Repositório RCAAP

Primary production and hydrographic measurements were taken at three different points at a bight (Lat. 23º30'S; Long. 45º06'W) during the winter and summer (1975-76). Some photosynthetic characteristics of the natural populations were also simulated in laboratory experiments. The relation between primary production and the environmental parameters, as well as with the different values of C: chlorophyll obtained, showed that the region is oligotrophic. However the cell size composition of phytoplarikton may promove a maximum uptake of nutrients and improve the cellular reproduction. High values found for Ik showed that the population is adapted to high intensities as long as no physical barrier is established. Besides the ecological aspects presented the results allow us to suggest the viability of growing filter-feeding organisms as an option for marine culture.

A produção primária de Pterocladia capillacea foi medida através da dosagem de oxigénio (método de Winkler) em condições de laboratório, utilizando-se luz incandescente . Foi discutida em detalhe, uma metodologia adequada para a avaliaçao da produção primaria de algas bentonicas macroscópicas, usando-se frascos transparentes e pretos, com base naquela utilizada para estudos de fitoplâncton. A quantidade de 1,0 ml de alga para frascos com capacidade de 270 ml, temperatura entre 24,0 e 28,0ºC, intensidade luminosa de 40,0 Klux e período de incubação de 2 horas, apresentaram resultados satisfatórios. Esta metodologia pode ser aplicada para algas de morfologia semelhante à de P. capillacea.

An upwelling event was observed during February 1971 in the coastal region between Cabo Frio and Saquarema Point. Isolated upwelled water observed on a first survey, with a temperature of 17ºC, oxygen concentration of 4.2 ml/liter and inorganic phosphate concentration of 0.6 µg-at/liter, cleanly indicating its subsurface origin, was replaced, after a period of four to seven days, by coastal water with a temperature of 22ºC, oxygen concentration of 5.0 ml/liter and inorganic phosphate concentration of less than 0.3 µg-at,/liter. The evidence indicates that this replacement took place due to an eastward coastal current with a maximum velocity of nearly 5.0 nautical miles per day. The subsurface distribution of the chemical and physical properties indicates that the upwelling occurred mostly in the narrowest portion of the continental shelf.

Drift bottles were released during the Project "Coastal Eydrodinamics" (FINEP) in July-August 1977, in front of the coast of São Paulo State, in order to study the surface circulation of this area. Of 580 bottles launched 54 (9,3%) were recovered. 63% were found at SW and 37% at NW and NE. Part of the bottles performed long routes southwards revealing the presence of the Brazil Current. Bottles launched near the coast (± Long. 046º10'W to the west) were driven by a stronger current northwards, presenting velocities higher than of those which drifted southwards. These facts seem to confirm that in the winter months the Brazil Current flews nearer the coast, forming meanders and eddies which retard the flew of the current. The rotating currents observed at the fixed station (Lat. 25º01'S-Long. 045º42'W) would explain the recovery of bottles from the same station in opposite directions. Those found at NW and NE, released east of Long. 046º00'W, performed their routes after a longer period of time; they have remained a longer time in the rotating current The more frequent winds, blowing from NE and NNE will explain the greater number of recoveries at SW of the releasing station, while stronger winds from SW would be, in part, responsible for the greater velocity of the current northwards.

The author describes two new species: Protoperidinium steidingerae and Gonyaulax Rutnerae, and a third, little known species, Protoperidinium norpacenses. Balech. The three of them were collected in plankton tows in the South Brazilian littoral. The present study of P. norpacense completes the original description and shows some differences with the thecae from the tropical Pacific. Its relationships with P. heteracamtum Dangeard are discussed. P. steidingerae has been described, by Steidinger & Williams as P. oblongum. It is close to P. venustum but it has several very peculiar features: pointed anterior horn; first apical plate conspicuously shorter than the epitheca; neither 1' nor 3' reach the apex where 2' is largely connected with 41 on the ventral side; seemingly there are no platelets P and X, Gonyaulax kutnerae, belongs to the tamarensis group: its size, shape and weak thecawalls and tabular details tell it apart from the other species of the group. The only species which is somewhat alike is G. brvisulcatum Dangeard which is almost a nomm nudum. Recently Taylor (1976) described as G. brevisulcatum a species which clearly differs from G. kutnerae and which seems to be a Peridinella.

The vertical distribution of each developmental stage of Paracalanus crassirostris was studied in a shallow water station at Ubatuba, SP, Brazil (23º30'S-45º07'W). Samples were collected monthly at the surface, 2m and near bottom levels . Salinity, temperature, dissolved oxygen, tide height, light penetration arid solar radiation were also recorded. Data were analysed by the general linear model. It showed that the amount of individuals at any developmental stage is affected diversely by hour, depth, hour-depth interaction and environmental factors throughout the year and that these effects are stronger in summer. All developmental stages were spread in the water column showing no regular vertical migrations. On the other hand, the number of organisms caught in a particular hour seemed to dependmore on the tide than on the animals behaviour. The results of the present paper showed, as observed by some other authors, the lack of vertical migration of a coastal copepod which is a grazer of fine particles throughout its life.

