Protection of Marine Fish Stocks at Risk of Extinction

Musick, J. A.; Berkeley, Steve; Cailliet, Gregor M.; Camhi, Merry; Huntsman, Gene R.; Nammack, Marta; Warren, Melvin L.

doi:10.1577/1548-8446(2000)025<0006:pomfsa>2.0.co;2

Cited by 80 publications

(28 citation statements)

References 5 publications

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“…The growth parameters showed that this shark is a slow growth and long-lived species, which has consequently a low resilience to overfishing. Estimates of the intrinsic rate of increase for Sphyrna lewini (r ~ 0.08 -0.105 year -1 ) are low and fall under the low productivity category (r < 0.14) (Musick et al, 2000; Consideration of proposals for Amendment of Appendices I and II, 2010). Therefore, Sphyrna lewini is a low-productivity species, and is likely to become threatened with extinction unless international fin trade and bycatch regulations, such as monitoring and closure areas, are established.…”

Section: Discussionmentioning

confidence: 99%

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Kotas¹,

Mastrochirico

Petrere

2011

Braz. J. Biol.

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Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL). The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L ∞ = 266 cm; K = 0.05/year; L 0 = 47 cm. For females, L ∞ = 300 cm; K = 0.05/year; L 0 = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter.Keywords: elasmobranchs, fisheries biology, conservation.Idade e crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834), da costa sul do Brasil ResumoO estudo da idade e do crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834), na costa sul do Brasil, baseou-se na leitura de anéis em seções de vértebras de 115 machos, 116 fêmeas e de 14 exemplares com sexo indeterminado, com comprimentos totais (CT) entre 48 e 344 cm. Modelos de crescimento de von Bertalanffy foram mais bem ajustados aos dados de idade e comprimento retrocalculados, considerando sexos em separado. Os parâmetros de crescimento obtidos para os machos foram L ∞ = 266 cm; K = 0,05/ano; L 0 = 47 cm. Para as fêmeas L ∞ = 300 cm; K = 0,05/ano; L 0 = 51 cm. Uma fêmea adulta atingiu um CT de 217 cm e uma idade de 31,5 anos. Por sua vez, um macho adulto tinha 29,5 anos e CT de 234 cm. A estimativa de longevidade para machos e fêmeas foi de 55 anos. O índice de erro percentual médio (IAPE), que avalia a precisão na leitura de idades, foi de 5,6%. A análise do incremento marginal baseada no índice MIR e aplicada em tubarões com CT < 105 cm, comparada com o percentual de bandas opacas e hialinas mensais, obtido através de leituras de vértebras inteiras, indicou um padrão anual na formação dos anéis, ou seja, anéis de inverno.Palavras-chave: elasmobrânquios, biologia pesqueira, conservação.

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Section: Discussionmentioning

confidence: 99%

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Kotas¹,

Mastrochirico

Petrere

2011

Braz. J. Biol.

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“…The reproductive characteristics of other three hermaphrodite grouper species studied by Coleman et al (1996), and Sluka AND Sullivan, (1988) showed that these characteristics may affect stocks sustainability. Nowadays it is known that some protogynous stocks may be far more vulnerable to fishing than are comparable gonochoristic stocks (Schaaf and Huntsman, 1994;Musick et al, 2001;Coleman et al, 2001). Many reef fishes are known to aggregate in large numbers at specific times and places to reproduce.…”

Section: (68/76 Dqg '6and86621mentioning

confidence: 99%

Reproductive biology of the dusky grouper Epinephelus marginatus (Lowe, 1834)

Bertoncini

Machado

Hostim‐Silva

et al. 2003

Braz. arch. biol. technol.

