Surface sediments

POZDNIAKOVA A. I., GERMENCHUK M. G. Results of soils background monitoring in the observation zone of belarusian nuclear power plantОсновной экологической задачей перед пуском в эксплуатацию любого промышленного объекта является создание сети экологического мониторинга. Так как подобных радиационно-экологически опасных объектов в Республике Беларусь ранее не было, в зоне воздействия станции создана система комплексного мониторинга, которая позволяет наблюдать за изменениями экосистемы в динамике и оценивать негативную нагрузку на каждый компонент в системе в связи с другими. Как правило, при оценке экологической обстановки на окружающую среду вокруг атомной электростанции основное внимание уделяется воздействию радиоактивных выбросов и сбросов радиационно-опасного объекта. Однако, атомная электростанция, как любой промышленный объект и во время строительства, и во время эксплуатации оказывает воздействие нерадиационного характера. Данная статья содержит результаты изучения и оценки ...

A Tafonomia é uma ferramenta usada em interpretações paleoambientais que remonta ao processo de deposição dos palinomorfos. A interpretação dos processos tafonômicos fornece subsídios para a compreensão das condições ambientais passadas, através de marcas preservadas nos palinomorfos. A área de estudo localiza-se na Praia Vermelha, bairro da Urca, município do Rio de Janeiro, entrada da Baía de Guanabara. Foi estudada a preservação dos esporos ocorrentes em um perfil estratigráfico, formado por sedimentos turfosos e areno-lamosos, abrangendo o intervalo de tempo entre cerca de 4.520 a 4.270 anos A.P. Oito níveis foram selecionados e amostrados. Os esporos encontrados foram agrupados de acordo com o tipo de deterioração, em danos de corrosão/degradação, mecânicos e sem danos. A percentagem de cada tipo de dano foi calculada em relação ao total de esporos contados e a concentração em relação a 1cm 3 de sedimento. Foi encontrado um grande número de esporos com danos de corrosão e degradação, característicos de exposição ao ar, indicando ter havido ocasiões de menor disponibilidade de água no local. O predomínio de esporos sem danos em alguns níveis sugere uma sedimentação subaquosa, corroborado pelas análises sedimentológicas realizadas.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

High sedimentation rates in fjords provide excellent possibilities for high resolution sedimentary and geochemical records over the Holocene. As a baseline for an improved interpretation of geochemical data from fjord sediment cores, this study aims to investigate the inorganic/organic geochemistry of surface sediments and to identify geochemical proxies for terrestrial input and river discharge in the Trondheimsfjord, central Norway. Sixty evenly distributed surface sediment samples were analysed for their elemental composition, total organic carbon (C org), nitrogen (N org) and organic carbon stable isotopes (δ 13 C org), bulk mineral composition and grain size distribution. Our results indicate carbonate marine productivity to be the main CaCO 3 source. Also, a strong decreasing gradient of marinederived organic matter from the entrance towards the fjord inner part is consistent with modern primary production data. We show that the origin of the organic matter as well as the distribution of CaCO 3 in Trondheimsfjord sediments can be used as a proxy for the variable inflow of Atlantic water and changes in river runoff. Furthermore, the comparison of I-2 grain size independent Al-based trace element ratios with geochemical analysis from terrigenous sediments and bedrocks provides evidence that the distribution of K/Al, Ni/Al and K/Ni in the fjord sediments reflect regional sources of K and Ni in the northern and southern drainage basin of the Trondheimsfjord. Applying these findings to temporally wellconstrained sediment records will provide important insights into both the palaeoenvironmental changes of the hinterland and the palaeoceanographic modifications in the Norwegian Sea as response to rapid climate changes and associated feedback mechanisms.

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere. Highlights ► Halodinium verrucatum sp. nov. is described, Hexasterias problematica is emended. ► LSU and SSU rDNA is obtained for Halodinium verrucatum and Hexasterias problematica. ► Molecular phylogeny and DAPI-staining demonstrate these are ciliate resting cysts. ► micro-FTIR of resting cysts and tintinid loricae supports this affiliation. ► The distribution and ecology of both palynomorphs is discussed.

