Impact of eutrophication on shallow marine benthic foraminifers over the last 150 years in Osaka Bay, Japan

High-resolution foraminiferal analysis was conducted on a short sediment core from the inner part of Osaka Bay, Japan. Changes in foraminiferal assemblages were associated with eutrophication, bottom water hypoxia, and changes in red tide-causing algae. Before the 1920s, the calcareous species Ammonia beccarii, and the agglutinated species Eggerella advena and Trochammina hadai were rare, but calcareous foraminifers in general were abundant. Between the 1920s and 1940s, calcareous foraminifers decreased abruptly in abundance, while A. beccarii, E. advena and T. hadai increased in abundance. This faunal change corresponded in time to an increase in nutrients flowing in through the Yodo River, and bottom water hypoxia related to eutrophication. In the 1960s and 1970s, A. beccarii, E. advena and T. hadai further increased in abundance to become dominant, and many calcareous foraminifers nearly disappeared, corresponding to increasing bottom water hypoxia related to the rapid increase in discharged nutrients during the high economic growth period from 1953 to 1971. After the 1990s, A. beccarii decreased rapidly in abundance and E. advena and Uvigerinella glabra increased in abundance. The main components of red tide-causing algae changed from dinoflagellates to diatoms in the 1980s through 1990s, thus there was a change in the food supply to the benthos, which may have caused the increase in abundance of E. advena and U. glabra.     

Monitoring of the toxic dinoflagellate Alexandrium catenella in Osaka Bay,Japan using a massively parallel sequencing (MPS)-based technique

Since 2002, blooms of Alexandrium catenella sensu Fraga et al. (2015) and paralytic shellfish toxicity events have occurred almost yearly in Osaka Bay, Japan. To better understand the triggers for reoccurring A. catenella blooms in Osaka Bay, phytoplankton community was monitored during the spring seasons of 2012–2015. Monitoring was performed using massively parallel sequencing (MPS)-based technique on amplicon sequences of the 18S rRNA gene. Dense blooms of A. catenella occurred every year except in 2012, however, there was no significant correlation with the environmental parameters investigated. Plankton community diversity decreased before and middle of the A. catenella blooms, suggesting that the decline in diversity could be an indicator for the bloom occurrence. The yearly abundance pattern of A. catenella cells obtained by morphology-based counting coincided with the relative sequence abundances, which supports the effectiveness of MPS-based phytoplankton monitoring.     

Distribution of ostracod and benthic foraminiferal assemblages during the last 550 kyr in the East-Corsica basin,western Mediterranean Sea: A paleo-environmental reconstruction

The study of Quaternary sediments covering the last 550 kyr from the borehole GDEC-4-2, East-Corsica basin, was performed through the study of benthic meiofaunal assemblages (ostracoda and benthic foraminifera) whose distribution responds to climate changes, and glacial–interglacial variability in particular. The interglacial ostracod group is mainly composed of the Argilloecia acuminata, Cytheropteron alatum, Henryhowella sp., Polycope sp. and Cytherella sp., which indicate an enhanced surface productivity and possibly high bottom water temperature during these warm intervals. Benthic foraminifera, such as Hoeglundina elegans, Sigmoilopsis schlumbergeri, Bigenerina nodosaria and Hyalinea balthica are predominant during interglacial periods and also show an increasing surface productivity associated to warm intervals. Increase in surface productivity would contribute to an enhanced export of organic matter to sea floor at the GDEC-4-2 site during interglacial periods. The bottom temperature drop coupled with the important sedimentary inputs (associated to a significant quantity of refractory organic matter) during glacial periods was highlighted by the predominance of ostracoda, such as Paradoxostoma sp., Cytheropteron testudo, Bathycythere vanstraateni, Macrocypris sp., Echinocythereis echinata and benthic foraminifera as Bolivina spathulata, Bulimina costata, and Bulimina marginata. The distribution of some benthic foraminifera species describing a turnover system allowed the characterization of the last three climate cycles (MIS 8–9, MIS 6–7, MIS 1–5) probably marked by changes of bottom water paleoceanographic conditions in terms of temperature, salinity, bottom current intensity and surface productivity. The cyclic variations of the allochthonous group recorded over the last 550 kyr suggest a major role played by the eustatic factor, with the latter possibly favouring down slope transport. The distribution of this group allowed thus establishing a link between shelf-basin sediment transfer and climate, with enhanced shelf-basin sediment transfer during glacial low stands.     