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Investigations were carried out about the reproductive biology of the dusky grouper, Epinephelus marginatus (Lowe, 1834) a serranid protogynous hermaphrodite fish inhabitant of rocky bottoms from shallow waters up to 200 m depth. Samples were caught in the islands that form Arvoredo Biological Marine Reserve (SC - Brazil) and the coastal islands near Florianópolis region from March 1998 to May 2000. Data from samples of juvenile groupers on intertidal pools were used to link their occurrence in the pools to the post-spawning season. To describe the histological changes on gonads along the reproductive cycle and to establish maturation scales, 109 groupers were histologically tested for sex determination. First maturation size was determined for females (L50=470 mm; r²=0.99). The results of calculated gonadosomatic (GSI) and hepatosomatic (HSI) indexes, showed that maturation occurred along the spring months and the spawning activity during the summer with a peak in December. Liver recovery (HSI elevation) was evident in the autumn, was the post spawning season. The relationship between length and weight was W = 9 · 10-6 · TL3.1149 (r²=0.998; n=246).
Este trabalho trata sobre a biologia reprodutiva da garoupa verdadeira, Epinephelus marginatus (Lowe, 1834) um peixe teleósteo pertencente à família Serranidae, hermafrodita protogínico e característico do litoral rochoso, que vive desde águas rasas até os 200 m de profundidade. As amostragens foram realizadas nas ilhas que compõem a Reserva Biológica Marinha do Arvoredo (SC) e ilhas costeiras próximas da região de Florianópolis entre março de 1998 e maio de 2000. Dados de coletas de juvenis em poças de marés foram utilizados visando relacionar a sua ocorrência nestes ambientes com o período de pós-reprodução. Procedeu-se à análise histológica de 109 exemplares, a partir da qual foram descritas as alterações histológicas nas gônadas ao longo do seu ciclo sexual e foram estabelecidas as escalas de maturação. Desta forma determinou-se um tamanho de primeira maturação para as fêmeas (L50=470 mm; r²=0,99). O comportamento dos valores dos índices calculados (Índice Hepatossomático (IHS) e Índice Gonadossomático (IGS)) elucidou um período reprodutivo com maturação das gônadas ao longo dos meses de primavera, vindo a desovar na estação do verão, sendo nítida a recuperação do fígado (elevação do IHS) no outono, pós reprodução. Calculou-se também a relação peso comprimento P = 9 · 10-6 · CT 3,1149 (r²=0,998; n=246)

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“…Contemporary approaches to inform stock vulnerability or status for data-poor situations take the form of state indicators (Garcia and Staples 2000;Jennings 2005), qualitative risk assessments (Stobutzki et al 2001), and inferences about vulnerability based on life history characteristics (Musick et al 2000;King and McFarlane 2003). Such approaches strive to apply transparent protocols to simple or limited data.…”

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confidence: 99%

Length‐Based Reference Points for Data‐Limited Situations: Applications and Restrictions

2009

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Current fisheries management policies generally require an assessment of stock status, which is a difficult task when population and fisheries data are limited. Three simple metrics based on catch length compositions (i.e., that reflect exclusive take of mature individuals, P mat; that consist primarily of fish of optimal size, the size at which the highest yield from a cohort occurs, P opt; and that demonstrate the conservation of large, mature individuals, P mega) can be used to monitor population status relative to exploitation. The metrics (collectively referred to as Px) were intended to avoid growth and recruitment overfishing, but there was no quantitative linkage to stock status and calculation of future sustainable catches. We attempt to make this connection by exploring the relationship of Px measures to fishing mortality and spawning biomass (SB). The relationships are compared specifically to the current target reference point (0.4 times the virgin, or unfished, SB [SB0]) and limit reference point (0.25SB0) used for the U.S. West Coast groundfish fishery by using simulations based on a deterministic age‐structured population dynamics model. Sensitivity to fishery selectivity, life history traits, and recruitment compensation (steepness) is explored. Each Px measure showed a wide range of possible values depending on fishery selectivity, steepness, and the ratio of the length at maturity (L mat) to the optimal fishing length (L opt). Although the values of Px may be compatible with sustainable fishing, these values are not always sufficient to ensure stock protection from overfishing. Moreover, values for Px cannot be interpreted adequately without knowledge of the selectivity pattern. A new measure, P obj (the sum of P mat, P opt, and P mega), is introduced to distinguish selectivity patterns and construct a decision tree for development of stock status indicators. Heuristic indicator values are presented to demonstrate the utility of this approach. Although several caveats remain, this approach builds on the recommendations of previous literature by giving further guidance related to interpreting catch length composition data under variable fishery conditions without collecting additional information. It also provides a link to developing harvest control rules that inform proactive fisheries management under data‐limited conditions.

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Protection of Marine Fish Stocks at Risk of Extinction

Cited by 80 publications

References 5 publications

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

Reproductive biology of the dusky grouper Epinephelus marginatus (Lowe, 1834)

Length‐Based Reference Points for Data‐Limited Situations: Applications and Restrictions

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