The geostrophic circulation and the hydrographic conditions on the edge of the continental shelf off Cabo Frio (RJ) were investigated along two vertical sections sampled on July 1968. The main characteristics resulting from this analysis are the occurrences of east and west flows3 with speeds up to ± 2 cm.s-1 and -49 cm.s-1, respectively. The eastward motion presents a volume transport of 0.52 Sv (0.40 Sv) and the highest speeds are reached under the pycnocline, near the edge of the continental shelf. The main flow westward, presents the highest speeds on the upper layer, and the low values of volume transport of -2.24 Sv (-2.68 Sv) suggest that the hydrographic observations have been made in the cyclonic shear region of the Brazil Current. Details on the volume transport are presented, on the T-S diagram corresponding to classes bounded by intervals of thermosteric anomaly and temperature.

Current, temperature and salinity data from two sections and 13 days time series are analysed. Additional data from other efforts are summarized with other contributions yielding a tentative winter surface circulation model of the area. From the summary, mechanisms of the upwelling at Cabo Frio are suggested.

A collection of 291 sipunculans from the continental shelf off southern Brazil is described. Ten species are included, two new to science (Phascolion medusae and Aspidosiphon longirhyncus). The latter comprises 74% of the specimens collected. Four are recorded for the first time in the southwestern Atlantic Oceccn (Golfingia eremita, G. pellucida, A. Albus, and A. exhaustus). The remaining two (G. misakiana and P. hedraeum) have been recorded from Brazilian waters before. While most of the material represents a warm, shallow water community (the southern end of the South Brazilian Province), another group of species found south of 34ºS in deepercooler water points to the possibility of a zoogeographical barrier on the continental slope in these latitudes.

Temporal variation of some physical and chemical observations was performed during four days with six hour of intervals at two fixed stations at the Enseada do Flamengo, Ubatuba, São Paulo. The salinity (34.3‰ - 35.1‰) and temperature values (about 26ºC) are typical of local coastal waters. The dissolved oxygen shows super saturation content with some exceptions. The nitrogen (nitrite and nitrate) forms have very low values, with a maximum of 1.0 µg-at/l (nitrate). Other nutrients, like phosphates (0.15 - 0.80 µg-at/l) and silicates (5.0-21.5 µg-at/l) and the relationship N:P (1:3)3 show the poor terrigenous contribution and small bioproductivity. The pH and alcalinity was normal for sea water.

Considerando a reconhecida importância dos anelídeos poliquetos nas comunidades de fundo inconsolidados e para que se pudesse conhecer a composição de suas populaçoes, na região do infralitoral, bem como suas interrelações com esse ambiente, decidiu-se ampliar trabalho preliminar que abrangeu a faixa entre-marés. Foram amostradas 31 estações, sendo 24 na Enseada do Flamengo (continente) e 7 na Enseada das Palmas (Ilha Anchieta). As coletas que consistiram na amostragem quantitativa global da macrofauna béntica, foram cíclicas de março de 1976 a fevereiro de 1977. Foram efetuadas medidas de temperatura, salinidade e oxigênio da água de fundo, bem como a coleta de amostras de sedimento para analise granulométrica e mineralógica, conteúdo de agua, calcário e matéria orgânica. Como introdução é descrita a área abrangida pela pesquisa e discutida a metodologia, com vistas à avaliação dos parâmetros ambientais. A temperatura da ãgua variou de 19,5ºC em julho a 29,5ºC em fevereiro. A sanilidade oscilou entre 30,0035,60 ‰ e o conteúdo de oxigénio dissolvido alcançou em média 4,10 ml/l. É característica da area a diversidade de ambientes, onde em conseqüência do hidrodinamismo o fundo é composto por sedimentos que vão desde areia grossa até silte, predominando os compostos por areia muito fina. Na maioria das vezes os sedimentos se revelaram pobres em matéria orgânica e com teores de calcário em geral inferiores a 8%. Os parâmetros analisados constituem fatores ecologicos, cuja importância na distribuição dos anelídeos poliquetos será avaliada na segunda parte deste trabalho.

A discussion of the tidal, wind-driven, and density-driven aspects of the circulation in Bay of Ilha Grande and Bay of Sepetiba (Brazil) based on historical data and hydrographie and current mete'r data collected in September of 1977, is presented in this paper. The data analysis has shewn a remarkable contrast between the circulations of these two adjacent Bays. The circulation in Bay of Sepetiba is strongly tidalwhereas Bay of Ilha Grande has a weak tidal circulation superimposed by a quasi-steady flow induced by density gradients. The stratification is maintained because Bay of Ilha Grande, beeing deeper, allows colder and saltier shelf water to flow eastward towards the fresher and warmer water flowing out of Bay of Sepetiba, highly influencedby river runoff. The velocity and density fields have shown seiche oscillations that agree very well with theoretically derived modes inherent to the local geometry and density stratification.

