Shell size, body mass and average pO2 in mantle cavity water of different marine mollusc species

Marine invertebrates with open circulatory system establish low and constant oxygen partial pressure (Po2) around their tissues. We hypothesized that as a first step towards maintenance of low haemolymph and tissue oxygenation, the Po2 in molluscan mantle cavity water should be lowered against normoxic (21 kPa) seawater Po2, but balanced high enough to meet the energetic requirements in a given species. We recorded Po2 in mantle cavity water of five molluscan species with different lifestyles, two pectinids (Aequipecten opercularis, Pecten maximus), two mud clams (Arctica islandica, Mya arenaria), and a limpet (Patella vulgata). All species maintain mantle cavity water oxygenation below normoxic Po2. Average mantle cavity water Po2 correlates positively with standard metabolic rate (SMR): highest in scallops and lowest in mud clams. Scallops show typical Po2 frequency distribution, with peaks between 3 and 10 kPa, whereas mud clams and limpets maintain mantle water Po2 mostly <5 kPa. Only A. islandica and P. vulgata display distinguishable temporal patterns in Po2 time series. Adjustment of mantle cavity Po2 to lower than ambient levels through controlled pumping prevents high oxygen gradients between bivalve tissues and surrounding fluid, limiting oxygen flux across the body surface. The patterns of Po2 in mantle cavity water correspond to molluscan ecotypes.

Geochemistry and lithology of clayey nannofossil ooze turbidites and hemipelagites at ODP Holes 135-834A and 135-835A

The western Lau Basin, between the Central and Eastern Lau Spreading Centers and the Lau Ridge, contains several small, elongate, fault-bounded, partially sediment-filled sub-basins. Sites 834 and 835 were drilled in the oldest part of the Lau Basin in two of these small extensional basins close to the Lau Ridge, formed on late Miocene to early Pliocene oceanic crust. Both sites show a similar sediment sequence that consists of clayey nannofossil oozes and mixed sediments interbedded with epiclastic vitric sands and silts. The vitric sands and silts are largely restricted to the deeper part of the sediment column (early Pliocene-late Pliocene), and the upper part of the sediment column at both sites consists of a distinctive sequence of brown clayey nannofossil ooze, stained by iron and manganese oxyhydroxides (late Pliocene-Holocene). However, the clayey nannofossil ooze sequence at Site 835 is anomalously thick and contains several medium- to very thick beds of matrix-supported, mud-clast conglomerate (interpreted as muddy debris-flow deposits), together with large amounts of redeposited clayey nannofossil ooze and coherent rafted blocks of older hemipelagic material. Redeposited clayey nannofossil oozes can be distinguished from hemipelagic nannofossil oozes using several sedimentological criteria. These include variation in color hue and chroma, presence or absence of bioturbation, presence or absence of scattered foraminifers, grain-size characteristics, variability in calcium carbonate content, presence or absence of pumice clasts, and micropaleontology. Clayey nannofossil ooze turbidites and hemipelagites are also geochemically distinct, with the turbidites being commonly enriched in Mn, Ni, Pb, Zn, Cr, and P. The sediment sequence at Site 835 is dominated by allochthonous sediments, either muddy debris-flow deposits, coherent rafted blocks, or thick clayey nannofossil ooze turbidites. Since 2.9 Ma, only 25% of the 133 m of sediments deposited represents hemipelagic deposition, with an average sedimentation rate of 1.5 cm/k.y.. Allochthonous sediments were the main sediment type deposited during the Brunhes geomagnetic Epoch and make up 80% of the thickness of sediment deposited during this period. Short intervals of mainly hemipelagic deposition occurred from 0.4 to 0.9 Ma, 1.0 to 1.4 Ma, and 1.7 to 2.1 Ma. However, allochthonous sediments were again the dominant sediment type deposited between 2.1 and 2.5 Ma, with a large slide complex emplaced around 2.5 Ma. We conclude that the adjacent high ground, surrounding the basin in which Site 835 was drilled, was affected by marked instability throughout the late Pliocene and Pleistocene. In contrast, sedimentation at Site 834 during this period has been dominated by hemipelagic deposition, with redeposited sediments making up slightly less than 17% of the total thickness of sediment deposited since 2.3 Ma. However, there was a marked increase in frequency and magnitude of redeposited sediments at around 0.2 Ma at Site 834, which broadly corresponds to the onset of a major episode of turbidite and debris-flow emplacement beginning about 0.4 Ma at Site 835. This episode of instability at both sites may be the effect of the approach and passing of the Central Lau propagator at the latitude of Sites 834 and 835 at about 0.5 Ma.

