Relationship between individual chamber and whole shell Mg/Ca ratios in Trilobatus sacculifer and implications for individual foraminifera palaeoceanographic reconstructions.

Precisely targeted measurements of trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) reveal inter-chamber heterogeneities in specimens of the planktic foraminifer Trilobatus (Globigerinoides) sacculifer. We find that Mg/Ca ratios in the final growth chamber are generally lower compared to previous growth chambers, but final chamber Mg/Ca is elevated in one of thirteen sample intervals. Differences in distributions of Mg/Ca values from separate growth chambers are observed, occurring most often at lower Mg/Ca values, suggesting that single-chamber measurements may not be reflective of the specimen's integrated Mg/Ca. We compared LA-ICPMS Mg/Ca values to paired, same-individual Mg/Ca measured via inductively coupled plasma optical emission spectrometry (ICP-OES) to assess their correspondence. Paired LA-ICPMS and ICP-OES Mg/Ca show a maximum correlation coefficient of R = 0.92 (p < 0.05) achieved by applying a weighted average of the last and penultimate growth chambers. Population distributions of paired Mg/Ca values are identical under this weighting. These findings demonstrate that multi-chamber LA-ICPMS measurements can approximate entire specimen Mg/Ca, and is thus representative of the integrated conditions experienced during the specimen's lifespan. This correspondence between LA-ICPMS and ICP-OES data links these methods and demonstrates that both generate Mg/Ca values suitable for individual foraminifera palaeoceanographic reconstructions.

Spatial distribution of benthic foraminifera in the Lagos Lagoon (Nigeria): Tracing the impact of environmental perturbations.

Lagos Lagoon is among Africa's largest estuarine ecosystems, bordered by one of the fastest growing megacities in the world and the ultimate repository of contaminants carried in industrial, municipal and agricultural wastes. The high levels of pollutants have progressively deteriorated the water quality, adversely affected lagoon ecosystems, impacted the livelihood of the coastal population and pose serious risks to human health. Benthic foraminifera are excellent proxies and sensitive bioindicators of environmental disturbances but comprehensive studies on the structure, distribution, diversity and impact of pollution upon foraminiferal communities have not yet been conducted in the Lagos Lagoon. To demonstrate the potential of foraminifera as proxies of environmental perturbations, benthic foraminifera were investigated on a lagoon-wide basis. Lagos Lagoon comprises areas that range from low levels of direct impact to those of severely affected by various forms of anthropogenic disturbance. The goals of this study are to analyze patterns of distribution and species richness, to document foraminiferal community structures, and to identify taxa that track documented records of pollution in Lagos Lagoon sediments. Heat maps were generated from abundance records for selected species to illustrate environmental preferences and relative resistance levels to individual forms of anthropogenic disturbance. Sediments were analyzed for a range of physicochemical properties, via a multi-parameter sensor probe-device, including temperature, pH, depth and total dissolved solids (TDS). Quantitative analysis of 24 sediment samples yielded a total 3872 individuals of benthic foraminifera that belong to 42 species and 25 genera. They comprise 10 porcellaneous, 22 hyaline perforate and 10 agglutinated species. Ammobaculites exiguus, Ammotium salsum, Ammonia aoteana, Ammonia convexa and Trochammina sp. 1 have been found to be the most abundant species. For the first time, the complete present-day foraminifera fauna is illustrated here via scanning electron microscopy. The features recorded allow to assess the spatial effects of pollution upon foraminiferal assemblages on a lagoon-wide basis. The data generated may ultimately form the basis to assess the progressive deterioration of Lagos Lagoon ecosystems from cores by using benthic foraminifera as bioindicators of environmental perturbation.

Simulated future conditions of ocean warming and acidification disrupt the microbiome of the calcifying foraminifera Marginopora vertebralis across life stages.