A finite element, two-dimensional hydrodynamical numerical model developed by Wang & White (1976) was applied to study the tidal and wind-driven rculations in the coastal domain formed by Bay of Ilha Grande and Bay of Sepetiba. The tidal circulation was modeled by imposing a co-oscillating tidal signal at the open boundaries of the domain. The amplitude and phase of the tidal constipants adopted to run the numerical experiment were based on harmonic analysis of previous investigations in the region, plus data obtained from two tide gauges ins tailed near the open boundaries of the modeled domain. The numerical simulation of the wind-driven circulation was based on wind data statistics covering 16 months of data. The effect of the wind in the local circulation was weighted by the frequency distribution of wind directions as well as the associated most probable wind forces. The numerical model was also used to simulate seiche oscillations in the coupled system formed by Bay of Ilha Grande and Bay of Sepetiba. The model results are in agreement with the results derived in Part I of this paper, where field data was analysed and discussed.

The populations of polychaetous annelids from the shallow infralittoral were analyzed for their composition and relationships with environmental parameters. As suggested by a previous survey, the area was divided in five sectors, according to local peculiarities. Some factors as the nature of sediments and abundance of organic matter have a selective function and seem to play an important role conditioning the degree of faunistic affinity between the different sectors.

A mesosoale study was made of the Ilha Grande area. The local circulation described through -progressive vector diagrams showed a clochwise bottom circulation determined in June 1976, while in the upper 10 m the direction of the flow entering the Ilha Grande Bay was towards the center in the west and towards the Marambaia sandbank in the east side of the Bay. Short periods and amplitude fluctuations were evaluted using power spectral analysis, Fourier and Maximum Entropy Method, which showed that in the upper 10 m predominant periods decrease from 1.1h (A = 6.3cm sec-1) (position = 3C) to 1.0h (A = 7.4 cm sec-1) (position = 2D) and increase to 5.8h (A = 6.8 cm., sec-1) (position = ID), while at the bottom layer the predominant period increases from 0.4 h (A = 5.0 cm sec-1) (position = 3G) to 6.4h (A = 7.0 cm sec-1) (position = 2G) and to 4.4h (A = 7.9 cm sec-1) (position = 1G) . From the original data it has been possible to determine an "intense pulsation" between 30-70 cm sec-1 in the upper 10 m with about 1.0h period and 10-20 min duration in all the stations.

Nonatus longilineus gen. sp. nov., here described has been found on the southern coast of Brazil. Forty genera of Capitellidae are also recognized and characterized.

Benthic macro fauna (Decapoda) was sampled by beam trawl at 6 stations in Bay of Fortaleza and adjacents Escuro e Claro rivers (São Paulo, Ubatuba, Brasil). Samples were taken monthly during 1973-1974. Diversity was high in muddy sand sites of Bay of Fortaleza and low at very shallow stations located in the rivers, where the effects of extreme fluctuations of salinity were evident. The changes in species composition appeared to correspond most clearly to differences in salinity. The total number of species of decapods collected in the areas was 27 (14 species of Natantia and 13 of Reptantia). Juveniles of Penaeus brasiiiensis and Penaeus paulensis reach the rivers. Callinectes danae live in the Bay and in the rivers. Xiphopeneus kroyeri is a specie who inhabit the Bay of Fortaleza in high populational density.

In a turle-grass bed (Thalassia testedinum) next to a coral reef (Acropora spp.), 105 species of fish were observed, 42% of them belonged to the community of benthic residents, 45% to suprabenthic nomads and 13% were transients, the importance of Millepora complanata as shelter for the benthic residents is emphasized; it is thought that the distribution of the species observed is based upon trophic differences.

The distribution of primary production (mgC/m³) and chlorophyll-a (mg/m³) in surface waters at the regions between Cabo Frio (Lat. 22º 31'S - Long. 41º 52'W) and Santa Marta Grande Cape (Lat. 28º 43'S - Long 47º 52'W) is presented. The results were obtained during four oceanographic cruises: May/76, Sept-Oct/76, Jan-Feb/77 and Jan/78 by R/V "Prof. W. Besnard". The highest values for chlorophyll-a and primary production were observed during summer. In general, in all the experiments, coastal waters showed a greater primary production potential. The reasons for the eutrophication of coastal waters are discussed.

Plankton was collected in Nov.-Dec. 1972, during the Cato-6 Expedition (R/VMelville). Distribution of Siphonophores and Medusae and ecological implications pointed out by these organisms are discussea. 25 species of Siphonophorae were obtained corresponding to tropical, temperate, and Antarctic Sub ant arctic categories. 5 species of Medusae appeared , showing the peculiar erratic distribution typical of these organisms. Faunistic data are presented in tables and maps. Effects of Brazil, Falkland Currents and upwelling, centers appear well defined by the distribution of the siphonophores. Cosmopolitan siphonophores, typical of temperate and warm waters inhabited a band (zone of Rio Grande rise) between the southernmost and northernmost progressions of Brazil and Falkland Currents. These populations are carried toward South-american coasts by the anticyclonic circulation of the Central South Atlantic, forming a convergence; and a divergence towards the north is responsible for development of upwelling systems.