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Hiroshi Kitazato - One of the best experts on this subject based on the ideXlab platform.

  • Different ingestion patterns of 13C-labeled bacteria and algae by deep-sea Benthic foraminifera
    2006
    Co-Authors: Hidetaka Nomaki, Petra Heinz, Takeshi Nakatsuka, Motohiro Shimanaga, Naohiko Ohkouchi, Nanako O. Ogawa, Kazuhiro Kogure, Eiko Ikemoto, Hiroshi Kitazato
    Abstract:

    Benthic foraminiferal food sources were examined in the central part of Sagami Bay, Japan (water depth 1450 m) based on an in situ feeding experiment with 13 C-labeled food materials. In this study, 3 different 13 C-labeled food materials were used: the unicellular marine algae Dunaliella tertiolecta, the marine diatom Chaetoceros sociale, and the marine bacterium Vibrio algi- nolyticus. The first two are representatives of phytodetritus and the third of organic matter produced in the sediments. Each type of food material was injected into a series of in situ culture cores and incubated for up to 21 d. We observed that some Benthic foraminiferal species selectively ingested 13 C-labeled algae from the sedimentary organic matter. On the other hand, Benthic foraminifera ingested 13 C-labeled bacteria unselectively from sedimentary organic matter. Total Benthic forami- nifera assimilated 8.8 mg C m -2 d -1 of sedimentary organic matter without phytodetritus assimilation. Based on the assimilation rates estimated in this experiment, we recognized 3 types of feeding strat- egy among deep-sea Benthic foraminifera in Sagami Bay. There are those that ingest (1) fresh phyto- detritus selectively (phytophagous species: Uvigerina akitaensis, Bolivina spissa, Bolivina pacifica); (2) fresh phytodetritus selectively but sedimentary organic matter as well when phytodetritus is absent (seasonal-phytophagous species: Bulimina aculeata, Textularia kattegatensis, Globobulimina affinis); and (3) sedimentary organic matter at random (deposit feeders: Cyclammina cancellata, Chilostomella ovoidea). These different types of carbon utilization should be considered not only for understanding modern ecosystems on the deep-sea floor but also for paleoceanographic reconstruc- tions using the abundance and distribution, or isotopic composition, of Benthic foraminifera.

  • species specific ingestion of organic carbon by deep sea Benthic foraminifera and meiobenthos in situ tracer experiments
    2005
    Co-Authors: Hidetaka Nomaki, Petra Heinz, Takeshi Nakatsuka, Motohiro Shimanaga, Hiroshi Kitazato
    Abstract:

    We measured organic carbon uptake rates by deep-sea Benthic foraminifera and studied differences among species, living depth, and seasons to investigate how these protists contribute to carbon consumption on the deep-sea floor. In situ feeding experiments using

Andrew J. Gooday - One of the best experts on this subject based on the ideXlab platform.

  • bipolar gene flow in deep sea Benthic foraminifera
    2007
    Co-Authors: Jan Pawlowski, Jose Fahrni, Beatrice Lecroq, David Longet, N Cornelius, Laurent Excoffier, Tomas Cedhagen, Andrew J. Gooday
    Abstract:

    Despite its often featureless appearance, the deep-ocean floor includes some of the most diverse habitats on Earth. However, the accurate assessment of global deep-sea diversity is impeded by a paucity of data on the geographical ranges of bottom-dwelling species, particularly at the genetic level. Here, we present molecular evidence for exceptionally wide distribution of Benthic foraminifera, which constitute the major part of deep-sea meiofauna. Our analyses of nuclear ribosomal RNA genes revealed high genetic similarity between Arctic and Antarctic populations of three common deep-sea foraminiferal species (Epistominella exigua, Cibicides wuellerstorfi and Oridorsalis umbonatus), separated by distances of up to 17 000 km. Our results contrast with the substantial level of cryptic diversity usually revealed by molecular studies, of shallow-water Benthic and planktonic marine organisms. The very broad ranges of the deep-sea foraminifera that we examined support the hypothesis of global distribution of small eukaryotes and suggest that deep-sea biodiversity may be more modest at global scales than present estimates suggest.

