RCAAP Repository

The distribution and variation of total organic matter (TOM) during the rainy season, was studied in the sediments of the coastal lagoon of Huizache-Caimanero, Sinaloa. Two well defined areas werw detected: one with more than 9% TOM, NE of the lagoon, and other with less than 9% TOM, SW of the lagoon. An almost homogeneous TOM concentration was found from the surface to 15-20 cm depth of the sediment core. This is probably due to the continuous addition of TOM from the terrestrial and submerged vegetation.

In this paper the feasibility of estimating the chlorophyll content of ocean waters through the use of multispectral remote sensors on board of orbiting satellites, is discussed. Some aspects of the physical foundations of the interaction processes of visible light (380-770 nm) with the atmosphere and liquid mass and some models for this detection, are also discussed.

A methodology for the determination of the best potential fishing zones, for sardine, in the Brazilian coastal area of the Southwestern Tropical Atlantic Ocean, between latitudes 21º45'S and 25º00'S and longitudes 40º50'W and 47º00'W is presented. By using this methodology, a fishing chart model is developed from observations relative to the months of July, August, September, November and December. Marine fishing chart containing such zones are presented for the September month. The potentiality of the VHRR-IR and the surface charts of NOAA's satellite, as a help in the determination of the fishing zones is also demonstrated.

Abundances of Zooplankton volumes, fish eggs and larvae were determined for 812 oceanographic stations on six survey cruises to the southern Brazilian continental shelf. Contour charts of Zooplankton volumes are presented. A marked seasonality on Zooplankton volumes and number of fish eggs and larvae was observed. The highest values were obtained during late spring and summer seasons and the lowest in the autumn. The mean values of Zooplankton volumes, eggs and larvae for different depth zones and subareas were presented. Major part of fish larvae were classified into 55 families. The most abundant group were those of family Engraulidae, Myctophidae and Gonostomatidae. The larvae of Clupeidae were abundant in the late-spring and summer cruises.

The material analysed here is part of a collection made with a 91 van Dorn bottle in a 5 m depth station at Ubatuba - São Paulo, between June 1976 and May 1977. Two sets of general linear models were constructed, one for the winter months (June, July and August) and the other for the summer ones (December, January and February). In each set, copepodid stages and adults were studied separately, in relation to hour of sampling, depth, interaction hour-depth, and environmental factors (light penetration, dissolved oxygen, salinity and temperature, considered as a whole). All the stages studied were spread in the water column and show no vertical migration. The hour was not significant for any stage except for copepodid V female in winter. This results agree with a previous analysis of the same material performed with the data of each two months throughout the year (Milstein, 1978).

The feeding habits of Urophycis brasiliensis, were studied on the basis of stomach analyses of 130 specimens, collected from three different sites in coastal waters of the Departament of Montevideo, Uruguay, on June 26th, September 3 th and November 6th of 1978. These data were completed by a morphological study of the digestive tract, revealing a system adapted for ingesting mobile prey of considerable size, principally benthic organisms and fish. The diet varied with specimens size; smaller individuals chose decapod crustaceans whereas larger ones took fish.

Prey electivity of two littoral fishes that belong to intermedial links of the trophic sub-web of the trophic sub-web of Caleta San Carlos, Corral bay is studied. Stomach content has been analyzed by mean of the numerical method and prey abundance in the environment has been evaluated with 0.1 m² samples, taken with SCUBA techniques. For each prey that's consumed by these fishes, Ivlev's electivity index was fitted; besides that, the correlation between food availability and the amount that is consumed by each of these predators was established. The results have been interpreted according to the behaviour of these fishes in relation to the top predator of the community. The results suggest that electivity has a component that's induced by the adaptive responde of these fishes with the top predator.

The investigation of the flsioecological aspects of marine species of commercial interest is of great importance, as some problems related to fisheries could partially or totally be resolved on fisiological basis (Alvarez & Dias, 1971). In this paper, the metabolic demands of Panulirus agus (Latreille) are studied, measured through oxygen consumption in µ1 of O2 /g/h, and compared to the data available for Panulirus laevicauda (Latreille) The study is based in 80 juvenile spiny tobster in several molting stages, hand captured by diving during low tide in coastal waters off the County ofFortaleza. For oxygen consumption determination, the method recommended by Schlieper(1972) was used, the dissolved oxygen measures effected with the aid of an "Oxygen Meter Model 51-A-YSI" The values were refered in µ1 O2 /g/h. The calculation of relationships consumption O2/weight were made using the linear model y = a+ bX, by the method of least squares. The following conclusions were obtained: 1. The O2 consumption, in the different molting stages dim inished as the animal weight increased. 2. No significant difference in O2 consumption was found between males and females. 3. The spiny lobster in study nas in the differents molting stages, low metabolic demands stages D presenting the highest O2 consumption. 4. For each molting stage equation relating weight and O2 consumption were calculated as follows: P. argus P. laevicauda molt A C = 97.55 - 1.36 W r = 0,97 molt A C = 86.17 - 0,99 W molt B C = 87.96 - 1.02 W r = 0.95 molt B C = 87.51 - 1,08 W molt C C = 86.03 - 0.92 W r = 0.98 molt C C = 91.03 - 1,20 W molt D C =107.47 - 1.84 W r = 0.98 molt D C = 87.77 - 0,97 W 5. The calculated values based on the equations are quite similar to those values obtained, thus the utilization of me equations being valid