Foraminifera host diverse microbial communities that can shift in response to changing environmental conditions. To characterize climate change impacts on the foraminifera microbiome across life stages, we exposed adult Marginopora vertebralis (Large Benthic Foraminifera) to pCO2 and temperature scenarios representing present-day, 2050 and 2100 levels and raised juveniles under present-day and 2050 conditions. While treatment condition had no significant effect on the seawater microbial communities, exposure to future scenarios significantly altered both adult and juvenile microbiomes. In adults, divergence between present-day and 2050 or 2100 conditions was primarily driven by a reduced relative abundance of Oxyphotobacteria under elevated temperature and pCO2 . In juveniles, the microbial shift predominantly resulted from changes in the proportion of Proteobacteria. Indicator species analysis identified numerous treatment-specific indicator taxa, most of which were indicative of present-day conditions. Oxyphotobacteria, previously reported as putative symbionts of foraminifera, were indicative of present-day and 2050 conditions in adults, but of present-day conditions only in juveniles. Overall, we show that the sensitivity of the M. vertebralis microbiome to climate change scenarios extends to both life stages and primarily correlates with declines in Oxyphotobacteria and shifts in Proteobacteria under elevated temperature and pCO2 .

Características Sociodemográficas e Risco de Transmissão da COVID-19 em Moçambique / Sociodemographic Characteristics and Transmission Risk of COVID-19 in Mozambique

Objectivo: Mapear o potencial risco de transmissão do novo coronavírus em Moçambique de modo a identificar os distritos cujas características sociodemográficas favorecem a propagação do vírus. Métodos: Usou-se a modelação espacial para determinar o risco relativo de propagação da COVID-19 num distrito em relação ao outro com base nos seguintes factores sociodemográficos: densidade populacional, tamanho médio de agregado familiar, percentagem da população jovem de 15-34 anos e percentagem da população que vive num raio de 2 km de uma estrada classificada. Primeiro, para cada factor foi estimado um risco relativo dividindo os distritos em quintis, e, em segundo lugar, os riscos individuais de cada factor foram somados com igual peso para estimar o risco agregado de transmissão da COVID-19 por distrito. Resultados: Dezanove distritos localizados sobretudo nos principais centros urbanos e no corredor da Beira apresentam alto risco de propagação da COVID-19 em função das suas características sociodemográficas; 24 distritos mostram risco médio-alto e distribuem-se pelas regiões centro e sul do país; 60 distritos localizados nas regiões centro e sul e no interior da região norte apresentam risco médio e; 58 distritos mostram risco médio-baixo ou baixo de transmissão da COVID-19 e encontram-se no litoral centro-norte do país. Conclusão: Os distritos cujo perfil sociodemográfico é favorável à rápida propagação do novo coronavírus são os das grandes cidades e os localizados nas principais rotas de transporte. No entanto, este padrão de risco é susceptível de alterações em função da celeridade, abrangência e níveis de observância das medidas de prevenção e/ou de mitigação da COVID-19. Assim, recomenda-se que as medidas de prevenção e mitigação tenham em conta o risco potencial em cada distrito em função das suas características sociodemográficas.

Objective: To map the potential risk of COVID-19 transmission in Mozambique in order to identify districts with sociodemographic characteristics that favour the spread of coronavirus. Methods: Spatial modelling was used to determine the relative risk of COVID-19 transmission in a certain district in relation to other districts based on the following sociodemographic factors: population density, mean number of household members, the percentage of the young population aged 15-34 and the proportion of a district's population living within two kilometres of a classified road. First, a relative risk due to each factor was estimated grouping the districts into quintiles and, second, the individual risks were added with equal weight to estimate the aggregate relative risk of COVID-19 transmission per district. Results: Nineteen districts located in the main urban centres and along the Beira corridor were found to be at a high relative risk of COVID-19 transmission; 24 districts located mainly in central and southern regions display a medium-high risk category; 60 districts located in the central and southern regions and in the hinterland of the northern region show a medium risk category and; 58 districts exhibit a medium-low or low risk category of COVID-19 transmission and are mainly located at the eastern part of the central-north region. Conclusion: The districts with sociodemographic profile favouring the spread of the new coronavirus are those in the big cities and those located along the main transportation routes. However, the pattern of risk is subject to changes due to the speed, coverage and level of compliance with COVID-19 prevention and mitigation measures. It is recommended that COVID-19 prevention and mitigation measures should take into account the potential risk of each district.

