Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the “Threshold Effect Level” values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted.     

Impairment of sea urchin sperm quality by UV-B radiation: predicting fertilization success from sperm motility

Sperm quality of the sea urchin, Anthocidaris crassispina, after exposure to environmentally realistic UV-B irradiances, was assessed by changes in sperm motility (measured by the computer-assisted sperm analysis (CASA) system), and related to subsequent fertilization success. Percentage motile sperm of A. crassispina declined significantly after exposure to a UV-B dose of 16.2 kJ m(-2), while sperm motion velocity as measured by curvilinear velocity (VCL), straight line velocity (VSL), and average path velocity (VAP) showed significant reduction after exposure to a UV-B dose of 5.4 kJ m(-2). A parallel study showed that fertilization success was significantly reduced after sperm were exposed to UV-B doses > or = 5.4 kJ m(-2). Notably, the four sperm motility parameters were strongly correlated with fertilization success (P < 0.001), followed the increasing order: VSL (r = 0.8) < % motile sperm (r = 0.804) < VCL (r = 0.912) < VAP (r = 0.928). Fertilization success is best predicted by VAP using the exponential model: y = 8.678 + 90.202/[1 + exp(82.83 - x)/10.27)] (r(2) = 0.95). Thus, impairment of sperm motility of sea urchin, as measured by the CASA method, can be used to predict reproductive success and ecological effects.     

Regional diversity in some aspects of Indian demography

Regional variations in the demography of India are explored using official data for the period 1971-1981. Socioeconomic and cultural determinants of such differentials, particularly female education and economic diversification, are addressed.     

Urban growth in Siberia and the Soviet Far East: multiplier effects of Japanese-supplied plants

The author analyzes changes in population growth rates and in the structure of the labor force in Soviet cities where Japanese-supplied industrial plants are located. Data for cities of over 50,000 inhabitants were obtained from available Soviet statistical sources; operations research techniques were then used to yield information at the city level     

Microbialite morphostratigraphy as a tool for correlating Late Cambrian-Early Ordovician sequences

Microbialite morphostratigraphy is a new tool for intrabasinal correlation using diverse microbialite structures (morphotypes). The recognition of the succession of morphotypes over constrained temporal intervals and broad areas is a function of the complex interactions that operate to create the structure. Because so many nonlinked variables (e.g., biotic, sedimentological, physicochemical) are involved, similar morphotypes do not reoccur over long temporal intervals. To demonstrate the technique, the upper Cambrian-lowermost Ordovician shelf strata of the Great Basin, United States, were correlated using both morphostratigraphy and standard lithostratigraphy. Six morphozones and one morphosubzone were recognized, as were four main lithologic successions. Because the boundaries between the morphozones and lithologic successions did not coincide, it is inferred that the characteristics of the various microbialite structures are not solely controlled by physical factors. The principles for establishing a morphostratigraphy outlined in this article allow for the potential to correlate along other ancient marine margins in both the same Cambrian and Ordovician interval, as well as any interval in the Phanerozoic in which diverse microbialite structures occur.