Eggs and larvae of the cutlassfish, Trichiurus lepturus, were collected during the survey cruises of the project FINEP to determinate spawning areas and season. Six cruises were made from 1975 to 1977 in southern Brazil (23º S -29º S). Spawning occurred throughout the year, but intensively in the cruise, May 1976 (autumn). The heavy spawning area was offshore region of Ilha Grande and of Ilha de Sta. Catarina. Mean temperature of the spawning area was 24.09 ºC, ranging from 21.15 to 26.29 ºC and mean salinity was 35.31 ‰, ranging from 35.04 to 35.52 ‰. Catch data of cutlassfish fishery showed a gradual increase last several years in the two states: São Paulo and Santa Catarina.

Some biological parameters of the oyster (Crassostrea rhizopharae), during the spawning and post-spawning periods, were analised in relation to the infestation by the pea crab (Pinnotheres ostreum) The biological parameters considered were: size, total weight, wet and dry meat weight, and condition index. Utilizing the &#967;2 test these parameters and infestation by the pea crab were shown to to be associated. The incidence of pea crabs was higher during the spawning period than in the post-spawning period, reaching a maximum (20.3% infestation) in oysters with a size of 6 to 7 cm. The values of the condition index and percent of meat (wet and dry weight) for these oysters were significantly (P < 0.05) lower than for uninfested oysters. From these results there seems to be no doubt that the pea crab (V. ostreum) injures the mangrove oysters which supports the conclusion that these crabs are true parasites for C. rhizophorae.

The organic matter content in the fine-fraction of 200 marine sediments samples and in 50 whole continental samplel along the Estado de São Paulo coast, between Cananéia and Ubatuba, show a close relation between organic content and depositional environment. Samples were collected in coastal plains lagoon-estuarine mangroves and inner continental shelf environments representative of that coastal region.

During the spawning period, fishes of the familes Mugilidae and Centropomidae concentrate on the river mouths or brackishwater lagoons. Those species are reared in fish-ponds ("viveiros") in northeastern Brazil, mainly at Pernambuco State. Presently, polyculture trials are made with those species, together with three others of the family Gerridae, with or without artificial feeding or fertilization. The yields are very high per ha /year. A review of the biology of those species, together with the hydrological conditions of the fish-ponds, are presented. The author recommends that similar fish-ponds should be built in other northeastern regions as well as in the south, and the obtention of fry through hypophysation method (now used in Israel and Taiwan for Mugilidae), replacing the present method of simply catching youngs measuring 10 to 15 cm total length and putting them in those fish-ponds. In this way we would contribute to a high and quick production of animal protein, necessary to a great part of Brazilian population.

The primary production by C14, standing crop as ratio of particulate carbon/nitrogen and biossay tests concerning to dissolved nitrogen and phosphorus were investigated in the SW estuahne mangrove area of the Bay of Todos os Santos (Brazil) during 10 months. The phytoplankton displaied in this area a mean density of 9x10(5) cells/liter. The primary productivity showed an average range of 9.52 to 10.93 mgC/m³/h, representing the rate about 45 g C/m³ /year or 181 g C/m² /year. Phytoplankton fraction under 35µ at the stations 0 and 1 was responsible for the most C14 uptake. A negative relationship between primary production and limiting nitrogen and phosphorus was verified. February samples exhibited the most drastic situation regarding to N and P, as limiting factors; an opposite situation corresponded Jo June and July. The relationship between particulated carbon and nitrogen showed a concentration area among the ranges of400/1400 mgC/m³/ and 4/28 mgN/m³, The ratios C/N revealed the most of times a short variation.

The present study is intended to evaluate the potential of an estuarine area surrounded by mangrove at Todos os Santos Bay (Bahia State , Brazil), for supporting aquaculture activities. From October 1977 to July 1978 samples were collected monthly on alternate tides for determination of particulate organic carbon and total proteins The following environmental parameters were also considered: salinity. temperature, pH, transparence, dissolved oxygen, silicates, ammonia, nitrites, nitrates, phosphates and precipitation. Although the area presented low ceil density and low photossinthetic activity, high values for the standing crop were found, demonstrating the importance of detritic material for the particulate organic matter.