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere. Highlights ► Halodinium verrucatum sp. nov. is described, Hexasterias problematica is emended. ► LSU and SSU rDNA is obtained for Halodinium verrucatum and Hexasterias problematica. ► Molecular phylogeny and DAPI-staining demonstrate these are ciliate resting cysts. ► micro-FTIR of resting cysts and tintinid loricae supports this affiliation. ► The distribution and ecology of both palynomorphs is discussed.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

В статье рассмотрены вопросы загрязнения поверхностных отложений территории бывшего завода «Радикал» тяжелыми металлами-ртутью, цинком, медью и свинцом в период 2002 и 2014 годов. Определено среднее содержание элементов, рассчитаны геохимические критерии, благодаря чему дана экологогеохимическая оценка территории. Выявлено, что чрезвычайно опасное загрязнение присуще почвенным отложениям северо-западной части территории электролизного цеха завода «Радикал» Ключевые слова: ртуть, тяжелые металлы, поверхностные отложения, геохимические критерии, завод «Радикал» The paper deals with surface sediments pollution by heavy metals (mercury, zinc, copper and lead) of territory of "Radical" former factory from 2002 to 2014 years. An average content of elements is determined, the geochemical criteria are designed, so given the ecological and geochemical assessment of the territory. It is revealed that it is extremely dangerous pollution inherent for soil sediment of northwestern part of the cell room of "Radical" factory

Level of occurrence and characteristics of some important edaphic components were studied in the intertidal surface sediments from core mangrove forest of Sundarbans in a comprehensive way for the first time. Sediments were characterized to be dominated by finer particles of silt and clay with moderate to high carbon content (0.40 2.76%), low cation exchange capacity (average of 11.10 me100 g-1), low available nitrogen (about 10% of total nitrogen), high salt content with alkaline nature (pH, 7.5 – 8.2) and well supply of easily available form of phosphorous (17.75 57.0 mg.kg-1as P2O5) and potassium (12.7-22.5 meq.100g-1). Statistical analysis revealed that clay deposition was favored at high pH (p <0.05) and fresh water silt fraction had a strong affinity for exchangeable potassium (p <0.05). It also distinctly highlighted the prevalence of effective winnowing activity with considerable deposition of organic matter from multiple sources in the sedimentary system. This resulte...

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

In coastal environments, resuspension is a key issue regarding contaminant remobilisation from the sediments. A first attempt to quantify both sedimentary bed erosion and related plutonium isotope remobilisation from eroded particles was carried out through flume experiments. Erosion fluxes under controlled hydrodynamic stresses and their resulting plutonium remobilisation were measured for cohesive sediments sampled at several locations (8 to 97 m depth) near the Rhone river mouth (North-western Mediterranean Sea). Surface sediments were characterised in terms of plutonium content (238 Pu and 239,240 Pu) and particle size distribution. Laboratory resuspension experiments were performed under realistic hydrodynamic conditions close to those prevailing in coastal zones. Critical shear stresses of erosion ranged between 0.068 and 0.087 N m À 2 whereas erosion rate varied within a factor of 3 (57-176 g m À 2 h À 1). After 1 hour of resuspension, the plutonium activity increased in the seawater particulate phase by factors ranging from 2 to 14, depending on the site at which the sediment was sampled. Plutonium fluxes ranged between 2 and 56 mBq m À 2 h À 1 for 239,240 Pu depending on location. The highest fluxes were measured for sediments from the deepest site, where the highest Pu activities and mud content were found. During our resuspension experiments, no significant increase was found in dissolved Pu activities. These laboratory experiments have provided a unique opportunity to investigate the behaviour of plutonium at the sediment-water interface in a coastal environment. They emphasised the importance of sediment resuspension in plutonium remobilisation and its possible dispersion on continental shelves.

