Growth in length and mass, improvements condition, as well final condition of c. 700 g Atlantic cod Gadus morhua were significantly less at 45% 56% O 2 saturation than 65%, 75%, 84% 93% saturation. Hypoxia decreased food consumption. In turn, consumption explained 97% the variation growth. Conversion efficiency varied slightly, but significantly, with level dissolved , except that group reared had a lower expected conversion efficiency. Slow growth low was not due to increased activity,...

Specific dynamic action ( SDA ) is the postprandial increase in oxygen uptake. Whereas it easy to measure fishes that remain calm and motionless during entire digestion period, spontaneous locomotor activity a frequent problem leads overestimation of amplitude magnitude (area under curve, bound by standard metabolic rate, SMR ). Few studies have attempted remove effect fish on . A new method, non‐parametric quantile regression, described estimate even when pronounced circadian cycles are...

ABSTRACT Beaked redfishes ( Sebastes fasciatus and mentella ) of the northwest Atlantic have recently reached record abundance levels in estuary northern Gulf St. Lawrence, dominated by . Knowledge their diet composition is essential to understand trophic role that these groundfish play ecosystem. The objective present study was compare performance visual examination DNA metabarcoding stomach contents same individual redfish caught Lawrence. Using a universal metazoan mitochondrial...

Understanding the effects of global change, including temperature, pH, and oxygen availability, on commercially important species is crucial for anticipating consequences these resources their ecosystems. In Gulf St. Lawrence (GSL), redfish ( Sebastes spp. ) have been under moratorium from 1995 to 2024, with a massive recruitment observed in 2011–2013. However, little known about metabolic thermal physiology, making predictions response changing GSL conditions challenging. To address this,...

The rise in ocean temperatures predicted due to the global warming will impact survival and structure of various marine organisms, particular ectothermic organisms. Phenotypic plasticity enables species cope with environmental changes, providing a vital buffer for evolutionary changes. Yet, dynamics molecular mechanisms underpinning these plastic responses remain largely unexplored. Here, we assessed acclimation environment on organisms capacity thermal plasticity. We conducted genome-wide...

Oxygen saturation levels that killed 50 and 5% of cod Gadus morhua over 96 h averaged 21·2 27·7%, respectively. No fish survived at 10% only a few 16% saturation, whereas no mortality occurred 34 40% oxygen saturation. Since metabolic rate consumption increase with increasing temperature, we hypothesized would be less tolerant to hypoxic conditions 6 than 2° C. However, temperature (2 6° C) had measurable impact on survival. Small (mean & S.D.; 45·2 ± 4·2 cm) large (57·5 3·8 the same...

Diel feeding patterns of herring Clupea harengus and mackerel Scomber scombrus in the southern Gulf St Lawrence were examined based on samples obtained by midwater trawling between 19 26 June 2001. Within 3 h time periods, stomach contents tended to be more similar fish from same tow than different tows. Thus, contrast previous diet studies, which have used individual stomachs as independent observations, was experimental unit statistical analyses this study. fullness identified using...

Greenland halibut (Reinhardtius hippoglossoides), especially juveniles, are frequently found in severely hypoxic areas (18%–25% saturation) of the St. Lawrence Estuary. We investigated tolerance this species to hypoxia and evaluated consequences low oxygen levels on metabolic capacity. At 5 °C, juveniles had a higher critical threshold than adults (15% versus 11% saturation), indicating that they were less tolerant hypoxia. Severe (19% did not affect juveniles' standard rate but...

Final thermal preferendum ( T ) experiments were conducted in a horizontal gradient tank from the beginning of August 2001 to mid‐November using Atlantic cod Gadus morhua 6·5 79·0 cm fork length L F ). The value varied significantly P < 0·005) with = 7·23–0·054 ), smaller (younger) fish choosing higher temperatures than larger (older) fish. 6·9° C for 3·0° those cm. Experiments comparing positions between gradients 0·5–11·0 and 4·5–14·5° demonstrated that determined by temperature...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 469:233-248 (2012) - DOI: https://doi.org/10.3354/meps10136 Trophic interactions between key predatory fishes and crustaceans: comparison of two Northwest Atlantic systems during a period ecosystem change Earl Dawe1,*, Mariano Koen-Alonso1, Denis Chabot2, Don Stansbury1, Darrell Mullowney1 1Fisheries Oceans...

This analysis shows good intentions in the selection of valid and precise oxygen uptake ( M˙ O2 ) measurements by retaining only slopes declining dissolved level a respirometer that have very high values coefficient determination, r2 , are not always successful at excluding nonlinear slopes. Much worse, potentially removing linear low because signal-to-noise ratio, this procedure can overestimate calculation standard metabolic rate (SMR) fish. To remedy possibility, few simple diagnostic...

Redfish ( Sebastes mentella and S. fasciatus ) are back at spectacular record high levels in the Gulf of St. Lawrence (GSL) effects this massive resurgence on other components food web remain largely unknown. To better understand trophic implications surging redfish biomass within GSL ecosystem, 3,690 stomachs containing were collected during two periods: one characterised by low abundance (1993–1999) a period (2015–2019). Taxonomical analysis stomach contents from individuals different...

In the northern Gulf of St. Lawrence (nGSL), redfish (Sebastes mentella and Sebastes fasciatus combined) are at record levels abundance following strong recruitment three consecutive cohorts in 2011-2013 have become by far most abundant demersal fish region. Understanding trophic relationships is essential for effective management conservation species nGSL ecosystem. To date, description quantification diet region been restricted to conventional stomach content analysis (SCA). Using fatty...

Mass-balance models using inverse methodology have been constructed for the northern Gulf of St. Lawrence ecosystem in mid-1980s, before groundfish collapse. The results highlight effects major mortality sources (fishing, predation, and other mortality) on fish invertebrate communities. Main predators were large cod (Gadus morhua) followed by redfish (Sebastes spp.), capelin (Mallotus villosus), fisheries. Large most important predator small cod, with cannibalism accounting at least 44% cod....