Andrew is a PhD candidate in Environment and Resources at Stanford University researching linkages between oceanography and sustainable development. He draws on past field research experiences in marine science and professional experiences working in sustainable development for the World Bank, UN, and international NGOs. Andrew has a B.A. and M.Sc. in Environmental Science from the University of Virginia.
- Estimating the pelagic ocean's benefits to humanity can enhance Ocean governance MARINE POLICY 2022; 136
- Towards an ocean-based large ocean states country classification MARINE POLICY 2021; 134
Benthic Carbon Mineralization and Nutrient Turnover in a Scottish Sea Loch: An Integrative In Situ Study
2016; 22 (5-6): 443-467
Based on in situ microprofiles, chamber incubations and eddy covariance measurements, we investigated the benthic carbon mineralization and nutrient regeneration in a ~65-m-deep sedimentation basin of Loch Etive, UK. The sediment hosted a considerable amount of infauna that was dominated by the brittle star A. filiformis. The numerous burrows were intensively irrigated enhancing the benthic in situ O2 uptake by ~50 %, and inducing highly variable redox conditions and O2 distribution in the surface sediment as also documented by complementary laboratory-based planar optode measurements. The average benthic O2 exchange as derived by chamber incubations and the eddy covariance approach were similar (14.9 ± 2.5 and 13.1 ± 9.0 mmol m-2 day-1) providing confidence in the two measuring approaches. Moreover, the non-invasive eddy approach revealed a flow-dependent benthic O2 flux that was partly ascribed to enhanced ventilation of infauna burrows during periods of elevated flow rates. The ratio in exchange rates of ΣCO2 and O2 was close to unity, confirming that the O2 uptake was a good proxy for the benthic carbon mineralization in this setting. The infauna activity resulted in highly dynamic redox conditions that presumably facilitated an efficient degradation of both terrestrial and marine-derived organic material. The complex O2 dynamics of the burrow environment also concurrently stimulated nitrification and coupled denitrification rates making the sediment an efficient sink for bioavailable nitrogen. Furthermore, bioturbation mediated a high efflux of dissolved phosphorus and silicate. The study documents a high spatial and temporal variation in benthic solute exchange with important implications for benthic turnover of organic carbon and nutrients. However, more long-term in situ investigations with like approaches are required to fully understand how environmental events and spatio-temporal variations interrelate to the overall biogeochemical functioning of coastal sediments.
View details for DOI 10.1007/s10498-016-9300-8
View details for Web of Science ID 000391427600004
View details for PubMedID 32336935
View details for PubMedCentralID PMC7154884
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- Eddy correlation measurements of oxygen uptake in deep ocean sediments LIMNOLOGY AND OCEANOGRAPHY-METHODS 2009; 7: 576-584