A short note on the catch composition and weight-length relationship of tunas, billfishes and sharks of north Brazil

Asano-Filho, Mutsuo; Holanda, Francisco Carlos Alberto Fonteles; Santos, Francisco José da Silva; Lucena, Flávia; Pantaleão, Gisele de Sousa Lima

doi:10.1590/s1679-87592004000300008

Cited by 6 publications

(5 citation statements)

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“…Males dominated all bimesters except bimester IV (July-August). We found similar proportions in the bimesters I, IV, and V. These values differed from those reported in other studies, where the females dominated the samples in the Atlantic Ocean (García-Cortéz & Mejuto, 2002;Asano-Filho et al, 2004;Coelho et al, 2009;Travassos-Tolotti et al, 2013;Ruiz-Abierno et al, 2021b). This sex ratio is reported in the Mexican Central Pacific for the first time.…”

Section: Discussionsupporting

confidence: 55%

SEX RATIO AND SIZE STRUCTURE OF Carcharhinus longimanus, Galeocerdo cuvier AND, Alopias superciliosus INCIDENTALLY CAUGHT IN A LONGLINE FISHERY FROM THE CENTRAL MEXICAN PACIFIC

Márquez-Farías,

Carrillo-Colín,

Santana-Hernández

et al. 2023

ACMAR

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Knowledge of life history and fish reproduction is essential to understand the population dynamics of exploited shark populations. We provide information regarding the length, weight, and sex ratio of Carcharhinus longimanus (oceanic whitetip shark), Galeocerdo cuvier (tiger sharks), and Alopias superciliosus (bigeye thresher sharks) from longline boats based on Manzanillo (39–45 m longline vessels), Colima, Mexico, from 1986 to 2001. We analyzed a total of 264 oceanic whitetip sharks with 107 females (86-186 cm FL) and 157 males (68-184 cm FL); 67 tiger sharks with 36 females (105-193 cm FL) and 31 males (103-207 cm FL) and 67 bigeye thresher sharks with 22 females (131-209 cm FL) and 45 males (138-204 cm FL). The sex ratio for the whole sample differed significantly from the expected 1:1 in the oceanic whitetip shark and bigeye thresher shark, probably due to the mobility nature of the species. The length-frequency distribution of the bigeye thresher shark revealed a high frequency of individuals of large size in the catches. This shark is, on average, larger and heavier than the oceanic whitetip shark and the tiger shark. Factors affecting the catch susceptibility of this particular group of species and their lengths (or ages) are discussed. Keywords: Length-frequency, life history, Mexican Pacific, pelagic sharks

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Section: Discussionsupporting

confidence: 55%

SEX RATIO AND SIZE STRUCTURE OF Carcharhinus longimanus, Galeocerdo cuvier AND, Alopias superciliosus INCIDENTALLY CAUGHT IN A LONGLINE FISHERY FROM THE CENTRAL MEXICAN PACIFIC

Márquez-Farías,

Carrillo-Colín,

Santana-Hernández

et al. 2023

ACMAR

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“…Samplings from leased vessels based in Natal (RN) and Santos (SP) have provided information on morphometrics, age and growth, diet, and size structure (Zavala-Camin, 1978;Fagundes et al, 2001). More recently, the bigeye tuna was abundantly recorded in experimental fisheries carried out from 2000 to 2002 in the area from 02 to 05 o N, where the CPUE was 22 Kg/100 hooks, composing 38.7 % of the overall tuna catch (Asano-Filho et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