  • Benthic foraminifera protista as tools in deep water palaeoceanography environmental influences on faunal characteristics
    2003
    Co-Authors: Andrew J. Gooday
    Abstract:

    foraminiferal research lies at the border between geology and biology. Benthic foraminifera are a major component of marine communities, highly sensitive to environmental influences, and the most abundant Benthic organisms preserved in the deep-sea fossil record. These characteristics make them important tools for reconstructing ancient oceans. Much of the recent work concerns the search for palaeoceanographic proxies, particularly for the key parameters of surface primary productivity and bottom-water oxygenation. At small spatial scales, organic flux and pore-water oxygen profiles are believed to control the depths at which species live within the sediment (their 'microhabitats'). Epifaunal/shallow infaunal species require oxygen and labile food and prefer relatively oligotrophic settings. Some deep infaunal species can tolerate anoxia and are closely linked to redox fronts within the sediment; they consume more refractory organic matter, and flourish in relatively eutrophic environments. Food and oxygen availability are also key factors at large (i.e. regional) spatial scales. Organic flux to the sea floor, and its seasonality, strongly influences faunal densities, species compositions and diversity parameters. Species tend to be associated with higher or lower flux rates and the annual flux range of 2-3 g Corg m-2 appears to mark an important faunal boundary. The oxygen requirements of Benthic foraminifera are not well understood. It has been proposed that species distributions reflect oxygen concentrations up to fairly high values (3 ml l-1 or more). Other evidence suggests that oxygen only begins to affect community parameters at concentrations < 0.5 ml l-1. Different species clearly have different thresholds, however, creating species successions along oxygen gradients. Other factors such as sediment type, hydrostatic pressure and attributes of bottom-water masses (particularly carbonate undersaturation and current flow) influence foraminiferal distributions, particularly on continental margins where strong seafloor environmental gradients exist. Epifaunal species living on elevated substrata are directly exposed to bottom-water masses and flourish where suspended food particles are advected by strong currents. Biological interactions, e.g. predation and competition, must also play a role, although this is poorly understood and difficult to quantify. Despite often clear qualitative links between environmental and faunal parameters, the development of quantitative foraminiferal proxies remains problematic. Many of these difficulties arise because species can tolerate a wide range of non-optimal conditions and do not exhibit simple relationships with particular parameters. Some progress has been made, however, in formulating proxies for organic fluxes and bottom-water oxygenation. Flux proxies are based on the Benthic foraminiferal Accumulation Rate and multivariate analyses of species data. Oxygen proxies utilise the relative proportions of epifaunal (oxyphilic) and deep infaunal (low-oxygen tolerant) species. Yet many problems remain, particularly those concerning the calibration of proxies, the closely interwoven effects of oxygen and food availability, and the relationship between living assemblages and those preserved in the permanent sediment record.

Vincent M.p. Bouchet - One of the best experts on this subject based on the ideXlab platform.

  • Indicative value of Benthic foraminifera for biomonitoring: Assignment to ecological groups of sensitivity to total organic carbon of species from European intertidal areas and transitional waters
    2021
    Co-Authors: Vincent M.p. Bouchet, Pierre-guy Sauriau, Letizia Di ,bella, Fabrizio Frontalini, Emmanuelle Geslin, Fabio Francescangeli, Maria Virginia Alves Martins, Ahuva Almogi-labin, Simona Avnaim-katav, Alejandro Cearreta
    Abstract:

    This work contributes to the ongoing work aiming at confirming Benthic foraminifera as a biological quality element. In this study, Benthic foraminifera from intertidal and transitional waters from the English Channel/European Atlantic coast and the Mediterranean Sea were assigned to five ecological groups using the weighted-averaging optimum with respect to TOC of each species. It was however not possible to assign typical salt marsh species due to the presence of labile and refractory organic matter that hampers TOC characterization. Tests of this study species’ lists with Foram-AMBI on two independent datasets showed a significant correlation between Foram-AMBI and TOC, confirming the strong relation between foraminifera and TOC. For one of the validation datasets, associated macrofaunal data were available and a significant correlation was found between the foraminiferal Foram-AMBI and the macrofaunal AMBI. The here proposed lists should be further tested with sensitivity-based indices in different European regional settings.

