Benthic foraminifera of surface samples and sediment cores off Senegal and Gambia, West Africa

Water depth zonation of fifty nine benthonic foraminiferal species in marine sediment surfaces has been described. Some species are combined to groups which mark particular depth zones: an upper and lower shelf-fauna, an upper and lower slope fauna, and a shelf-slope fauna. Dependence on latitude could be ascertained for Textularia panamensis, and submergence effects for Hyalinea balthica.

Distribution of benthic foraminifera in surface sediments of the Portuguese continental margin

Living and dead benthic Foraminifera of 26 sediment surface samples from the East Atlantic continental margin (off Portugal) are studied. The stations are located on two profiles off Cape Mondego and off Cape Sines, ranging in water depth from 45 to 3905 meters. The highest values of standing crop are on the shelf (200 m) (up to 420 specimens/10 cm**3). Below 1000 m water depth standing crop is low (5 -24 specimens/10 cm**3). 151species and species groups are distinguished. Most of the living species do occur in a wide depth range. Faunal depth boundaries are at 50/100m, at 600/800 m, and at 1000 m. Results published from the North Atlantic and the East Mediterranean do not differ from those obtained in samples off Portugal. Depth of water (e.g. hydrostatic pressure) or another factor being controlled by depth (e.g. limitation of food supply) seems to be the most important factor of the benthic foraminiferal distribution.

(Table 1) Vertical distribution of relative contents of the main planktonic groups in the water column of the Kuril-Kamchatka region at Station VITYZ5635

Determinations were made of contents of carbon, lipids, nitrogen and, in some material, protein, carbohydrates, elementary composition of lipids and their spectral composition in total plankton samples from different depths (from the surface to 3000 m) and in several species of macroplanktonic deep-water crustaceans (decapods and mysids) living at different depths. Content of organic carbon and lipids in total plankton is high (40 to 60 and 35 to 70% of dry weight, respectively) and it does not change significantly with increasing depth. Deep-water macroplanktonic crustaceans have extremely high content of organic carbon and lipids, but there are no significant differences in this respect between species that live in different layers of the deep-water zone. Elementary composition of lipids indicates that they are highly saturated, with a marked predominance of unsaponifiable fraction, about 20% of which consists of methane hydrocarbons.

Geochemistry and sedimentation rates of ODP Leg 199 sites and of surface sediments in the eastern Pacific ocean

We present the first high-resolution organic carbon mass accumulation rate (MAR) data set for the Eocene equatorial Pacific upwelling region, from Sites 1218 and 1219 of the Ocean Drilling Program. A maximum Corg MAR anomaly appears at 41 Ma and corresponds to a high carbonate accumulation event (CAE). Independent evidence suggests that this event (CAE-3) was a time of rapid cooling. Throughout the Eocene, organic carbon burial fluxes were an order of magnitude lower than fluxes recorded for the Holocene. In contrast, the expected organic carbon flux, calculated from the biogenic barium concentrations for these sites, is roughly equal to modern. A sedimentation anomaly appears at 41 Ma, when both the measured and the expected organic carbon MAR increases by a factor of two-three relative to the background Eocene fluxes. The rain of estimated Corg and barium from the euphotic zone to the sediments increased by factors of three and six, respectively. We suggest that the discrepancy between the expected and measured Corg in the sediments is a direct consequence of the increased metabolic rates of all organisms throughout the Eocene oceans and sediments. This hypothesis is supported by recent work in ecology and biochemical kinetics that recognizes the fundamental basis of ecology as following from the laws of thermodynamics. This dependence is now elucidated as the Universal Temperature Dependence (UTD) "law" of metabolism and can be applied to all organisms over their biologically relevant temperature range. The general pattern of organic carbon and barium deposition throughout the Eocene is consistent with the UTD theory. In particular, the anomaly at 41 Ma (CAE-3) is associated with rapid cooling, an event that triggered slower metabolic rates for all organisms, slower recycling of organic carbon in the water and sediment column, and, consequently, higher deposition of organic carbon in the sediments. This "metabolism-based" scenario is consistent with the sedimentation patterns we observe for both Sites 1218 and 1219.

