Sophia C. Johannessen
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View article: Carbon dynamics control comtemporary mercury burial in Arctic Ocean sediments
Carbon dynamics control comtemporary mercury burial in Arctic Ocean sediments Open
Mercury (Hg) contamination is a familiar concern in the Arctic. However, this study shows that variations of Hg concentration in 30 sediment cores collected across the North American Arctic Margin (NAAM) and in the deep central Arctic Ocea…
View article: Additionality Revisited for Blue Carbon Ecosystems: Ensuring Real Climate Mitigation
Additionality Revisited for Blue Carbon Ecosystems: Ensuring Real Climate Mitigation Open
View article: Changes in sediment regimes and mass accumulation rates in Eeyou Istchee eelgrass habitat, James Bay, Canada
Changes in sediment regimes and mass accumulation rates in Eeyou Istchee eelgrass habitat, James Bay, Canada Open
View article: Protection of seabed sediments in Canada's marine conservation network for potential climate change mitigation co-benefit
Protection of seabed sediments in Canada's marine conservation network for potential climate change mitigation co-benefit Open
Marine conserved areas (MCAs) can provide a range of ecological and socio-economic benefits, including climate change mitigation from the protection and enhancement of natural carbon storage. Canada's MCA network is expanding to encompass …
View article: Causes of Historical Decline of the Glass Sponge Reefs in British Columbia, Canada
Causes of Historical Decline of the Glass Sponge Reefs in British Columbia, Canada Open
View article: Spatio-temporal dimensions of organic carbon-mineral interactions in a source-to-sink system
Spatio-temporal dimensions of organic carbon-mineral interactions in a source-to-sink system Open
Rivers play a key role in the global carbon cycle by transferring organic carbon (OC) from the terrestrial biosphere to marine sediments, which act as an important long-term carbon sink. Associations between biospheric OC and mineral phase…
View article: Oxygen dynamics in a deep‐silled fjord: Tight coupling to the open shelf
Oxygen dynamics in a deep‐silled fjord: Tight coupling to the open shelf Open
Oxygen is declining globally in subsurface seawater. Fjords are particularly susceptible to hypoxia, because entrance sills restrict water circulation. We studied the oxygen dynamics of the Kitimat Fjord System on the west coast of Canada,…
View article: Why blue carbon cannot truly offset fossil fuel emissions
Why blue carbon cannot truly offset fossil fuel emissions Open
Blue carbon will not solve climate change. The effect is too small; existing sediment carbon stock is a liability; and there is a timescale mismatch between ancient fossil fuel emissions and uptake by vegetation. Clearer communication woul…
View article: How can blue carbon burial in seagrass meadows increase long-term, net sequestration of carbon? A critical review
How can blue carbon burial in seagrass meadows increase long-term, net sequestration of carbon? A critical review Open
Blue carbon sequestration in seagrass meadows has been proposed as a low-risk, nature-based solution to offset carbon emissions and reduce the effects of climate change. Although the timescale of seagrass carbon burial is too short to offs…
View article: Partitioning the Export of Distinct Biogenic Carbon Pools in the Northeast Pacific Ocean Using a Biogeochemical Profiling Float
Partitioning the Export of Distinct Biogenic Carbon Pools in the Northeast Pacific Ocean Using a Biogeochemical Profiling Float Open
We leverage observations from chemical and bio‐optical sensors mounted on a biogeochemical profiling float in the Northeast Pacific Ocean to quantify the cycling and export potential of distinct biogenic carbon pools, including particulate…
View article: Robie W. Macdonald, OC, FRSC (1947–2022)
Robie W. Macdonald, OC, FRSC (1947–2022) Open
Robie (Rob) Macdonald studied large-scale ocean systems, including the global carbon cycle, climate change, and contaminants, in the Arctic and Pacific Oceans.He was recognized internationally as one of the country's primary experts on the…
View article: Correction to: Identification of a Seasonal Subsurface Oxygen Minimum in Rivers Inlet, British Columbia
Correction to: Identification of a Seasonal Subsurface Oxygen Minimum in Rivers Inlet, British Columbia Open
View article: <i>In situ</i>microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions
<i>In situ</i>microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions Open
Douglas Channel and the adjacent Hecate Strait (British Columbia, Canada) are part of a proposed route to ship diluted bitumen (dilbit). This study presents how two types of dilbit naturally degrade in this environment by using an in situ …
View article: Has primary production declined in the Salish Sea?
Has primary production declined in the Salish Sea? Open
Declining primary production has been proposed as an explanation for the declines in coho (Oncorhynchus kisutch) and Chinook (Oncorhynchus tshawytscha) salmon in the Salish Sea since the 1970s. Marine sediments maintain a continuous record…
View article: Foundation Species Abundance Influences Food Web Topology on Glass Sponge Reefs
Foundation Species Abundance Influences Food Web Topology on Glass Sponge Reefs Open
Foundation species support communities across a wide range of ecosystems. Non-trophic interactions are considered the primary way foundation species influence communities, with their trophic interactions having little impact on community s…
View article: In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. (Metagenomic data support).