  • Benthic foraminifera provide a promising tool for ecological quality assessment of marine waters
    2012
    Co-Authors: Vincent M.p. Bouchet, Elisabeth Alve, Brage Rygg, Richard J Telford
    Abstract:

    a b s t r a c t This study defines criteria for the use of Benthic foraminifera (protists) as a quick and efficient bio- monitoring tool to implement marine legislation. Various sampling and preparation procedures are investigated in an attempt to find the optimal methodology for environmental monitoring using soft- sediment foraminifera with the objective of assessing ecological quality status (EcoQS). Twenty-seven sampling stations in silled basins along the Norwegian Skagerrak coast, NE North Sea, are investi- gated for environmental parameters and living (stained, including soft-shelled forms) and dead Benthic foraminifera. Diversity, expressed as the effective number of species (exp Hbc) and community compo- sition are used to evaluate EcoQS using living (stained) Benthic foraminifera. Correlation studies show that bottom-water dissolved oxygen concentration at the time of sampling ((O2)tos) is the main envi- ronmental factor controlling variation in diversity. Variables such as grain size, C/N, TOC and TN are less important. Correlation between foraminiferal diversity and (O2)tos, as well as correlation between com- munity data and (O2)tos, suggest that Benthic foraminifera represent an efficient bio-monitoring tool to evaluate EcoQS. A clear pattern from "bad" to "high" EcoQS is established using the strong link between the Benthic foraminiferal diversity and the bottom-water oxygen gradient. The study shows that EcoQS can be evaluated quickly and accurately using the following method: sample the top 1 cm of sediment, dry-pick about 250 living (stained) individuals of >125 m-sized fossilisable (i.e. most of those remain- ing subsequent to drying) foraminifera from each of three replicates. exp(H � bc) based on living Benthic foraminifera is a promising tool to assess EcoQS. For fossil assemblages, exp(Hbc) has potential for eval- uating temporal changes in in situ PaleoEcoQS and for defining reference conditions from pre-impacted times.

  • effects of short term environmental disturbances on living Benthic foraminifera during the pacific oyster summer mortality in the marennes oleron bay france
    2007
    Co-Authors: Vincent M.p. Bouchet, Pierre-guy Sauriau, Jean-pierre Debenay, Joel Radfordknoery, Patrick Soletchnik
    Abstract:

    Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oleron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) Benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic conditions whereas Brizalina variabilis and Haynesina germanica were sensitive to organic degradation and hypoxia. Cribroelphidium gunteri was the most opportunistic during recolonisation. Benthic foraminifera showed that short-term biochemical changes in the sediment are toxic and may be involved in the summer mortality of Pacific oysters.

Fabrizio Frontalini - One of the best experts on this subject based on the ideXlab platform.

  • Indicative value of Benthic foraminifera for biomonitoring: Assignment to ecological groups of sensitivity to total organic carbon of species from European intertidal areas and transitional waters
    2021
    Co-Authors: Vincent M.p. Bouchet, Pierre-guy Sauriau, Letizia Di ,bella, Fabrizio Frontalini, Emmanuelle Geslin, Fabio Francescangeli, Maria Virginia Alves Martins, Ahuva Almogi-labin, Simona Avnaim-katav, Alejandro Cearreta
    Abstract:

    This work contributes to the ongoing work aiming at confirming Benthic foraminifera as a biological quality element. In this study, Benthic foraminifera from intertidal and transitional waters from the English Channel/European Atlantic coast and the Mediterranean Sea were assigned to five ecological groups using the weighted-averaging optimum with respect to TOC of each species. It was however not possible to assign typical salt marsh species due to the presence of labile and refractory organic matter that hampers TOC characterization. Tests of this study species’ lists with Foram-AMBI on two independent datasets showed a significant correlation between Foram-AMBI and TOC, confirming the strong relation between foraminifera and TOC. For one of the validation datasets, associated macrofaunal data were available and a significant correlation was found between the foraminiferal Foram-AMBI and the macrofaunal AMBI. The here proposed lists should be further tested with sensitivity-based indices in different European regional settings.