Planktonic foraminifera genomic variations reflect paleoceanographic changes in the Arctic: evidence from sedimentary ancient DNA.

Deciphering the evolution of marine plankton is typically based on the study of microfossil groups. Cryptic speciation is common in these groups, and large intragenomic variations occur in ribosomal RNA genes of many morphospecies. In this study, we correlated the distribution of ribosomal amplicon sequence variants (ASVs) with paleoceanographic changes by analyzing the high-throughput sequence data assigned to Neogloboquadrina pachyderma in a 140,000-year-old sediment core from the Arctic Ocean. The sedimentary ancient DNA demonstrated the occurrence of various N. pachyderma ASVs whose occurrence and dominance varied through time. Most remarkable was the striking appearance of ASV18, which was nearly absent in older sediments but became dominant during the last glacial maximum and continues to persist today. Although the molecular ecology of planktonic foraminifera is still poorly known, the analysis of their intragenomic variations through time has the potential to provide new insight into the evolution of marine biodiversity and may lead to the development of new and important paleoceanographic proxies.

Impacts of ocean acidification on intertidal benthic foraminiferal growth and calcification.

Foraminifera are expected to be particularly susceptible to future changes in ocean carbonate chemistry as a function of increased atmospheric CO2. Studies in an experimental recirculating seawater system were performed with a dominant benthic foraminiferal species collected from intertidal mudflats. We investigated the experimental impacts of ocean acidification on survival, growth/calcification, morphology and the biometric features of a calcareous species Elphidium williamsoni. Foraminifera were exposed for 6 weeks to four different pH treatments that replicated future scenarios of a high CO2 atmosphere resulting in lower seawater pH. Results revealed that declining seawater pH caused a decline in foraminiferal survival rate and growth/calcification (mainly through test weight reduction). Scanning electron microscopy image analysis of live specimens at the end of the experimental period show changes in foraminiferal morphology with clear signs of corrosion and cracking on the test surface, septal bridges, sutures and feeding structures of specimens exposed to the lowest pH conditions. These findings suggest that the morphological changes observed in shell feeding structures may serve to alter: (1) foraminiferal feeding efficiency and their long-term ecological competitiveness, (2) the energy transferred within the benthic food web with a subsequent shift in benthic community structures and (3) carbon cycling and total CaCO3 production, both highly significant processes in coastal waters. These experimental results open-up the possibility of modelling future impacts of ocean acidification on both calcification and dissolution in benthic foraminifera within mid-latitude intertidal environments, with potential implications for understanding the changing marine carbon cycle.

Thermal tolerance and range expansion of invasive foraminifera under climate changes.

The Eastern Mediterranean is experiencing a large-scale invasion of alien tropical species from the Red Sea. This "Lessepsian invasion" began with the opening of the Suez Canal and is promoted by the ongoing oceanic warming. The environmental differences between the Red Sea and the Mediterranean act as a buffer allowing the invasion of certain species. This provides an opportunity to study the differences in temperature sensitivity between two sibling species of the cosmopolitian foraminifera Amphistegina. Both species are very common in the Red Sea. Whilest, only one is a successful invader and the other is absent in the Eastern Mediterranean. Here we show that the two species are different in their temperature sensitivity, which explains their selective invasion into the Mediterranean. These differences demonstrate that in respect to climate change resilient marine species can be distinguished by their ability to compensate for temperature changes by adjusting their physiological performance and by having tolerance to a wider temperature range. Moreover, we demonstrate that selective filtering mechanisms during invasion can prefer species that are more resilient to colder rather than expected warmer temperatures.