Diatom analyses in the water column, sediment traps, surficial sediments as well as in a short sediment core from Hagelseewli (2339 m asl, Swiss Alps) give information about the present-day seasonal cycle of diatom blooms, taphonomic processes in the lake basin and the lake's history. Analyses of surficial sediments show that water depth and thus light and nutrient availability is the most important factor influencing the production and distribution of diatom assemblages in Hagelseewli, and that periphytic diatom valves deposited in the deeper part of the basin originate from the shallow, littoral parts and are transported to the central part by processes such as lateral currents or sediment focussing. The lake is characterised by a very short period (2-3 months) of open water. Water-column and sediment-trap data revealed that planktonic diatoms bloom during and after the ice break-up, whereas mainly periphytic Fragilaria species entered the traps during the ice-covered period. These results suggest that plankton development is strongly inhibited by the ice-cover, with longer periods of ice-cover favouring Fragilaria species in Hagelseewli. The diatom analysis of a short sediment core that includes the last five centuries revealed several changes in the proportion of planktonic diatoms to Fragilaria species. The colder phases of the Little Ice-Age correspond to phases of lower concentration of planktonic diatoms. The highest, statistically significant amount of variance in the downcore diatom data is explained by winter precipitation, which directly influences the length of the ice-cover but inversely influences the light regime.

In coastal environments, resuspension is a key issue regarding contaminant remobilisation from the sediments. A first attempt to quantify both sedimentary bed erosion and related plutonium isotope remobilisation from eroded particles was carried out through flume experiments. Erosion fluxes under controlled hydrodynamic stresses and their resulting plutonium remobilisation were measured for cohesive sediments sampled at several locations (8 to 97 m depth) near the Rhone river mouth (North-western Mediterranean Sea). Surface sediments were characterised in terms of plutonium content (238 Pu and 239,240 Pu) and particle size distribution. Laboratory resuspension experiments were performed under realistic hydrodynamic conditions close to those prevailing in coastal zones. Critical shear stresses of erosion ranged between 0.068 and 0.087 N m À 2 whereas erosion rate varied within a factor of 3 (57-176 g m À 2 h À 1). After 1 hour of resuspension, the plutonium activity increased in the seawater particulate phase by factors ranging from 2 to 14, depending on the site at which the sediment was sampled. Plutonium fluxes ranged between 2 and 56 mBq m À 2 h À 1 for 239,240 Pu depending on location. The highest fluxes were measured for sediments from the deepest site, where the highest Pu activities and mud content were found. During our resuspension experiments, no significant increase was found in dissolved Pu activities. These laboratory experiments have provided a unique opportunity to investigate the behaviour of plutonium at the sediment-water interface in a coastal environment. They emphasised the importance of sediment resuspension in plutonium remobilisation and its possible dispersion on continental shelves.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

We used a novel approach of applying magnetic analyses to investigate the material released from the receding glacier Werenskioldbreen on Spitsbergen, Svalbard, Arctic Norway. Surface sediments were taken from the bay Nottinghambukta and the Werenskioldbreen foreland, along two main proglacial streams. Magnetic analyses, namely the low-field mass magnetic susceptibility, anhysteretic susceptibility mass normalized and hysteresis parameters, served to determine magnetic properties and identify the magnetic composition of the study material. We selected two distinct types of sediments. The first group, consisting of magnetite and pyrrhotite, has more single-domain grains in comparison to the second one, containing only magnetite. In the second group, multi-domain particles dominate. Deposits from the north stream, glacier river and an area close to the estuary of Nottinghambukta include magnetite and pyrrhotite. Magnetite was found in the south stream and in the outside part of the bay. Magnetic composition reflects different source rocks of sediments. This study demonstrates the utility of the magnetic method in analysing the current state of glacier environments.

