits of defenses in natural environment. We conducted a factorial experiment, where we manipulated amount of herbivory, growing depth and nutrient availability, and measured resistance to herbivory as well as genetic variation and costs of phlorotannins, putative defensive secondary metabolites, in the brown alga Fucus vesiculosus. Herbivory on algae varied with depth: grazing did not cause losses close to the surface, but, most of the algal production was consumed at the deeper end of the algal belt. The higher the genotypic phlorotannin content the less damage the genotype received implying that phlorotannins acted as a resistance trait. Production of phlorotannins was associated with costs for growth. Consistent with the prediction that the cost of defense will be greatest when resources are limiting, the cost appeared only in the deep end of the algal belt where growth was slowed down. Phlorotannins displayed phenotypic plasticity; the three factors influenced phlorotannins interactively, with the main tendencies of nutrient enrichment decreasing and herbivory and increasing depth increasing phlorotannins. Despite this plasticity, variation of phlorotannins was mainly due to the genotype of algae. These results emphasize the role of herbivory as a selective agent for algal defenses and the importance of genetic variation in the constitutive level of phlorotannins in interactions with natural enemies. The cost of phlorotannins may constrain the evolution of resistance in environments where growth is limited by light availability. [ABSTRACT FROM AUTHOR]

An approach towards a systematic revision of Marionina Michaelsen, 1890 is made through an historical overview of its nomenclature and definition, and a thorough characterization of its type species, the South Georgian marine littoral Pachydrilus georgianus Michaelsen, 1888. Relevant sections of early enchytraeid literature provide the background for appreciating the complex taxonomic history of the genus and giving a final word as to the controversial validity of its name, authority and date. Marionina in its current acceptation comprises about 100 nominal species, but the paper documents how, since its establishment, the genus has been an artificial assemblage of unrelated taxa, whose taxonomy cannot be sorted out (1) without finding new morphological characters and improving the standard of descriptions, and (2) without using a total evidence approach (morphology and molecules) within a phylogenetic framework. Confusion about the identity of the type species, originally briefly described and only partially figured, is unravelled upon examination of the syntypes available in Hamburg and Berlin. Since neither series proved to be monospecific, a lectotype is designated to assure correct and consistent application of the name in the future. [ABSTRACT FROM AUTHOR]

We identified geomorphological, sedimentary and biological evidence of high lake levels around the current Jilantal Salt Lake through field investigations and through analyses of regional remote sensing images. There are four groups of shorelines at elevations of around 1060, 1050, 1044 and 1035 m a.s.l., being 37, 27, 21 and 12 m above the current salt lake surface, respectively. Littoral deposits of sand and gravels are found at elevations between 1070 and 1080 m a.s.l., 47 to 57 m higher than the current salt lake surface, although palaeoshoreline landforms are only preserved at several sites. At Herimuxini, on the northern margin of the Ulan Buh Desert, typical lacustrine sediments and sand-gravel littoral deposits also occur at elevations of 1080 m a.s.l. and below. A 11-km-long typical spit extends eastward from this shoreline gradually reducing in elevation from 1050 to 1035 m a.s.l. In some sand-gravel quarries along the southern bank of the Yellow River on its Great Bend, such as those located near the Hydrological Gauge Station and Shilazhao Town, shoreline features were identified. Littoral deposits overlying the alluvial-diluvial layers occur in a sand quarry near Balagong in Hangjin County. There are also beachrock and littoral deposits preserved on the cut-and-built terraces at several sites along the southern piedmont of Langshan-Yinshan Mountains. In addition, a profile revealing subaqueous delta sediments was identified near Wuhai, where the Yellow River enters the basin. Typical lake sediments also exist at the Togtoh Platform on the eastern end of the Hetao Plain. Aquatic Mollusk shells are common in the littoral deposits, including several species of Corbicula, Radix lagotis, R. xauricularia and Gyraulus convexiusculus. Ostracode shells can also be identified in finer sediments. Typical vertical prograding sequences are evident in outcrops where lacustrine sediments were well preserved. Wave-rolled cobbles and beachrock are very commonly preserved on the top of profiles in the embankments at higher elevations. All this evidence suggests that there was once a huge palaeo-lake covering the Jilantai region and most part of the Hetao Plain with the highest lake level reaching ∼1080 m a.s.I. We refer to the huge paleolake, which was larger than modern Lake Baikal, as "Megalake Jilantai-Hetao." OSL dating results indicate that the megalake formed before ∼60-50 ka , and the four shorelines at elevations between 1060 and 1035 m a.s.l. likely represent the lake level variations from ∼.60- ∼50 ka to the early Holocene. The discovery of the Megalake Jilantai-Hetao likely will impact understanding of the development of the Yellow River during the late Quaternary, the evolution of the Ulan Buh and Kubq deserts, neotectonism in the region, and possibly regional climatic changes. [ABSTRACT FROM AUTHOR]

