(Table T1) Density, porosity, void ratio, diffusivity and permeability of ODP Site 185-1149 sediments

The subduction of oceanic plates regulates crustal growth, influences arc volcanism, and refertilizes the mantle. Continental growth occurs by subduction of crustal material (seawater components, marine sediments, and basaltic crust). The geochemical and physical evolution of the Earth's crust depends, in large part, on the fate of subducted material at convergent margins (Armstrong, 1968, doi:10.1029/RG006i002p00175; Karig and Kay, 1981, 10.1098/rsta.1981.0108). The crustal material on the downgoing plate is recycled to various levels in the subduction zone. The recycling process that takes place in the "Subduction Factory" is difficult to observe directly but is clearly illuminated using chemical tracers. Von Huene and Scholl (1991, doi:10.1029/91RG00969) and Plank and Langmuir (1993, doi:10.1038/362739a0) preliminarily calculated a large flux of subducted materials. By mass balancing the chemical tracers and measuring the fractionations that occur between them, the Subduction Factory work and the effect on the Earth's evolution can be estimated. In order to elucidate this mass balance, Ocean Drilling Program Leg 185 drilled two deepwater shales into the oceanic crust situated in the Mariana-Izu Trenches and recovered core samples of incoming oceanic crust. The calculations of mass circulation in the subduction zone, however, did not take into account the mass transfer properties within subducted oceanic crust, although the dewatering fluid and diffused ions may play an important role in various activities such as seismogeneity, serpentine diapiring, and arc volcanism. Thus, this paper focuses on the quantitative measurements of the physical and mass transfer properties of subducted oceanic crust.

Tissue metal concentrations and metal transfer functions of Glaucous Gulls (Larus hyperboreus) from Bjørnøya and Jan Mayen

Heavy metals (Cd, Cu, Fe, Mn and Zn) concentrations were determined in different tissues (muscle, kidney, liver, brain, gonads, heart and feathers) of Glaucous Gulls (Larus hyperboreus) from Bjornoya and Jan Mayen. The age and spatial dependent variations in heavy metals were quantified and interpreted in view of the three chemometric techniques, i.e. non-parametric Mann-Whitney U test, redundancy gradient analysis and detrended correspondence analysis. The Glaucous Gulls from Bjornoya contained significantly higher (p < 0.05) levels of Cd, Cu and Zn than those inhabited Jan Mayen. Adult birds were characterized by greater (p < 0.01) concentration of muscle, hepatic and renal heavy metals in comparison to chicks. Insignificantly higher slope constant Zn/Cd for the liver than for the kidney may reflect insignificant Cd exposure. Estimate of transfer factor (TF) allows us to assess variations in heavy metal concentrations during the individual development of Glaucous Gulls. It may be stated that there is a distinct increase of bioaccumulation of all the studied metals during subsequent stages of the bird life.

Ocean acidification affects the phyto-zoo plankton trophic transfer efficiency

The critical role played by copepods in ocean ecology and biogeochemistry warrants an understanding of how these animals may respond to ocean acidification (OA). Whilst an appreciation of the potential direct effects of OA, due to elevated pCO2, on copepods is improving, little is known about the indirect impacts acting via bottom-up(food quality) effects. We assessed, for the first time, the chronic effects of direct and/or indirect exposures to elevated pCO2 on the behaviour, vital rates, chemical and biochemical stoichiometry of the calanoid copepod Acartia tonsa. Bottom-up effects of elevated pCO2 caused species-specific biochemical changes to the phytoplanktonic feed, which adversely affected copepod population structure and decreased recruitment by 30 %. The direct impact of elevated pCO2 caused gender-specific respiratory responses in A.tonsa adults, stimulating an enhanced respiration rate in males (> 2-fold), and a suppressed respiratory response in females when coupled with indirect elevated pCO2 exposures. Under the combined indirect+direct exposure, carbon trophic transfer efficiency from phytoplankton-to-zooplankton declined to < 50 % of control populations, with a commensurate decrease in recruitment. For the first time an explicit role was demonstrated for biochemical stoichiometry in shaping copepod trophic dynamics. The altered biochemical composition of the CO2-exposed prey affected the biochemical stoichiometry of the copepods, which could have ramifications for production of higher tropic levels, notably fisheries. Our work indicates that the control of phytoplankton and the support of higher trophic levels involving copepods have clear potential to be adversely affected under future OA scenarios.