Live benthic foraminiferal faunas along a bathymetrical transect (140-4800 m) in the Bay of Biscay (NE Atlantic)

In a 10-stations bathymetrical transect in the Bay of Biscay, we observed important changes in the density, composition and microhabitats of live foraminiferal faunas from the outer continental shelf to the abyssal plain. Four zones are recognised: (1) at the upper continental shelf (140 m water depth), foraminiferal densities are very high and the superficial sediment is occupied by Bolivina subaenariensis and Valvulineria bradyana. Globobulimina spp., Chilostomella oolina and Nonion fabum dominate the infaunal niches, which are positioned close to the sediment-water interface due to a strong compaction of the vertical succession of redox zones. (2) At the upper continental slope stations (300-1000 m), foraminiferal densities are high and the superficial sediments are dominated by Uvigerina mediterranea/peregrina. Deeper in the sediment, intermediate infaunal niches are occupied by Melonis barleeanus. Due to a deeper oxygen penetration, the deep infaunal taxa Globobulimina spp. and C. oolina live at a considerable depth in the sediment. (3) At the mid and lower slope stations (1000-2000 m) in the superficial sediment Cibicidoides kullenbergi and Hoeglundina elegans progressively replace U. mediterranea. U. peregrina is still a dominant taxon, reflecting its preference for a somewhat intermediate organic flux level. Deep infaunal taxa become increasingly rare. (4) At the lower slope and abyssal plane stations (deeper than 2000 m), faunal densities are very low and the fauna is composed exclusively by shallow infaunal species, such as Nuttallides umboniferus and Melonis pompilioides. The foraminiferal data together with the pore water data in the sediment give evidence of the presence of a trophic gradient from very eutrophic settings at the upper continental shelf towards oligotrophic settings at the abyssal area.     

Abyssal NE Atlantic benthic foraminifera during the last 15 kyr: Relation to variations in seasonality of productivity

Benthic foraminiferal faunas (> 63 μm) and stable isotopes from the last 15 kyr were studied in BENGAL programme (high-resolution temporal and spatial study of the BENthic biology and Geochemistry of a north-eastern Atlantic abyssal Locality) kasten core 13078#16 from the Porcupine Abyssal Plain, NE Atlantic (48°49.91 N, 16°29.94 W, water depth 4844 m). Changes occurred in the accumulation rates, species composition, diversity, and stable isotopes during the last 15 kyr. Today, the area is strongly influenced by seasonal inputs of phytodetritus following the spring blooms in surface water primary productivity. Variations in the relative abundance of the two most abundant species, Epistominella exigua and Alabaminella weddellensis, which today show significant increases in abundance with the presence of phytodetritus on the sea-floor, are interpreted as resulting from changes in the seasonality of productivity. Seasonal productivity was higher during the Holocene than during the last deglaciation and Younger Dryas, probably coinciding with the retreat of the polar front to higher latitudes. This hypothesis is consistent with simultaneous decreases in the percentage of the polar planktic foraminifera Neogloboquadrina pachyderma (s), and increases in the percentage of Globigerina bulloides, a warmer water planktic foraminifera indicative of phytoplankton blooms and enhanced productivity. The relative abundance of the ‘phytodetritus species’ (E. exigua and A. weddellensis) covary between 14.7 and 8.1 kyr, but not between 7.8 and 1.2 kyr. Major decreases in the numbers per gram and accumulation rates of planktic and benthic foraminifera occurred at ∼ 12–8.5 kyr and at ∼ 4 kyr which correspond to decreases in the % sediment coarse fraction and published data on inorganic carbon contents suggesting that dissolution may have increased at these times. Relationships between benthic foraminiferal faunas and benthic stable isotope records suggest no simple relationship between faunal abundances and test isotope chemistry. For example, the abundances of phytodetritus species do not show strong correlations with either the δ¹³C values of E. exigua or the Δδ¹³C _{E. exigua − P. wuellerstorfi} record, which have previously been suggested as indicative of seasonality of productivity.     

