(Table 1) Cesium-137 concentrations and salinity in surface waters from the Atlantic and Pacific Oceans in January-May 1978

Cesium-137 concentrations of surface waters were measured during Cruise 20 of R/V Dmitry Mendeleev across the Atlantic and Pacific Oceans. The measurements were combined with simultaneous salinity measurements. The radioactivity field of surface waters is governed by presence of closed circulation systems and their component currents. Crossing the oceans from west to east decrease in cesium-137 concentrations was noted. In surface waters in the northeastern periphery of the southern anticyclonic gyre in the Pacific Ocean Cs-137 concentrations increased (up to 21.5 Bq/m**3) due to a series of nuclear tests on the Muroroa Atoll.

Thermal reaction norms of growth in Atlantic and Pacific silverside fishes

How organisms may adapt to rising global temperatures is uncertain, but concepts can emerge from studying adaptive physiological trait variations across existing spatial climate gradients. Many ectotherms, particularly fish, have evolved increasing genetic growth capacities with latitude (i.e. countergradient variation (CnGV) in growth), which are thought to be an adaptation primarily to strong gradients in seasonality. In contrast, evolutionary responses to gradients in mean temperature are often assumed to involve an alternative mode, 'thermal adaptation'. We measured thermal growth reaction norms in Pacific silverside populations (Atherinops affinis) occurring across a weak latitudinal temperature gradient with invariant seasonality along the North American Pacific coast. Instead of thermal adaptation, we found novel evidence for CnGV in growth, suggesting that CnGV is a ubiquitous mode of reaction-norm evolution in ectotherms even in response to weak spatial and, by inference, temporal climate gradients. A novel, large-scale comparison between ecologically equivalent Pacific versus Atlantic silversides (Menidia menidia) revealed how closely growth CnGV patterns reflect their respective climate gradients. While steep growth reaction norms and increasing growth plasticity with latitude in M. menidia mimicked the strong, highly seasonal Atlantic coastal gradient, shallow reaction norms and much smaller, latitude-independent growth plasticity in A. affinis resembled the weak Pacific latitudinal temperature gradient.

Contents of P2O5, Corg, Sr, and Ba in phosphorites and host sediments from the Atlantic and Pacific oceans

Sr contents in phosphorites on shelves of the Southwest Africa, and of Chile and Peru increase with degree of their lithification, from 0.05 to 0.28% and from 0.13 to 0.16% respectively. Phosphorites from Pacific submarine seamounts have the average Sr content 0.11%, and bone phosphate from Pacific floor 0.13%. Shelf phosphorites are characterized by high correlation coefficients between Sr and P2O5 (R = +0.82) and constant Sr/P2O5 ratio (0.0084). In phosphorites from submarine sea-mounts and in bones from the ocean floor Sr/P2O5 ratio is only a little higher than a half of that in shelf phosphorites. This indicates specific and different genesis of phosphorites from submarine mountains. Ba content in recent phosphorites from the shelf of the Southwest Africa changes with increasing degree of lithification. At first their Ba contents rise from 0.031 to 0.188%, then they diminish to 0.016%, and thereafter again increase to 0.070%. This is due to successive predominance of one of the following processes going in different directions: co-precipitation with phosphate gels or formation of true separate Ba phase, loss of phosphate in crystallization and "self-purification" of concentrations, and surface adsorption. In Peru-Chile shelf phosphorites the average Ba content is 0.017%, in phosphorites from Pacific seamounts 0.192%, and in fossilized bones 0.010%.

Contents of P2O5 and REE in phosphorites from shelves and Pacific seamounts

Recent phosphorites from the Namibian shelf are characterized by low REE contents, depletion in REE compared to host sediments and sharp deficiency of lanthanum and europium. In Late Quaternary and Pre-Quaternary phosphorites from ocean shelves REE contents and patterns in general are the same as in host sediments. Phosphorites from seamounts are enriched in REE compared to shelf phosphorites and their patterns are close to one of seawater. Behavior of REE in shelf phosphorites is determined by the fact that in early stages of phosphorite formation REE are associated not primarily with phosphate, but with organic matter and terrigenous impurities. Only in the later stages of diagenesis phosphate begins to play a leading role in concentration of REE. In metasomatic phosphorites on seamounts concentration of REE depends on age and depth of these rocks, i.e. it is determined by duration and conditions of contact with sea water.

(Table 1) Zoobenthos from the gas-hydrate seep area near the Paramushir Island and its chemical composition

Distributions of Mn, Fe, Cu, Cd, Cr, Co and Ni in sea water are investigated (42 samples, dissolved and particulate forms) in the vicinity of the underwater gas vent field on the northwestern slope of the Paramushir Island. While regular background distributions of the elements occur in the shore zone, there is a column of elevated concentrations of particulate matter, particulate Mn, and dissolved Mn, Fe, Cu, Cd, Cr, Co and Ni that coincides with location of the gas plume. This column can be traced as high as 780 m above the bottom. High metal concentrations in water of the plume are attributable to physico-chemical concentration at the phase interface; the source of elevated mineral concentrations is obviously flux of dissolved minerals from interstitial waters, which extends to considerable distances in vertical direction.

Tab. 1: Geographical, temperature and chemical features of sites on Bear Island and Spitsbergen

In arctic populations of Macrothrix hirsuticornis life cycles are mainly governed by temperature. This was found by using laboratory cultures in combination with the analysis of population samples from waters in Svalbard. In arctic waters ex-ephippio-++ usually produce gamogenetic F1-++ together with a high percentage of oo, which have to fertilize the resting eggs. Temperatures around 14°C, which are very rare in waters of Svalbard, will induce parthenogenetic oo in the F1 and even the F2-generation, a mode of reproduction normally found in Macrothrix-populations of Central Europe. This was found in laboratory cultures of M. hirsuticornis from Bear Island, and there was evidence, that a similar cycle occurs in warm wells in Spitsbergen. The arctic distribution of M. hirsuticornis mainly depends on temperature, which regulates the speed of individual development. But this can only be understood together with the length of time, during which suitable life conditions are given. Physiological adaptations to life in waters in high latitudes could not be found, in spite of the extreme northern occurrence of M. hirsuticornis.