  • environmental controls on the distribution of living stained Benthic foraminifera on the continental slope in the campos basin area sw atlantic
    2018
    Co-Authors: Cintia Yamashita, Fabrizio Frontalini, Maria Virginia Alves Martins, Silvia Helena De Mello E Sousa, Thaisa Marques Vicente, Renata Hanae Nagai, Sueli Susana Godoi, Dante C Napolitano, Leticia Burone
    Abstract:

    Abstract Living (stained) Benthic foraminifera from deep-sea stations in the Campos Basin, southeastern Brazilian continental margin, were investigated to understand their distribution patterns and ecology, as well as the oceanographic processes that control foraminiferal distribution. Sediments were collected from 1050 m to 1950 m of water depth during the austral winter of 2003, below the Intermediate Western Boundary Current (IWBC) and the Deep Water Boundary Current (DWBC). Based on statistical analysis, vertical flux of particulate organic matter and the grain size of sediment seem to be the main factors controlling the spatial distribution of Benthic foraminifera. The middle slope (1050 m deep) is characterized by relatively high foraminiferal density and a predominance of phytodetritus-feeding foraminifera such as Epistominella exigua and Globocassidulina subglobosa. The occurrence of these species seems to reflect the Brazil Current System (BCS). The above-mentioned currents are associated with the relatively high vertical flux of particulate organic matter and the prevalence of sandy sediments, respectively. The lower slope (between 1350 and 1950 m of water depth) is marked by low foraminiferal density and assemblages composed of Bolivina spp. and Brizalina spp., with low particulate organic matter flux values, muddy sediments, and more refractory organic matter. The distribution of this group seems to be related to episodic fluxes of food particles to the seafloor, which are influenced by the BCS at the surface and are deposited under low deep current activity (DWBC).

  • assessing the effect of mercury pollution on cultured Benthic foraminifera community using morphological and edna metabarcoding approaches
    2018
    Co-Authors: Fabrizio Frontalini, Letizia Di ,bella, Mattia Greco, Franck Lejzerowicz, Emanuela Reo, Antonio Caruso, Claudia Cosentino, Antonella Maccotta, Giovanna Scopelliti, Maria Pia Nardelli
    Abstract:

    Abstract Mercury (Hg) is a highly toxic element for living organisms and is known to bioaccumulate and biomagnify. Here, we analyze the response of Benthic foraminifera communities cultured in mesocosm and exposed to different concentrations of Hg. Standard morphological analyses and environmental DNA metabarcoding show evidence that Hg pollution has detrimental effects on Benthic foraminifera. The molecular analysis provides a more complete view of foraminiferal communities including the soft-walled single-chambered monothalamiids and small-sized hard-shelled rotaliids and textulariids than the morphological one. Among these taxa that are typically overlooked in morphological studies we found potential bioindicators of Hg pollution. The mesocosm approach proves to be an effective method to study Benthic foraminiferal responses to various types and concentrations of pollutants over time. This study further supports foraminiferal metabarcoding as a complementary and/or alternative method to standard biomonitoring program based on the morphological identification of species communities.

  • Benthic foraminifera as bioindicators of pollution a review of italian research over the last three decades
    2011
    Co-Authors: Fabrizio Frontalini, Rodolfo Coccioni
    Abstract:

    Abstract Since the 1950s, numerous studies have demonstrated the value of Benthic foraminifera in detecting ecosystem contamination. The interest in Benthic foraminifera has partly been driven by government policies and programs aimed at developing suitable, non-invasive bioindicators of marine environmental quality. This paper accomplishes two things: it reveals that Italian experience has significantly contributed to the advancement of our understanding of this topic and summarizes the most important results that have served to greatly improve our knowledge in this field. Although many issues are still a matter of debate, since it is difficult to separate natural vs human-induced pollution and a foraminiferal protocol has not yet been produced, foraminifera have been proven to be successful candidates as part of an integrated monitoring program.