(Table 1) Abundance of diagenetic carbonate nodules in bottom sediments from the Gulf of California at Station DM9-666

New data on phosphorites collected by dredging and trawling at depths from 2700 to 520 m in the open Atlantic Ocean (i.e. outside of the shelf and the continental slope) are reported. Aphanitic, granular, brecciated, and conglomerate-like types are distinguished among the phosphorites. A comparison of the studied phosphorites with ones from the Atlantic shelf of Africa and from seamounts of other oceans is made.

Distribution of molluscs on the Atlantic continental shelf off Southern Spanish Sahara, West Africa

Two hundred and seventy five mollusc species from the continental shelf off Southern Spanish Sahara (depth: 32-60 m) were identified. Their distribution pattern is strongly influenced by the nature of the bottom (firm substrate, shelter, stability of sediment) rather than other factors at that depth interval. This faunal assemblage shows great affinity to the Mediterranean and Lusitanian faunas, and comprises only few (22 %) exclusively Senegalese and species living south of Senegal.

Chemical composition of rhyolites of ODP Site 103-639

Holes 639E and 639F were drilled along the western slope of a tilted fault block in an attempt to recover complete syn- and pre-rift stratigraphic sections and continental basement. Both holes ended in an apparent talus pile or conglomerate that includes cobbles of altered rhyolitic rock. Three small pieces of rhyolite (comprising about 20 cm of sample) were recovered from the bottoms of Holes 639E and 639F in the core catchers of the deepest cores. This note presents geochemical data from these rhyolitic rocks. Also recovered were quartz sandstones, graywackes, metasandstones, and quartz breccias. This assemblage of continentally derived 'basement' material was overlain by mudstones, limestones, and crystalline dolomites (see 'Site 639' chapter; Shipboard Scientific Party, 1987, doi:10.2973/odp.proc.ir.103.110.1987).

Description of lithofacies associations and their interpreted settings from sequences of sediment core CRP-1 (Table 2)

Cape Roberts Project drillcore 1 was obtained from Roberts Ridge, a sea-floor high located at 77°S, 16 km offshore from Cape Roberts in western McMurdo Sound, Antarctica. The recovered core is about 147 m long with the upper 43.15 metres below the sea floor (revised figure) being dated as Quarternary and the older part of the sequence being Miocene. The core includes nine facies: sandy diamict, muddy diamict, gravel/conglomerate, mud(stone), clay(stone) and carbonate. These facies occure in associations that are repeated in particulare sequences throughout the core, and are interpreted as representing different depositional environments through time. Seven lithofacies associations are interpreted as representing offshore shelf, ice protected/below wave-base; prodeltaic/offshore shelf; delta front/sandy shelf; ice system; subglacial till/rainout diamict/debris flow diamicts singly or in combination; and a carbonate-rich shelf bank. The facies associations are used to infer that the Quaternary section represents deposition on a polar shelf with perhaps two or three glacial fluctuations. The Quaternary carbonate unit indicates a period of ice sheet retreat, but local glacial activity may have increased with an increase in costal precipitation. The Miocene section represents polythermal glacial systems. The older Miocene section is glacially dominated whereas the younger section is much less so. The glacially dominated section may provide evidence for a major glacial advance thar resulted un a low stand of global eustatic sea level at that time. After the low stand, eustatic sea level was gradually rising during deposition of the younger section dominated more by non-glacial processes.

The Idler magazine.

Editors: v. 1-5, Feb. 1892-July 1894, Jerome K. Jerome and Robert Barr.

Modified final judgement : hearings before the Subcommittee on Communications of the Committee on Commerce, Science, and Transportation, United States Senate, One Hundredth Congress, first session ... December 10 and 11, 1987.

Includes bibliographical references.

Early-Middle Jurassic stratigraphy of the Fortrose-Chaslands region, southernmost South Island, New Zealand

The 40 km of coastline from Fortrose to Chaslands Mistake (southeastern South Island, New Zealand) comprises sediments that are part of the Early-Middle Jurassic of the Murihiku Terrane. The sediments are dominantly fluvial with some marine beds and alluvial fan deposition, and display an evolution of fluvial style which progresses from perennial flow to seasonal flow. The McPhee Cove Conglomerate is a prominent unit to the north. It has been used to separate two formations which would otherwise, on inherent lithological grounds, be difficult to distinguish. This paper discusses several similar conglomerates which occur in the south, but which are separated from the type area of the McPhee Conglomerate by major tectonic disruption. Hence, the existing lithostratigraphic nomenclature to the north, including the McPhee Cove Conglomerate, cannot be simply extended southwards. The Fortrose-Chaslands area appears to consist of two tectonic blocks, the Slope Point Block and the Brothers Block, which are separated from each other and from the adjacent Papatowai Block by major strike faults (or fault zones). A change is proposed to the existing stratigraphy which involves recognising all terrestrial sediments as part of the False Island Formation. Four prominent clast-supported conglomerate horizons are named as members of the False Islet Formation: the White Head Conglomerate, Black Bluff Conglomerate. Hoiho Conglomerate, and Slope Point Conglomerate Members. The latter contains five named conglomerate beds.