Surface sediments and three sediment cores from the western basin and one sediment core from the Sandusky basin were analyzed to document spatial and temporal changes in five phosphorus fractions and total phosphorus (TP). The areal distributions of the bioavailable fractions NaCl-Pi, NaBD-Pi, and NaOH-Pi and the refractory organic fraction Res-P were broadly consistent and contrasted with those of the detrital fraction HCl-Pi which showed that high concentrations occurred mostly in high-energy littoral zones and low concentrations largely in profundal depositional areas. The contrasting distributions were induced by interactions among tributary inputs, wave action, circulation, and biogeochemical cycling and transfer in the basin. As revealed by the Sandusky basin sediment record, the detrital fraction HCl-Pi was dominant (70% of TP) during European settlement and decreased rapidly by 28.0% in the early 1910s due largely to impoundments of the Maumee and Sandusky Rivers. While HCl-Pi has ever since remained relatively constant, NaCl-Pi, NaBD-Pi, and NaOH-Pi increased significantly between 1950 and 1970 in the two basins. However, the post-regulation sediment records differed considerably among these coring sites. There was a marked increase of TP in two cores, corresponding to recent return of eutrophication and massive harmful algal blooms but contrasting with a relatively constant, low loading into the lake. This signified the role of internal loading as derived partialy from legacy pollution. Furthermore, NaCl-Pi has increased progressively throughout all the records. We conclude that the increased levels of NaCl-Pi in surface sediments may have altered the internal loading and contributed to the resurgences of harmful algal blooms in Lake Erie.

Dinoflagellates constitute a large proportion of the planktonic biomass from marine to freshwater environments. Some species produce a preservable organic-walled resting cyst (dinocyst) during the sexual phase of their life cycle that is an important link between the organisms, the environment in which their parent motile theca grew, and the sedimentary record. Despite their abundance and widespread usage as proxy indicators for environmental conditions, there is a lack of knowledge regarding the dinocyst wall chemical composition. It is likely that numerous factors, including phylogeny and life strategy, determine the cyst wall chemistry. However, the extent to which this composition varies based on inherent (phylogenetic) or variable (ecological) factors has not been studied. To address this, we used micro-Fourier transform infrared (FTIR) spectroscopy to analyze nine cyst species produced by either phototrophic or heterotrophic dinoflagellates from the extant orders Gonyaulacales, Gymnodiniales and Peridiniales. Based on the presence of characteristic functional groups, two significantly different cyst wall compositions are observed that correspond to the dinoflagellate's nutritional strategy. The dinocyst wall compositions analyzed appeared carbohydrate-based, but the cyst wall produced by phototrophic dinoflagellates suggested a cellulose-like glucan, while heterotrophic forms produced a nitrogen-rich glycan. This constitutes the first empirical evidence nutritional strategy is related to different dinocyst wall chemistries. Our results indicated phylogeny was less important for predicting composition than the nutritional strategy of the dinoflagellate, suggesting potential for cyst wall chemistry to infer past nutritional strategies of extinct taxa preserved in the sedimentary record.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

The composition and spatial variation of diatom assemblage in surface sediments of Caçó Lake (shallow, mesotrophic and weakly acid lake - Maranhão State, Brazil) were analyzed in order to know the distribution pattern of the species along the lake during rainy season (April 1999). Four zones were established in the lake based on 21 diatoms species and habitat affinities. The first three zones (prime three meters deep to six meters deep) were marked by the occurrence of Pinnularia gigas, Frustulia rhomboides, Encyonopsis krasskei, Eunotia camelus, E. femoriformis and E. monodon. Zone IV (seven to nine meters deep) was inhabited mainly by Surirella biseriata and Fragilariforma floridana. During the beginning of the rainy season, the diatom assemblage in Caçó Lake was composed mainly by benthic and epiphytic forms that reflected the low lake levels and the abundance of littoral vegetation present in this lake.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are important and ubiquitous classes of persistent organic pollutants. PAHs and PCBs can be found in the dust, soils, sediments, and atmospheric environment (Larsen and Baker 2003). PAHs are of particular concern, and 16 priority PAHs are regulated by the US Environmental Protection Agency (USEPA). Several PAHs are known carcinogens, such asbenz[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (BaP), dibenz[a,h]anthracene (DBA), and indeno[1,2,3-cd]pyrene (InP) (Ma et al. 2009).