The input of foraminiferal infaunal populations to sub-fossil assemblages along an elevational gradient in a salt marsh: application to sea-level studies in the mid-Atlantic coast of North America

The suitability of marsh sites for sea-level studies was examined based on a field study along a transect from high to low marsh. Living foraminifera at Bombay Hook (Delaware, USA) are considered to be shallow infaunal (i.e., uppermost 10 cm). Peak concentrations were found at 1–10 cm in the high marsh, 1–5 cm in the intermediate marsh, and 3–5 cm in the low marsh. However, sporadic deep infaunal inputs in the low marsh could significantly contribute to the sub-fossil assemblage. In the upper 10 cm buried (death + sub-fossil) and living assemblages showed a strong correlation, and the seasonal pattern of the buried assemblage paralleled the living one, suggesting that the buried assemblage reflected the most recent reproductive inputs. The cumulative standing crop of each dominant species was used to estimate their contribution to the buried assemblage in order to assess if the community is vertically homogeneous and, therefore, if the infaunal production causes differential sub-surface enrichment. The results showed that a “shallow” (0–5 cm) infaunal contribution is able to explain much of the sub-fossil assemblage beneath the surface in the high and intermediate marsh plots. However, in the low marsh plot, the deep infaunal contribution was greatest and significantly affected the sub-fossil assemblage. Therefore, modern analogues for sea-level studies in mid-Atlantic North American marshes should include the uppermost 5 cm. The interval proposed for the high and intermediate marsh is thin enough that epifaunal species are not underrepresented and encompasses only ~8 years (based on burial rates) providing a high temporal resolution. Handling editor: J. Saros     

Spatial distribution of live benthic foraminifera in the Rhône prodelta: Faunal response to a continental–marine organic matter gradient

Benthic foraminifera were collected in the Rhône prodelta (Gulf of Lions, Mediterranean Sea), an enriched zone with high organic matter content. In June 2005, sediment cores were sampled at depths ranging from 20 to 100 m. Four distinct foraminiferal assemblages were determined in the study area, reflecting the geographical distribution of the impact of river supply. The living foraminiferal faunas present a typical picture, with strongly impoverished faunas composed exclusively of stress-tolerant taxa (Fursenkoina fusiformis, Bulimina aculeata, Leptohyalis scottii, and Adelosina longirostra) in the immediate vicinity of the river mouth. This assemblage is well adapted to a high input of continental organic matter and a minimum oxygen penetration depth into the sediment. To the southwest, under the main corridor followed by the river plume, high organic input with a dominantly terrestrial signature (more refractory) may be stressful for many taxa which need organic matter of a more labile quality. In this area, Nonion scaphum, Nonionella turgida and Rectuvigerina phlegeri are present in low densities. On the edge of this area, these taxa show much higher densities. A greater proportion of marine organic carbon could explain their increasing abundances in this area. Towards the east and towards the deepest stations, in the outer part of the enriched zone, biodiversity increases. Faunas at these stations have intermediate densities and contain a number of taxa (Cassidulina carinata, Epistominella vitrea, Valvulineria bradyana, Nonionella iridea/bradyi) at the deepest stations; Bolivina dilatata/spathulata and Textularia porrecta at the eastern stations) that seem to benefit from more marine organic matter. The comparison of geochemical measurements and foraminiferal data strongly suggests that the spatial distribution of foraminifera in the Rhône prodelta is mainly governed by the quality and the quantity of organic matter reaching the sediment–water interface. Since bottom waters are well oxygenated (215–260 µmol/L), and oxygen penetration into the sediment is less than 1 cm at all stations, benthic ecosystem oxygenation appears to have only a minor impact on regional differences in faunal distribution.     

