Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-04T20:12:54.148Z Has data issue: false hasContentIssue false

Population structure of nurse sharks, Ginglymostoma cirratum (Orectolobiformes), caught off Ceará State, Brazil, south-western Equatorial Atlantic

Published online by Cambridge University Press:  18 October 2010

Jones Santander-Neto
Affiliation:
Universidade Federal Rural de Pernambuco, Departamento de Pesca e Aqüicultura, Avenida Dom Manuel de Medeiros s/n, Dois Irmãos, CEP 52171-900, Recife, PE, Brazil
Renata A. Shinozaki-Mendes
Affiliation:
Universidade Federal Rural de Pernambuco, Departamento de Pesca e Aqüicultura, Avenida Dom Manuel de Medeiros s/n, Dois Irmãos, CEP 52171-900, Recife, PE, Brazil
Leonardo M. Silveira
Affiliation:
Universidade Federal do Ceará, Departamento de Engenharia de Pesca, Avenida Mister Hull, s/n, CEP 60021-970, Fortaleza, CE, Brazil
Bruno Jucá-Queiroz
Affiliation:
Universidade Federal do Ceará, Departamento de Engenharia de Pesca, Avenida Mister Hull, s/n, CEP 60021-970, Fortaleza, CE, Brazil
Manuel A.A. Furtado-Neto
Affiliation:
Universidade Federal do Ceará, Departamento de Engenharia de Pesca, Avenida Mister Hull, s/n, CEP 60021-970, Fortaleza, CE, Brazil Universidade Federal do Ceará, Instituto de Ciências do Mar (LABOMAR), Avenida da Abolição, 3207, Meireles, CEP 60165-081, Fortaleza, CE, Brazil
Vicente V. Faria*
Affiliation:
Universidade Federal do Ceará, Instituto de Ciências do Mar (LABOMAR), Avenida da Abolição, 3207, Meireles, CEP 60165-081, Fortaleza, CE, Brazil
*
Correspondence should be addressed to: V.V. Faria, Universidade Federal do Ceará, Instituto de Ciências do Mar (LABOMAR), Avenida da Abolição, 3207, Meireles, CEP 60165-081, Fortaleza, CE, Brazil email: [email protected]

Abstract

The nurse shark, Ginglymostoma cirratum, is considered an endangered species in Brazil and its capture by fisheries forbidden. Despite such legislation, nurse sharks continue to be caught as these laws are unenforced and fisheries are not monitored. The goal of the present study was to describe the population structure of nurse sharks caught off Ceará State, north-eastern Brazil, based on the following aspects: abundance and size, sex-ratio, fisheries incidence and seasonality of captures. Landings were monitored weekly during a two-year period. A total of 189 specimens were recorded. Total length (TL) varied between 73 and 274 cm. The male–female ratio did not differ significantly (1.19♀:1♂). TL of individuals landed as carcasses was estimated based on interdorsal length. The following equation was obtained for males and females: TL = 12.606ID + 14.24 (R2 = 0.9505). Most of the landed sharks were juveniles (86.2%). No seasonal pattern of abundance and TL variation was observed. Management of this fishery is required in order to prevent localized over-fishing of nurse sharks.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Arthaud, I.D.B. (1999) Fauna de tubarões alvo da pesca artesanal na praia de Mucuripe, Fortaleza—CE (Chondrichthyes, Elasmobranchii). BSc Monograph. Federal University of Ceará—UFC Fortaleza, Brazil.Google Scholar
Bradshaw, C.J.A., Fitzpatrick, B.M., Steinberg, C.C., Brook, B.W. and Meekan, M.G. (2008) Decline in whale shark size and abundance at Ningaloo Reef over the past decade: the world's largest fish is getting smaller. Biological Conservation 141, 18941905.CrossRefGoogle Scholar
Cadenat, J. and Blache, J. (1981). Requins de Méditerranée et d'Atlantique (plus particulièrement de la côte occidentale d'Afrique). Paris: Office de la Recherche Scientifique et Technique Outre-Men (ORSTOM). [Faune Tropicale Series, No. 21.]Google Scholar
Carrier, J.C. (1985) Nurse sharks of Big Pine Key: comparative success of three types of external tags. Florida Scientist 48, 146154.Google Scholar
Carrier, J.C. and Luer, C.A. (1990) Growth rates in the nurse shark, Ginglymostoma cirratum. Copeia 1990, 686692.CrossRefGoogle Scholar
Castro, J.I. (2000) The biology of the nurse shark, Ginglymostoma cirratum, off the Florida East Coast and the Bahama Islands. Environmental Biology of Fishes 58, 122.CrossRefGoogle Scholar
Castro, A.L.F. and Rosa, R.S. (2005) Use of natural marks on population estimates of the nurse shark, Ginglymostoma cirratum, at Atol das Rocas Biological Reserve, Brazil. Environmental Biology of Fishes 72, 213221.CrossRefGoogle Scholar
Compagno, L.J.V., Dando, M. and Fowler, S. (2005) Sharks of the world. Princeton: Princeton University Press.Google Scholar
Garla, R.C., Garcia-Júnior, J., Veras, L.B. and Lopes, N.P. (2008) Fernando de Noronha as an insular nursery area for lemon sharks, Negaprion brevirostris, and nurse sharks, Ginglymostoma cirratum, in the equatorial western Atlantic Ocean. JMBA2—Biodiversity Records (published online: http://www.mba.ac.uk/jmba/pdf/6163.pdf).CrossRefGoogle Scholar
Jennings, S., Reynolds, J.D. and Mills, S.C. (1998) Life history correlates of responses to fisheries exploitation. Proceedings of the Royal Society of London B 265, 333339.CrossRefGoogle Scholar
Kohler, N.E., Casey, J.G. and Turner, P.A. (1998) NMFS Cooperative Shark Tagging Program, 1962–93: an atlas of shark tag and recapture data. Marine Fisheries Review 60, 187.Google Scholar
Rosa, R.S., Castro, A.L.F., Furtado-Neto, M., Monzini, J. and Grubs, R.D. (2006a) ‘Ginglymostoma cirratum’. In IUCN 2008. 2008 IUCN Red List of Threatened Species. Available at http://www.iucnredlist.org (accessed 3 May 2009).Google Scholar
Rosa, R.S., Castro, A.L.F., Furtado-Neto, M., Monzini, J. and Grubs, R.D. (2006b) ‘Ginglymostoma cirratum(Western Atlantic subpopulation). In IUCN 2008. 2008 IUCN Red List of Threatened Species. Available at http://www.iucnredlist.org (accessed 3 May 2009).Google Scholar
Rosa, R.S. and Gadig, O.B.F. (2008) ‘Ginglymostoma cirratum’ In Machado, A.B.M., Drummond, G.M. and Paglia, A.P. (eds) Livro vermelho da fauna brasileira ameaçada de extinção. Volume 2. Brasília: Ministério do Meio Ambiente, pp. 2829.Google Scholar
SSG (2004) IUCN/SSC Shark Specialist Group Report. IUCN Species Survival Commission 2000–2004 Quadrennial Reports. The World Conservation Union. CD-ROM.Google Scholar
Walker, T. (1998) Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries. Marine and Freshwater Research 49, 553572.CrossRefGoogle Scholar
Zar, J.H. (1999) Biostatistical analysis, 4th edition. Upper Saddle River, NJ: Prentice-Hall.Google Scholar