Twenty-eight littoral ciliates including one new genus and seven new species were collected from King George Island, Antarctica. Among them, 21 species are morphologically and taxonomically described in this paper: Bickella antarctica nov. gen., nov. spec., Chlamydonella apoprostomata nov. spec., Condylostoma spatiosum Ozaki and Yagiu in Yagiu, 1944, Diophrys scutum Dujardin, 1842, Diophrys aff. oligothrix Borror, 1965, Diophrys appendiculata (Ehrenberg, 1838), Euplotes balteatus (Dujardin, 1841), Euplotes dragescoi nov. spec., Euplotes petzi nov. spec., Euplotes rariseta Curds et al., 1974, Euplotes vannus (Mueller, 1786), Hartmannula angustipilosa Deroux and Dragesco, 1968, Hemigastrostyla szaboi Wilbert and Song, 2005, Holosticha antarctica nov. spec., Holosticha apodiademata nov. spec., Holosticha diademata (Rees, 1884), Litonotus sp., Metaurostylopsis marina (Kahl, 1932), Pleuronema coronatum Kent, 1881, Pseudocohnilembus persalinus Evans and Thompson, 1964, Urotricha antarctica nov. spec. The new genus, Bickella nov. gen., is a free-swimming folliculinid having typical Folliculina morphology except for the absence of lorica. [ABSTRACT FROM AUTHOR]

Deglaciation took place in eastern Jämtland and Ångermanland in central Sweden c. 10 500–10 200 cal. yr BP. In the present study, vegetation development and shore displacement during the earliest ice-free period are investigated by 14C dating of sediment from six isolated lake basins and by pollen analysis. A brief but distinct peak in Hippophaë occurs in all pollen diagrams coincident with basin isolation, followed by up to 500 years (varying locally) by an Alnus rise. The Alnus curve does not display a synchronous rise in the area. Its expansion below the highest shore level is time-transgressive and controlled mainly by the timing of basin isolation. The relationship between regional Alnus expansion and changes in hydrology and climate is discussed. The pollen diagrams show Pinus predominance with Corylus to the east (more coastal areas) and Betula predominance (though less pronounced) to the west during the period 10 200–9000 cal. yr BP. However, comparisons between sites suggest marked variability in the forest development. Shore displacement in easternmost Jämtland c. 10 300–9000 cal. yr BP is equal to or slightly more rapid than that of SE Ångermanland, contrary to the present pattern of isostatic recovery. A rapid shore level regression c. 10 300–10 000 cal. yr BP may be related to drainage of the Ancylus Lake. [ABSTRACT FROM AUTHOR]

