Todos os Santos Bay is a large bay (800 km 2 ) located adjacent to the city of Salvador, Bahia. The margins of the bay are undergoing rapid industrial development by both the public and private sectors. This paper presents the general oceanographic conditions in the bay based upon the distribution of temperature, salinity and total suspended material. The salinity distributions obtained from cruises during March, May, and September, 1977, show that the main body of the bay is dominated by

more »

... conditions. Brackish water and estuarine conditions occur only within the channels of the Paraguacu River and Subae River, the dominant sources of fresh waterinto the bay for short periods of time.The distribution of suspended material ranges generally between 0.5-2 mg/I in the eastern region of the bay with an average of 1.5 mg/l based on 99 samples. The western part of the bay, which receives water from the Paraguacu River and Subae River, has an average of 3.8 mg/l based on 27 samples. Within the channel of the Paraguacu River, values range between 10-70 rng/I, depending on location and river flow. Vertical profiles of suspended material in the bay often show increasing concentration with depth, apparently due to resuspension by tidal currents. Suspended material concentrations in near-bottom waters during different stages of tidal cycles indicate that resuspended sediments may dominate the particulate load in some areas while having a negligible contribution elsewhere. Approximately 90070 of the suspended material is deposited from waters with salinities of less than 30070. It is estimated that no more than 10% of the suspended material is transported' out onto the continental' shelf. RESUMO A Bate de Todcs os Santos, Bahia, compreende uma area de aproximadamente 800 km 2 • Em suas margens esta ocorrendo urn rapido desenvolvimento industrial. Este traba-Iho apresenta as condlcoes oceanograficas gerais da baia, baseando-se sobretudo na distribuicao da salinidade e da quantidade total de material em suspensao, sendo observado urn total de 450 amostras. A distribuicao da salinidade obtida de alguns cruzeiros realizados durante marco, maio e setembro de 1977 mostra que toda a baia e dominada por condicoes marinhas. Agua salobra e condicoes estuarinas ocorrem ao longo dos canais dos rios Paraguacu e Subae, os quais se eonstituem nas principais fontes de agua doce para dentro da baia. Durante os fortes aguaceiros, aguas com baixos valores de salinidade ocorrem ao longo das margens so por curtos periodos de tempo. Na regiao leste da baia, a distribuicao do material em suspensao varia geralmente de 0,5~2,O mgll com uma media de 1,5 rng/l. A parte oeste, que acolhe as aguas do Rio Paraguacu e do Rio Subae, apresenta uma media de 3,8 mg/I. Dentro do canal do Rio Paraguacu, os valores alcancam 10-70mg/I, dependendo da localizacao e do fluxo do rio. Perfis verticals de material em suspensao freqiientemente mostram crescimento da concentracao com a profundidade, devido sobretudo ao processo de ressuspensao pelas correntes de mare.