The last 1000 years of natural and anthropogenic low-oxygen bottom-water on the Louisiana shelf, Gulf of Mexico

The relative abundance of three species of low-oxygen tolerant benthic foraminifers, the PEB index, in foraminiferal assemblages from sediment cores is used to trace the history of low-oxygen bottom-water conditions on the Louisiana shelf. Analyses of a network of box cores indicate that the modern zone of chronic seasonal hypoxia off the Mississippi Delta began to develop around 1920 and was well established by 1960. The pattern of development over the last century is consistent with the interpretation that the formation of modern chronic hypoxia is related to anthropogenic activities resulting in increased transport of nutrients to the Louisiana shelf.The PEB index in two gravity- and box core pairs (MRD05-4 and 05-6) indicates that low-oxygen bottom-water events have occurred periodically on the Louisiana Shelf for at least the last 1000 ¹⁴C years. The pre-1900 low-oxygen bottom-water events are likely caused by intervals of increased Mississippi River discharge and widespread wetland export. The PEB record in gravity cores indicates that the pre-1900 low-oxygen bottom-water events were not as well developed or as geographically extensive as the modern hypoxia zone. We conclude that the development of low-oxygen bottom-water on the Louisiana shelf is a natural process that has been negatively modified by human activities in the last 100 years.     

The pathogenesis of endemic fluorosis: Research progress in the last 5 years

Fluorine is one of the trace elements necessary for health. It has many physiological functions, and participates in normal metabolism. However, fluorine has paradoxical effects on the body. Many studies have shown that tissues and organs of humans and animals appear to suffer different degrees of damage after long‐term direct or indirect exposure to more fluoride than required to meet the physiological demand. Although the aetiology of endemic fluorosis is clear, its specific pathogenesis is inconclusive. In the past 5 years, many researchers have conducted in‐depth studies into the pathogenesis of endemic fluorosis. Research in the areas of fluoride‐induced stress pathways, signalling pathways and apoptosis has provided further extensive knowledge at the molecular and genetic level. In this article, we summarize the main results.     

A Record of the Cubed Snailfish, <Emphasis Type="Italic">Liparis tessellatus</Emphasis> (Pisces: Liparidae), in Peter the Great Bay,Sea of Japan

A specimen of the cubed snailfish, Liparis tessellatus was captured in Peter the Great Bay, Sea of Japan. The capture of L. tessellatus from this area a century after the first record is evidence that at present this species still inhabits Peter the Great Bay.Original Russian Text Copyright © 2005 by Biologiya Morya, Sokolovskii, Sokolovskaya.     

Regional versus local drivers of water quality in the Windermere catchment,Lake District,United Kingdom: The dominant influence of wastewater pollution over the past 200 years

Freshwater ecosystems are threatened by multiple anthropogenic stressors acting over different spatial and temporal scales, resulting in toxic algal blooms, reduced water quality and hypoxia. However, while catchment characteristics act as a ‘filter’ modifying lake response to disturbance, little is known of the relative importance of different drivers and possible differentiation in the response of upland remote lakes in comparison to lowland, impacted lakes. Moreover, many studies have focussed on single lakes rather than looking at responses across a set of individual, yet connected lake basins. Here we used sedimentary algal pigments as an index of changes in primary producer assemblages over the last ~200 years in a northern temperate watershed consisting of 11 upland and lowland lakes within the Lake District, United Kingdom, to test our hypotheses about landscape drivers. Specifically, we expected that the magnitude of change in phototrophic assemblages would be greatest in lowland rather than upland lakes due to more intensive human activities in the watersheds of the former (agriculture, urbanization). Regional parameters, such as climate dynamics, would be the predominant factors regulating lake primary producers in remote upland lakes and thus, synchronize the dynamic of primary producer assemblages in these basins. We found broad support for the hypotheses pertaining to lowland sites as wastewater treatment was the main predictor of changes to primary producer assemblages in lowland lakes. In contrast, upland headwaters responded weakly to variation in atmospheric temperature, and dynamics in primary producers across upland lakes were asynchronous. Collectively, these findings show that nutrient inputs from point sources overwhelm climatic controls of algae and nuisance cyanobacteria, but highlights that large‐scale stressors do not always initiate coherent regional lake response. Furthermore, a lake's position in its landscape, its connectivity and proximity to point nutrients are important determinants of changes in production and composition of phototrophic assemblages.     