Adaptive evolution of phenotypic plasticity requires that plastic genotypes have the highest global fitness. We studied selection by spatial heterogeneity of interspecific competition and flooding, and by temporal heterogeneity of flooding on morphological plasticity of 52 genotypes of the clonal shore plant Ranunculus reptans. Competition reduced clone size, rosette size, leaf length and stolon internode thickness. Flooding had similar effects and reduced competition. Differences in selection between environments imply potential for either local adaptation or for indirect evolution of phenotypic plasticity. We also detected direct selection for plastic reductions in internode length in response to flooding and for a plastic increase in internode length in response to competition. Plastic responses of some morphological traits to flooding were in line with selection thereon, suggesting that they indeed are adaptive and might have evolved in response to direct selection on plasticity. [ABSTRACT FROM AUTHOR]

Residential development of lakeshores affects the structure and function of riparian and littoral habitats. Organic detritus in sediments is a critical component of littoral food webs, but the effects of urbanization on sediment characteristics are unexplored. We characterized the quantity of organic sediments in Pacific Northwest lakes along a development gradient and found a 10-fold decline in the proportion of detritus in littoral sediments associated with density of lakeshore dwellings. In a comparison between two fully developed lakes and two undeveloped reference lakes, we examined several possible controls on sedimentary organic content, including terrestrial inputs, decomposition rates and associated macroinvertebrate communities, and physical retention by coarse wood. The littoral sediments of undeveloped lakes ranged from 34 to 77% organic by mass, whereas the range on urban lakes was an order of magnitude less, ranging from 1 to 3% organic. We found no significant differences in terrestrial litter inputs between the two sets of lakes. Leaf litter decomposition rates did not vary significantly between the two sets of lakes, and we found higher densities of shredder macroinvertebrate taxa in the littoral zones of undeveloped lakes. Sedimentary organic matter on undeveloped lakes accumulated in shallow waters and declined with distance from shore, whereas the opposite pattern existed on urban lakes. Our results suggest that coarse wood physically retains organic matter in littoral zones where it can enter the detrital energy pathway, and the loss of this feature on urban lakes alters littoral sediment characteristics, with potentially far-reaching consequences for lake food webs. [ABSTRACT FROM AUTHOR]

In this contribution we document an anomalous mucilage growth which occurred in June 2003 along the rocky cliffs of the Portofino Promontory (Ligurian Sea, NW Mediterranean Sea), and we describe its dynamics and its negative effects on many benthic taxa. The zooxanthellate scleractinian Cladocora caespitosa underwent ‘bleaching’ and about 40% of biomass of the erect algae was detached by mucilage ‘lianas’ created and strengthened by bottom currents. The 2003 event differed from any other previously occurred in the northern Tyrrhenian Sea, in that the mucilage aggregates were formed by the free-living form of the Phaeophyceae Acinetospora crinita (Harvey) Kornmann, a not usually dominant species in mucilage aggregates from the north Tyrrhenian Sea. The damage suffered by the benthic organisms living in this area was curtailed by a severe storm, occurred in July, which removed the mucilage to deeper depths, preventing irreversible damages. Only slow growing, perennant organisms, such as corallinales or scleractinians, were seriously affected, but a survey carried out 1 year later, in June 2004, allowed to appreciate a complete recovery of those organisms. This anomalous mucilage event occurred in coincidence of the 2003 European heatwave, and the anomalous temperature increase of seawater has to be regarded as the major contributing event that led to the mucilage outbreak. [ABSTRACT FROM AUTHOR]

Greater dwarf lemurs ( Cheirogaleus major) are small nocturnal primates from the rain forests of eastern Madagascar. I investigated a population of Cheirogaleus major in a littoral rain forest of Southeast Madagascar during 2 rainy seasons to supplement the sparse information available for the species. I collected data on morphology, group composition, sleeping behavior, home range, and social organization via mark/recapture, radio telemetry, and focal individual observations. I identified 2 presumed family groups, and my data from radiotracking revealed a monogamous social organization. In each group, I found an adult pair and its presumed offspring sharing home ranges and sleeping sites together. I also observed gregarious behavior of group members during their nocturnal activity. I found no difference in body measurements between sexes, but body mass and tail circumference increased significantly from November to February, indicating a fatting period before hibernating. [ABSTRACT FROM AUTHOR]

