A high-resolution physical–biogeochemical model for marine resource applications in the northwest Atlantic (MOM6-COBALT-NWA12 v1.0)

Geoscientific model development, Journal Year: 2023, Volume and Issue: 16(23), P. 6943 - 6985

Published: Nov. 29, 2023

Abstract. We present the development and evaluation of MOM6-COBALT-NWA12 version 1.0, a 1/12∘ model ocean dynamics biogeochemistry in northwest Atlantic Ocean. This is built using new regional capabilities MOM6 coupled with Carbon, Ocean Biogeochemistry Lower Trophics (COBALT) biogeochemical Sea Ice Simulator version-2 (SIS2) sea ice model. Our goal was to develop provide information support living-marine-resource applications across management time horizons from seasons decades. To do this, we struck balance between broad, coastwide domain simulate basin-scale variability capture cross-boundary issues expected under climate change; high enough spatial resolution accurately features like Gulf Stream separation advection water masses through finer-scale coastal features; computational economy required run long simulations multiple ensemble members that are needed quantify prediction uncertainties produce actionable information. assess whether capable supporting intended by evaluating three categories metrics: basin-wide indicators model's performance, ecosystem drive it, times efficiency. Overall, both ecosystem-relevant simulated well Where notable biases errors types indicator, they mainly consistent challenges simulating separation, path, variability: for example, shelf north Cape Hatteras too warm salty have minor biases. During development, identified few parameters exerted influence on solution, including horizontal viscosity, mixed-layer restratification, tidal self-attraction loading, which discuss briefly. The performance adequate running numerous simulations, even inclusion 40 additional tracers. these results show this first efficiently historical mean conditions variability, laying groundwork future studies analyze detail, improve parameterizations components better local features, predictions projections timescales.

Language: Английский

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Assessing indirect biodiversity conservation benefits of fisheries closures in the Gulf of St. Lawrence, Canada

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(1), P. e0316754 - e0316754

Published: Jan. 9, 2025

Marine biodiversity loss is a pressing global issue, intensified by human activities and climate change. Complementary to marine protected areas (MPAs), Other Effective Area-Based Conservation Measures (OECMs) have emerged as key tool mitigate this providing long-term protection. However, while OECMs primarily target specific taxa, they can also offer indirect conservation benefits (BCBs) wider range of taxa. In study, we assess the BCBs eleven in Gulf St. Lawrence, focusing on their role supporting life-history processes commercially important species such Atlantic halibut, Greenland redfish. We apply an integrated assessment that combines knowledge data previously unconnected provide information support OECM management. Our analysis reveals eight overlap with potential spawning habitats for these species, suggesting benefits. projected climate-driven changes bottom temperature, oxygen concentration, pH levels pose threat habitats, potentially undermining effectiveness OECMs. These findings underscore need adaptive management strategies incorporate climate-informed ecosystem indicators broaden focus beyond economically species. Such approaches are crucial ensuring continue both direct face accelerating change, thereby contributing efforts.

Language: Английский

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Large burial flux of modern organic carbon in the St. Lawrence estuarine system indicates a substantial atmospheric carbon sink

Earth and Planetary Science Letters, Journal Year: 2025, Volume and Issue: 652, P. 119204 - 119204

Published: Jan. 12, 2025

Language: Английский

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Ocean deoxygenation caused non‐linear responses in the structure and functioning of benthic ecosystems

Global Change Biology, Journal Year: 2023, Volume and Issue: 30(1)

Published: Nov. 2, 2023

Abstract The O 2 content of the global ocean has been declining progressively over past decades, mainly because human activities and warming. Nevertheless, how long‐term deoxygenation affects macrobenthic communities, sediment biogeochemistry their mutual feedback remains poorly understood. Here, we evaluate response benthic assemblages biogeochemical functioning to decreasing concentrations along persistent bottom‐water dissolved gradient Estuary Gulf St. Lawrence (QC, Canada). We report several non‐linear biodiversity functional responses concentrations, identify an threshold that occurs at approximately 63 μM. Below this threshold, community change, bioturbation rates drastically decrease near zero. Consequently, sequence electron acceptors used metabolize sedimentary organic matter is squeezed towards surface while reduced compounds accumulate closer (as much as 0.5–2.5 cm depending on compound) sediment–water interface. Our results illustrate capacity bioturbating species compensate for consequences hypoxia can help predict future changes in ecosystems.