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx

Subfossil biotic assemblages in surface sediments of lakes have been used to infer ecological conditions across environmental gradients.. Local variables are usually the major drives of assemblage composition, but in remote oceanic islands biogeographic filters may play a significant role. To assess the contribution of local and regional filters in the composition of subfossil diatoms and chironomid assemblages in surface sediments forty-one lakes in Azores archipelago ()were studied and related to environmental variables. Ordination techniques were used to identify the drivers that best explain the composition of these assemblages. Both assemblages are influenced by multiple limnological variables (conductivity, pH, nutrients). However, diatom assemblages differed mainly in the proportion of planktonic versus benthic species along the lakes' depth gradient while Chironomids differed significantly between islands but not between lake depths.. Thus, biogeographic filters play an important role in shaping islands freshwater communities, particularly insect ones, more influenced by geographic variables. Results demonstrate the accuracy and potential of biotic remains in sediments for applied studies of lake ecology, trophic status, climatic trends and ecological reconstruction and evolution of lakes. In the Azores, the application of this information in the development of inference models, is envisaged as further step to accomplish these goals.

Lake water salinity, an important indicator of lake hydrological conditions, is critical to deciphering terrestrial paleoclimatic and paleoenvironmental changes. The proportion of C 37:4 alkenone to total C 37 alkenones (%C 37:4) and the relative abundance of archaeol to caldarchaeol (ACE) are promising salinity indices in lacustrine settings. Developing regional calibrations for both indicators is challenging due to limited datasets and a poor understanding of the factors that influence them. Here we present %C 37:4 and ACE data collected from 55 lakes in mid-latitude Asia with a wide salinity range, to evaluate how well the two proxies can be correlated with salinity and to infer potential influencing factors. The %C 37:4 values only show a weak negative correlation with salinity from all investigated lakes. The occurrence of C 37:3 alkenone isomer and abnormal values in the alkenone C 37 /C 38 ratio might signal species shifts or environmental factors that compromise the %C 37:4-salinity relationship in our data set. Seasonal bias in alkenone production could further obscure this %C 37:4-salinity relationship. A stronger relationship emerges after removing samples influenced by these factors: %C 37:4 = − 8.56 * log 10 (salinity) + 80.6, r 2 = 0.62, n = 37; or %C 37:4 = − 13.46 * log 10 (salinity) + 101.48, with uncertainty in both variables considered. The ACE values show a strong positive correlation with salinity from all investigated lakes: ACE = 2.27 * 10 −4 * salinity + 25.4, r 2 = 0.75, n = 68; or ACE = 1.86 * 10 −4 * salinity + 38.1, with uncertainty in both variables considered. However, substantial deviations of the ACE values in low salinity range (<60,000 mg/L) and majority of the ACE shift in the range of 60,000-100,000 mg/L suggest that the ACE primarily responds to Euryarchaeota/Archaea community changes when a salinity threshold is crossed. Accordingly, both lake salinity indicators have the potential to reconstruct past salinity changes when their influencing factors could be constrained, and the two independent proxies, when they are used together, could further refine salinity reconstructions.

Subfossil biotic assemblages in surface sediments of lakes have been used to infer ecological conditions across environmental gradients.. Local variables are usually the major drives of assemblage composition, but in remote oceanic islands biogeographic filters may play a significant role. To assess the contribution of local and regional filters in the composition of subfossil diatoms and chironomid assemblages in surface sediments forty-one lakes in Azores archipelago ()were studied and related to environmental variables. Ordination techniques were used to identify the drivers that best explain the composition of these assemblages. Both assemblages are influenced by multiple limnological variables (conductivity, pH, nutrients). However, diatom assemblages differed mainly in the proportion of planktonic versus benthic species along the lakes' depth gradient while Chironomids differed significantly between islands but not between lake depths.. Thus, biogeographic filters play an important role in shaping islands freshwater communities, particularly insect ones, more influenced by geographic variables. Results demonstrate the accuracy and potential of biotic remains in sediments for applied studies of lake ecology, trophic status, climatic trends and ecological reconstruction and evolution of lakes. In the Azores, the application of this information in the development of inference models, is envisaged as further step to accomplish these goals.