Dissimilarity between living and dead benthic foraminiferal assemblages in the Aveiro Continental Shelf (Portugal).

This study compares living (LA) and dead (DA) benthic foraminiferal assemblages and identifies different factors that possibly cause differences in the distribution of both assemblages in the Aveiro Continental Shelf (Portugal). A total of 44 sediment samples was collected during summers of 1994 and 1995 along transects (east-west direction) and between 10 and 200 m water depth. Complex statistical analyses allow us to compare the abundance and composition of the LAs and DAs in function of depth, grain-size and total organic matter in all studied stations even in those where the numbers of individuals were rare in one or both assemblages. The highest densities and diversities of the LAs are found in the middle continental shelf on gravel deposits (coarse and very coarse sands) mostly due to the substrate stability, reduced deposition of fine sedimentary particles, availability of organic matter with high quality related to oceanic primary productivity likely induced by upwelling events, and oxygenated porewaters conditions. The DAs have, in general, higher densities and diversities than the LAs. In the outer continental shelf, the dissimilarity between both assemblages is higher due to the accumulation of tests, low dilution by sedimentary particles and scarcity of living foraminifera. Based on the comparison of LAs and DAs and considering the characteristics of the study area and the species ecology, it has been possible to understand the cause of temporal deviation between the LAs and DAs of benthic foraminifera. This deviation is much more pronounced in the inner shelf where the energy of the waves and the currents induce very dynamic sedimentary processes preventing the development of large LAs and the preservation of DAs. Some deviation also occurs in the middle shelf due to the seasonal loss of empty tests. The most well-preserved time-averaged DAs were found in the outer continental shelf.

Xenophyophores (Rhizaria, Foraminifera) from the Eastern Clarion-Clipperton Zone (equatorial Pacific): the Genus Psammina.

Xenophyophores are important megafaunal organisms in the abyssal Clarion-Clipperton Zone (CCZ; equatorial Pacific), a region hosting commercially significant deposits of polymetallic nodules. Previous studies assigned those with attached, fan-like tests to Psammina limbata, a species described from the central CCZ based on morphology. Here, we redescribe the holotype of P. limbata and then show that limbata-like morphotypes collected in the eastern CCZ include three genetically distinct species. Psammina aff. limbata is closest morphologically to P. limbata. The others are described as P. microgranulata sp. nov. and P. rotunda sp. nov. These fan-shaped species form a well-supported clade with P. tortilis sp. nov., a morphologically variable species exhibiting features typical of both Psammina and Semipsammina. A second clade containing Psammina sp. 3, and two species questionably assigned to Galatheammina branches at the base of this group. The genus Psammina includes another 9 described species for which there are no genetic data, leaving open the question of whether Psammina as a whole is monophyletic. Our study increases the number of xenophyophore species described from the eastern CCZ from 8 to 11, with a further 25 morphotypes currently undescribed. Many additional species of these giant foraminifera undoubtedly await discovery in abyssal settings.

Effect of seawater temperature, pH, and nutrients on the distribution and character of low abundance shallow water benthic foraminifera in the Galápagos.