First record of a brachiopod (Brachiopoda: Terebrataliidae) in the fouling of hydrotechnical installations in Peter the Great Bay,Sea of Japan

Large mature individuals of the brachiopod Coptothyris adamsi Davidson, 1871 were found in the fouling of a pier in Koz’mina Bight (Nakhodka Bay, Peter the Great Bay, Sea of Japan) in September 2006. The population density of the brachiopod in the fouling reached 100 specimens/m² and greatly exceeded the density of this species in benthic communities (4 specimens/m²). This is the first record of a brachiopod on anthropogenic substrates in the Far-Eastern seas of Russia. It is of particular interest because (1) C. adamsi is listed in the Red Book of Russia and (2) construction of an international oil terminal is planned for Koz’mina Bight. The brachiopod population can be used to monitor environmental conditions during the construction and further functioning of the oil terminal in Koz’mina Bight.     

Vegetation history with implication of climate changes and human impacts over the last 9000 years in the Lake Nanyi area,Anhui Province,East China

Palynological analyses in combination with radiocarbon dating on a Holocene borehole from the Lake Nanyi, Anhui Province, East China demonstrate a well-documented local vegetation evolution since 9000 cal BP, which is the first record of Holocene climate change and human impact in this region. Since 9000 cal BP a mixed evergreen and deciduous broad-leaved forest dominated by Cyclobalanopsis and Quercus developed in this area, indicating a warm climate condition with enhanced insolation. A mixed evergreen and deciduous broad-leaved forest was fully developed between 6600–4500 cal BP, which corresponds to the Holocene Climate Optimum with the strong influence of East Asian summer monsoon (EASM). After 3000 cal BP the broad-leaved forest decreased rapidly, while land herbs and ferns increased. It seems that the climate condition in East China was similar to the present after Holocene Climate Optimum. Pollen results show a potential interface between environment changes and human activities. Pollen diagram demonstrates that human impacts on the natural vegetation remained weak at the early stage but significantly enhanced upwards. The distinctive fluctuations of the pollen contents among AP (trees and shrubs), and the possible agriculture indicators might infer the potential human behaviors for environment changes. Due to the enlargement of organized farming and increase in population, natural forest was eventually replaced by farmland since 3000 cal BP. This study would increase our knowledge of Holocene vegetation transition related to the monsoon dynamics on a long timescale in East China and provide an environmental background for more detailed studies on cultural developments in the middle and lower reaches of the Yangtze River region.     

Reproductive biology of the guitarfish <Emphasis Type="Italic">Rhinobatos hynnicephalus</Emphasis> (Batoidea: Rhinobatidae) in Ariake Bay,Japan

Size at sexual maturity, reproductive cycle, and fecundity of the guitarfish, Rhinobatos hynnicephalus, were examined in Ariake Bay, Japan. Females reached sexual maturity at a larger size than males [total length (TL) at 50% sexual maturity: males, 431 mm; females, 476 mm]. Monthly gonadosomatic indices of males decreased abruptly from July to August. Histological examinations confirmed the presence of mature spermatozoa in the testes in July, with semen in seminal vesicles in July and August. Preovulatory ova were observed in females with near-term embryos in August. Parturition occurred in August, immediately followed by mating, ovulation, and fertilization. Gestation period is approximately 1 year. Fertilized uterine eggs without embryonic development were present throughout the annual reproductive cycle. Embryonic development began in June and ended in August, indicating that R. hynnicephalus undergoes embryonic diapause (9 months). Fecundity increased with TL and ranged from 1 to 9 (mean, 4.4) embryos per litter.     

