Brazilian Sardine Research Articles

Comparative studies of coastal pelagic fish reproductive habitats: the Brazilian sardine (Sardinella aurita)

We extend a framework of comparative climatology of reproductive habitats of neritic pelagic fishes, heretofore focused on temperate eastern ocean upwelling systems, by adding a tropical western ocean example. Maritime weather reports off southeastern Brazil are summarized to yield distributions of wind stress, Ekman transport, wind mixing index, insolation, cloud cover and sea surface temperature for two-month segments of the seasonal cycle. These are used to describe seasonal aspects of the oceanography of the region. Vigorous coastal upwelling occurs in the vicinity of Cabo Frio-Cabo Sāo Tomé through most of the year, relaxing only during austral fall. Directly downstream of this upwelling center lies the coastal bight between Cabo Frio and Cabo Santa Marta Grande, within which offshore Ekman transport and wind-induced turbulent mixing fall to coastwise minima. The near-coastal water column within the bight, while vertically homogeneous during winter, becomes stably stratified during summer. We infer a rather enclosed circulation pattern within the bight, with the main Brazil Current flow skirting across the bight opening rather than following the coastline into the bight interior. This coastal bight constitutes the primary reproductive habitat of the Brazilian sardine. Peak spawning activity during summer serves to place larvae into a stable, enriched environment, where they enjoy high likelihood of retention. In the manner of achieving these advantages, the reproductive strategy of this population appears to be a nearly exact analogue to those of sardine populations inhabiting eastern boundary current upwelling systems, in spite of its western ocean boundary location and the fact that a warmer water genus is involved. The conclusion is that this Sardinella population is solving similar dominant environmental problems to those faced by the more temperate Sardinops and Sardina stocks of eastern boundary systems, only at a warmer temperature range. These findings lend support to the idea that our various fragments of experience of environmental effects on fish populations are not unconnected anecdotes, as they are often treated, but are amenable to scientific generalization.

Age and growth of the southeastern Brazilian sardine, Sardinella brasiliensis 1981-1983

Brazilian sardine datawere collected between September 1981 and August 1982 from the southeastern Brazilian waters. Otoliths were read using reflected ligth on the surface of the whole structure. Three methods were used to determine the time of ring formation, being the mean length per ring the best one. There are two annual rings clearly visible, one laid down in November/December, and the other one laid down in March/April. A method of age determination is described, being the maximum age 3 years.

Age and growth of the southeastern Brazilian sardine, Sardinella brasiliensis

A idade da sardinha Sardinella brasiliensis foi determinada pelo exame de otolitos de exemplares provenientes de desembarques da pesca comercial e artesanal, na area compreendida entre 22oS (Cabo Frio, RJ) e 28oS (Cabo de Santa Marta, Grande, SC), durante o periodo 1981-83. Este estudo e parte de um programa mais amplo de nominado Programa Integrado de Estu dos Biologicos sobre Sardinha, desenvolvido na regiao sudeste do Brasil desde 1981, objetivando conhecer as variacoes dos parâmetros biologicos da especie, e fornecer subsidios a avaliacao pesqueira do recurso. Foram contados os aneis translucidos dos otolitos, colocados inteiros em recipientes de fundo preto, imersos em alcool 70% e iluminados com luz incidente sob estereomicroscopio binocular. Alem das contagens, foram efetuadas medidas das distancias do nucleo do otolito ao bordo, e do nucleo a cada anel translucido, bem como observacoes da natureza do bordo. Foram utilizados tres metodos para determinar a epoca e periodicidade de formacao dos aneis. Os parâmetros de crescimento L ;, K e t0 foram estimados, e as curvas ajustadas usando-se a equacao de von Bertalanffy. Os resultados mostraram que os otolitos possuem de 0 a 7 aneis, sendo formados dois aneis por ano: um entre novembro-dezembro, e outro entre marco-abril. Estas epocas estao intimamente ligadas ao periodo de reproducao. Descreveu-se um metodo para a determinacao da idade de sardinha, tendo sido identificadas clas ses etarias de 0 a 3 anos. Verificou-se tambem a ocorrencia de dois grupos de peixes dentro de um dado periodo de de sova (outubro e marco), que representa riam individuos que nascem no inicio da estacao de desova, e aqueles que nas cem posteriormente; ambos grupos formam uma classe anual. Os parâmetros de crescimento obtidos foram: classe anual 1982: Lt = 230,99 [1-e-0,7225(t+0,2496)] classe anual 1983: Lt = 226,09 [1-e-0,7194(t+0,3432)].