In order to help predict the effects of anthropogenic stressors on shallow water carbonate environments, it is important to focus research on regions containing natural oceanographic gradients, particularly with respect to interactions between oceanography and ecologically sensitive carbonate producers. The Galápagos Archipelago, an island chain in the eastern equatorial Pacific, spans a natural nutrient, pH, and temperature gradient due to the interaction of several major ocean currents. Further, the region is heavily impacted by the El Niño-Southern Oscillation (ENSO) and the Galápagos exhibited widespread coral bleaching and degradation following the strong ENSO events of 1982-1983 and 1997-1998. These findings are coupled with reports of unusually low abundances of time-averaged benthic foraminiferal assemblages throughout the region. Foraminifera, shelled single-celled protists, are sensitive to environmental change and rapidly respond to alterations to their surrounding environment, making them ideal indicator species for the study of reef water quality and health. Here, statistical models and analyses were used to compare modern shallow water benthic foraminiferal assemblages from 19 samples spanning the Galápagos Archipelago to predominant oceanographic parameters at each collection site. Fisher α diversity indices, Ternary diagrams, Canonical Correspondence Analysis, regression tree analysis and FORAM-Index (FI; a single metric index for evaluating water quality associated with reef development) implied a combined impact from ENSO and upwelling from Equatorial Undercurrent (EUC) waters to primarily impact foraminiferal abundances and drive assemblage patterns throughout the archipelago. For instance, repeated ENSO temperature anomalies might be responsible for low foraminiferal density, while chronically high nutrients and low aragonite saturation and low pH-induced by EUC upwelling and La Niña anomalies-likely inhibited post-ENSO recovery, and caused foraminiferal assemblages to exhibit a heterotrophic dominance in the southern archipelago. What resulted are low FI values in the southern collection sites, indicating environments not conducive to endosymbiont development and/or recovery.

Morphological deformities of benthic foraminifera in response to nearshore pollution of the Red Sea, Egypt.

The Red Sea encompasses a wide range of tropical marine habitats that are stressed due to anthropogenic activities. The main anthropogenic activities are hydrocarbon exploration and important trading harbors. This work aims to assess the influence of the Red Sea coastal heavy metal contamination on the marine meiofauna along three sites (Ras Gharib, Safaga, and Quseir). Eight heavy metal (Cu, Cd, Zn, Pb, Cr, Co, Ni, and Mn) contents are considered in four benthic foraminiferal species (Elphidium striatopunctatum, Amphistegina lobifera, Amphisorus hemprichii, and Ammonia beccarii). Quseir Harbor showed the highest level of pollution followed by Safaga and Ras Gharib sites. The analyzed benthic foraminiferal tests displayed noteworthy high concentrations of Cd, Zn, and Pb in Quseir Harbor which could be attributed to the anthropogenic activities in the nearshore areas. Some foraminiferal tests exhibited abnormalities in their apertures, coiling, and shape of chambers. A comparison between normal and deformed foraminiferal tests revealed that the deformed ones are highly contaminated with elevated heavy metal contents such as Fe, Mn, Ni, and Cd. Statistics in addition to geo-accumulation and pollution load indices reveal a whistling alarm for the Quseir harbor. The present data are necessary to improve conservation and management of the Red Sea ecosystem in the near future.

Benthic foraminiferal and organic matter compounds as proxies of environmental quality in a tropical coastal lagoon: The Itaipu lagoon (Brazil).

Lagoons in the southeast coast of Brazil have experienced eutrophication due to the exponential increase of human population and sewage discharges. Living benthic foraminifera have demonstrated to be good bioindicators of such impacts. This study aims to evaluate the organic matter accumulation effects on the foraminiferal distribution in the Itaipu lagoon (Brazil). On the basis of the biotic and abiotic analyses, three sectors are identified. The Sector I, an inner area, is characterized by high dissolved oxygen values and foraminiferal species with preference for marine conditions, demonstrating the sea influence. The Sector II, in the mangrove margins, is associated to sandy sediment and biopolymers and mainly represented by euryhaline species. The Sector III is marked by low density or absence of living foraminifera and corresponds to a low quality organic matter enriched area (North, Southwest and Centre).

Disentangling thermal stress responses in a reef-calcifier and its photosymbionts by shotgun proteomics.