Benthic foraminifera in surface sediments of the Persian Gulf

During "Meteor"cruise 1965 the author collected 134 samples of surface sediments from the Iranian part of the Persian Gulf. Benthic Foraminifera populations have been analysed for determining their depth zonation. These data are supposed to allow detailed depth interpretation of Pleistocene sediments found in cores. In addition, the ecological information might be usefull to reconstruct the depositional environment of fossil sediments in similar shallow epicontinental seas. The investigation is published in two parts: the present part 1 contains the catalogue of species with short discussions of taxonomic problems, notes on the distribution within the Persian Gulf and 11 plates, partly with scanning electron micrographs. The results of the statistical analysis are given in data tables which include number of species, percentages of 2 (and 5) ranked species, standing crop and foraminiferal numbers. The author used "species groups" to avoid ambiguities with species requiring additional taxonomic studies. However, species numbers within these units are estimated to yield applicable diversity information. - A total of 52 species and 7 "species groups" were separated, 2 new species were described.

Phosphorus dynamics in waters of the Pacific Ocean

Tagged phosphorus was used to measure principal indices of mineral phosphorus variations in the euphotic zone of the East Pacific, i.e. total rate of uptake of phosphate phosphorus by microplankton (A_t), fraction consumed by phytoplankton (A_p/A_t), and turnover time (T). A_t reached its greatest values (150-280 ng/l/hour) in the upwelling zone of the Peru traverse, where development of phytoplankton was induced by upwelling. In other areas of this traverse values were 40-80 ng/l/hour in surface layers. In less productive waters on two other profiles (off Central America and California), values were lower, between 20 and 40 ng/l. On the vertical profile maxima of A_t were found at the upper boundary of the thermocline. Turnover time of PO4 phosphorus (T) in zones of phytoplankton abundance was very short, between 1.5 and 4 days. At most other stations it was 10-40 days, increasing to 100-200 days or longer at the lower boundary of the euphotic zone. In areas of phytoplankton abundance it accounted for 60-80% of total uptake of PO4 phosphorus. But in zones of elevated bacterial abundance, A_p/A_t fell to 20-40%. Data indicating lack of correlation between PO4 phosphorus and productivity are presented. It is emphasized that the above measures of PO4 phosphorus dynamics can be used for obtaining measures of functional condition and successional phase of marine plankton communities.

Distribution of planktic foraminifera in surface sediments and sedimentation rates of sediment cores from the Ibero-Moroccan continental rise and slope

Cores from the Atlantic Ibero-Moroccan continental rise and slope contain fine-grained Late Pleistocene and Holocene sediments. These young sediments cover the continental margin in large lensformed litho- and biostratigraphically well-defined units. The total sedimentation rates range from 4 cm/ 1000 yrs. to 27 cm/1000 yrs. off Portugal and from 6 cm/1000 yrs. to 14 cm/1000 yrs. off Morocco. Only a small proportion of these sediments usually consists of sand-sized particles (>0.063 mm) which are mostly dominated by foraminifera. Both planktonic and benthic foraminifera are much more abundant in Late Pleistocene and Holocene samples from the upper slope in comparison to those from the deeper slope and from the abyssal plains. Total sedimentation rates during cool and warm climatic stages are rather similar for both groups of foraminifera. For example, in Late Holocene sediments 7 x 10**3 benthic and 201 x 10**3 planktonic foraminifera (fraction 0.63 -0.20 mm) per 100 cm**2 and 1000 yrs. are preserved in the Tagus, 10-19 X 10**3 benthic and about 1.3 X 10**6 planktonic foraminifera are preserved in the Seine abyssal plain sediments. Values from the upper slope sediments are higher for benthic foraminifera by a factor of 60 off Portugal and 60 to 70 off Morocco. The values for planktonic ones differ by factors of 6-12 and 6 respectively. These numbers seem to reflect differences in production and preservation. Production rates of planktonic foraminifera generally seem to be somewhat higher during Holocene than during Late Pleistocene, and the rates of benthic foraminifera appear rather higher during Late Pleistocene than during Holocene.

