Seasonal Cycles, Hypoxia, and Renewal in a Coastal Fjord (Barkley Sound, British Columbia)

Pawlowicz, Rich

doi:10.1080/07055900.2017.1374240

Cited by 20 publications

(15 citation statements)

References 32 publications

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“…The southern shelf waters of WCVI get advected into the deep waters of Barkley Sound during summer (Pawlowicz, 2017). The implied oxygen utilization rate value from this study is close to the 2.4 ± 0.5 mL L −1 yr −1 value observed in the deep waters near Barkley Sound (Pawlowicz, 2017). This value is within the range of observed oxygen utilization rates at similar depths in different shelf regions (e.g., Hartnett & Devol, 2003; Siedlecki et al., 2015).…”

Section: Discussionmentioning

confidence: 99%

Spatial and Temporal Origins of the La Perouse Low Oxygen Pool: A Combined Lagrangian Statistical Approach

et al. 2022

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A shortage of dissolved oxygen in seawater can adversely impact marine life and ecosystems. Low oxygen conditions at depth occur in many coastal regions, driven by both local productivity and remote changes in the source waters. A low‐oxygen dense pool of water is observed every summer over the mid‐shelf off southwest Vancouver Island in the Juan de Fuca Eddy region. We trace the dense pool waters back to their source using Lagrangian Particle tracking in an ocean model. The model accuracy is evaluated against a set of dense observations collected in August 2013. Only locations where the model represents water properties well are used as starting locations for the tracking. These locations are selected using a K‐Means clustering algorithm. Tracking particles backwards in time showed that the low oxygen dense pool is primarily composed of water from the California Undercurrent, shallower water from further offshore of the Washington shelf, and offshore water. Waters from the northern shelf were not a primary source even though summer currents are from the north. Correspondingly, the water primarily arrived in the south Vancouver Island region in spring, months before the cruise. A kernel density estimate shows the final water properties of the dense pool are well represented by this mixture. The dense water pathways up and onto the shelf are primarily through coastal submarine canyons in early summer. Combining high spatial resolution observations, a carefully evaluated numerical model, Lagrangian tracking, and statistical techniques reveal detailed answers not obtainable through a single method.

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Section: Discussionmentioning

confidence: 99%

Spatial and Temporal Origins of the La Perouse Low Oxygen Pool: A Combined Lagrangian Statistical Approach

et al. 2022

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“…S1). In the summer 2021 heat wave, a maximum temperature at 5m depth of 21.6ºC was reached on August 04, 2021 (Pawlowicz, 2017; Xuereb et al, 2018; Chen et al, 2021; Ocean Networks Canada). Our control temperature (12ºC) was that of the Bamfield Inlet at the time of the temperature experiment and was the temperature the cucumbers were acclimated to.…”

Section: Methodsmentioning

confidence: 99%

Heat stress does not induce wasting symptoms in the giant California sea cucumber (Apostichopus californicus)

Taylor

Farr

Lim

et al. 2022

Preprint

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Oceanic heat waves have significant impacts on disease dynamics in marine ecosystems. A severe sea cucumber wasting event occurred in Nanoose Bay, British Columbia, Canada, following an extreme heat wave, resulting in mass mortality of Apostichopus californicus. Here, we sought to determine if heat stress in isolation could trigger wasting symptoms in A. californicus. We exposed sea cucumbers to i) a simulated marine heat wave (22°C), ii) an elevated temperature treatment (17°C), or iii) control conditions (12°C). We measured the presence of skin ulcers, mortality, posture maintenance, antipredator defences, spawning, and organ evisceration during the 79-hour thermal exposure, as well as 7-days post-exposure. Both the 22°C and 17°C treatments elicited stress responses where individuals exhibited a reduced ability to maintain posture and an increase in stress spawning. The 22°C heat wave was particularly stressful, as it was the only treatment where mortality was observed. However, none of the treatments induced wasting symptoms as observed in the Nanoose Bay event. This study provides evidence that sea cucumber wasting is not triggered by heat stress in isolation, leaving the cause of the mass mortality event observed in Nanoose unknown.

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“…2017) demonstrated that carbon transfers to the deep ocean are surprisingly significant in winter months. Fjord research by Pawlowicz (2017) revealed the seasonally cyclic nature of low oxygen waters. Soontiens and Allen (2017) used ONC data to model constraints on ocean water mixing in fjords.…”

Section: Coastal Sitesmentioning

confidence: 99%

Canada’s Internet-Connected Ocean

et al. 2022

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Over fifteen years ago, Ocean Networks Canada (ONC) began with the world’s first large-scale, interactive, real-time portal into the ocean, bringing continuous, real-time data to the surface for applications in scientific research, societal benefits, and supporting Canada’s ocean industry. This marked the dawn of the Internet-connected ocean, enabling a more fulsome understanding of the ocean through ocean intelligence. These open data have improved our ability to monitor and understand our changing ocean offshore all three coasts of Canada, thanks to diversity of sensor systems to monitor earthquakes and tsunamis, deep sea biodiversity, whales, hydrothermal vents, neutrinos, ocean noise, ocean acidification, forensics experiments, and the impact of climate change, including sea ice thinning in the Arctic. This pioneering approach began in the late 1990s, when scientists began developing a new way of doing ocean science that was no longer limited by weather and ship-time. They imagined a permanent presence in the ocean of sensors to allow a continuous flow of ocean data via the Internet. This big science began to take shape early this century, when a partnership between United States and Canadian institutions was established. ONC evolved out of this international collaboration with seed funding from the Canada Foundation for Innovation, while in the United States, the Ocean Observatories Initiative (OOI) was funded. ONC works closely with OOI on that span the countries’ west coast border. Recently similar observing initiatives in Europe have begun, led by EMSO, which now has a close collaboration with ONC as an Associate Member.

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Seasonal Cycles, Hypoxia, and Renewal in a Coastal Fjord (Barkley Sound, British Columbia)

Cited by 20 publications

References 32 publications

Spatial and Temporal Origins of the La Perouse Low Oxygen Pool: A Combined Lagrangian Statistical Approach

Spatial and Temporal Origins of the La Perouse Low Oxygen Pool: A Combined Lagrangian Statistical Approach

Heat stress does not induce wasting symptoms in the giant California sea cucumber (Apostichopus californicus)

Canada’s Internet-Connected Ocean

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