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

Matsuura, Yasunobu

doi:10.1590/S0373-55241977000200005

Abstracts

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.

Um dos objetivos do estudo quantitativo do ictioplâncton é esclarecer a relação entre a mortalidade de larvas e o recrutamento do estoque nos anos sucessivos. Para computar a abundância de larvas é necessário obter as informações sobre a eficiência da captura. Dois fatores têm que ser considerados: um, o escape de larvas pequenas através da malha da rede e, outro, a "avoidance" de larvas maiores durante o dia. Este trabalho apresenta as observações feitas sobre a variação diurna de ocorrência de larvas de peixes, realizadas em 1969 e 1971 em duas estações fixas localizadas no sul do Brasil. As larvas mais abundantes pertenciam a Sardinella brasilensis. Outras que predominaram foram: Bregmaceros atlanticus, Euthynnus allettevatus e Havengula spp. Foram observadas coletas mais abundantes de larvas de sardinha na camada superior. As larvas de sardinha foram coletadas principalmente durante a noite. O "undersampling" foi considerado devido à "avoidance". A razão entre capturas médias durante a noite e o dia foi tão grande que é preciso uma consideração sobre o fator de "avoidance" das larvas de sardinha para a computaçao de abundância do mesmo.

A study of the undersampling problem of fish larvae observed at the fixed stations in south Brazil^* * This paper was presented at the CICAR Ichthyoplankton Workshop (UNESCO) 1974, México City.

Yasunobu Matsuura

Instituto Oceanográfico da Universidade de São Paulo

SYNOPSIS

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.

RESUMO

Um dos objetivos do estudo quantitativo do ictioplâncton é esclarecer a relação entre a mortalidade de larvas e o recrutamento do estoque nos anos sucessivos.

Para computar a abundância de larvas é necessário obter as informações sobre a eficiência da captura. Dois fatores têm que ser considerados: um, o escape de larvas pequenas através da malha da rede e, outro, a "avoidance" de larvas maiores durante o dia.

Este trabalho apresenta as observações feitas sobre a variação diurna de ocorrência de larvas de peixes, realizadas em 1969 e 1971 em duas estações fixas localizadas no sul do Brasil.

As larvas mais abundantes pertenciam a Sardinella brasilensis. Outras que predominaram foram: Bregmaceros atlanticus, Euthynnus allettevatus e Havengula spp. Foram observadas coletas mais abundantes de larvas de sardinha na camada superior.

As larvas de sardinha foram coletadas principalmente durante a noite. O "undersampling" foi considerado devido à "avoidance". A razão entre capturas médias durante a noite e o dia foi tão grande que é preciso uma consideração sobre o fator de "avoidance" das larvas de sardinha para a computaçao de abundância do mesmo.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

(Received March 25, 1976)

AHLSTROM, E. H. 1954. Distribution and abundance of egg and larval populations of the Pacific sardine. Fishery Bull. Fish Wildl. Serv. U.S., 56(93): 83-140.
______ 1959. Vertical distribution of pelagic fish eggs and larvae off California and Baja California. Fishery Bull. Fish Wildl. Serv. U.S., 60(161):107-146.
______ 1965. A review of the effects of the environment of the Pacific sardine. Spec. Pubis int. Comn. NW. Atlant. Fish., (6):53-74.
BRIDGER, J. P. 1956. On day and night variation in catches of fish larvae. J. Cons. perm. int. Explor. Mer, 22(1):42-57.
______ 1958. On efficiency tests made with a modified Gulf III high-speed tow net. J. Cons. perm. int. Explor. Mer, 23(3):357-365.
CLUTTER, R. I. & ANRAKU, M. 1968. Avoidance of samplers. In: Zooplankton sampling. Monogr. oceanogr. Methodol., (2):57-76.
ISAACS, J. D. 1964. Night-caught and day-caught larvae of the California sardine. Science, N.Y., 144(3622):1132-1133.
RUSSEL, F. S. 1926. The vertical distribution of marine macroplankton. 3. Diurnal observations on the pelagic young of teleostean fishes in the Plymouth area. J. mar. biol. Ass. U. K., 14:387-414.
______ 1928. The vertical distribution of marine macroplankton. 8. Further observations on the diurnal behaviour of the pelagic young of teleostean fishes in the Plymouth area. J. mar. biol. Ass. U. K., 15: 829-850.
SILLIMAN, R. P. 1943. Studies on the Pacific pilchard or sardine (Sardinops caerulea) 6. Thermal and diurnal changes in the vertical distribution of eggs and larvae. Spec. Scient. Rep., U. S. Fish Wildl. Serv., (22):1-17.
UNESCO. 1968. Reports of ICES SCOR-UNESCO Symposium of hydrodynamics of plankton samplers and the meeting of working party 3. In: Zooplankton sampling. Monogr. oceanogr. Methodol., (2):160-163.
WALLACE, W. 1924. First report on young herring in the southern North sea and English channel. Part 1. Distribution and growth of larval and post-larval stages. Fishery Invest., Lond., Ser. II, 7(4).
WHITEHEAD, P. J. P. 1973. The clupeid fishes of the Guianas. Bull. Br. Mus. nat. Hist., Zool., 25(suppl. 5):1-227.