Microspectrophotometry of visual pigments and oil droplets in a marine bird, the wedge-tailed shearwater Puffinus pacificus: Topographic variations in photoreceptor spectral characteristics

Microspectrophotometric examination of the retina of a procellariiform marine bird, the wedge-tailed shearwater Puffinus pacificus, revealed the presence of five different types of vitamin A(1)-based visual pigment in seven different types of photoreceptor. A single class of rod contained a medium-wavelength sensitive visual pigment with a wavelength of maximum absorbance (lambda(max)) at 502 nm. Four different types of single cone contained visual pigments maximally sensitive in either the violet (VS, lambda(max) 406 nm), short (SWS, lambda(max) 450 nm), medium (MWS, lambda(max) 503 nm) or long (LWS, lambda(max) 566 nm) spectral ranges. In the peripheral retina, the SWS, MWS and LWS single cones contained pigmented oil droplets in their inner segments with cut-off wavelengths (lambda(cut)) at 445 (C-type), 506 (Y-type) and 562 nm (R-type), respectively. The VS visual pigment was paired with a transparent (T-type) oil droplet that displayed no significant absorption above at least 370 run. Both the principal and accessory members of the double cone pair contained the same 566 nm lambda(max) visual pigment as the LWS single cones but only the principal member contained an oil droplet, which had a lambda(cut) at 413 nm. The retina had a horizontal band or 'visual streak' of increased photoreceptor density running across the retina approximately 1.5 mm dorsal to the top of the pecten. Cones in the centre of the horizontal streak were smaller and had oil droplets that were either transparent/colourless or much less pigmented than at the periphery. It is proposed that the reduction in cone oil droplet pigmentation in retinal areas associated with high visual acuity is an adaptation to compensate for the reduced photon capture ability of the narrower photoreceptors found there. Measurements of the spectral transmittance of the ocular media reveal that wavelengths down to at least 300 nm would be transmitted to the retina.

The mysterious case of Carter Brown: Or, who really killed the Australian author?

Considers the exporting of intellectual property and the ways Sydney publisher Horwits Publications, author Alan Geoffrey Yates and multinational conglomerate Signet negotiated geographical and cultural boundaries to produce one of Australia's successful literary exports. Evolution of Australian paperback publishers to hardcover publishers; Details of a contract for Yates' Peter Carter Brown novels; Procedure followed in editing novels of Yates submitted to Horwitz and Signet; Marketing campaign for Signet in the U.S.; Impact of the pressure of writing deadlines on the quality of the novels.

Accumulation and fate of mercury in an Everglades aquatic food web

This project examined the pathways of mercury (Hg) bioaccumulation and its relation to trophic position and hydroperiod in the Everglades. I described fish-diet differences across habitats and seasons by analyzing stomach contents of 4,000 fishes of 32 native and introduced species. Major foods included periphyton, detritus/algal conglomerate, small invertebrates, aquatic insects, decapods, and fishes. Florida gar, largemouth bass, pike killifish, and bowfin were at the top of the piscine food web. Using prey volumes, I quantitatively classified the fishes into trophic groups of herbivores, omnivores, and carnivores. Stable-isotope analysis of fishes and invertebrates gave an independent and similar assessment of trophic placement. Trophic patterns were similar to those from tropical communities. I tested for correlations of trophic position and total mercury. Over 4,000 fish, 620 invertebrate, and 46 plant samples were analyzed for mercury with an atomic-fluorescence spectrometer. Mercury varied within and among taxa. Invertebrates ranged from 25–200 ng g −1 ww. Small-bodied fishes varied from 78–>400 ng g −1 ww. Large predatory fishes were highest, reaching a maximum of 1,515 ng−1 ww. Hg concentrations in both fishes and invertebrates were positively correlated with trophic position. I examined the effects of season and hydroperiod on mercury in wild and caged mosquitofish at three pairs of marshes. Nine monthly collections of wild mosquitofish were analyzed. Hydroperiod-within-site significantly affected concentrations but it interacted with sampling period. To control for wild-fish dispersal, and to measure in situ uptake and growth, I placed captive-reared, neonate mosquitofish with mercury levels from 7–14 ng g−1 ww into field cages in the six study marshes in six trials. Uptake rates ranged from 0.25–3.61 ng g−1 ww d −1. As with the wild fish, hydroperiod-within-site was a significant main effect that also interacted with sampling period. Survival exceeded 80%. Growth varied with season and hydroperiod, with greatest growth in short-hydroperiod marshes. The results suggest that dietary bioaccumulation determined mercury levels in Everglades aquatic animals, and that, although hydroperiod affected mercury uptake, its effect varied with season. ^

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.