Analysis of pmoA and 16S rRNA gene clone libraries of methanotrophic bacteria in Lake Constance revealed an overall dominance of type I methanotrophs in both littoral and profundal sediments. The sediments exhibited minor differences in their methanotrophic community structures. Type X methanotrophs made up a significant part of the clone libraries only in the profundal sediment and were also found only there as a prominent peak by T-RFLP analyses. [ABSTRACT FROM AUTHOR]

Benthic plants play an important role in sediment transport and settling in river channels. Investigations of the influence of plants on sediment transport were assumed in the first half of the 20th century, but comprehensive investigations were carried out only at the end of the 20th century. The ideas generated by Russian fluvioglacial geomorphology gave an impetus to these investigations. In the turn of the second millennium, the role of plants in the channel processes also became an object of research in the south Baltic countries. The link between bank and littoral plants and their influence on channel processes were investigated in the Verseka, Jiesia and Šušve rivers. Analysis of longitudinal channel profiles allowed distinguishing concave and convex river sectors, choosing reference areas and recording the distribution pattern of bank and littoral plants and channel relief forms. The bathymetric measuring of reference areas was complemented with channel cross-section data revealing the distribution pattern of plants and variations of bottom relief and sediments in the cross-sections of river channels. All the study rivers have their valleys formed in relief complexes of different genesis what predetermines the present hydrodynamic status of their channels. Moreover, all the mentioned rivers have been embanked. The embankments were responsible for deformations of longitudinal channel profiles. All profiles include concave and convex sectors with different slope angles. The inclinations of convex sectors as a rule are higher; somewhere they exceed the inclination of concave sectors a few times. The distribution of benthic plants in the river channels depends on channel morphology. Oxbow lakes and bights provide especially good conditions for thick vegetation. The depth of flows is an important decisive factor for the distribution of plant species. Some species of plants can grow only at a certain depth. It is known that channel bottom sediments largely influence the distribution pattern of plants. In gravel, pebble and drifting sand sediments, plants take root hard. The sectors of stable sand are overgrown with pondweeds. Some species of plants easily take root and flourish in clayey sediments of different degree of silting. Plants with floating leaves grow on loose organic silts of oxbow lakes and bights. In the last few decades, silt sediments have been accumulating on sandy and even gravel sediments. Similar processes are taking place in small and large rivers of Lithuania and neighbouring countries. Littoral vegetation of rivers directly predetermines benthic plants of channels. Shady bottom sectors of small rivers often have no plants. The bottom of these sectors is covered by gravel with pebbles and even boulders. Sand sediments are also widespread in shady river sectors. As a rule, they represent small (10-20 cm high, 0.3-0.5 m wide and 1-1.5 m long) beds of permanently moving sand. In the sunny river channel sectors, vegetation flourishes producing a direct influence on channel processes. Various species of pondweeds and elodea are widespread. They reinforce the sand beds with their roots. These sectors are characterized by sediment drift stabilization. Local aggradation of sediments takes place in the areas where sunny channel sectors of small rivers coincide with the sectors of reduced inclination values of longitudinal profiles. In these sectors, rivers become wider, their fairways are dissected and the stream channels are shallower. Shoals appear, emerging from the water during summer water sinking.… [ABSTRACT FROM AUTHOR]