Although many studies measure the abundance of benthic microalgae (BMA), at the meters squared scale, comparing these studies is difficult due to the variety of sampling, extraction, and analysis techniques. This difficulty is exacerbated by the fact that BMA abundance has high spatial and temporal variability, at all spatial scales. A suitable standard sampling regimen would reduce variation in estimates due to different sample collection and processing greatly facilitating comparisons between studies. This study examined the effect of varying the volume of extraction solvent, sampling core diameter, and sample replication on BMA biomass estimates. Key findings, applicable to all spatial scales, to accurately determine biomass were the use of a minimum sediment to extraction solvent ratio of 1:2 and use of a sampling core diameter of 19 mm. Across a wide range of sediment types, at the meters squared scale and using spectrophotometric techniques, a minimum replication number of 8 was found to be appropriate. We report the significant effect coring depth and units of expression have on BMA biomass estimates across a range of sediment types, highlighting the potential pitfalls when comparing studies.

High sedimentation rates in fjords provide excellent possibilities for high resolution sedimentary and geochemical records over the Holocene. As a baseline for an improved interpretation of geochemical data from fjord sediment cores, this study aims to investigate the inorganic/organic geochemistry of surface sediments and to identify geochemical proxies for terrestrial input and river discharge in the Trondheimsfjord, central Norway. Sixty evenly distributed surface sediment samples were analysed for their elemental composition, total organic carbon (C org), nitrogen (N org) and organic carbon stable isotopes (δ 13 C org), bulk mineral composition and grain size distribution. Our results indicate carbonate marine productivity to be the main CaCO 3 source. Also, a strong decreasing gradient of marinederived organic matter from the entrance towards the fjord inner part is consistent with modern primary production data. We show that the origin of the organic matter as well as the distribution of CaCO 3 in Trondheimsfjord sediments can be used as a proxy for the variable inflow of Atlantic water and changes in river runoff. Furthermore, the comparison of I-2 grain size independent Al-based trace element ratios with geochemical analysis from terrigenous sediments and bedrocks provides evidence that the distribution of K/Al, Ni/Al and K/Ni in the fjord sediments reflect regional sources of K and Ni in the northern and southern drainage basin of the Trondheimsfjord. Applying these findings to temporally wellconstrained sediment records will provide important insights into both the palaeoenvironmental changes of the hinterland and the palaeoceanographic modifications in the Norwegian Sea as response to rapid climate changes and associated feedback mechanisms.

We investigate the distribution of archaeal lipids in a 5.8-m-long sedimentary core recovered from Lake Qinghai to extract regional hydroclimate and temperature signals since the last deglaciation for this important region. The paleohydrology was reconstructed from the relative abundance of thaumarchaeol (%thaum) and the archaeol and caldarchaeol ecometric (ACE) index. The %thaum-inferred lake-level record was extended to deglaciation, showing three periods (11.9–13.0, 14.1–14.7 and 15.1–17.2 cal ka BP) with relatively higher lake levels than those during the early Holocene. The ACE record demonstrates three periods (10.6–11.2, 13.2–13.4 and 17.4–17.6 cal ka BP) of elevated salinity when the lake was shallow. Filtered TEX86 record based on archaeal lipid distributions corresponded to relatively higher lake levels, implying that a certain lake size is required for using the TEX86 paleothermometer. At 1–4 cal ka BP, the reconstructed temperature fluctuated significantly and correlated...

Subfossil biotic assemblages in surface sediments of lakes have been used to infer ecological conditions across environmental gradients.. Local variables are usually the major drives of assemblage composition, but in remote oceanic islands biogeographic filters may play a significant role. To assess the contribution of local and regional filters in the composition of subfossil diatoms and chironomid assemblages in surface sediments forty-one lakes in Azores archipelago ()were studied and related to environmental variables. Ordination techniques were used to identify the drivers that best explain the composition of these assemblages. Both assemblages are influenced by multiple limnological variables (conductivity, pH, nutrients). However, diatom assemblages differed mainly in the proportion of planktonic versus benthic species along the lakes' depth gradient while Chironomids differed significantly between islands but not between lake depths.. Thus, biogeographic filters play an important role in shaping islands freshwater communities, particularly insect ones, more influenced by geographic variables. Results demonstrate the accuracy and potential of biotic remains in sediments for applied studies of lake ecology, trophic status, climatic trends and ecological reconstruction and evolution of lakes. In the Azores, the application of this information in the development of inference models, is envisaged as further step to accomplish these goals.

