Woods Hole Oceanographic Institution

About: Woods Hole Oceanographic Institution is a nonprofit organization based out in Falmouth, Massachusetts, United States. It is known for research contribution in the topics: Population & Mantle (geology). The organization has 5685 authors who have published 18396 publications receiving 1202050 citations. The organization is also known as: WHOI.

Metal Stable Isotopes in Paleoceanography

Abstract: Considered esoteric only a few years ago, research into the stable isotope geochemistry of transition metals is moving into the geoscience mainstream. Although initial attention focused on the potential use of some of these nontraditional isotope systems as biosignatures, they are now emerging as powerful paleoceanographic proxies. In particular, the Fe and Mo isotope systems are providing information about changes in oxygenation and metal cycling in ancient oceans. Zn, Cu, Tl, and a number of other metals and metalloids also show promise. Here we review the basis of stable isotope fractionation as it applies to these elements, analytical considerations, and the current status and future prospects of this rapidly developing research area.

Annual biogenic particle fluxes to the interior of the North Atlantic Ocean; studied at 34°N 21°W and 48°N 21°W

Abstract: In order to clarify the annual quality, quantity and export processes of biogenic particles from the euphotic zone to the deep ocean interior, an array of automated time-series sediment traps were deployed for 1 year from 4 April 1989 to 17 April 1990 at 34°N 21°W and 48°N 21°W as part of the Joint Global Ocean Flux Program (JGOFS) North Atlantic Bloom Experiment (NABE). Three sediment traps with 13 time-series sediment collectors were placed at both stations approximately 1 and 2 km below the surface and 0.7 km above the bottom. They collected settling particles during 26 14-day intervals for 376 days with an 20-day hiatus in September-October 1989 for changeover of the trap moorings. The collection periods of the six traps were synchronized, forming a spatio-temporal matrix of 156 samples. The annual mass flux at about 2 km deep during this experiment was 22 and 27 g m−2 y−1 at the 34 and 48°N stations, consisting of biogenic particles with traceable quantities of lithogenic particle flux. The spring particle bloom, characterized by the sedimentation of particles relatively enriched by Norg, began in January at the 34°N station and in March at the 48°N station. The bloom continued for 4.5 and 3 months and provided 62 and 50% of the annual biogenic particle mass flux at 2 km at the 34 and 48°N stations. The surface bloom penetrated to the ocean interior within a few weeks, with apparently accelerated settling speed at deeper layers. The order of susceptibility of biogenic elements to mineralization while settling in the 0.7–1 km a.b. water column was, from least to most resistant: P, Norg, Corg, Si and Ca. The C/N/P ratio at 0.7 km a.b. was 154:18:1 at the 34°N station and 148:18:1 at the 48°N station.

Testing the Cretaceous greenhouse hypothesis using glassy foraminiferal calcite from the core of the Turonian tropics on Demerara Rise

Abstract: Glassy Turonian foraminifera preserved in clay-rich sediments from the western tropical Atlantic yield the warmest equivalent ?18O sea-surface temperatures (SSTs) yet reported for the entire Cretaceous-Cenozoic. We estimate Turonian SSTs that were at least as warm as (conservative mean ~30 °C) to significantly warmer (warm mean ~33 °C) than those in the region today. However, if independent evidence for high middle Cretaceous pCO2 is reliable and resulted in greater isotopic fractionation between seawater and calcite because of lower sea-surface pH, our conservative and warm SST estimates would be even higher (32 and 36 °C, respectively). Our new tropical SSTs help reconcile geologic data with the predictions of general circulation models that incorporate high Cretaceous pCO2 and lend support to the hypothesis of a Cretaceous greenhouse. Our data also strengthen the case for a Turonian age for the Cretaceous thermal maximum and highlight a 20–40 m.y. mismatch between peak Cretaceous-Cenozoic global warmth and peak inferred tectonic CO2 production. We infer that this mismatch is either an artifact of a hidden Turonian pulse in global ocean-crust cycling or real evidence of the influence of some other factor on atmospheric CO2 and/or SSTs. A hidden pulse in crust cycling would explain the timing of peak Cretaceous-Cenozoic sea level (also Turonian), but other factors are needed to explain high-frequency (~10–100 k.y.) instability in middle Cretaceous SSTs reported elsewhere.

Some biochemical and physiological aspects of growth and gametogenesis in Crassostrea gigas and Ostrea edulis grown at sustained elevated temperatures.

Abstract: Crassostrea gigas (Thunberg) and Ostrea edulis L. were grown at sustained temperatures of 12°, 15°, 18° and 21°C for a period of 19 weeks. Regular assays of weight specific ammonia excretion rate were made, following which animals were sacrificed for estimation of dry meat weight, dry shell weight, biochemical composition (percentage carbon, nitrogen, carbohydrate, ash) and gonadal development (histological assessment). Crassostrea gigas grew from an intial live weight of 5·2 g to values of 23·5, 28·2, 34·6 and 38·7 g at 120, 150, 180 and 21 °C respectively.

Climate change and coral reef connectivity

Abstract: This review assesses and predicts the impacts that rapid climate change will have on population connectivity in coral reef ecosystems, using fishes as a model group. Increased ocean temperatures are expected to accelerate larval development, potentially leading to reduced pelagic durations and earlier reef-seeking behaviour. Depending on the spatial arrangement of reefs, the expectation would be a reduction in dispersal distances and the spatial scale of connectivity. Small increase in temperature might enhance the number of larvae surviving the pelagic phase, but larger increases are likely to reduce reproductive output and increase larval mortality. Changes to ocean currents could alter the dynamics of larval supply and changes to planktonic productivity could affect how many larvae survive the pelagic stage and their condition at settlement; however, these patterns are likely to vary greatly from place-to-place and projections of how oceanographic features will change in the future lack sufficient certainty and resolution to make robust predictions. Connectivity could also be compromised by the increased fragmentation of reef habitat due to the effects of coral bleaching and ocean acidification. Changes to the spatial and temporal scales of connectivity have implications for the management of coral reef ecosystems, especially the design and placement of marine-protected areas. The size and spacing of protected areas may need to be strategically adjusted if reserve networks are to retain their efficacy in the future.