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1.
J Fish Biol ; 81(3): 1133-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22880744

RESUMO

The whalefish Cetichthys indagator is reported for the first time in the North Atlantic Ocean. This record increases to five the number of specimens ever caught and represents the northernmost occurrence of this species in the northern hemisphere.


Assuntos
Peixes/anatomia & histologia , Animais , Oceano Atlântico , Peixes/classificação , Especificidade da Espécie
2.
J Fish Biol ; 80(2): 427-43, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22268439

RESUMO

The chemistry of black seabream Spondyliosoma cantharus otoliths from three main fishery grounds (Olhão, Sagres and Sesimbra) located along c. 400 km of the Portuguese south and west coasts was examined. Element:Ca ratios were determined in whole otoliths and otolith cores of young adult specimens of 2-3 years of age. Using the data from whole otoliths, it was possible to discriminate among S. cantharus from the three fishing grounds with an average accuracy of 91%. Differences among fishing grounds were significant for all element:Ca ratios, and otoliths from Sagres had significantly higher levels of all ratios compared to the other fishing grounds. In contrast, the chemical composition of the otolith core, representative of the larval stage, showed limited variation among the fishing grounds, with an average discrimination accuracy of only 44%, although the Mg:Ca ratio of the otolith cores was also significantly higher for the Sagres samples. The data suggest that larval stages experienced a homogenous environment consistent with an offshore oceanic spawning. Juveniles appeared to display local residency on the inshore fishing grounds, areas probably characterized by greater environmental heterogeneity. Spondyliosoma cantharus population structure is consistent with distinct local population units that share a spawning ground providing recruits to different coastal fishery areas.


Assuntos
Meio Ambiente , Membrana dos Otólitos/química , Dourada , Animais , Oceano Atlântico , Larva , Dinâmica Populacional , Portugal
3.
J Fish Biol ; 76(9): 2216-37, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20557660

RESUMO

Recreational shore fishing along 250 km of the south and south-west coast of Portugal was studied based on roving creel and aerial surveys. Surveys were conducted between August 2006 and July 2007, following a stratified random-sampling design and provided information on catch and effort, harvest and discards, angler demographics and fishing habits. Overall, 192 roving creel surveys, 24 aerial surveys and 1321 interviews were conducted. Based on the aerial surveys, a mean +/-s.e. total fishing effort of 705,236 +/- 32,765 angler h year(-1) was estimated, corresponding to 166,430 +/- 9792 fishing trips year(-1). Average time spent per fishing trip was 4.7 h. A total of 48 species, belonging to 22 families, were recorded in roving creel surveys. The most important species was Diplodus sargus, accounting for 44% of the total catches by number and 48% by mass. Estimated mean +/-s.e. total annual recreational shore fishing catch was 160.2 +/- 12.6 t year(-1) (788,049 +/- 54,079 fishes year(-1)), of which 147.4 +/- 11.9 t year(-1) (589,132 +/- 42,360 fishes year(-1)) was retained. Although overall shore-based recreational catches only corresponded to 0.8% of the commercial landings (only common species considered), D. sargus catches by recreational shore anglers were considerable, corresponding to 65% of the commercial landings. The implications of these results for integrated fisheries management and conservation are discussed, and future research proposed.


Assuntos
Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Pesqueiros/estatística & dados numéricos , Recreação , Animais , Oceano Atlântico , Peixes/classificação , Densidade Demográfica , Portugal
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