Plankton samples were collected from 13 stations on the estuary of the river Paraíba do Norte (06º 56' to 07º 09'Lat. S). Copepoda were the most abundant holoplanktonic organism and from the meroplankton the larvae of Cirripedia were the best represented in the interior of the estuary. Gastropoda larvae occurred in almost all the stations being always more abundant than Lamellibranchiae ones, mostly near the mouth of the channel. Decapoda larvae and eggs and larvae of fishes were also frequent. The spatial and temporal distribution of zooplankton will be studied in the future.

This is a preliminary study undertaken to investigate the composition and distribution of amphipods with reference to depth, salinity and sediment at Enseada da Fortaleza (Area 1) and parts of Rio Claro and Rio Escuro (Area 2), Ubatuba, São Paulo State. Eighteen specif of gammarids occurred in the region, of which fourteen known species had been recorded previously for the Brazilian coast. Some of these species as Atylus minikoi and Corophium sp were found at the two areas, while others were recorded at only one of the areas.

The possibility of the use of electropherogrames of plasma proteins in polyacrylamide slab gel in the study of populations of marine cat-fishes was examined. A total of 176 samples of plasma from four species. Sciadeichtys luniscutis. Arius spixii, Genidens genidens and Netuma barbas was used. Inter-specific as well as intra-specific differences were found and the locus E of the plasma of all the four species showed a typical dialelic variation. The locus is recommended as one of alternatives which deserve due consideration in the planing of studies of populations of these species by means of biochemical methods.

Monthly variations in the chemical composition of the mussel (Perna perna) cultivated and the environment factors were studied in the Guamache Bay (Margarita Island, Venezuela). The study was carried out on mussels of 65-70 mm shell lenght and on a size that was monthly increased in 5 mm from 40-45 mm to 100-105 mm. The weight of meat ranged from 8,05 to 10,87 g, the weight of shell from 8,88 to 11,00 g and weight of the intervalve water from 2,64 to 6,83 g. In both experiences the water fluctuated between 72,2 and 86,7% ashes from 2,25 to 3,58% and proteins between 9,10 and 16,05% . The influence of the meteorological conditions on temperature and salinity was analized. The percentage of oxygen saturation was always over 80%. The primary nutrients registered low values only the ammonia mean, reached 2,43 µg-at/L Chlorophyll "a" fluctuated between 0,25 and 4,50 µg/L. The results showed that the variations in the chemical composition of mussels was independent of the size and they would be caused by the environment conditions.

Menella coeruieoalba is a dolphin widely distributed in temperate and tropical waters. This species is recorded for our marine fauna on the basis of a 2.35 m long specimen found at 20 km North of the East rocky jetty on the access channel into Lagoa dos Patos, RS, (MORG 064) and also from a sightning in front of Santa Catarina coast. Its vertebral formula is: C 7 + D 14 + L 21 + Ca 34 = 76, with 23 Chevron bones. The number of alveoli is 48-48 / 43-42, its presents 14 pairs of ribs, 8 of them double-headed. The skull measurements of this specimen are compared with other three from the Southern Hemisphere. Through colour slides obtained in front of Rio de Janeiro coasts, Steno bredanensis was recorded. This dolphin also presents a wide distribution similar to the previous species. During the first cruise of the R/V "Atlântico Sul" two pods of the spotted dolphin, Stenella cfr. plagiodon were sighted and photographed. This species can be easily identified on the basis of the clear brown tegument with numerous white rounded spots, in adults. One of the skull (MCNRS 026) studied may belong to this species.

Studies on cetaceans at Argentina, Uruguay and Brazil can be divided in three periods. During the first one (1861-1963), studies of the Argentines Burmeister, Gallardo, Lahille and Marelli were done on dolphin and porpoise osteology, occasionally on whales, these wire followed by those of Miranda Ribeiro and Carvalho in Brazil. The second period (1969-1976) begins with the studies of the North Américan Gilmore (1969) in Patagonia. From this year on, numerous forcing expeditions came to Argentina and Uruguay, to study the right whale, Eubalaena australis behavior in Patagonia and the La Plata river dolphin. Pontoporia blainvillei biology at Punta del Diablo, Uruguay. These expeditions have contributed to a better knowledge of whales and dolphins, not only in South if not also, abroad. During thin period studies on bekzvior, bioacustics, population dynamics and bio-ecological studies ; began. Simultaneously it is observed that Latin Americm researches, specially those of Uruguay and Brazil, become interested ind doing cetological research on systematic aspects. The third period (1976- ) it is characterized by an increased effort on this field and also by a better exchange of information between the three S. W. Atlantic countries. In Brazil, during the last two years, a gret interest on the minke whale conservation problem has developed, not only at the public opinion, but also at the government level.