A5071432540- Marine and coastal ecosystems
- Ocean Acidification Effects and Responses
- Arctic and Antarctic ice dynamics
- Marine Biology and Ecology Research
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Diatoms and Algae Research
- Microbial Community Ecology and Physiology
- Atmospheric and Environmental Gas Dynamics
- Asymmetric Hydrogenation and Catalysis
- Marine and fisheries research
- Water Quality and Pollution Assessment
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organometallic Complex Synthesis and Catalysis
- Coordination Chemistry and Organometallics
- Marine Bivalve and Aquaculture Studies
- Wastewater Treatment and Nitrogen Removal
University of Victoria
2012-2022
Fisheries and Oceans Canada
2013-2014
University of Alberta
2008
Using multiple lines of evidence, we demonstrate that volcanic ash deposition in August 2008 initiated one the largest phytoplankton blooms observed subarctic North Pacific. Unusually widespread transport from a eruption Aleutian Islands, Alaska deposited over much NE Pacific, followed by large increases satellite chlorophyll. Surface ocean pCO 2 , pH, and fluorescence reveal bloom started few days after ashfall. Ship‐based measurements showed increased dominance diatoms. This evidence...
We compared net community production determined from an in situ O 2 /Ar mass balance (O /Ar‐NCP) with incubation measurements of new and primary the subarctic northeast Pacific. In /Ar‐NCP was strongly correlated to 24‐h 15 NO 3 − uptake integrated over mixed layer ( N‐NewP), if were separated into high low‐productivity conditions. Under high‐productivity conditions, estimates similar N‐NewP, whereas under low productivity conditions up two times higher than N‐NewP. The relationship between...
A recently recovered and compiled set of inorganic carbon data collected in the Canadian Arctic since 1970s has revealed substantial change, as well variability, carbonate system Beaufort Sea Canada Basin. Whereas role this area a net atmospheric sink been confirmed, high pCO2 values upper halocline underscore potential for CO2 outgassing sea ice retreats upwelling increases. In addition, increasing total decreasing alkalinity are CaCO3 saturation states, such that undersaturation with...
The Arctic Ocean is a region particularly prone to ongoing ocean acidification (OA) and climate-driven changes. influence of these changes on phytoplankton assemblages, however, remains poorly understood. In order understand how OA enhanced irradiances (e.g., resulting from sea-ice retreat) will alter the species composition, primary production, eco-physiology phytoplankton, we conducted an incubation experiment with assemblage Baffin Bay (71°N, 68°W) under different carbonate chemistry...
Abstract During the Canada's Three Oceans and Joint Ocean Ice Study projects in summers of 2007 2008, we measured particulate organic carbon to nitrogen ratios (POC:PON) throughout euphotic zone Subarctic Arctic waters. Average depth‐integrated values (2.65 ± 0.19) Beaufort Sea Canada Basin (BS‐CB domain) were much lower than both Redfield ratio (6.6) average (3.9 5.6) across other Arctic‐Subarctic domains. uptake C N ( ρ : ) also (0.87 0.14) BS‐CB four domains (2.10 3.51). Decreasing...
Abstract The silicon isotopic composition of silicic acid (δ 30 Si(OH) 4 ) and biogenic silica Si‐bSiO 2 were measured for the first time in marine Arctic waters from Mackenzie River delta to deep Canada Basin late summer 2009. In upper 100 m water column, δ signals (+1.82‰ +3.08‰) negatively correlated with relative contribution water. Si isotope fractionation factor estimated using an open system model, ε = −0.97 ± 0.17‰, agrees well laboratory global‐ocean estimates. Nevertheless,...
Addition of acetonitrile to the complex [Ru(η5-indenyl)(PR2)(PPh3)] (1) gives unusual metalation product [Ru(η5-indenyl)(CH2CN)(HPR2)(PPh3)] (2), which has been structurally characterized. This reaction clearly demonstrates high Brønsted basicity at terminal phosphido ligand in 1. 31P{1H} NMR studies show that less acidic N-donor solvents simply disrupt Ru−P π-bond 1 give adducts [Ru(η5-indenyl)(L)(HPR2)(PPh3)] (L = benzonitrile (6) or pyridine (7)), are equilibrium with and free L. The...
Marine oxygen minimum zones (OMZs) support 30-50% of global fixed-nitrogen (N) loss but comprise only 7% total ocean volume. This N-loss is driven by canonical denitrification and anaerobic ammonium oxidation (anammox), the distribution activity these two processes vary greatly in space time. Factors that regulate are complex, including organic matter availability, concentrations, NO2- NH4+ concentrations. While both anammox produce N2, overall geochemical outcome different, as incomplete...
Abstract We present a decade of dissolved and particulate silica concentrations within five biological “hot spots” in the Pacific Arctic Region (PAR) first measurements both biogenic production rates ( ρ Si) kinetics silicon utilization from period four years at same sites. The were located Bering Chukchi Seas identified as part Distributed Biological Observatory (DBO). Across all hot spots, highest silicic acid (Si(OH) 4 ) found near bottom euphotic zone often correlated with increased Si....
Abstract. We have assembled and conducted primary quality control on previously publicly unavailable water column measurements of the dissolved inorganic carbon system associated biogeochemical parameters (oxygen, nutrients, etc.) made 26 cruises in subarctic Arctic regions dating back to 1974. The are primarily from western side Canadian Arctic, but also include data that cover an area ranging North Pacific Gulf St. Lawrence. were subjected (QC) identify outliers obvious errors. This set...
Abstract We present measurements of the silicon isotopic composition silicic acid (δ 30 Si‐Si(OH) 4 ) from seawater collected along a transect following one main flow paths Pacific‐origin waters through Arctic Ocean during Canadian GEOTRACES and Distributed Biological Observatory expeditions in summer 2015. The δ signals track modification as they transit west to east, reflect distribution water masses, dissolution biogenic silica (bSiO 2 ), biological utilization Si surface waters. have...
Abstract. We have assembled and conducted primary quality control on previously publically-unavailable water column measurements of the dissolved inorganic carbon system associated biogeochemical parameters (oxygen, nutrients, etc.) made 25 cruises in subarctic Arctic regions dating from as far back 1974. The are primarily western side Canadian Arctic, but also include data ranging North Pacific to Gulf St. Lawrence. were subjected (QC) identify outliers obvious errors. This dataset...