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Redfish (Sebastes spp.) in the Northwest Atlantic (NWA) extend from Baffin Island in the north to the Gulf of Maine in the south. The two most abundant species are Sebastes mentella and Sebastes fasciatus, which are morphometrically similar and difficult to visually distinguish. Redfish are long-lived, slow-growing, late-maturing, tend to produce large year classes episodically, and have complex population structure. Intraspecific genetic groups are abundant in the NWA. They are often semipelagic and patchily distributed, which makes them difficult to survey. These are all characteristics that cause difficulties for stock assessment and for sustainable fisheries management. This was the focus of The Ocean Frontier Institute Northwest Atlantic Redfish Symposium in 2018. In this paper, we synthesize the information known about NWA redfish. To improve the scientific basis for sustainable harvest strategies, key research recommendations involve (1) improved biological sampling including species and ecotype; (2) developing integrated stock assessment models; (3) developing harvest strategies with management reference points that are appropriate for redfish; (4) improving fishing technology and practices to avoid capture of small nonmarketable redfish and other species. Les sebastes (Sebastes spp.) dans l'Atlantique Nord-Ouest (ANO) sont presents de l'ile de Baffin au Nord jusqu'au golfe du Maine au Sud. Les deux especes les plus abondantes sont Sebastes mentella et Sebastes fasciatus, semblables sur le plan morphometrique et difficiles a distinguer visuellement. Les sebastes vivent longtemps, croissent lentement, maturent tardivement, ont tendance a produire episodiquement de grandes classes d'age, et la structure de leurs populations est complexe. Des groupes genetiques intraspecifiques sont abondants dans l'ANO. Ils sont souvent semi-pelagiques et ont une repartition parcellaire, ce qui rend leur recensement difficile. Toutes ces caracteristiques sont cause de difficultes pour l'evaluation des stocks et pour la gestion durable des peches et elles constituaient le theme central du symposium sur les sebastes de l'Atlantique Nord-Ouest de 2018 de l'Ocean Frontier Institute. Nous presentons une synthese de l'information connue sur les sebastes de l'ANO. Afin d'ameliorer les fondements scientifiques de strategies de recolte durables, les principales recommandations concernant la recherche comprennent (1) l'amelioration de l'echantillonnage biologique, notamment en ce qui concerne l'espece et l'ecotype, (2) l'elaboration de modeles integres d'evaluation des stocks, (3) l'elaboration de strategies de recolte qui integrent des points de reference de gestion adaptes aux sebastes et (4) l'amelioration des technologies et pratiques de peche pour eviter la prise de sebastes et poissons d'autres especes trop petits pour etre commercialisables. [Traduit par la Redaction], 1. Introduction Redfish (Sebastes spp.) are members of the Scorpaenidae family of bony fishes that are commonly found in waters of the North Pacific and North Atlantic. In the Northwest [...]

This study evaluated the link between swimming endurance and condition of Atlantic cod Gadus morhua that had been fed or starved during the 16 weeks preceding the tests, and assessed whether muscle metabolic capacities explain such links. The condition factor [(somatic mass × fork length-3) × 100] of starved cod was 0.54±0.1 whereas that of fed cod was 0.81±0.1. In white and red muscle, we measured four glyeolytic enzymes: phosphofructokinase (PFK), pyruvate kinase (PK), creatine kinase (CK) and lactate dehydrogenase (LDH), two mitochondrial enzymes: cytochrome c oxidase (CCO) and citrate synthase (CS), a biosynthetic enzyme, nueleoside diphosphate kinase (NDPK), glycogen and protein levels and water content. Muscle samples were taken at three positions along the length of the fish; starvation affected the metabolic capacities of white muscle more than those of red muscle. The levels of glycolytic enzymes and glycogen changed more in white than red muscle during starvation. Both in fed and starved cod, muscle metabolic capacities varied with position along the fish; starvation reduced this longitudinal variation more in white than red muscle. In white muscle of fed cod, the glycolytic enzyme levels increased from head to tail, while in starved cod this longitudinal variation disappeared. In red muscle mitochondrial enzyme levels were highest in the caudal sample, but fewer differences were found for glycolytic enzymes. Swimming endurance was markedly affected by fish condition, with starved fish swimming only 30% of the time (and distance) of fed fish. This endurance was closely linked with the number of burst-coast movements during the test and the activity of CCO and LDH in white muscle. The number of burst-coast movements was significantly linked with condition factor and PFK activity in caudal red muscle and gill arch mass. Our data indicated that cod use both glycolytic and oxidative capacities to support endurance swimming.... [ABSTRACT FROM AUTHOR]