Análise econômica da produção da sardinha na região sudeste do Brasil

A surplus-yield model of Schaefer (1954; 1957) was used to study a maximum sustainable yield of the Brazilian sardine. Applying the prices of sardine and operation cost, an economical yield of sardine was discussed. The maximum sustainable yield of sardine was estimated on 173 thousands metric tons and the optimum fishing effort was 28,292 sets of net. With the operation cost of Cr$ 71,040.00 per cruise, the price of sardine has to be higher than Cr$ 10,00/kg.

A study of the life history of Brazilian sardine, Sardinella brasiliensis: IV. Distribution and abundance of sardine larvae

A study of the life history of Brazilian sardine, Sardinella brasiliensis: IV. Distribution and abundance of sardine larvae

A study of the life history of Brazilian sardine, Sardinella brasiliensis: IV. Distribution and abundance of sardine larvae

Data on distribution and abundance of larvae of the Brazilian sardine, Sardinella brasiliensis, are presented based on samples collected in waters off southern Brazil during 1969 to 1971. The distribution pattern and relative abundance of sardine larvae during three spawning seasons are discussed. Relative abundance, using regional census estimates, was calculated each year. In general, larval abundance in each subarea coincided with that of eggs, although the area of distribution of larvae was larger than the spawning area. Estimates of larval abundance showed that the 1970-71 spawning season was the poorest, both in larval and egg abundance, despite the enlarged size of the area surveyed. The average temperature at stations where sardine larvae occurred was 23.4º C, ranging from 14.6 to 27.4º C, and the average salinity was 35.6º /oo, ranging from 35.0 to 36.7º /oo. Distribution of the larvae in different depth zones was analysed. Larvae usually were most abundant in the 51-100 m depth zone. No tendency for a unidirectional transport of larvae was observed; apparently they move from the spawning ground in all possible directions, spreading over the continental shelf. An estimate of survival rate of larvae, based on length frequency data pooled from the three years, was calculated. Undersampling of larvae during daytime was observed. The mean night-day catch ratio, based on larvae from all length classes sampled, was 3.93.

A study of the undersampling problem of fish larvae observed at the fixed stations in south Brazil

The problem of daytime undersampling of larvae observed at two fixed stations made in the spawning ground of the Brazilian sardine is discussed. The size frequency composition of sardine is also discussed. The predominant species on the stations was the larvae of Sardinella brasiliensis. The larvae of Harengula spp., Scombridae, Bregmacerotidae, Ophidiidae were also collected, but not so abundantly. When compared to other larvae, the undersampling of sardine larvae during daytime was extremely high. Because the sampling was done both vertically and horizontally at one fixed station and marked undersampling was observed at both stations, it was concluded that the undersampling was caused by avoidance. It was necessary to take this problem into careful consideration for computation of larval abundance.

A study of the life history of Brazilian sardine, Sardinella brasiliensis: III. development of sardine larvae

Larvae and juveniles of S. brasiliensis (Steindachner, 1879), ranging from 6.4 mm to 35.5 mm, were identified from plankton samples taken in waters off the southern Brazilian coast from 1969 through 1971. Changes in the pattern of pigmentation, body proportions and formation of fin rays are described. During transformation stage a considerable advancement of the dorsal and anal fins was observed. Changes in body proportions are pronounced at the size of 19 mm. Complete ossification of all fin rays is attained at the size of 20 mm, but ossification of the ventral scutes is delayed and completed only at the size of 30 mm. Ossification of the vertebral column was completed at the size of about 16 mm.