(Table 1, pages 283), Elemental concentrations of ferromanganese crusts from Lake Biwa, Japan

Ferromanganese crusts were sampled from the surface of a stone collected at a depth of 20 m in the northern part of Lake Biwa, Japan. These samples were analysed for 37 elements by neutron activation, X-ray fluorescence, and ICP-AE. The crusts were found to be enriched with Ba, P, B, As, and sometimes with Co, Ni, Cu and Sb. The elements were classified into 4 groups based on the varieties of host minerals (Fe-oxides, Mn-oxides or allochthonous materials) in which they were incorporated : elements mainly associated with 1) Mn-oxides : Ba, Ni, Cs, Sr and Co ; 2) Fe-oxides : P, B and As; 3) allochthonous materials : Na, K, Rb, Al, Ti, Sc, Hf and Th ; and 4) Mn-oxides plus allochthonous materials : rare earth elements and major heavy metals. The elemental compositions in the Lake Biwa concretions, including the crusts and Mn-deposits studied previously by these authors, were compared with those in other freshwater and oceanic concretions. As a result, the concentrations of rare earth elements and major heavy metals were found to be much lower, whereas those of B, P and As were higher in the Lake Biwa than in the oceanic concretions. These differences could be well explained in terms of the effects of sea salt, growth rates of the concretions, and pH of the formation environment.

Radiolarian-based bransfer function for the estimation of sea surface temperatures in the Southern Ocean (Atlantic Sector)

A new radiolarian-based transfer function for sea surface temperature (SST) estimations has been developed from 23 taxa and taxa groups in 53 surface sediment samples recovered between 35° and 72°S in the Atlantic sector of the Southern Ocean. For the selection of taxa and taxa groups ecological information from water column studies was considered. The transfer function allows the estimation of austral summer SST (December-March) ranging between -1 and 18°C with a standard error of estimate of 1.2°C. SST estimates from selected late Pleistocene squences were sucessfully compared with independend paleotemperature estimates derived from a diatom transfer function. This shows that radiolarians provide an excellent tool for paleotemperature reconstructions in Pleistocene sediments of the Southern Ocean.

Distribution of deep-sea meiobenthos in surface sediments off North Carolina

Observations on the ecology and distribution of meiofauna occurring on the outer continental shelf and continental slope at depths from 50 to 2500 m in the region where the Blake Plateau cuts across the North Carolina slope are reported. Total numbers of meiofauna ranged from 151/100 cm**3 of sediment at 400 m to 1196/100 cm**3 of sediment at 250 m. Sediments of the upper region (50-500 m) consisted of medium-sized calcareous sands with relatively low organic carbon contents, while the deeper sediments (600-2500 m) consisted of sandy silts and silts with organic carbon contents 6-10 times that of the shallower sediments. Two basic faunas appear to be present in the areas investigated; a shallow-water fauna extending from 50 to 500 m and a deep-water fauna from 800 to 2500 m. The shallow-water fauna consists of nematodes (the dominant taxon) and relatively large numbers of harpactacoid copepods, ostracods, benthic foraminifera, polychaetes, gastrotrichs and several other groups, while below 500 m only nematodes and foraminifera are present in large numbers, the latter being especially abundant between 800 and 2000 m. A major change in the meiofauna occurs on the Blake Plateau between the depths of approximately 400-500 m and 600-750 m where the composition of the sediment changes from sand to silty sand. From 50 m to 400-500 m gastrotrichs, turbellaria, tardigrades, kinorhynchs, halicarids, hydrozoans, gnathostomulids, lamellibranchs and cumaceans are commonly encountered; these groups are absent below 500 m. In addition, there are significant reductions in the numbers of harpactacoids, ostracods, nemerteans and polychaetes below 500 m. Examination of the nematode population also show faunal differences between the shallower sediments (50-500 m) and the deeper sediments (600-2500 m). High indices of affinity exist among the faunas between 50 and 500 m and among the faunas between 800 and 2500 m; the fauna at 600-750 m represents a transition between these two regions, but it is more closely related to the deep-water fauna. Changes in the distribution of both the total meiofuna and also the nematodes are highly correlated with changes in sediments composition and bottom water temperatures. It is suggested that changes in grain size and accompanying changes in sources of nutrition, which are the results of Gulf Stream and other current activity, are the dominant environmental factors influencing the meiofauna of the area.

