Variabilidade temporal das características oceanográficas e ecológicas da região de influência fluvial do rio Itajaí-açu.

Abstract

The region of fluvial influence (ROFI) of Itajaí-Açu River was assessed through fourteen surveys covering thirty sampling stations in a radial shape with origin in the estuarine inlet. The total sampled area was of 100 km 2 , with depth ranging from 6 to 25 m, and until 10 Km offshore. The surveys were nearly monthly, from October 2002 to December 2003. The variables collected were salinity, temperature, suspended particulate matter, dissolved oxygen, chlorophyll a, picoplankton (autothrophic and heterothrophic) and zooplankton. River discharge and meteorological data were also obtained to help in the general characterization. The results indicated that in terms of averaged values of each variable, the sampling area is poorly related with the river discharge, or in other words, the sampling area is wider than the ROFI. Only salinity showed reasonably agreement with river discharge, although during the winter the region is affected by the Plata estuarine front. Further analysis on the data gathered must cope with spatial variability, either horizontal, e.g., plume dispersion, as vertical, e.g., plume buoyancy flow.

Caracterização de feições oceanográficas na plataforma de Santa Catarina através de imagens orbitais

“…Foram observadas também frentes oceanográficas, sendo uma muito próxima da costa, e outra acompanhando a quebra de plataforma. A primeira certamente está relacionada ao aporte local de uma série de pequenos rios que deságuam ao longo do litoral catarinense, não necessariamente produzindo gradientes térmicos, mas produzindo umaágua costeira rica em nutrientes e material orgânico (Schettini et al, , 2005.…”

The holoplankton of the Santa Catarina coast, southern Brazil

“…Besides the new data for zooplankton, the publications used in this work referring to the coastal region were as follows: Schettini et al (2002) to the Babitonga Bay; Duarte (1999), Resgalla Jr and Veado (2006) and R.D. Nunes, unpublished data to the Armação do Itapocoroy Bay; Rörig et al (1997) to Navegantes Beach; Schettini et al ( , 2005 A checklist of zooplankton species was drawn up, and comparisons were made with the fauna of the coastal environments to the north, São Paulo (C.L. De La Rocha, unpublished data) and Paraná (Montú 1987, Montú andCordeiro 1988), and to the south, in Rio Grande do Sul (Montú 1980, Montú andGloeden 1986, E. Muxagata, unpublished data), in order to determine the limits of distribution of species and establish the similarity between the areas.…”

“…According to B.M. Castro Filho, unpublished data, Miranda (1982), Piola et al (2000Piola et al ( , 2005, Schettini et al (2005) and Hille et al (2008), the water masses occurring on the shelf are the Tropical Water (TW) of the Brazilian Current, with temperatures over 20°C and salinity higher than 36.4, and the South Atlantic Central Water (SACW), characterized by temperatures below 20 • C and salinity ranging from 36.4 to 34.5. The latter lies at greater depths and is responsible for strong thermal gradients in the water column, indicating processes of upwelling on the continental shelf (Miranda 1982).…”

Hidrodinâmica e nutrientes inorgânicos dissolvidos no estuário do Rio Perequê, SC

“…A clorofila-α, por outro lado, apresenta valores maiores nas águas costeiras e mais salinas adjacente ao estuário (e.g. Pereira Filho et al, 2001;Schettini et al, 2005). Ainda que os níveis de nutrientes no estuário sejam elevados, a turbidez também o é, fazendo com que a luminosidade seja um fator limitante para a produção primária.…”