In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. (Metagenomic data support). Open
This file repository contains the co-assembly of all samples from the manuscript entitled "In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine c…
View article: In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. (Metagenomic data support).
In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine conditions. (Metagenomic data support). Open
This file repository contains the co-assembly of all samples from the manuscript entitled "In situ microcosms deployed at the coast of British Columbia (Canada) to study dilbit weathering and associated microbial communities under marine c…
View article: Fate of diluted bitumen spilled in the coastal waters of British Columbia, Canada
Fate of diluted bitumen spilled in the coastal waters of British Columbia, Canada Open
There is public concern about the behaviour of spilled diluted bitumen (dilbit) in marine and estuarine waters. We provide a preliminary assessment of the results of laboratory experiments and models, in the context of environmental condit…
View article: Rain, Runoff, and Diatoms: the Effects of the North Pacific 2014–2015 Warm Anomaly on Particle Flux in a Canadian West Coast Fjord
Rain, Runoff, and Diatoms: the Effects of the North Pacific 2014–2015 Warm Anomaly on Particle Flux in a Canadian West Coast Fjord Open
Sediment traps were deployed at 50 m depth in Douglas Channel, a fjord on the west coast of Canada, for 3 years (July 2013–July 2016). Particle flux was related to rain, freshwater discharge, and phytoplankton blooms. The North Pacific war…
View article: Reply to Oreska <i>et al</i> ‘Comment on Geoengineering with seagrasses: is credit due where credit is given?’
Reply to Oreska <i>et al</i> ‘Comment on Geoengineering with seagrasses: is credit due where credit is given?’ Open
In their comment on the review paper, ‘Geoengineering with seagrasses: is credit due where credit is given?,’ Oreska et al 2018 state that some of the concerns raised in the review ‘warrant serious consideration by the seagrass research co…
View article: Reply to Macreadie <i>et al</i> Comment on ‘Geoengineering with seagrasses: is credit due where credit is given?’
Reply to Macreadie <i>et al</i> Comment on ‘Geoengineering with seagrasses: is credit due where credit is given?’ Open
Macreadie et al (this issue; M 2017 Environ. Res. Lett. ) challenged the conclusion presented by Johannessen and Macdonald ( 2016 Environ. Res. Lett. ) that global estimates of carbon sequestration by seagrass meadows were too high. Here w…
View article: Has primary productivity declined in the Strait of Georgia since the 1970s
Has primary productivity declined in the Strait of Georgia since the 1970s Open
A strong decline in phytoplankton productivity has been proposed as a principal cause of the decline in salmon survival in the Strait of Georgia over the last four decades. The best estimate of total annual primary productivity in the Stra…
View article: Advection, Surface Area, and Sediment Load of the Fraser River Plume Under Variable Wind and River Forcing
Advection, Surface Area, and Sediment Load of the Fraser River Plume Under Variable Wind and River Forcing Open
The Fraser River is the source of most particulate matter in the Strait of Georgia, and its dispersal is modulated by the Fraser's plume. Here we examine the plume's shape, location, and area, and the variation of these parameters with cha…
View article: Short-term variability in particle flux: Storms, blooms and river discharge in a coastal sea
Short-term variability in particle flux: Storms, blooms and river discharge in a coastal sea Open
The flux and composition of particles sinking in the surface ocean vary on a wide range of time scales. This variability is a component of underwater weather that is analogous to rain. The rain of particles in the coastal ocean is affected…
View article: Underwater optical environment in the coastal waters of British Columbia, Canada
Underwater optical environment in the coastal waters of British Columbia, Canada Open
We describe the underwater light field of the Strait of Georgia in spring and summer, using apparent optical properties (reflectance, attenuation coefficient of downwelling irradiance, the average cosine of downwelling irradiance, and the …
View article: Geoengineering with seagrasses: is credit due where credit is given?
Geoengineering with seagrasses: is credit due where credit is given? Open
Blue carbon, the carbon fixed by vegetated coastal ecosystems including seagrasses, is reported to have a large potential to sequester atmospheric carbon dioxide. Planting, expanding or protecting seagrass meadows has, accordingly, been pr…
View article: It is not just about the ice: a geochemical perspective on the changing Arctic Ocean
It is not just about the ice: a geochemical perspective on the changing Arctic Ocean Open
Much concern has accompanied the dramatic decrease in area covered by permanent pack ice in the Arctic Ocean during the past two decades. Ice is undeniably the most obvious feature distinguishing the Arctic Ocean, and its loss seizes publi…