The last 50 years of climate‐induced melting of the Maliy Aktru glacier (Altai Mountains,Russia) revealed in a primary ecological succession

In this article, we report and discuss the results obtained from a survey of plants, microorganisms (bacteria and fungi), and soil elements along a chronosequence in the first 600 m of the Maliy Aktru glacier's forefront (Altai Mountains, Russia). Many glaciers of the world show effects of climate change. Nonetheless, except for some local reports, the ecological effects of deglaciation have been poorly studied and have not been quantitatively assessed in the Altai Mountains. Here, we studied the ecological changes of plants, fungi, bacteria, and soil elements that take the form of a primary ecological succession and that took place over the deglaciated soil of the Maliy Aktru glacier during the last 50 year. According to our measurements, the glacier lost about 12 m per year during the last 50 years. Plant succession shows clear signs of changes along the incremental distance from the glacier forefront. The analysis of the plant α‐ and β‐diversity confirmed an expected increase of them with increasing distance from the glacier forefront. Moreover, the analysis of β‐diversity confirmed the hypothesis of the presence of three main stages of the plant succession: (a) initial (pioneer species) from 30 to 100 m; (b) intermediate (r‐selected species) from 110 to 120–150 m; and (c) final (K‐selected species) from 150 to 550. Our study also shows that saprotrophic communities of fungi are widely distributed in the glacier retreating area with higher relative abundances of saprotroph ascomycetes at early successional stages. The evolution of a primary succession is also evident for bacteria, soil elements, and CO₂ emission and respiration. The development of biological communities and the variation in geochemical parameters represent an irrefutable proof that climate change is altering soils that have been long covered by ice.     

Online Mendelian Inheritance in Animals (OMIA): a record of advances in animal genetics,freely available on the Internet for 25 years

For the last 25 years, Online Mendelian Inheritance in Animals (OMIA) has been providing free global access to an ever‐increasing record of discoveries made by animal geneticists around the world. To mark this 25‐year milestone, this document provides a brief account (including some pre‐history) of how OMIA came to be; some timelines of important discoveries and advances in the genetics of the animal species covered by OMIA, gleaned from the OMIA database; and an analysis of the current state of knowledge regarding likely causal variants of single‐locus traits in OMIA species, also gleaned from the OMIA database.     

The population demography of Betula maximowicziana,a cool‐temperate tree species in Japan,in relation to the last glacial period: its admixture‐like genetic structure is the result of simple population splitting not admixing

Conservation of the local genetic variation and evolutionary integrity of economically and ecologically important trees is a key aspect of studies involving forest genetics, and a population demographic history of the target species provides valuable information for this purpose. Here, the genetic structure of 48 populations of Betula maximowicziana was assessed using 12 expressed sequence tag–simple sequence repeat (EST‐SSR) markers. Genetic diversity was lower in northern populations than southern ones and structure analysis revealed three groups: northern and southern clusters and an admixed group. Eleven more genomic‐SSR loci were added and the demographic history of these three groups was inferred by approximate Bayesian computation (ABC). The ABC revealed that a simple split scenario was much more likely than isolation with admixture, suggesting that the admixture‐like structure detected in this species was due to ancestral polymorphisms. The ABC analysis suggested that the population growth and divergence of the three groups occurred 96 800 (95% CI, 20 500–599 000) and 28 300 (95% CI, 8700–98 400) years ago, respectively. We need to be aware of several sources of uncertainty in the inference such as assumptions about the generation time, overlapping of generations, confidence intervals of the estimated parameters and the assumed model in the ABC. However, the results of the ABC together with the model‐based maps of reconstructed past species distribution and palaeoecological data suggested that the modern genetic structure of B. maximowicziana originated prior to the last glacial maximum (LGM) and that some populations survived in the northern range even during the LGM.