The Black Dogfish in the Gulf of St. Lawrence
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• STOCK STATUS REPORT LAURENTIAN REGION Maurice Lamontagne Institute P.O. Box. 1000, Mont-Joli, Qudbec, GSH 3Z4, CANADA June 1996 DFO, Atlantic Fisheries, Stock Status Report 96/6 1 THE BLACK DOGFISH IN THE GULF OF ST. LAWRENCE which means that the eggs develop inside the female and young sharks are born almost fully formed. The embryos, which are carried in small numbers, may grow to 14 cm (5'/z") in length . It is presumed that, as is true of all sharks in the • Squalidae family, it grows slowly, reaches sexual maturity at a late age and has low fertility . OVERVIEW OF THE BLACK DOGFISH STATE OF THE RESOURCE The black dogfish (Centroscyllium fabricii) is a small shark with a wide Information on the black dogfish in the distribution throughout the North Atlantic Gulf of St. Lawrence comes primarily along the continental shelf, at depths of from research surveys . Some information 275 to 1,400 m (150 to 750 fathoms) . Its is also available from deepwater fishery distribution is thought to extend from the by-catches (redfish and shrimp), but these Gulf of Mexico to Iceland and Morocco, by-catches are always discarded . and perhaps as far as South Africa. Observations that have been made during Despite the black dogfish's wide summer surveys carried out aboard the distribution and great abundance, almost Alfred Needler since 1990 show that, in nothing is known about its biology, apa rt the Gulf, the black dogfish is limited to from a few brief references to its the deep waters (more than 275 m) of the taxonomy and occurrence . Like all sharks Laurentian Channel . It is generally found in the Squalidae family, of which it is a from the Sept Iles region as far as Cabot member, the black dogfish is ovoviparous , Strait and outside the Gulf (Figure 1) . Pêches Rs#teries FIet oawns and oceans Cmadâ Laurentian Region DFO, Atlantic Fisheries Stock Status Report 96/61 information on movements and interactions between concentrations of black dogfish. However, because of its biological characteristics (it is believed to grow slowly and mature late, and it definitely has low fertility), the black dogfish may be harmed by commercial exploitation . Should markets develop and catches increase, it will be necessa ry to act cautiously when the fishery is expanded . For more information : Scott, W . B ., and M. G. Scott . 1988. Atlantic Fishes of Canada . Can . Bull . Fish . Aquat . Sci . 219 : 731 p . Templeman, W ., 1966 . Distribution of .Sharks in the Canadiân Atlantic . Bull . Fish. Res . Board Can . 140 : 83 p . Prepared by: • Dominique Gascon Tel : (418) 775-0631 Fax : (418) 775-0740 E-mail : d_gascon@qc .dfo .ca This report is available :,, ;; .: Stock Assessment `Regionil -Office Laurentian Region Department of Fisheries`"and Maurice-Lamontagne .Ïnstitnte;,:y, P.O. .Box .1000, Mont-Joli : ; Québec ._.: `.: G5H 3Z4 La version française de tx 'document -est • disponible à l'adresse ci-dessus .. ; ` '- -. ° ~ 4 June 1996 • Aiguillat noir dans le golfe du Saint-Laurent . L'aiguillat noir est un petit requin apparenté à l'aiguillat commun qu*on retrouve dans les eaux profondes du Golfe . À peu près rien n'est connu de sa biologie. mais on peut présumer qu'elle ressemble à celle de l'aiguillat commun : croissance lente, maturité tardive. et fécondité réduite. Cette espèce est probablement sensible à une exploitation le moindrement intense . Il n'y a pas pour l'instant d'exploitation, mais certains producteurs veulent mettre en marché 450 t d'aiguillat noir à titre expérimental . La seule information sur son abondance provient des relevés de recherche: à cause de sa nature grégaire, les résultats sont très variables et il est difficile de se faire une idée précise de son abondance . Cependant, le niveau de capture proposé ne représente qu'environ 13% de la plus faible estimation de biomasse entre 1990 et 1995 et ne mettra pas en risque la conservation de l'espèce à court terme . Il est cependant impossible de prédire pour l'instant quel pourrait être un niveau soutenable de captures. • :~ .