Dmitry Aleynik - Academia.edu (original) (raw)
Papers by Dmitry Aleynik
Conductivity, Temperature, Depth (CTD) measurements were obtained with sea-bird SBE-9 vertical pr... more Conductivity, Temperature, Depth (CTD) measurements were obtained with sea-bird SBE-9 vertical profiler, mounted on the Rosette, at 26 CTD stations during the International research cruise R/V POSEIDON, POS 363, in March 2008 in the North-Western shelf area of the Black Sea.
Geophysical Research Letters, 2006
Whether the North Atlantic Ocean is warming or cooling is an important question both in physical ... more Whether the North Atlantic Ocean is warming or cooling is an important question both in physical oceanography and climate change. The Argo profiling buoys provide an accurate and stable instrument for determining the tendencies in heat content from the surface to 2000 m from 1999 to 2005. To calculate temperature and heat content anomalies two reference climatologies are used. These are the well known WOA2001 climatology (Stephens et al., 2002), and a new WOCE Global Hydrographic climatology (Gouretski and Koltermann, 2004). The former climatology is used for our main results, and the latter is used for evaluating the sensitivity of our results to the climatology. Our scheme allows us to estimate the anomaly of heat content (AHC) in the North Atlantic and its smaller sub-domains (i.e. 10°b oxes) for the period 1999-2005. We have found a dipole structure in the time averaged AHC: negative values are concentrated in the southern and middle latitudes of the North Atlantic whilst positive values are found north of 50°N. The upper 1500 m of the North Atlantic is warming throughout the period 1999 to 2005. Citation: Ivchenko,
Scientific Reports
Developments in animal electronic tagging and tracking have transformed the field of movement eco... more Developments in animal electronic tagging and tracking have transformed the field of movement ecology, but interest is also growing in the contributions of tagged animals to oceanography. Animal-borne sensors can address data gaps, improve ocean model skill and support model validation, but previous studies in this area have focused almost exclusively on satellite-telemetered seabirds and seals. Here, for the first time, we develop the use of benthic species as animal oceanographers by combining archival (depth and temperature) data from animal-borne tags, passive acoustic telemetry and citizen-science mark-recapture records from 2016–17 for the Critically Endangered flapper skate (Dipturus intermedius) in Scotland. By comparing temperature observations to predictions from the West Scotland Coastal Ocean Modelling System, we quantify model skill and empirically validate an independent model update. The results from bottom-temperature and temperature-depth profile validation (5,324 o...
Shapefile showing management areas for the Scottish west coast region, as recommended by the anal... more Shapefile showing management areas for the Scottish west coast region, as recommended by the analysis of connectivity estimates generated using a hydrodynamic model. The methods used to generate the layout are described by Adams et al. (2016); a threshold connection probability of 0.01 (weak: in either direction) between individual farm sites contained within each area was applied.<br>
Scientific Reports, 2018
A correction to this article has been published and is linked from the HTML and PDF versions of t... more A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celti... more Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celtic Sea is analysed using observational data and numerical modelling. In a deep layer (500-800m) in the centre of the canyon shear variance was elevated by an order of magnitude. Corresponding large vertical oscillations of deep isotherms, and a local maximum of horizontal velocity were replicated numerically using the MITgcm. The elevated internal tidal activity in the deep part of the canyon is explained in terms of the downward propagation and focusing of multiple internal tidal beams generated at the shelf break. The near-circular shape of the canyon head and steep bottom topography throughout the canyon (steeper than the tidal beam) create favourable conditions for the lens-like focusing of tidal energy in the canyon's centre. Observations and modeling show that the energy focusing greatly intensifies local diapycnal mixing, that leads to local formation of a baroclinic eddy.
Journal of Applied Ecology, 2021
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Environmental Management of Marine Ecosystems, 2018
Frontiers in Marine Science, 2019
The northwest shelf of the Black Sea has suffered well-documented declines in biodiversity since ... more The northwest shelf of the Black Sea has suffered well-documented declines in biodiversity since the 1960s, and by the 1990s was considered a dead zone with virtually no sign of macroscopic epibenthic life. It was characterised by high levels of anthropogenic input, massive phytoplankton blooms, and periodically hypoxic to anoxic bottom waters. An important contributor to primary production on the northwest shelf is the red alga Phyllophora spp. growing in waters to 70 m depth. Phyllophora is a habitat forming taxon supporting complex assemblages of bivalves, sponges, and ascidians, with an associated rich fish fauna. From 1990 on, nutrient loads entering the system plummeted and the severity of algal blooms decreased. Changes to benthic communities, however, were far less rapid, and the trajectory and rate of any recovery of the dead zone, in particular Zernov's Phyllophora Field, is far from certain. This study used towed underwater video imagery from research cruises in summer 2006 and spring 2008 to classify and map macro-epibenthic assemblage structure, and related this to putative physical, chemical and spatial drivers. Distinct and relatively stable benthic communities were in evidence across the northwest shelf at that time. These communities were largely structured by substrate type and depth, but there is some evidence that nutrients continued to play a role. Phyllophora spp. was present across much, but not all, of its former range, but at far lower percent cover than previously. The pattern of abundance of Phyllophora in 2006-2008 did not correlate with the documented pre-eutrophication pattern from 1966. There is some evidence that fastergrowing opportunistic species have hindered recovery. We conclude that while there was evidence of sustained recovery, by 2008 the macro-epibenthic communities of the northwest shelf of the Black Sea were far from their pre-eutrophication state.
