Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Radiolarians from the Southwest Pacific

Radiolarians are very rare in all Leg 90 sites. They are relatively more frequent only in Neogene sediments from Sites 586 and 594, and in Eocene sediments at Site 592. In this chapter radiolarian abundances are recorded as comparative percentages for 92 Neogene morphotypes at Site 586B. Relative abundances only are estimated at Sites 592 and 594, where preservation is poor to moderate. A tentative correlation of radiolarian events at Hole 586B and Site 594 shows that only a few species can be found in both tropical and subantarctic areas. New evolutionary lineages are proposed. 1. Middle Miocene eucyrtids like Eucyrtidium teuscheri group evolved into a widespread species (E. teuscheri teuscheri) ranging from middle Miocene to Holocene and a temperate species (E. teuscheri orthoporus) ranging from middle Miocene to early Pleistocene. 2. Phormostichoartus pitomorphus appears to be a temperate descendant of the cosmopolitan P. fistula and disappears in early Pleistocene time. 3. The discovery of Lamprocyrtis daniellae n.sp. calls into question the lineage L. heteroporos -> L. nigriniae. 4. The evolution of Lamprocyclas maritalis from an ancestor group (L. aff. maritalis) is located in the early part of the Pterocanium prismatium Zone.

Seawater carbonate chemistry, the abiotic conditions in the fluid surrounding the embryo, growth, calcification of the cuttlefish Sepia officinalis in a laboratory experiment

This study investigated the effects of seawater pH (i.e., 8.10, 7.85 and 7.60) and temperature (16 and 19 °C) on (a) the abiotic conditions in the fluid surrounding the embryo (viz. the perivitelline fluid), (b) growth, development and (c) cuttlebone calcification of embryonic and juvenile stages of the cephalopod Sepia officinalis. Egg swelling increased in response to acidification or warming, leading to an increase in egg surface while the interactive effects suggested a limited plasticity of the swelling modulation. Embryos experienced elevated pCO2 conditions in the perivitelline fluid (>3-fold higher pCO2 than that of ambient seawater), rendering the medium under-saturated even under ambient conditions. The growth of both embryos and juveniles was unaffected by pH, whereas 45Ca incorporation in cuttlebone increased significantly with decreasing pH at both temperatures. This phenomenon of hypercalcification is limited to only a number of animals but does not guarantee functional performance and calls for better mechanistic understanding of calcification processes.

Organic geochemistry of sediments at DSDP Legs 56-57 Holes

The quantity, type, and maturity of the organic matter of Quaternary and Tertiary sediments from the Japan Trench (DSDP Leg 56, Sites 434 and 436; and Leg 57, Sites 438, 439 and 440) were determined. The hydrocarbons in lipid extracts were analyzed by capillary- column gas chromatography and combined gas chromatography/ mass spectrometry. Kerogen concentrates were investigated by microscopy, and vitrinite-reflectance values were determined. Measured organic-carbon values were in the range of 0.13 to 1.00 per cent. Extract yields, however, were extremely low. Normalized to organic carbon, total extracts ranged from 4.1 to 15.7 mg/g Corg. Gas chromatography of non-aromatic hydrocarbons showed that all sediments, except one Oligocene sample, contained very immature, mainly terrigenous organic material. This was indicated by n-alkane maxima at C29 and C31 and high odd-carbon-number predominances. Unsaturated steroid hydrocarbons were found to be major cyclic compounds in lower- and middle-Miocene samples from the upper inner trench slope (Sites 438 and 439). Perylene was the dominating aromatic hydrocarbon in all but the Oligocene sample. Microscopy showed kerogens rich in terrigenous organic particles, with a major portion of recycled vitrinite. Nevertheless, almost all the liptinite particles appeared to be primary. This is a paradox, as the bulk of the samples were composed of hemipelagic mineral matter with a major siliceous biogenic (planktonic) component. A trend of reduced size and increased roundness can be seen for the vitrinite/ inertinite particles from west to east (from upper inner trench slope to outer trench slope). All sediments but one are relatively immature, with mean huminite-reflectance values (Ro)in the range of 0.30 to 0.45 per cent. The oldest and deepest sediment investigated, an Oligocene sandstone from Site 439, yielded a mean vitrinitereflectance value of 0.74 per cent and a mature n-alkane distribution. This sample may indicate a geothermal event in late Oligocene time. It failed to affect the overlying lower Miocene and may have been caused by an intrusion. Boulders of acidic igneous rocks in the Oligocene can be interpreted as witnesses of nearby volcanic activity accompanied by intrusions.

