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Describes the seasonal pattern of periphytic diatom populations growing on glass slides in the Bay of Paranagua, southern Brazil in relation to environmental parameters. Variation of temperature, salinity and precipitation and Secchi readings during high and low tides at surface and bottom layers in the water column; Diatom species colonizing glass slides in the bay; Photosynthetic rate and biomass accumulation.

The spatial distribution of copepod populations on the eastern continental shelf off Rio de Janeiro State, Brazil, was analysed in relation to the hydrographic regime in December-January (summer 1991/92) and July (winter 1992). Advection of cold and nutrient-rich South Atlantic Central Water (SACW) onto the shelf was a prevailing circulation mechanism in both seasonal cruises. The SACW occupied a larger proportion of bottom layers in summer as compared to winter, but only in the latter a well-defined upwelling event was recorded off Cape Frio. Two calanoid copepods were representative of shelf areas influenced bySACW intrusions: Calanoides carinatus, which occurred mainly during summer and Ctenocalanus vanus, recorded at high densities in both periods. Paracalanus quasimodo was the dominant copepod at inner- and mid-shelf stations both in summer and winter, followed by Temora spp. and Oncaea spp. These coastal species peaked at the upwelling site. A highly diversified and comparatively less abundant copepod assemblage, dominated by Clausocalanus furcatus and Oithona plumifera, was recorded in outer-shelf stations occupied by the oligotrophic Tropical Waters of the Brazil Current. We conclude that regional and seasonal contrasts in copepod species composition and abundance are controlled to a great extent by the advection and upwelling of the SACW onto the shelf. [ABSTRACT FROM AUTHOR]