We measured fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) simultaneously in two typical fringing zones, sandy shore and salt marsh, of coastal lagoon, Lake Nakaumi, Japan, in mid-summer 2003. Our aim was to quantify net the greenhouse gases (GHGs) fluxes and examine key factors, which control variation of the GHGs fluxes in the two sites. Net CO2 and CH4 fluxes were markedly different between the two sites; magnitudes and variations of the both fluxes in sandy shore were lower than those of salt marsh. Meanwhile, magnitude and variation of net N2O flux in the two sites were similar. In sandy shore, temporal and spatial variation of the three GHGs fluxes were highly controlled by water level fluctuation derived from astronomic tide. In salt marsh, spatial variation of the three GHGs fluxes were correlated with aboveground biomass, and temporal variation of CO2 and CH4 fluxes were correlated with soil temperature. The sum of global warming potential, which was roughly estimated using the observed GHGs fluxes, was ca. 174-fold higher in salt marsh than in sandy shore. [Copyright &y& Elsevier]

Spatio-temporal distribution of nitrogen was examined along the gradient from open water to lakeshore in Lake Taihu, China. Two types of undulating littoral zones were selected: natural reed belt and bare lakeshore. The reed belt affected nitrogen transformation and was sink for internal-lake nitrogen, whereas the bare lakeshore showed little effect. During the growing season, NO-N concentration increased by up to 3–5 times from open water to reed belt, while NH-N concentration decreased. It suggested that nitrification was the main nitrogen process in reed belt. Total dissolved nitrogen (TDN) showed little spatial variation, indicating that most of nitrogen released from sediment did not move into open water again. Significant temporal variation of dissolved nitrogen occurred and was similar in both the littoral zone and the open water. Maximum TDN and NH-N concentrations occurred in January, and NO-N in March. Minimum NH-N and NO-N concentrations occurred in July and August, respectively. An increasing total soil nitrogen was found in the surface sediments from reed belt to open water. This further suggested that the reed-covered littoral zone had strong nitrogen transformation potential. [ABSTRACT FROM AUTHOR]

1. Biodiversity assessments of lakes depend on the ability to identify the complement of species present, although the degree of sampling required is often uncertain. We utilise long-term data to predict rotifer species richness in three habitats in three Polish lakes using rarefaction sampling methods. 2. Richness in littoral and psammon habitats did not saturate, even with up to 130 samples. Highest richness was observed in psammon habitat (119 species) in Lake Mikolajskie, followed by littoral habitat in Lakes Łuknajno (114 species) and Kuc (110 species). Littoral habitats in Lakes Łuknajno (56%) and Kuc (51%) had the most species not shared with other habitats in the same lake. 3. Species richness (Chao2) estimates ranged between 44 for pelagic and 135 for psammon habitat in Lake Mikolajskie, to 100 for psammon and 137 for littoral habitat in Lake Kuc, and 65 for pelagic and 162 for littoral habitat in Lake Łuknajno. Whole lake estimates were 167, 205 and 171 species, respectively, for these lakes, higher than the 150 to 160 species predicted by Dumont and Segers (Hydrobiologia, 1996, 341, 125). 4. Using standardised sampling, richness was significantly higher in littoral than either pelagic or psammon habitats. Contrasts of standardised rarefaction curves revealed that richness in Lakes Kuc and Mikolajskie was described as well by littoral-only or psammon-only samples, respectively, as by those randomly drawn from across all habitats in the lake. 5. Species richness estimates for Lake Mikolajskie were highest in summer, followed by autumn and spring. Interannual estimates differed by up to 427%, nearly an order of magnitude greater than maximal seasonal variation of 70%. 6. Results indicate that much higher sampling intensity is required to establish species richness than is presently carried out in most lakes. Because many species can be detected only with very intensive sampling, conservation programmes must consider sampling intensity when designing studies. [ABSTRACT FROM AUTHOR]