  • Benthic foraminifera for heavy metal pollution monitoring a case study from the central adriatic sea coast of italy
    2008
    Co-Authors: Fabrizio Frontalini, Rodolfo Coccioni
    Abstract:

    Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coastal and marginal marine settings. Their community structure provides information on the general characteristics of the environment and some species are sensitive to specific environmental parameters. Among various criteria, the occurrence of test abnormalities may represent a useful bioindicator for monitoring environmental impacts in coastal regions. A study of living Benthic foraminifera was carried out in 42 sediment samples collected from the central Adriatic coast of Italy. Benthic foraminiferal assemblages from this area are rich, well preserved, and dominated by Ammonia parkinsoniana, and subordinately by Ammonia tepida, Aubignyna perlucida, Eggerella scabra, and Nonionella turgida. Heavy metal concentrations have been analysed which indicate low polluted environmental conditions. foraminiferal species and heavy metal concentrations were investigated both with bivariate (correlation matrix) and multivariate techniques of principal component analysis (PCA) and cluster analysis. Statistical analysis shows a possible control of these pollutants both on the taxonomic composition of the Benthic foraminiferal assemblages and the development of test malformations. Increasing heavy metal contents lead to an increase in relative abundance of A. tepida A. perlucida, N. turgida and E. scabra, and a relative concurrent decrease in relative abundance of A. parkinsoniana and higher percentages of deformed specimens (FAI) and species (FMI). Our results confirm that A. parkinsoniana prefers clean to low polluted environments and show that it is a very sensitive and un-tolerant species to heavy metal pollution being deeply affected by heavy metal content even at low concentrations. Our findings also confirm the capacity of the A. tepida to tolerate increasing heavy metal concentrations, and highlights that A. perlucida, N. turgida and E. scabra can be considered as tolerant species at least in low polluted environments. Following this, A. parkinsoniana and A. tepida can be reciprocally considered good bioindicator of heavy metal pollution over the surveyed area. The development of test abnormalities with a variety of malformations is a noticeable feature over the study area where the living deformed assemblages are largely dominated by a few species. The low percentages of deformed specimens (foraminiferal Abnormality Index up to 4.7, with 2 on average) match well with the low concentrations of heavy metals that lead to low polluted environmental conditions. This study confirms and supports the suitability of studying Benthic foraminifera as a technique for the in situ continuous bio-monitoring of heavy metal pollution of coastal marine sediments.

Sven Uthicke - One of the best experts on this subject based on the ideXlab platform.

  • high risk of extinction of Benthic foraminifera in this century due to ocean acidification
    2013
    Co-Authors: Sven Uthicke, Paolo Momigliano, Katharina Fabricius
    Abstract:

    Increased atmospheric CO2 concentrations lead to decreased pH and carbonate availability in the ocean (Ocean Acidification, OA). Carbon dioxide seeps serve as ‘windows into the future’ to study the ability of marine invertebrates to acclimatise to OA. We studied Benthic foraminifera in sediments from shallow volcanic CO2 seeps in Papua New Guinea. Conditions follow a gradient from present day pH/pCO2 to those expected past 2100. We show that foraminiferal densities and diversity declined steeply with increasing pCO2. foraminifera were almost absent at sites with pH 700 μatm pCO2). Symbiont-bearing species did not exhibit reduced vulnerability to extinction at <7.9 pH. Non-calcifying taxa declined less steeply along pCO2 gradients, but were also absent in samples at pH < 7.9. Data suggest the possibility of an OA induced ecological extinction of shallow tropical Benthic foraminifera by 2100; similar to extinctions observed in the geological past.