The proliferation of key marine ecological engineers and carbonate producers often relies on their association with photosymbiotic algae. Evaluating stress responses of these organisms is important to predict their fate under future climate projections. Physiological approaches are limited in their ability to resolve the involved molecular mechanisms and attribute stress effects to the host or symbiont, while probing and partitioning of proteins cannot be applied in organisms where the host and symbiont are small and cannot be physically separated. Here we apply a label-free quantitative proteomics approach to detect changes of proteome composition in the diatom-bearing benthic foraminifera Amphistegina gibbosa experimentally exposed to three thermal-stress scenarios. We developed a workflow for protein extraction from less than ten specimens and simultaneously analysed host and symbiont proteomes. Despite little genomic data for the host, 1,618 proteins could be partially assembled and assigned. The proteomes revealed identical pattern of stress response among stress scenarios as that indicated by physiological measurements, but allowed identification of compartment-specific stress reactions. In the symbiont, stress-response and proteolysis-related proteins were up regulated while photosynthesis-related proteins declined. In contrast, host homeostasis was maintained through chaperone up-regulation associated with elevated proteosynthesis and proteolysis, and the host metabolism shifted to heterotrophy.

The distribution of benthic foraminifera in Bel Torrente submarine cave (Sardinia, Italy) and their environmental significance.

The use of benthic foraminifera as ecological indicators in submarine caves of temperate seas have never been studied before and it represents a new approach, verified by this research. The Bel Torrente submarine cave (Gulf of Orosei, Sardinia, Italy) was surveyed by GUE (Global Underwater Explorers) scuba divers in order to georeferencing the cave before positioning the sampling stations, from the entrance to 430 m inside the cave. A total of 15 water samples were collected to investigate abiotic parameters (temperature, salinity, pH) while 15 sediment samples were collected to analyze grain size and benthic foraminifera. Benthic foraminifera, investigated for the first time in a submarine cave of temperate areas, were exclusively found from the entrance to 300 m inside the cave. Species distribution and assemblage diversity have been found to be correlated to the environmental gradient towards the inner cave, mainly due to the decreasing of temperature and salinity and the increasing of the flow energy. Water acidification seems responsible for the transition from a calcareous hyaline-dominated assemblage to an agglutinant-dominated one, occurring between 120 and 150 m from the entrance. Common taxa of the Sardinian coastal marine area are present only close to the entrance of the cave, while species found in the inner part are nearly exclusively epifaunal clinging/attached or infaunal taxa, with tolerance for wide variability of environmental parameters, such as Gavelinopsis praegeri, and opportunist infaunal taxa such as Eggerella advena. The agglutinant taxa found in the cave are conversely very rare in coastal marine assemblages of the area. This suggests a very efficient dispersal mechanism for the colonization of the caves, involving probably juvenile foraminifera at a "propagule" stage.

Priorização de doenças zoonóticas da One Health para o envolvimento multissectorial em Moçambique / One Health's prioritization of zoonotic diseases for multisectoral involvement in Mozambique

