The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonat... more The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonate system such that saturation states of calcium carbonate (CaCO3) minerals are decreasing, and this is having a detrimental impact on early life stages of select shellfish species. The global, secular decrease in CaCO3 saturation states is occurring on top of a backdrop of large natural variability in coastal settings; progressively shifting the envelope of variability and leading to longer and more frequent exposure to adverse conditions. This is a great concern in the State of Alaska, a high-latitude setting vulnerable to rapid changes in the marine carbonate system, where an emerging shellfish industry plans major growth over the coming decades. Currently, the Alutiiq Pride Shellfish Hatchery (APSH) in Seward, Alaska is the only hatchery in the state, and produces many shellfish species with early life stages known to be sensitive to low CaCO3 saturation states. Here we present the fi...
ABSTRACT Rising CO2 levels in the atmosphere and ocean have lead to an anthropogenically induced ... more ABSTRACT Rising CO2 levels in the atmosphere and ocean have lead to an anthropogenically induced acidification phenomenon in high latitude seas. These areas are projected to become persistently undersaturated with respect to important carbonate minerals as early as mid-century and seasonal aragonite undersaturations have already been observed in surface and shallow subsurface waters over of the continental shelf seas surrounding Alaska. Some calcifying marine organisms, including pteropods, foraminifers, mollusks, and coralline algae that could be susceptible to reduced calcification rates under increasing ocean acidity are keystone species in the Pacific-Arctic region. Recent observations along the only long term time-series in the northern Gulf of Alaska found that the high seasonal and spatial variability of the carbonate parameters are largely controlled by physical circulation and glacial discharge. In general, surface DIC and TA concentrations decreased between May and September due to primary production and dilution from the region's numerous glacial sources. Conversely, concentrations of DIC and TA increased in the bottom waters of the inner shelf between May and September likely due to a combination of remineralization of exported organic matter and seasonally induced upwelling. Analysis of the calcite and aragonite saturation states (Omega) showed an increase in the surface layer from May to September. However, in the bottom waters over the inner shelf the Omega of calcite and aragonite was suppressed and aragonite undersaturations were observed within 50 m of the surface. In the Bering Sea, prior to sea ice retreat in 2008, calcite and aragonite Omega ranged from 1.3 to 3.2 and 0.8 to 2.0 respectively in the upper 30 m over the shelf. Two inshore stations likely impacted by the outflows of the Yukon and Kuskokwim Rivers showed aragonite undersaturation (0.91 - 0.84) from the surface to the bottom. In summer, DIC concentrations in the upper 30 m were drawn down by primary production and diluted by sea ice melt. At most locations, calcite and aragonite Omega had increased compared to spring. However, beneath the mixed layer (30 - 150 m), DIC concentrations increased between spring and summer likely due to the remineralization of exported organic matter. This increase in DIC caused a suppression of the carbonate mineral Omega near the bottom where calcite and aragonite Omega as low as 1.08 and 0.68, respectively were observed. Biological amplification of ocean acidification effects in subsurface waters could reduce the ability of some calcifying species to produce shells or tests with profound implications for Bering Sea benthic ecosystems, including the commercially valuable crab fishery. In both the northern Gulf of Alaska and the eastern Bering Sea, the observed aragonite undersaturations were directly related to the intrusion of anthropogenic CO2 indicating that these are likely recent occurrences.
Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters... more Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters free of sea ice. Here, we document a massive phytoplankton bloom beneath fully consolidated pack ice far from the ice edge in the Chukchi Sea, where light transmission has increased in recent decades because of thinning ice cover and proliferation of melt ponds. The bloom was characterized by high diatom biomass and rates of growth and primary production. Evidence suggests that under-ice phytoplankton blooms may be more widespread over nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in these waters may be underestimated by up to 10-fold.
... David Kadko,1 Robert S. Pickart,2 and Jeremy Mathis1 ... On land, the fibers were sealed in p... more ... David Kadko,1 Robert S. Pickart,2 and Jeremy Mathis1 ... On land, the fibers were sealed in plasticpetrie dishes then counted by gamma spectrometry using established procedures to deter-mine the 228Ra/226Ra ratios [eg, Michel et al., 1981; Rutgers van der Loeff et al., 1995 ...
Calcium carbonate (CaCO 3 ) mineral saturation states for aragonite (Ω aragonite ) and calcite (Ω... more Calcium carbonate (CaCO 3 ) mineral saturation states for aragonite (Ω aragonite ) and calcite (Ω calcite ) are calculated for waters of the Chukchi Sea shelf and Canada Basin of the western Arctic Ocean during the Shelf-Basin Interactions project from 2002 to 2004. On the ...