Language: Английский

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Otoliths as chemical archives through ontogeny reveal distinct migratory strategies of Atlantic halibut within the Gulf of St. Lawrence

ICES Journal of Marine Science, Journal Year: 2024, Volume and Issue: 81(7), P. 1221 - 1233

Published: July 3, 2024

Abstract In marine fishes of commercial interest, defining habitat use and migration strategies through ontogeny can help better understand the structure dynamics harvested populations guide their management. The present study relied on otolith chemistry to identify three contingents within Atlantic halibut (Hippoglossus hippoglossus) stock in Gulf St. Lawrence (GSL). We differentiated two chemical signatures from edges, one for shallow (<100 m) another deep (>100 waters. By identifying transitions between habitats, we found that most display migrations waters during first 3 years life. After reaching maturity, distributing northern regions GSL became full-time residents areas GSL. contrast, summer plateau southern displayed migrating behaviour (summer) (winter) throughout lives, either an annual or irregular basis. Overall, our results demonstrate serve as natural markers geographically distinct environments, facilitating identification reconstruction environmental histories long-lived fishes.

Language: Английский

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Climate Change Impacts on the Nursery Function for Fish of Coastal Zones

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown, P. 206 - 225

Published: Jan. 1, 2024

Language: Английский

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Mixing behaviour and sources of Ag, Pd, and other trace elements in the Estuary and Gulf of St. Lawrence under winter conditions

Chemosphere, Journal Year: 2024, Volume and Issue: 363, P. 142935 - 142935

Published: July 23, 2024

The marine chemistry of platinum group elements is poorly documented despite robust evidence their widespread emissions and deposition around the globe. Here, we report concentrations discuss geochemical behaviours Ag, Pd other trace ultra-trace in Estuary Gulf St. Lawrence (EGSL). We highlight contrasting mixing these elements, i.e., conservative (Cd, Re) vs. non-conservative (Ag, Pd), samples collected during winter under ice-covered conditions. ascribe behaviour to differential affinity for reactive surfaces carried into estuary from frozen watersheds. also an increase Ag (up 40 pmol L

Language: Английский

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Deep inflow transport and dispersion in the Gulf of St. Lawrence revealed by a tracer release experiment

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: June 20, 2024

Abstract The Gulf of St. Lawrence is increasingly affected by bottom water hypoxia; however, the timescales and pathways deep transport remain unclear. Here, we present results from Deep Tracer Release eXperiment (TReX Deep), during which an inert SF 5 CF 3 tracer was released inshore Cabot Strait at 279 m depth to investigate inflow mixing rates. Dispersion also assessed via neutrally-buoyant Swish floats. Our findings indicate that moves inland 0.5 cm s −1 , with effective lateral diffusivity 2 × 10 over 1 year. Simplified 1D simulations suggest should reach estuary head in 1.7 years, bulk arriving after 4.7 years. Basin-wide vertical around −5 year; increases near basin slopes, suggesting turbulent boundary processes influence mixing. These are compared Lagrangian a regional 3D model evaluate capacity dispersion Gulf.

Language: Английский

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Can green hydrogen production be used to mitigate ocean deoxygenation? A scenario from the Gulf of St. Lawrence

Mitigation and Adaptation Strategies for Global Change, Journal Year: 2023, Volume and Issue: 28(8)

Published: Dec. 1, 2023

Abstract Ocean deoxygenation and expansion intensification of hypoxia in the ocean are a major, growing threat to marine ecosystems. Measures currently used protect biodiversity (e.g., protected areas) ineffective countering this threat. Here, we highlight example Gulf St. Lawrence eastern Canada, where oxygen loss is not only due eutrophication (which can be mitigated by nutrient controls) but also consequence circulation change warming. Climate-related will an increasingly widespread source risk over century. Again using as example, show that production green hydrogen industry comparable rate dissolved on large spatial scales, offering new possibilities for mitigation. However, mitigation approach has rarely been considered environments date. Given confluence increasing ecosystems from rapid emergence, worldwide, industrial sources pure oxygen, which likely located coastal regions, believe option proposed coming years, including private sector. We argue it urgent scientists, engineers, policymakers recognize address emerging potential. A coordinated research effort should established immediately order harness potential mitigate major impacts climate biodiversity, avoid any unintended negative consequences.

Language: Английский

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Macrozoobenthic Diversity along an Oxygen Gradient in the Deep Trough of the Gulf of St. Lawrence (Canada)

Diversity, Journal Year: 2023, Volume and Issue: 15(7), P. 854 - 854

Published: July 14, 2023

In 2015, we studied the macrozoobenthic community composition along a dissolved oxygen gradient in deep trough of Gulf St. Lawrence (Canada). We sampled seabed at nine stations using box corers (three replicates per station), starting outer and ending Lower River Estuary. found four different communities dominated by polychaetes, crustaceans, molluscs, with emphasis shifting from mollusc to polychaete as saturation decreased. Contrary our expectations, furthest upstream estuary lowest levels had highest species diversity, also density biomass values. Key genera hypoxic zone included bivalves (Thyasira), cumaceans (Diastylis), amphipods (Harpinia), polychaetes such Ampharete, Ceratocephale, Galathowenia, Trochochaeta. attribute this stability environmental conditions absence stress, where constant supply oxygen, even low concentrations, seems be more important than absolute concentration.

Language: Английский

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