A study of the life history of Brazilian sardine, Sardinella brasiliensis: II. spawning in 1970 and 1971

Distribution and abundance of eggs of Sardinella brasiliensis (=S. aurita), are presented for the years 1970 and 1971 and compared with that of the previous year (1969). The spawning size of three spawning seasons was calculated using Tanaka's method. Incubation time of sardine eggs was estimated using the method of Ahlstrom. During three spawning seasons a considerable change in the relative spawning size was observed. The spawning season (during spring and summer in the southern hemisphere) of 1970-71 was poor when compared with those of 1969-70 and 1971-72. A slight change in the average diameter of eggs in different spawning seasons was also observed. The relation between oceanographie conditions and spawning size was analysed. It is suggested that the warm water covering the spawning ground during the 1970-71 spawning season may have caused an unsuccessful spawning in this year.

A study of the life history of Brazilian sardine, Sardinella brasiliensis: III. development of sardine larvae

O presente trabalho e parte do projeto SOL e tem por objetivo descrever a morfologia das larvas da sardinha verdadeira, Sardinella brasiliensis (=S. aurita), com o intuito de determinar um padrao que possibilite a identificacao das mesmas. Sao feitas consideracoes sobre a morfologia das larvas de outros clupeideos existentes na regiao e ressaltadas as diferencas com relacao as larvas de S. brasiliensis. Os resultados, posteriormente, serao usados como base para o estudo quantitativo da abundância de larvas de sardinha. O material foi coletado na costa sul do Brasil de 1969 a 1971, com uma rede de plâncton do tipo conico-cilindrico. Durante o desenvolvimento das larvas, foi observado um consideravel deslocamento das bases das nadadeiras dorsal e anal, para uma posicao mais anterior. Com o tamanho de 19 mm (comprimento padrao), ocorre uma mudanca geral, consideravel, nas proporcoes corporais. A ossificacao de todos os raios das nadadeiras completa-se quando a larva atinge 20 mm, mas a ossificacao dos escudos ventrais so se completa quando ela atinge 30 mm de comprimento. A ossificacao das vertebras completa-se a 16 mm de comprimento. O tamanho de 19 mm foi considerado como o fim do estagio larval, e, apos este comprimento, consideramos a larva no estagio prejuvenil (=transformal).

A study of surface currents in the spawning area of Brazilian sardine

To obtain the movement of surface currents in the spawning area of Brazilian sardine, drift card release experiments were conducted in south Brazilian waters during the spawning seasons of 1969-1971. The results of these experiments and some considerations about the drift of sardine eggs and larvae are described. On the cruises of late spring, summer and early autumn all cards from stations west of Long. 44º45' W drifted southwest and were recovered near São Sebastião and those from stations east of Long. 44º45' W drifted northeast and were recovered on the coast line between Ilha Grande and Cabo Frio. The drift pattern of the cruise of September 1969 was somewhat different from the others. Most cards recovered were released from stations near shore (up to 30 nm).

A study of the life history of Brazilian sardines, Sardinella aurita: I. Distribution and abundance of sardine eggs in the region of Ilha Grande, Rio de Janeiro

Distribution and abundance of sardine eggs in the Ilha Grande region, Rio de Janeiro, Brazil, were studied during five cruises for the 1969 1970 period. Using the shipboard fertilized eggs and the planktonic eggs, morphological descriptions of Brazilian sardine eggs are given. Spawning occurs during the summer from September to March in the coastal water off Ilha Grande to Ilha de Sao Sebastiao down to a depth of 100 meters. Spawning may take place a few hours prior to midnight. lt was noticed that spawning has a close relationship to an area of cold water up welling. Spawning groups are isolated and spawning is small in scale in this region. Temperature and salinity in the spawning area range between 18-24oC and 35.1-35.9‰ respectively.

A study of the life history of Brazilian sardines, Sardinella aurita: I. distribution and abundance of sardine eggs in the region of Ilha Grande, Rio de Janeiro

Distribution and abundance of sardine eggs in the Ilha Grande region, Rio de Janeiro, Brazil, were studied during five cruises for the 1969 1970 period. Using the shipboard fertilized eggs and the planktonic eggs, morphological descriptions of Brazilian sardine eggs are given. Spawning occurs during the summer from September to March in the coastal water off Ilha Grande to Ilha de São Sebastião down to a depth of 100 meters. Spawning may take place a few hours prior to midnight. lt was noticed that spawning has a close relationship to an area of cold water up welling. Spawning groups are isolated and spawning is small in scale in this region. Temperature and salinity in the spawning area range between 18-24ºC and 35.1-35.9‰ respectively.