(Table S1) Age determination of Atlantic Ocean sediment cores

Well-dated benthic foraminifer oxygen isotopic records (d18O) from different water depths and locations within the Atlantic Ocean exhibit distinct patterns and significant differences in timing over the last deglaciation. This has two implications: on the one hand, it confirms that benthic d18O cannot be used as a global correlation tool with millennial-scale precision, but on the other hand, the combination of benthic isotopic records with independent dating provides a wealth of information on past circulation changes. Comparing new South Atlantic benthic isotopic data with published benthic isotopic records, we show that (1) circulation changes first affected benthic d18O in the 1000-2200 m range, with marked decreases in benthic d18O taking place at ~17.5 cal. kyr B.P. (ka) due to the southward propagation of brine waters generated in the Nordic Seas during Heinrich Stadial 1 (HS1) cold period; (2) the arrival of d18O-depleted deglacial meltwater took place later at deeper North Atlantic sites; (3) hydrographic changes recorded in North Atlantic cores below 3000 m during HS1 do not correspond to simple alternations between northern- and southern-sourced water but likely reflect instead the incursion of brine-generated deep water of northern as well as southern origin; and (4) South Atlantic waters at ~44°S and ~3800 m depth remained isolated from better-ventilated northern-sourced water masses until after the resumption of North Atlantic Deep Water (NADW) formation at the onset of the Bølling-Allerod, which led to the propagation of NADW into the South Atlantic.

Seismic reflection data, calcium/iron ratios, stable istopes, and magnetic susceptibility of sediment cores from the Pen Duick Escarpment, Gulf of Cadiz

Here we present a case study of three cold-water coral mounds in a juvenile growth stage on top of the Pen Duick Escarpment in the Gulf of Cadiz; Alpha, Beta and Gamma mounds. Although cold-water corals are a common feature on the adjacent cliffs, mud volcanoes and open slope, no actual living cold-water coral has been observed. This multidisciplinary and integrated study comprises geophysical, sedimentological and (bio)geochemical data and aims to present a holistic view on the interaction of both environmental and geological drivers in cold-water coral mound development in the Gulf of Cadiz. Coring data evidences (past or present) methane seepage near the Pen Duick Escarpment. Several sources and pathways are proposed, among which a stratigraphic migration through uplifted Miocene series underneath the escarpment. The dominant morphology of the escarpment has influenced the local hydrodynamics within the course of the Pliocene, as documented by the emplacement of a sediment drift. Predominantly during post-Middle Pleistocene glacial episodes, favourable conditions were present for mound growth. An additional advantage for mound formation near the top of Pen Duick Escarpment is presented by seepage-related carbonate crusts which might have offered a suitable substrate for coral settling. The spatially and temporally variable character and burial stage of the observed open reef frameworks, formed by cold-water coral rubble, provides a possible model for the transition from cold-water coral reef patches towards juvenile mound. These rubble "graveyards" not only act as sediment trap but also as micro-habitat for a wide range of organisms. The presence of a fluctuating Sulphate-Methane Transition Zone has an important effect on early diagenetic processes, affecting both geochemical and physical characteristics, transforming the buried reef into a solid mound. Nevertheless, the responsible seepage fluxes seem to be locally variable. As such, the origin and evolution of the cold-water coral mounds on top of the Pen Duick Escarpment is, probably more than any other NE Atlantic cold-water coral mound province, located on the crossroads of environmental (hydrodynamic) and geological (seepage) pathways.

Global distributions of diazotrophs nitrogen fixation rates - Depth integrated values computed from a collection of source datasets - Contribution to the MAREDAT World Ocean Atlas of Plankton Functional Types

The MAREDAT atlas covers 11 types of plankton, ranging in size from bacteria to jellyfish. Together, these plankton groups determine the health and productivity of the global ocean and play a vital role in the global carbon cycle. Working within a uniform and consistent spatial and depth grid (map) of the global ocean, the researchers compiled thousands and tens of thousands of data points to identify regions of plankton abundance and scarcity as well as areas of data abundance and scarcity. At many of the grid points, the MAREDAT team accomplished the difficult conversion from abundance (numbers of organisms) to biomass (carbon mass of organisms). The MAREDAT atlas provides an unprecedented global data set for ecological and biochemical analysis and modeling as well as a clear mandate for compiling additional existing data and for focusing future data gathering efforts on key groups in key areas of the ocean. The present data set presents depth integrated values of diazotrophs nitrogen fixation rates, computed from a collection of source data sets.