2012

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The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on the species, considering both the statistical and methodological contexts. Samples were collected in Natal city (Rio Grande do Norte State, Brazil) from February 1999 to January 2000, of tuna vessels and from surveys, aimed at providing information on the Brazilian Exclusive Economic Zone (EEZ) in the area around São Pedro and São Paulo Archipelago. Validation using marginal increment indicated that one ring is deposited per year. Mean length-at-age ranged of 54.3 to 177.5 cm (fork length) for ages 1 to 9 years. Von Bertalanffy, Richards, and Gompertz models were considered suitable for the bigeye tuna. Hence, the model-averaged asymptotic length ¯L∞ was estimated. The averaged model generated in the present study by back-calculation was considered appropriate for describing the growth of T. obesus.
A proposta do presente estudo foi fornecer a primeira informação sobre idade e crescimento de Thunnus obesus, capturado no Atlântico sudoeste equatorial usando espinhos dorsais, uma abordagem que tem sido utilizada com sucesso na determinação de idade de espécies de atuns. O estudo foi conduzido usando uma inferência de multi-modelos baseada na teoria de informação avaliada para dados de comprimento por idade retrocalculados e observados. Incertezas associadas aos parâmetros foram verificadas e os resultados foram comparados aos de outros estudos realizados para esta espécie, considerando os contextos estatísticos e metodológicos. As amostras foram coletadas na cidade de Natal (estado do Rio Grande do Norte, Brasil) de fevereiro de 1999 a janeiro de 2000, provenientes de embarcações comerciais e também prospecções, cujo objetivo foi prover informações sobre a Zona Econômica Exclusiva (ZEE) na área do entorno do Arquipélago de São Pedro e São Paulo. A validação usando incremento marginal indicou a deposição de um anel anual. Os comprimentos médios por idade variaram entre 54.3 a 175.7 cm (comprimento furcal) para idades de 1 a 9 anos. Os modelos Von Bertalanffy, Richards e Gompertz foram considerados adequados para a albacora bandolim e, desta forma, o comprimento assintótico para um modelo médio (¯L∞) foi estimado. O modelo médio gerado no presente estudo a partir dos comprimentos retrocalculados foi considerado apropriado para descrever o crescimento de T. obesus capturada no Atlântico

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“…Higher CPUE values were estimated for the third quarter (winter), which may be related to the migratory cycle of T. albacares proposed by Hazin (1993) for the equatorial Atlantic and cited by Asano‐Filho et al (2004) and Lan et al (2011), who suggest the occurrence of a migratory process in the east–west direction between April and June. According to Hazin (1993) and Zagaglia et al (2004), this short‐scale migration is benefitted by favourable thermal conditions as a function of the 27 and 28°C isotherms, which have seasonal meridional movements, allowing the T. albacares school to remain closer to Brazil in particular times of the year, especially the first and second quarters.…”

Section: Discussionmentioning

confidence: 68%

Section: Spatiotemporal Variation In Size Structure and Relationships...mentioning

confidence: 68%

Interactions between oceanographic variables and population structure of the yellowfin tuna Thunnus albacares (Bonnaterre, 1788) in the Western Central Atlantic

Nóbrega¹,

Lira

Oliveira³

et al. 2022

Fisheries Oceanography

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Pelagic fish species, such as tunas, represent important resources for the fishing fleets of several countries. Identifying spatiotemporal distributions of abundance, structure of sizes, weights and influences of environmental variables is extremely important to promote sustainable catches and efficient management plans for fisheries stocks. This present study aimed to analyse the spatiotemporal distribution of Thunnus albacares, their relationships with oceanographic variables, as well as size and weight structure, and the proportions of life stages/phases in catches, mainly within the Brazilian Exclusive Economic Zone. Data were obtained on longline fleet catches; the sea surface temperature (SST) and chlorophyll‐a (Chla) were measured in an area ranging from 42.2° to 24.8° W and 5.9° S to 8.8° N; the lunar cycle was also studied. Generalised Additive Models and spatial statistics techniques were used to model the effect of the variables on catch per unit effort (CPUE) and on length structure. The results indicate that the distribution, abundance and length structure of T. albacares are strongly associated with environmental (SST and Chla), temporal (year, months, seasons and moon phases) and spatial (latitude, longitude and hemisphere) variables. The comparison of catch sizes with the first length at maturity (L50) indicated that approximately half of the catches are on young specimens, showing great variation over the years, reaching 74.8% in 2012. These results show that providences should be taken focusing on mitigating young specimens' capture and the sustainable exploitation of tuna in the Atlantic. The patterns of CPUE and length strongly support the feeding and spawning migration hypotheses.

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A short note on the catch composition and weight-length relationship of tunas, billfishes and sharks of north Brazil

Cited by 6 publications

References 1 publication

SEX RATIO AND SIZE STRUCTURE OF Carcharhinus longimanus, Galeocerdo cuvier AND, Alopias superciliosus INCIDENTALLY CAUGHT IN A LONGLINE FISHERY FROM THE CENTRAL MEXICAN PACIFIC

SEX RATIO AND SIZE STRUCTURE OF Carcharhinus longimanus, Galeocerdo cuvier AND, Alopias superciliosus INCIDENTALLY CAUGHT IN A LONGLINE FISHERY FROM THE CENTRAL MEXICAN PACIFIC

Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

Interactions between oceanographic variables and population structure of the yellowfin tuna Thunnus albacares (Bonnaterre, 1788) in the Western Central Atlantic

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