Toxic cyanobacteria can have harmful or fatal impacts on aquatic organisms. In the archipelagos of the northern Baltic Sea, the open sea blooms often drift into littoral areas, where they decompose and release toxins and other chemical compounds in the water. However, the effects of cyanobacteria on the littoral organisms have not previously been investigated. We studied the effects of three cyanobacteria species (toxic Nodularia spumigena, non-toxic N. sphaerocarpa and non-toxic Aphanizomenon flos-aquae) and purified dissolved nodularin (produced by N. spumigena) on a common littoral amphipod Gammarus zaddachi. Nodularin was transferred to eggs, juveniles and adults of G. zaddachi, but no significant negative effects of dissolved nodularin were detected on adults, eggs or juveniles. However, survival of adults decreased by the exposure to toxic N. spumigena cells. The egg hatching rate and juvenile survival were not affected when exposed to the three cyanobacteria species. In contrast, a weak decrease in the egg production and an increased abortion of embryos from the brood pouch of females was observed, the later indicating a failure in parental care. Further, a decrease in grazing rate on the filamentous green alga Enteromorpha intestinalis was observed. The results suggest that toxic cyanobacteria blooms are not extremely fatal, but may have, in high concentrations, negative effects on the adult survival, fecundity, and feeding behaviour of gammarids inhabiting the littoral zone. [ABSTRACT FROM AUTHOR]

Crayfish often dominate freshwater ecosystems and can have strong effects on littoral habitat and biota through foraging. However, there is substantial debate regarding the trophic role of crayfish and implications of their foraging behavior on littoral ecosystems. We created a bioenergetics model for rusty crayfish (Orconectes rusticus) to determine how growth and prey choice constrain crayfish consumption, which affects littoral ecosystems. We simulated over 6400 potential rusty crayfish diets by varying the abundance of important prey. We judged how crayfish prey choice affects the amount and identity of prey that crayfish must consume to match observed growth. We compared our model predictions with stable isotope evidence from 10 northern Wisconsin lakes to determine energy sources and trophic position of rusty crayfish relative to other invertebrates. Our diet simulations and stable isotope analysis concurred that crayfish of all ages are primarily predators. Individuals that do not feed on zoobenthos must therefore consume large quantities of less desirable food such as macrophytes, which are an important component of littoral habitat. [ABSTRACT FROM AUTHOR]

The littoral forest of the Fort Dauphin region of south-east Madagascar is expected to lose numerous endemic plant and animal species in the near future as a result of deforestation and consequent habitat changes. The disruption of plant-animal interactions is of particular concern. This review describes the conservation status of the littoral forest of Sainte Luce, Fort Dauphin, and examines the role of animal-facilitated seed dispersal in regeneration. The main threats to this habitat are described and possible management implications are discussed in relation to existing initiatives. Protection of the largest remaining forest fragments has been agreed by local communities and a draft plan for forest management is currently under evaluation. Over the next few years plantations will be created to provide local people with wood for fuel and other purposes. An important flying fox Pteropus rufus roost site needs to be included in conservation plans because of its importance for long-distance seed dispersal. Despite the presence of natural barriers, the creation of forest corridors will be crucial for connecting isolated fragments and facilitating genetic exchange between subpopulations. Increased attention needs to be given to the need to promote conservation-related income activities. [ABSTRACT FROM AUTHOR]

We used natural abundance stable isotopes to establish the structure of the littoral zone food web of an oligotrophic, perched dune lake on Fraser Island, Australia. Mixing model analyses incorporating riparian vegetation, seston, and periphyton sources indicated that periphyton carbon was the most significant food resource for aquatic consumers, despite the abundance of allochthonous carbon sources. In order to examine the consequences of nutrient inputs from tourists visiting this remote lake, repeated additions of low levels of phosphate and 15N-enriched ammonium nitrate were made to three littoral zone sites. Additions led to significant increases in periphyton chlorophyll a (Chl a) concentrations in enriched sites but had no measurable effect on phytoplankton Chl a concentrations. Periphyton collected 5 h after the first nutrient addition had substantially enriched δ15N signatures, suggesting that periphyton rapidly assimilated the added nutrients (and 15N-tracer). After l0 d of additions, all other primary food sources for consumers also became 15N-enriched, indicating that ongoing nutrient inputs are likely to lead to increased primary production and detrital processing. Substantially enriched consumer δ15N signatures were also measured, indicating that the added nutrients were assimilated and passed through multiple trophic levels. Our results indicate that ongoing low-level nutrient additions by tourists to oligotrophic lakes could lead to increased primary (periphyton) and secondary (consumer) production. However, increases in periphyton production and biomass accrual could eventually escape control by grazers, leading to adverse ecological and aesthetic effects. [ABSTRACT FROM AUTHOR]