Geochemistry and microfossil content of surface sediments from the Equatorial Atlantic in samples 207 to 310 from the Meteor expedition in 1925

Als Alfred Merz mich aufforderte, die sedimentpetrographische Bearbeitung der "Meteor"-Expedition zu übernehmen, schwebte mir von vornherein als Ziel vor, die Sedimente nicht nur in größerer Zahl als bisher und im Zusammenhang mit den übrigen Wissenschaften vom Meer nach den bisherigen Untersuchungsmethoden zu beschreiben. Es war mir klar, daß neue Ergebnisse nur zu erwarten waren, wenn die Untersuchung der Sedimente und damit ihre Beschreibung auf Grund vertiefter und neuer Methoden unternommen wurde. Ich erhoffte von einer solchen verfeinerten Beschreibung auch ein klareres Bild der Abhängigkeit der Sedimente von ihrer Umwelt. Wir werden diese Abhängigkeit nur verstehen, wenn wir die allgemeinen Gesetzmäßigkeiten herausarbeiten können. Diese werden dann auch eine Anwendung auf andere Sedimente ermöglichen. Für solche Untersuchungen sind Tiefseesedimente günstig, weil wir bei ihnen relativ einfache Bildungsumstände haben, einfacher jedenfalls, als es in der Flachsee im allgemeinen der Fall ist, ungünstig aber, weil diese Umwelteinflüsse weniger bekannt und schwerer zu erforschen sind und die Auswahl der Untersuchungspunkte nicht nach sedimentpetrographischen Gesichtspunkten erfolgen konnte. Die ersten Jahre nach der Rückkehr von der Expedition wurden deshalb auf methodische Untersuchungen verwandt. Insbesondere kam es mir darauf an herauszubekommen, wie die feinsten Bestandteile der Sedimente zusammengesetzt sind. Diese "tonigen" Bestandteile bilden nicht nur den wesentlichen Anteil der Roten Tone und der Blauschlicke, wir finden sie auch, durch Kalk verdünnt, in den Globigerinenschlämmen wieder. Sie sind von der Wissenschaft bisher recht stiefmütterlich behandelt worden. Die Ausarbeitung der Methoden, die gerade auf diesem Gebiet Neuland betreten mußte, ließ sich nicht rasch erzwingen. Es kam hinzu, daß ich mir in Rostock erst meine Arbeitsmöglichkeiten schaffen mußte. Ich habe hier der Notgemeinschaft der Deutschen Wissenschaft und der Mecklenburgischen Regierung für ihre Unterstützung mit Apparaten und Personal wärmstens zu danken. Ferner mußte als Vorbedingung für die Deutung der Sedimente zunächst festgestellt werden, zu welchen geologischen Zeiten sie gebildet worden sind und wie groß ihre Bildungsgeschwindigkeit überhaupt ist. Diese Untersuchungen hat W. Schott mit Hilfe der Foraminiferenfaunen als Notgemeinschaftsstipendiat durchgeführt. Diese Vorarbeiten, insbesondere der Ausbau der Methoden, hatten den Nachteil, daß die Veröffentlichung der Ergebnisse nicht so rasch erfolgen konnte, wie ich es selbst gewünscht hätte. Bald nachdem die Darstellung der Methoden und die Foraminiferenuntersuchungen als erste Lieferung erschienen waren, stellte es sich als notwendig heraus, eine beträchtliche Kürzung des restlichen Teiles vorzunehmen. Das hat zur Folge, daß die erste Lieferung breiter dargestellt ist als die Ergebnisse. Als die Nachricht von der Kürzung und dem notwendigen raschen Abschluß des Werkes mir bekannt wurde (Januar 1935), mußte eine Reihe von Untersuchungen eingestellt werden, insbesondere mikroskopische Untersuchungen, die besonders viel Zeit und in der Darstellung viel Raum beanspruchen. Deshalb ist systematisch nur das Guinea-Becken durch V. Leinz und das Kapverden-Becken durch O. E. Radczewski untersucht worden.