  • calcification and photobiology in symbiont bearing Benthic foraminifera and responses to a high co2 environment
    2012
    Co-Authors: Nikolas Vogel, Sven Uthicke
    Abstract:

    Abstract The present study investigates impacts of ocean acidification on calcification rates and light responses of large Benthic foraminifera (LBF). Studies were conducted on diatom-bearing Amphistegina radiata and Heterostegina depressa and dinoflagellate-bearing Marginopora vertebralis in controls and manipulated seawater pCO2 conditions (467–1925 μatm pCO2). In a six week experiment, calcification and photobiology were investigated for all three species. Additionally, short-term experiments were carried out on H. depressa and M. vertebralis to determine photosynthetic rates in several pCO2 environments and impacts of elevated pCO2 in increasing light intensities (photosynthesis irradiance “P–I” curves) on M. vertebralis. In the long-term experiment, positive growth (inferred through cross-sectional surface area) was measured in all control and acidification conditions but growth rates of A. radiata and H. depressa were not affected by increased pCO2 (linear models, p > 0.05). However, M. vertebralis displayed significantly (planned comparison t = 2.61, p

  • temperature induced stress leads to bleaching in larger Benthic foraminifera hosting endosymbiotic diatoms
    2011
    Co-Authors: Petra Heinz, Christiane Schmidt, Michal Kucera, Sven Uthicke
    Abstract:

    Physiological mechanisms of bleaching were studied on larger Benthic foraminifera (LBF) hosting endosymbiotic diatoms. Amphistegina radiata, Heterostegina depressa, and Calcarina hispida were exposed to increasing temperatures in static temperature experiments (23u Ct o 33uC, 6 d). Photosynthetic activity (Fv:Fm, measured with a pulse-amplitude modulated fluorometer), chlorophyll a (a proxy for symbiont biomass), and motility (a proxy for overall fitness of the foraminifera) were reduced in specimens at 32u Ct o 33uC, and cytoplasm color changes associated with bleaching were observed. A 30-d flow-through experiment at three temperatures (26u Ct o 31uC) and three levels of inorganic nitrate concentration (0.5 to 1.4 mmol L21) confirmed negative effects of temperature at 31uC for A. radiata (including growth) and H. depressa. Another Calcarina species, Calcarina mayorii, was not affected. This suggests that temperature effects are species-specific. However, elevated nutrient concentrations did not affect any of the parameters measured. Temperatures . 30uC stress the foram–diatom endosymbiosis in some LBF species, which may lead to subsequent bleaching of the host. Given that a 2–3uC increase led to rapid bleaching of most species, we propose that, similar to corals, these species are threatened by sea-surface temperature increase predicted for tropical reef waters in the near future. Benthic foraminifera are unicellular eukaryotes (Rhizaria) with external shells, which are typically produced by active biomineralization of calcite. Together with calcare

  • Benthic foraminifera as ecological indicators for water quality on the great barrier reef
    2008
    Co-Authors: Sven Uthicke, Kristie Nobes
    Abstract:

    Abstract Benthic foraminifera are established indicators for Water Quality (WQ) in Florida and the Caribbean. However, nearshore coral reefs of the Great Barrier Reef (GBR) and other Pacific regions are also subjected to increased nutrient and sediment loads. Here, we investigate the use of Benthic foraminifera as indicators to assess status and trends of WQ on GBR reefs. We quantified several sediment parameters and the foraminiferan assemblage composition on 20 reefs in four geographic regions of the GBR, and along a water column nutrient and turbidity gradient. Twenty-seven easily recognisable Benthic foraminiferan taxa (>63 μm) were distinguished. All four geographic regions differed significantly ( p a concentrations were negatively correlated, and optical depth and distance to the mainland were positively correlated, with the abundance of symbiont-bearing taxa. Several large foraminifera were identified as indicators for offshore, clear water conditions. In contrast, heterotrophic rotaliids and a species retaining plastids ( Elphidium sp.) where highly characteristic for low light, higher nutrient conditions. Application of the FORAM index to GBR assemblage composition showed a significant increase in the value of this index with increased distance from the mainland in the Whitsunday region ( r 2  = 0.75, p