Variations in the attenuation of photosynthetically available radiation were analysed using extensive spatial sampling in two seasons in a subtropical wetland lake. Simultaneously with the attenuation measurements, the principal absorption and scattering components of the water column were also measured. The elevated spatial resolution used in the study allowed the determination of spatially distinct optical water classes within the lake. Changes in dissolved organic matter, phytoplankton and tripton concentrations led to a wide variation in the vertical attenuation coefficients. These changes depended on local characteristics of the ecosystem and time of year. The spatial distribution of the attenuation coefficients was examined in relation to the hydrological and geomorphological characteristics of the littoral area of the lake. The impacts of two small rivers on the light environment and attenuation components are shown. Finally, the resulting model was used to examine the possible impacts of changes in light availability at the lake bottom in relation to recent changes in lake water level. [ABSTRACT FROM AUTHOR]

1. High biomass of macrophytes is considered important in the maintenance of a clear-water state in shallow eutrophic lakes. Therefore, rehabilitation and protection of aquatic vegetation is crucial to the management of shallow lakes.2. We conducted field mesocosm experiments in 1998 and 1999 to study community responses in the plant-dominated littoral zone of a lake to nutrient enrichment at different fish densities. We aimed to find the threshold fish biomass for the different nutrient enrichment levels below which large herbivorous zooplankton escapes control by fish. The experiments took place in the littoral of Lake Vesijärvi in southern Finland and were part of a series of parallel studies carried out jointly at six sites across Europe.3. In 1998, when macrophyte growth was poor, a clear-water state with low phytoplankton biomass occurred only in unenriched mesocosms without fish or with low fish biomass (4 g fresh mass m−2). Both nutrient enrichment and high fish biomass (20 g fresh mass m−2) provoked a turbid water state with high planktonic and periphytic algal biomass. The zooplankton community was dominated by rotifers and failed to control the biomass of algae in nutrient enriched mesocosms. The littoral community thus had low buffer capacity against nutrient enrichment.4. In 1999, macrophytes, especially free-floatingLemna trisulcaL., grew well and the zooplankton community was dominated by filter-feeding cladocerans. The buffer capacity of the littoral community against nutrient enrichment was high; a clear-water state with low phytoplankton biomass prevailed even under the highest nutrient enrichment. High grazing rates by cladocerans, together with reduced light penetration into the water caused byL. trisulca, were apparently the main mechanisms behind the low algal biomass.5. Effects of fish manipulations were less pronounced than effects of nutrient enrichment. In 1999, clearance rates of cladocerans were similar in fish-free and low-fish treatments but decreased in the high-fish treatment. This suggests that the threshold fish biomass was between the low- and high-fish treatments. In 1998, such a threshold was found only between fish-free and low-fish treatments.6. The pronounced difference in the observed responses to nutrient enrichment and fish additions in two successive years suggests that under similar nutrient conditions and fish feeding pressure either clear or turbid water may result depending on the initial community structure and on weather. [ABSTRACT FROM AUTHOR]

The paper reviews the data of 10 yr of following up sewage (waste water) inflows of anthropological origin into the sea from all the coastal settlements in Croatia. In particular, we report the sea loading by biochemical oxygen demand (BOD 5 ), expressed by the inhabitant equivalent (I.E.), for seven littoral counties. We estimated the loading of a coastal sea area for each county separately. The objective was to avoid any over- or underestimation of amounts and significance of sewage inflows into the seawater. For this purpose, a precisely determined sea volume up to the 10 m isobath has been chosen. Because of the inadequate treatment of wastewater, the total loading of that maritime territory expressed in terms of i.e. was found to be 26% higher than expected from the actual number of inhabitants. However, daily input represents only 12‰ of the considered volume of the sea. Recipient spent only 0.7% of the disposable oxygen quantity in the sea. [ABSTRACT FROM AUTHOR]