O objectivo desta oficina de trabalho de 2 dias sobre Priorização de Doenças Zoonóticas One Health (OHZDP) foi identificar doenças zoonóticas de maior preocupação nacional para Moçambique, usando contribuições iguais de representantes da saúde humana, gado, ambiente, vida selvagem, pesquisa, parceiros de desenvolvimento, sectores de ensino superior. Durante a oficina de trabalho, os representantes identificaram uma lista de doenças zoonóticas relevantes para Moçambique, definiram os critérios para priorização e determinaram perguntas e pesos relevantes para cada critério. Sete doenças zoonóticas foram identificadas como prioritárias pelos participantes usando a ferramenta OHZDP, uma ferramenta de selecção semi-quantitativa desenvolvida pelos Centros de Controlo e Prevenção de Doenças dos EUA (CDC) (Anexo A)1, 2. As doenças zoonóticas priorizadas para Moçambique são vírus da raiva, tuberculose zoonótica, salmonelose, vírus da gripe aviária zoonótica, tripanasomose, brucelose e febre hemorrágica da Crimeia-Congo (Tabela 1). Os resultados finais do processo de priorização One Health e os pesos normalizados para todas as doenças zoonóticas discutidas na oficina de trabalho da OHZDP em Moçambique são mostrados no Anexo C. Este relatório resume o processo One HeO objectivo desta oficina de trabalho de 2 dias sobre Priorização de Doenças Zoonóticas One Health (OHZDP) foi identificar doenças zoonóticas de maior preocupação nacional para Moçambique, usando contribuições iguais de representantes da saúde humana, gado, ambiente, vida selvagem, pesquisa, parceiros de desenvolvimento, sectores de ensino superior. Durante a oficina de trabalho, os representantes identificaram uma lista de doenças zoonóticas relevantes para Moçambique, definiram os critérios para priorização e determinaram perguntas e pesos relevantes para cada critério. Sete doenças zoonóticas foram identificadas como prioritárias pelos participantes usando a ferramenta OHZDP, uma ferramenta de selecção semi-quantitativa desenvolvida pelos Centros de Controlo e Prevenção de Doenças dos EUA (CDC) (Anexo A)1, 2. As doenças zoonóticas priorizadas para Moçambique são vírus da raiva, tuberculose zoonótica, salmonelose, vírus da gripe aviária zoonótica, tripanasomose, brucelose e febre hemorrágica da Crimeia-Congo (Tabela 1). Os resultados finais do processo de priorização One Health e os pesos normalizados para todas as doenças zoonóticas discutidas na oficina de trabalho da OHZDP em Moçambique são mostrados no Anexo C. Este relatório resume o processo One Health usado para priorizar as principais doenças zoonóticas em Moçambique que devem ser conjuntamente abordadas usando uma abordagem multissectorial One Health, incluindo ministérios da saúde humana, animal e ambiental e outros sectores relevantes para as doenças zoonóticas priorizadas.alth usado para priorizar as principais doenças zoonóticas em Moçambique que devem ser conjuntamente abordadas usando uma abordagem multissectorial One Health, incluindo ministérios da saúde humana, animal e ambiental e outros sectores relevantes para as doenças zoonóticas priorizadas.

Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida).

High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna living in these environments, benthic foraminifera are often the most tolerant to low oxygen levels. Indeed, some species are able to survive complete anoxia for weeks to months. One known mechanism for this, observed in several species, is denitrification. For other species, a state of highly reduced metabolism, essentially a state of dormancy, has been proposed but never demonstrated. Here, we combined a 4 weeks feeding experiment, using 13C-enriched diatom biofilm, with correlated TEM and NanoSIMS imaging, plus bulk analysis of concentration and stable carbon isotopic composition of total organic matter and individual fatty acids, to study metabolic differences in the intertidal species Ammonia tepida exposed to oxic and anoxic conditions. Strongly contrasting cellular-level dynamics of ingestion and transfer of the ingested biofilm components were observed between the two conditions. Under oxic conditions, within a few days, intact diatoms were ingested, degraded, and their components assimilated, in part for biosynthesis of different cellular components: 13C-labeled lipid droplets formed after a few days and were subsequently lost (partially) through respiration. In contrast, in anoxia, fewer diatoms were initially ingested and these were not assimilated or metabolized further, but remained visible within the foraminiferal cytoplasm even after 4 weeks. Under oxic conditions, compound specific 13C analyses showed substantial de novo synthesis by the foraminifera of specific polyunsaturated fatty acids (PUFAs), such as 20:4(n-6). Very limited PUFA synthesis was observed under anoxia. Together, our results show that anoxia induced a greatly reduced rate of heterotrophic metabolism in Ammonia tepida on a time scale of less than 24 hours, these observations are consistent with a state of dormancy.

Effects of hypoxia caused by mussel farming on benthic foraminifera in semi-closed Gamak Bay, South Korea.