*

This paper was presented at the CICAR Ichthyoplankton Workshop (UNESCO) 1974, México City.

Publication Dates

Publication in this collection
06 June 2012
Date of issue
1977

History

Received
25 Mar 1976

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] AHLSTROM, E. H. 1954. Distribution and abundance of egg and larval populations of the Pacific sardine. Fishery Bull. Fish Wildl. Serv. U.S., 56(93): 83-140.

[2] ______ 1959. Vertical distribution of pelagic fish eggs and larvae off California and Baja California. Fishery Bull. Fish Wildl. Serv. U.S., 60(161):107-146.

[3] ______ 1965. A review of the effects of the environment of the Pacific sardine. Spec. Pubis int. Comn. NW. Atlant. Fish., (6):53-74.

[4] BRIDGER, J. P. 1956. On day and night variation in catches of fish larvae. J. Cons. perm. int. Explor. Mer, 22(1):42-57.

[5] ______ 1958. On efficiency tests made with a modified Gulf III high-speed tow net. J. Cons. perm. int. Explor. Mer, 23(3):357-365.

[6] CLUTTER, R. I. & ANRAKU, M. 1968. Avoidance of samplers. In: Zooplankton sampling. Monogr. oceanogr. Methodol., (2):57-76.

[7] ISAACS, J. D. 1964. Night-caught and day-caught larvae of the California sardine. Science, N.Y., 144(3622):1132-1133.

[8] RUSSEL, F. S. 1926. The vertical distribution of marine macroplankton. 3. Diurnal observations on the pelagic young of teleostean fishes in the Plymouth area. J. mar. biol. Ass. U. K., 14:387-414.

[9] ______ 1928. The vertical distribution of marine macroplankton. 8. Further observations on the diurnal behaviour of the pelagic young of teleostean fishes in the Plymouth area. J. mar. biol. Ass. U. K., 15: 829-850.

[10] SILLIMAN, R. P. 1943. Studies on the Pacific pilchard or sardine (Sardinops caerulea) 6. Thermal and diurnal changes in the vertical distribution of eggs and larvae. Spec. Scient. Rep., U. S. Fish Wildl. Serv., (22):1-17.

[11] UNESCO. 1968. Reports of ICES SCOR-UNESCO Symposium of hydrodynamics of plankton samplers and the meeting of working party 3. In: Zooplankton sampling. Monogr. oceanogr. Methodol., (2):160-163.

[12] WALLACE, W. 1924. First report on young herring in the southern North sea and English channel. Part 1. Distribution and growth of larval and post-larval stages. Fishery Invest., Lond., Ser. II, 7(4).

[13] WHITEHEAD, P. J. P. 1973. The clupeid fishes of the Guianas. Bull. Br. Mus. nat. Hist., Zool., 25(suppl. 5):1-227.