Resumo
The aim of this paper is to evaluate the apparent abundance of the croaker (Micropogon furnieri) along the central and southern coast of Brazil (from 23º50'S to 35ºS). The data on catch and effort of the fish taken in the same area and at the same time, with different gear, are analysed from January 1959 to December 1962. The different gears used were reduced to the same level of efficiency, and the apparent abundance was estimated according to the fishing area (area I - from 23º50'S to 26ºS, and area II - from 26ºS to 35ºS), by quarters and by year. The results allow us to draw the following conclusions: 1 - There is a tendency of increase of the apparent abundance from the beginning to the end of each year and of decrease in following years, in both areas. The decrease is greater in area II. 2 - The levels of apparent abundance, in both areas, was very different. The level in area II is higher. 3 - Variations in the availability during the year, were observed. Data suggest that they are determined in area I by extrinsic factors, and in area II by intrinsic factors. 4 - Different responses of the stock, in both areas, to fishing intensity was verified, supporting the hypothesis of occurrence of two different croaker stocks. The stock of area I probably has reached a state of equilibrium with the fishery while in area II the stock has not yet reached this stage.
Estimativa da abundância relativa de corvina na costa centro-sul do Brasil* * Os dados utilizados na preparação dêste trabalho foram cedidos pelo "Grupo de Pesquisas sôbre a Pesca Marítima", a quem agradecemos.
A. E. A. de M. Vazzoler
Instituto Oceanográfico da Universidade de São Paulo
SYNOPSIS
The aim of this paper is to evaluate the apparent abundance of the croaker (Micropogon furnieri) along the central and southern coast of Brazil (from 23º50'S to 35ºS). The data on catch and effort of the fish taken in the same area and at the same time, with different gear, are analysed from January 1959 to December 1962.
The different gears used were reduced to the same level of efficiency, and the apparent abundance was estimated according to the fishing area (area I - from 23º50'S to 26ºS, and area II - from 26ºS to 35ºS), by quarters and by year.
The results allow us to draw the following conclusions:
1 - There is a tendency of increase of the apparent abundance from the beginning to the end of each year and of decrease in following years, in both areas. The decrease is greater in area II.
2 - The levels of apparent abundance, in both areas, was very different. The level in area II is higher.
3 - Variations in the availability during the year, were observed. Data suggest that they are determined in area I by extrinsic factors, and in area II by intrinsic factors.
4 - Different responses of the stock, in both areas, to fishing intensity was verified, supporting the hypothesis of occurrence of two different croaker stocks. The stock of area I probably has reached a state of equilibrium with the fishery while in area II the stock has not yet reached this stage.
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Full text available only in PDF format.
BIBLIOGRAFIA
(Recebido em 2/1/1964)
- MARK, J. C. 1951. On the use of terms "abundance", "availability" and "apparent abundance" in fishery biology. Copeia, n.: 2, p. 163-169.
- SHIMADA, B. M. & SCHAEFER, M. B. 1956. A study of changes in fishing effort, abundance, and yeld for yellow-fin and skipjack tuna in the eastern Tropical Pacific Ocean. Bull. inter-Am. trop. Tuna Commn, vol. 1, n.ş 7, p. 351-469.
- VAZZOLER, A. E. A. DE M. 1963. Deslocamentos sazonais da corvina relacionados com as massas de água. Contrções Inst, oceanogr. Univ. S Paulo, ser. Ocean. Biol., n.ş 5, 8 p.
- VAZZOLER, A. E. A. DE M. & SÁ, E. M. DE 1963. Análise da pesca da corvina na costa centro-sul do Brasil. Bolm Inst, oceanogr., S Paulo, vol. 13, n.ş 2, p. 61-70.
Datas de Publicação
-
Publicação nesta coleção
15 Jun 2012 -
Data do Fascículo
1965
Histórico
-
Recebido
02 Jan 1964