Glacial North Atlantic: Sea surface conditions reconstructed by GLAMAP 2000

The response of the tropical ocean to global climate change and the extent of sea ice in the glacial nordic seas belong to the great controversies in paleoclimatology. Our new reconstruction of peak glacial sea surface temperatures (SSTs) in the Atlantic is based on census counts of planktic foraminifera, using the Maximum Similarity Technique Version 28 (SIMMAX-28) modern analog technique with 947 modern analog samples and 119 well-dated sediment cores. Our study compares two slightly different scenarios of the Last Glacial Maximum (LGM), the Environmental Processes of the Ice Age: Land, Oceans, Glaciers (EPILOG), and Glacial Atlantic Ocean Mapping (GLAMAP 2000) time slices. The comparison shows that the maximum LGM cooling in the Southern Hemisphere slightly preceeded that in the north. In both time slices sea ice was restricted to the north western margin of the nordic seas during glacial northern summer, while the central and eastern parts were ice-free. During northern glacial winter, sea ice advanced to the south of Iceland and Faeroe. In the central northern North Atlantic an anticyclonic gyre formed between 45° and 60°N, with a cool water mass centered west of Ireland, where glacial cooling reached a maximum of >12°C. In the subtropical ocean gyres the new reconstruction supports the glacial-to-interglacial stability of SST as shown by CLIMAP Project Members (CLIMAP) [1981]. The zonal belt of minimum SST seasonality between 2° and 6°N suggests that the LGM caloric equator occupied the same latitude as today. In contrast to the CLIMAP reconstruction, the glacial cooling of the tropical east Atlantic upwelling belt reached up to 6°-8°C during Northern Hemisphere summer. Differences between these SIMMAX-based and published U37[k]- and Mg/Ca-based equatorial SST records are ascribed to strong SST seasonalities and SST signals that were produced by different planktic species groups during different seasons.

Half-degree gridded nitrogen and phosphorus fertilizer use for global agriculture production during 1900-2013

In addition to enhance agricultural productivity, synthetic nitrogen (N) and phosphorous (P) fertilizer application in croplands dramatically altered global nutrient budget, water quality, greenhouse gas balance, and their feedbacks to the climate system. However, due to the lack of geospatial fertilizer input data, current Earth system/land surface modeling studies have to ignore or use over-simplified data (e.g., static, spatially uniform fertilizer use) to characterize agricultural N and P input over decadal or century-long period. We therefore develop a global time-series gridded data of annual synthetic N and P fertilizer use rate in croplands, matched with HYDE 3,2 historical land use maps, at a resolution of 0.5º latitude by longitude during 1900-2013. Our data indicate N and P fertilizer use rates increased by approximately 8 times and 3 times, respectively, since the year 1961, when IFA (International Fertilizer Industry Association) and FAO (Food and Agricultural Organization) survey of country-level fertilizer input were available. Considering cropland expansion, increase of total fertilizer consumption amount is even larger. Hotspots of agricultural N fertilizer use shifted from the U.S. and Western Europe in the 1960s to East Asia in the early 21st century. P fertilizer input show the similar pattern with additional hotspot in Brazil. We find a global increase of fertilizer N/P ratio by 0.8 g N/g P per decade (p< 0.05) during 1961-2013, which may have important global implication of human impacts on agroecosystem functions in the long run. Our data can serve as one of critical input drivers for regional and global assessment on agricultural productivity, crop yield, agriculture-derived greenhouse gas balance, global nutrient budget, land-to-aquatic nutrient loss, and ecosystem feedback to the climate system.