Diatom, chrysophyte cyst, benthic cladocera, planktonic cladocera, and chironomid assemblages were studied in the surface sediments of 68 small lakes along an altitudinal gradient from 300 to 2350 m in Switzerland. In addition, 43 environmental variables relating to the physical limnology, geography, catchment characteristics, climate, and water chemistry were recorded or measured for each lake. The explanatory power of each

Foi desenvolvida a temática sobre critérios a serem considerados durante a análise palinológica de sedimentos quaternários e sua interpretação. Técnicas de coleta e processamento de amostras, o reconhecimento de táxons botânicos através da morfologia polínica, o conhecimento da idade do material, da fitofisionomia e fitogeografia dos tipos de vegetação e sua interação, a experiência relatada em estudos anteriores, tudo em conjunto são fatores de domínio nas pesquisas palinológicas quaternárias. A escolha e aplicação destes conhecimentos foram comentadas visando aspectos favoráveis e desfavoráveis segundo o material em estudo.

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere. Highlights ► Halodinium verrucatum sp. nov. is described, Hexasterias problematica is emended. ► LSU and SSU rDNA is obtained for Halodinium verrucatum and Hexasterias problematica. ► Molecular phylogeny and DAPI-staining demonstrate these are ciliate resting cysts. ► micro-FTIR of resting cysts and tintinid loricae supports this affiliation. ► The distribution and ecology of both palynomorphs is discussed.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Sediments from the Tagus estuary (Portugal) were collected at 40 stations in July and December 2004. Total LAS concentrations ranged between 0.03 and 17.76 mg LAS•kg −1 dry weight in July, and between 0.09 and 9.57 mg LAS•kg −1 in December. Highest LAS concentrations were found at the upper northern part of the estuary, coincident with the localisation of an important waste water treatment station. According to the Predicted No Effect Concentration (PNEC) of 8.1 mg•kg −1 derived for this compound, Environmental Risk Assessment (ERA) identified a hazard for the ecosystem at the station with the highest LAS concentration, and similar results are obtained by Equilibrium Partitioning Method (EPM). Nevertheless, LAS concentrations decreased significantly between samplings in the stations with the highest LAS concentrations in July, whereas increased LAS concentrations at adjacent stations were found in December. In the remaining stations, LAS concentrations were up to three orders of magnitude lower, representing no hazard for the sediment community.

Level of occurrence and characteristics of some important edaphic components were studied in the intertidal surface sediments from core mangrove forest of Sundarbans in a comprehensive way for the first time. Sediments were characterized to be dominated by finer particles of silt and clay with moderate to high carbon content (0.40 2.76%), low cation exchange capacity (average of 11.10 me100 g-1), low available nitrogen (about 10% of total nitrogen), high salt content with alkaline nature (pH, 7.5 – 8.2) and well supply of easily available form of phosphorous (17.75 57.0 mg.kg-1as P2O5) and potassium (12.7-22.5 meq.100g-1). Statistical analysis revealed that clay deposition was favored at high pH (p &lt;0.05) and fresh water silt fraction had a strong affinity for exchangeable potassium (p &lt;0.05). It also distinctly highlighted the prevalence of effective winnowing activity with considerable deposition of organic matter from multiple sources in the sedimentary system. This resulte...

Level of occurrence and characteristics of some important edaphic components were studied in the intertidal surface sediments from core mangrove forest of Sundarbans in a comprehensive way for the first time. Sediments were characterized to be dominated by finer particles of silt and clay with moderate to high carbon content (0.40 2.76%), low cation exchange capacity (average of 11.10 me100 g-1), low available nitrogen (about 10% of total nitrogen), high salt content with alkaline nature (pH, 7.5 – 8.2) and well supply of easily available form of phosphorous (17.75 57.0 mg.kg-1as P2O5) and potassium (12.7-22.5 meq.100g-1). Statistical analysis revealed that clay deposition was favored at high pH (p &lt;0.05) and fresh water silt fraction had a strong affinity for exchangeable potassium (p &lt;0.05). It also distinctly highlighted the prevalence of effective winnowing activity with considerable deposition of organic matter from multiple sources in the sedimentary system. This resulte...