Seawater monitoring and geochemical and benthic foraminiferal analysis of sediments were conducted to identify the effects of hypoxia created by a mussel farm on benthic foraminifera in a semi-closed bay. Extremely polluted reductive conditions with a high content of organic matter (OM) at >12.0% and oxygen minimum zones (OMZs) with dissolved oxygen (DO) <0.4mg∙L(-1) were formed below the mussel farm in the northwest area of Gamak Bay, and gradually diffused toward the south. Highly similar patterns of variation were observed in species diversity, abundance frequency, and benthic foraminiferal assemblage distributed from Elphidium subarcticum-Ammonia beccarii in the northwest area through E. subarcticum-A. beccarii-Trochammina hadai, E. subarcticum-A. beccarii-Elphidiumclavatum, and E. clavatum-Ammonia ketienziensis in the southern area. These phenomena were caused by hydrodynamics in the current water mass. It was thought that E. subarcticum is a bioindicator of organic pollution caused by the mussel farm.

Effects of Elevated Temperature on the Shell Density of the Large Benthic Foraminifera Amphistegina lobifera.

This study investigated the effects of elevated temperature on shell density and Mg-ATPase activity of Amphistegina lobifera. This species is abundant in shallow reef habitats, and can be vulnerable to daily physicochemical fluctuations. To assess potential responses and acclimation mechanisms of A. lobifera to changing temperature conditions, we performed a blocked-design experiment exposing specimens collected from different reef sites (inshore and offshore) to three temperature treatments (Control: 24 °C, + 2 °C: 26 °C and + 5 °C: 29 °C) for 30 days. The final size and shell density of inshore reef foraminifera were unaffected by elevated temperature, and the enzyme activity in these individuals showed that they were able to acclimate to new temperature conditions. In contrast, offshore A. lobifera were more sensitive to changes in temperature, and heat stress caused growth impairment and inhibited Mg-ATPase activity. However, newly added chambers were not affected. These results suggested that Mg-ATPase plays an important role in regulating intracellular Mg2+ ions, but has little influence in the onset of calcification in A. lobifera. Moreover, it suggests that even though A. lobifera can regulate intracellular functions, local habitat seems to play a crucial role in determining how foraminifera respond to environmental changes.

Variation in the composition of corals, fishes, sponges, echinoderms, ascidians, molluscs, foraminifera and macroalgae across a pronounced in-to-offshore environmental gradient in the Jakarta Bay-Thousand Islands coral reef complex.

Substrate cover, water quality parameters and assemblages of corals, fishes, sponges, echinoderms, ascidians, molluscs, benthic foraminifera and macroalgae were sampled across a pronounced environmental gradient in the Jakarta Bay-Thousand Islands reef complex. Inshore sites mainly consisted of sand, rubble and turf algae with elevated temperature, dissolved oxygen, pH and chlorophyll concentrations and depauperate assemblages of all taxa. Live coral cover was very low inshore and mainly consisted of sparse massive coral heads and a few encrusting species. Faunal assemblages were more speciose and compositionally distinct mid- and offshore compared to inshore. There were, however, small-scale differences among taxa. Certain midshore sites, for example, housed assemblages resembling those typical of the inshore environment but this differed depending on the taxon. Substrate, water quality and spatial variables together explained from 31% (molluscs) to 72% (foraminifera) of the variation in composition. In general, satellite-derived parameters outperformed locally measured parameters.

Effects of cyclone-generated disturbance on a tropical reef foraminifera assemblage.

The sedimentary record, and associated micropalaeontological proxies, is one tool that has been employed to quantify a region's tropical cyclone history. Doing so has largely relied on the identification of allochthonous deposits (sediments and microfossils), sourced from deeper water and entrained by tropical cyclone waves and currents, in a shallow-water or terrestrial setting. In this study, we examine microfossil assemblages before and after a known tropical cyclone event (Cyclone Hamish) with the aim to better resolve the characteristics of this known signal. Our results identify no allochthonous material associated with Cyclone Hamish. Instead, using a swathe of statistical tools typical of ecological studies but rarely employed in the geosciences, we identify new, previously unidentified, signal types. These signals include a homogenising effect, with the level of differentiation between sample sites greatly reduced immediately following Cyclone Hamish, and discernible shifts in assemblage diversity. In the subsequent years following Hamish, the surface assemblage returns to its pre-cyclone form, but results imply that it is unlikely the community ever reaches steady state.