We studied the structural characteristics of the littoral epilithon in nine lentic water bodies at Hope Bay, Antarctic Peninsula, during summer 2002. At each site we measured the main physical and chemical variables and took epilithic samples for the analysis of dry weigh, ash, ash-free dry weight and chlorophyll a concentration. Distance from the sea of each water body was also considered. One site was selected for sampling lakes and ponds, except for Boeckella lake, where two sampling sites (A and B) were selected due to the heterogeneity of its littoral zone. Three stones for chlorophyll a analysis and another three to estimate dry weight, ash and ash-free dry weight, were taken randomly about 1 m away from the shore-line of each sampling site. Measurements of physical and chemical characteristics were obtained similarly. Water samples for chemical analysis were taken sub-superficially. Lakatos's system of classification and the Autotrophic Index were used to make functional inferences about the epilithic communities. Two PCA analyses were made to classify the water bodies according to environmental features and epilithic variables. In the latter, major patterns in data of epilithon were subsequently interpreted based on environmental data using external validation. Pingüi pond, located in the middle of the penguin rookery, was considered as a passive sample in both PCA analyses due to its extreme characteristics. Limnological features of the studied water bodies were similar to those of other Maritime Antarctic lakes. According to the Lakatos's index, 60% of the sampled lakes had high epilithic mass and a same proportion showed an inorganic type of epilithon The fact that 40% of the water bodies were autotrophic confirmed the importance of benthos as primary producer. According to environmental features, the well-defined groups of lakes emerged from the PCA were mainly determined by distance from the sea, pH, conductivity and salinity, and corresponded to the principal hydrological basins found in the region. Based on the results of the second PCA, littoral epilithon was affected by nitrate concentration and conductivity. In this ordination, water bodies from the same hydrological basin were separated probably as a result of a very complex inter-play of factors with a site-specific response to particular microhabitat characteristics. [ABSTRACT FROM AUTHOR]

Environmental and/or genetic among-site variation in plant quality may influence growth and fecundity of specialized herbivores inhabiting a particular site. Such variation is important as it generates spatial variation in selection for traits related to plant-herbivore interaction. Littoral macroalgae are known to respond plastically to environmental variation by modifying their chemistry or morphology. We studied geographic variation in phlorotannin, nitrogen, protein, and sugar (fucose, mannitol, and melibiose) concentrations of the brown algaFucus vesiculosusat 12 sites separated by 0.5 to 40 km in the naturally fragmented Archipelago Sea in the northern Baltic Sea. By this regional variation in algal chemistry we attempted to explain among-population variation in size and fecundity of the crustacean herbivoreIdotea baltica. We observed high spatial variation in all the measured chemical characteristics ofF. vesiculosus, as well as in female size and the number of eggs produced by the herbivores. Spatial variation in nitrogen or protein contents of the alga did not explain the variation of herbivore traits. However, egg size positively covaried with spatial variation in the concentration of mannitol, the major storage carbohydrate of the alga. Such a positive relationship may arise ifI. balticacan utilize the nutritive value of a mannitol-rich diet thereby being better able to provision the developing eggs with energy-rich metabolites. Unexpectedly, the concentration of phlorotannins, secondary metabolites having a putative role in defense against herbivory, positively covaried with the size of the herbivore. Among-population variation in host plant chemistry and covariation of that with herbivore growth and reproduction imply that herbivores respond to the local quality of their host plants, and that geographical structuring of populations has to be taken into account in studies of plant-herbivore interactions. [ABSTRACT FROM AUTHOR]