The concentrations of eight heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were measured in the sediment, the isolated microplastics from the sediment and the body wall of sea cucumbers from farms in China. Accordingly, the heavy metal concentrations in the sediment were below the class I upper limit of Chinese sediment quality guidelines. Among heavy metals, the median concentrations of Cd and As were higher in the body wall than in the corresponding sediment. Additionally, the median concentrations of Cd, Pb, and Zn were higher on the microplastics than in the corresponding sediment. Furthermore, there was no significant correlation among heavy metals in sediment, sea cucumber and microplastics. This study contributes to the understanding of the heavy metal accumulation in the sediment, the microplastics and the body wall of the sea cucumber.

The concentrations of eight heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were measured in the sediment, the isolated microplastics from the sediment and the body wall of sea cucumbers from farms in China. Accordingly, the heavy metal concentrations in the sediment were below the class I upper limit of Chinese sediment quality guidelines. Among heavy metals, the median concentrations of Cd and As were higher in the body wall than in the corresponding sediment. Additionally, the median concentrations of Cd, Pb, and Zn were higher on the microplastics than in the corresponding sediment. Furthermore, there was no significant correlation among heavy metals in sediment, sea cucumber and microplastics. This study contributes to the understanding of the heavy metal accumulation in the sediment, the microplastics and the body wall of the sea cucumber.

Resumo O presente trabalho pretende apresentar a importância de realizar uma rigorosa análise espacial de taxas diferenciais de deposição de pólen e esporos em ambientes subaquáticos para uma melhor correlação com a vegetação de origem. A análise espacial da deposição de palinomorfos em sedimentos superficiais de fundo de corpos aquáticos exibe padrões diferenciados de local para local e relaciona-se com a sedimentologia. Os resultados obtidos através da análise palinológica destes sedimentos são relacionados com as principais influências ambientais na sedimentação subaquática de pólen e esporos, ou seja, a batimetria, correntes e ventos dominantes.

Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 µm and long ultrasonication (N 1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the Review of Palaeobotany and Palynology xxx (2009) xxx-xxx ⁎ Corresponding author.

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere. Highlights ► Halodinium verrucatum sp. nov. is described, Hexasterias problematica is emended. ► LSU and SSU rDNA is obtained for Halodinium verrucatum and Hexasterias problematica. ► Molecular phylogeny and DAPI-staining demonstrate these are ciliate resting cysts. ► micro-FTIR of resting cysts and tintinid loricae supports this affiliation. ► The distribution and ecology of both palynomorphs is discussed.

A Palinologia de perfis sedimentares visando reconstituições paleoambientais necessita análises quantitativas que permitam inferir ambiente a partir dos palinomorfos. A porcentagem de grãos de cada táxon em relação ao total contado na amostra é amplamente utilizada neste estudo, mas muitas vezes pode distorcer significativamente os resultados por ser uma análise relativa. A análise absoluta de concentração polínica pode corrigir essas distorções, devendo ser também incluída na metodologia para assegurar resultados mais confiáveis.

Resumo O presente trabalho pretende apresentar a importância de realizar uma rigorosa análise espacial de taxas diferenciais de deposição de pólen e esporos em ambientes subaquáticos para uma melhor correlação com a vegetação de origem. A análise espacial da deposição de palinomorfos em sedimentos superficiais de fundo de corpos aquáticos exibe padrões diferenciados de local para local e relaciona-se com a sedimentologia. Os resultados obtidos através da análise palinológica destes sedimentos são relacionados com as principais influências ambientais na sedimentação subaquática de pólen e esporos, ou seja, a batimetria, correntes e ventos dominantes. Palavras-chave: sedimentos superficiais; ambiente aquático; Palinologia Abstract The present paper intends to show the importance of performing a rigorous analysis of the differential spatial rates of deposition of pollen and spores in underwater environments to a better correlation with the vegetation of origin. The spatial analysis of palynomorphs deposition in the surface layer of bottom sediments of water bodies shows different patterns from site to site and may be helpful in studies of sedimentology. The results of pollen analysis of these sediments are related to the major environmental influences on subaquatic sedimentation of pollen and spores, i.e., bathymetry, prevailing currents and winds.