Water column pH and carbonate mineral saturation states were calculated from dissolved inorganic ... more Water column pH and carbonate mineral saturation states were calculated from dissolved inorganic carbon (DIC) and total alkalinity data collected over the eastern Bering Sea shelf in the spring and summer of 2008. The saturation states (Ω) of the two most important carbonate minerals, calcite (Ωcalcite) and aragonite (Ωaragonite) were strongly coupled to terrestrial runoff from the Yukon and Kuskokwim
Received 25 August 2006; revised 30 November 2006; accepted 8 December 2006; published 4 May 2007... more Received 25 August 2006; revised 30 November 2006; accepted 8 December 2006; published 4 May 2007. [1] In September 2004 a detailed physical and chemical survey was conducted on an anticyclonic, cold-core eddy located seaward of the Chukchi Shelf in the western ...
Deep Sea Research Part II: Topical Studies in Oceanography, 2014
ABSTRACT In the Arctic Ocean, phytoplankton blooms on continental shelves are often limited by li... more ABSTRACT In the Arctic Ocean, phytoplankton blooms on continental shelves are often limited by light availability, and are therefore thought to be restricted to waters free of sea ice. During July 2011 in the Chukchi Sea, a large phytoplankton bloom was observed beneath fully consolidated pack ice and extended from the ice edge to >100 km into the pack. The bloom was composed primarily of diatoms, with biomass reaching 1291 mg chlorophyll a m-2 and rates of carbon fixation as high as 3.7 g C m−2 d−1. Although the sea ice where the bloom was observed was near 100% concentration and 0.8–1.2 m thick, 30–40% of its surface was covered by melt ponds that transmitted 4-fold more light than adjacent areas of bare ice, providing sufficient light for phytoplankton to bloom. Phytoplankton growth rates associated with the under-ice bloom averaged 0.9 d−1 and were as high as 1.6 d−1. We argue that a thinning sea ice cover with more numerous melt ponds over the past decade has enhanced light penetration through the sea ice into the upper water column, favoring the development of these blooms. These observations, coupled with additional biogeochemical evidence, suggest that phytoplankton blooms are currently widespread on nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in waters where under-ice blooms develop are ∼10-fold too low. These massive phytoplankton blooms represent a marked shift in our understanding of Arctic marine ecosystems.
... Jeremy Mathis, Assistant Professor, Chemical Oceanography; Director, Ocean Acidification Rese... more ... Jeremy Mathis, Assistant Professor, Chemical Oceanography; Director, Ocean Acidification Research Center, Institute of Marine Science, University of Alaska Fairbanks ... Field sampling will be conducted by KBL staff, with sample analysis by Jeremy Mathis and the OARC. ...
The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonat... more The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonate system such that saturation states of calcium carbonate (CaCO3) minerals are decreasing, and this is having a detrimental impact on early life stages of select shellfish species. The global, secular decrease in CaCO3 saturation states is occurring on top of a backdrop of large natural variability in coastal settings; progressively shifting the envelope of variability and leading to longer and more frequent exposure to adverse conditions. This is a great concern in the State of Alaska, a high-latitude setting vulnerable to rapid changes in the marine carbonate system, where an emerging shellfish industry plans major growth over the coming decades. Currently, the Alutiiq Pride Shellfish Hatchery (APSH) in Seward, Alaska is the only hatchery in the state, and produces many shellfish species with early life stages known to be sensitive to low CaCO3 saturation states. Here we present the fi...
ABSTRACT Rising CO2 levels in the atmosphere and ocean have lead to an anthropogenically induced ... more ABSTRACT Rising CO2 levels in the atmosphere and ocean have lead to an anthropogenically induced acidification phenomenon in high latitude seas. These areas are projected to become persistently undersaturated with respect to important carbonate minerals as early as mid-century and seasonal aragonite undersaturations have already been observed in surface and shallow subsurface waters over of the continental shelf seas surrounding Alaska. Some calcifying marine organisms, including pteropods, foraminifers, mollusks, and coralline algae that could be susceptible to reduced calcification rates under increasing ocean acidity are keystone species in the Pacific-Arctic region. Recent observations along the only long term time-series in the northern Gulf of Alaska found that the high seasonal and spatial variability of the carbonate parameters are largely controlled by physical circulation and glacial discharge. In general, surface DIC and TA concentrations decreased between May and September due to primary production and dilution from the region's numerous glacial sources. Conversely, concentrations of DIC and TA increased in the bottom waters of the inner shelf between May and September likely due to a combination of remineralization of exported organic matter and seasonally induced upwelling. Analysis of the calcite and aragonite saturation states (Omega) showed an increase in the surface layer from May to September. However, in the bottom waters over the inner shelf the Omega of calcite and aragonite was suppressed and aragonite undersaturations were observed within 50 m of the surface. In the Bering Sea, prior to sea ice retreat in 2008, calcite and aragonite Omega ranged from 1.3 to 3.2 and 0.8 to 2.0 respectively in the upper 30 m over the shelf. Two inshore stations likely impacted by the outflows of the Yukon and Kuskokwim Rivers showed aragonite undersaturation (0.91 - 0.84) from the surface to the bottom. In summer, DIC concentrations in the upper 30 m were drawn down by primary production and diluted by sea ice melt. At most locations, calcite and aragonite Omega had increased compared to spring. However, beneath the mixed layer (30 - 150 m), DIC concentrations increased between spring and summer likely due to the remineralization of exported organic matter. This increase in DIC caused a suppression of the carbonate mineral Omega near the bottom where calcite and aragonite Omega as low as 1.08 and 0.68, respectively were observed. Biological amplification of ocean acidification effects in subsurface waters could reduce the ability of some calcifying species to produce shells or tests with profound implications for Bering Sea benthic ecosystems, including the commercially valuable crab fishery. In both the northern Gulf of Alaska and the eastern Bering Sea, the observed aragonite undersaturations were directly related to the intrusion of anthropogenic CO2 indicating that these are likely recent occurrences.
Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters... more Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters free of sea ice. Here, we document a massive phytoplankton bloom beneath fully consolidated pack ice far from the ice edge in the Chukchi Sea, where light transmission has increased in recent decades because of thinning ice cover and proliferation of melt ponds. The bloom was characterized by high diatom biomass and rates of growth and primary production. Evidence suggests that under-ice phytoplankton blooms may be more widespread over nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in these waters may be underestimated by up to 10-fold.
... David Kadko,1 Robert S. Pickart,2 and Jeremy Mathis1 ... On land, the fibers were sealed in p... more ... David Kadko,1 Robert S. Pickart,2 and Jeremy Mathis1 ... On land, the fibers were sealed in plasticpetrie dishes then counted by gamma spectrometry using established procedures to deter-mine the 228Ra/226Ra ratios [eg, Michel et al., 1981; Rutgers van der Loeff et al., 1995 ...
Calcium carbonate (CaCO 3 ) mineral saturation states for aragonite (Ω aragonite ) and calcite (Ω... more Calcium carbonate (CaCO 3 ) mineral saturation states for aragonite (Ω aragonite ) and calcite (Ω calcite ) are calculated for waters of the Chukchi Sea shelf and Canada Basin of the western Arctic Ocean during the Shelf-Basin Interactions project from 2002 to 2004. On the ...
Water column pH and carbonate mineral saturation states were calculated from dissolved inorganic ... more Water column pH and carbonate mineral saturation states were calculated from dissolved inorganic carbon (DIC) and total alkalinity data collected over the eastern Bering Sea shelf in the spring and summer of 2008. The saturation states (Ω) of the two most important carbonate minerals, calcite (Ωcalcite) and aragonite (Ωaragonite) were strongly coupled to terrestrial runoff from the Yukon and Kuskokwim
Received 25 August 2006; revised 30 November 2006; accepted 8 December 2006; published 4 May 2007... more Received 25 August 2006; revised 30 November 2006; accepted 8 December 2006; published 4 May 2007. [1] In September 2004 a detailed physical and chemical survey was conducted on an anticyclonic, cold-core eddy located seaward of the Chukchi Shelf in the western ...
Deep Sea Research Part II: Topical Studies in Oceanography, 2014
ABSTRACT In the Arctic Ocean, phytoplankton blooms on continental shelves are often limited by li... more ABSTRACT In the Arctic Ocean, phytoplankton blooms on continental shelves are often limited by light availability, and are therefore thought to be restricted to waters free of sea ice. During July 2011 in the Chukchi Sea, a large phytoplankton bloom was observed beneath fully consolidated pack ice and extended from the ice edge to >100 km into the pack. The bloom was composed primarily of diatoms, with biomass reaching 1291 mg chlorophyll a m-2 and rates of carbon fixation as high as 3.7 g C m−2 d−1. Although the sea ice where the bloom was observed was near 100% concentration and 0.8–1.2 m thick, 30–40% of its surface was covered by melt ponds that transmitted 4-fold more light than adjacent areas of bare ice, providing sufficient light for phytoplankton to bloom. Phytoplankton growth rates associated with the under-ice bloom averaged 0.9 d−1 and were as high as 1.6 d−1. We argue that a thinning sea ice cover with more numerous melt ponds over the past decade has enhanced light penetration through the sea ice into the upper water column, favoring the development of these blooms. These observations, coupled with additional biogeochemical evidence, suggest that phytoplankton blooms are currently widespread on nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in waters where under-ice blooms develop are ∼10-fold too low. These massive phytoplankton blooms represent a marked shift in our understanding of Arctic marine ecosystems.
... Jeremy Mathis, Assistant Professor, Chemical Oceanography; Director, Ocean Acidification Rese... more ... Jeremy Mathis, Assistant Professor, Chemical Oceanography; Director, Ocean Acidification Research Center, Institute of Marine Science, University of Alaska Fairbanks ... Field sampling will be conducted by KBL staff, with sample analysis by Jeremy Mathis and the OARC. ...
Uploads
Papers by Jeremy Mathis