The Proceedings of the National Symposium on Power and Energy Systems, 2013
To quantify the risk and impact of CO2 seepage to the marine ecosystem ， the Quantifying and Moni... more To quantify the risk and impact of CO2 seepage to the marine ecosystem ， the Quantifying and Monitoring Potential Ecosystem lmpacts ofGeological Carbon Storage project is now undergoing in a bay in Scotland． In advance of the field expcriment of this pr〔) jec も we conducted the numerical simulatien of CO2 seepage， From
Aquaculture Environment Interactions, 2016
In modern large-scale salmon aquaculture, sites are managed within spatial units. In Scottish wat... more In modern large-scale salmon aquaculture, sites are managed within spatial units. In Scottish waters, several different definitions are used: operator-defined 'Farm Management Areas' (FMAs), regulator-defined 'Disease Management Areas' (DMAs) and 'Fish Health Management Reporting areas' (FHMRAs). FMAs balance many operational requirements, while the sole purpose of DMAs is to limit the spread of disease. FHMRAs are based on historical wild fish monitoring areas. One objective of these units is to monitor and limit the spread of water-borne agents such as infectious salmon anaemia and parasites such as sea lice, which present a perennial economic and ecological challenge. However, unit boundaries are either based on simplified hydrodynamic assumptions, or do not incorporate such information. Their effectiveness for infection control is therefore unclear. We used the latest developments in hydrodynamic modelling to predict population connectivity of sea lice between all current operational salmon aquaculture sites in the complex west coast of Scotland region over 1 yr (June 2013 to June 2014). Aggregating site connectivity matrices by management units, we identified the extent to which units supplied lice to (or received lice from) other units, and their effectiveness for infection control. Total estimated connectivity varied over time by a factor of 2. A general northward movement of simulated larvae was observed. Even the smallest management units reduced external infection by around 75% versus individually managed sites. Larger management units reduced estimated connectivity further. Optimised units derived by applying thresholds to site matrices suggested that management within water bodies at the scale of 50 to 100 km would be most effective.
Journal of Geophysical Research: Oceans, 2016
Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-b... more Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-break, in the vicinity of Whittard Canyon. The presence of this upwelling appears to be tied to the direction and strength of the local slope current, which is in itself highly variable. During typical summer time equatorward flow, an unbalanced pressure gradient force and the resulting disruption of geostrophic flow can lead to upwelling along the main axis of two small shelf break canyons. As the slope current reverts to poleward flow, the upwelling stops and the remnants of the upwelled features are mixed into the local shelf water or advected away from the region. The upwelled features are identified by the presence of subpycnocline high salinity water on the shelf, and are upwelled from a depth of 300 m on the slope, thus providing a mechanism for the transport of nutrients across the shelf break onto the shelf.
Journal of Geophysical Research: Oceans, 2016
Key points: Generation of internal tide in a circular canyon; Focusing of baroclinic tidal energy... more Key points: Generation of internal tide in a circular canyon; Focusing of baroclinic tidal energy in the canyon centre; Generation of a baroclinic eddy due to diapicnal mixing. Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celtic Sea is analysed using observational data and numerical modelling. In a deep layer (500-800 m) in the centre of the canyon shear variance was elevated by an order of magnitude. Corresponding large vertical oscillations of deep isotherms, and a local maximum of horizontal velocity were replicated numerically using the MITgcm. The elevated internal tidal activity in the deep part of the canyon is explained in terms of the downward propagation and focusing of multiple internal tidal beams generated at the shelf break. The near-circular shape of the canyon head and steep bottom topography throughout the canyon (steeper than the tidal beam) create favourable conditions for the lens-like focusing of tidal energy in the canyon's centre. Observations and modeling show that the energy focusing greatly intensifies local diapycnal mixing, that leads to local formation of a baroclinic eddy.
Ocean Science Discussions, 2014
Mesoscale variability in the central Rockall Trough between about 56 and 58° N has been investiga... more Mesoscale variability in the central Rockall Trough between about 56 and 58° N has been investigated using a combination of ship-borne, underwater glider and gridded satellite altimeter measurements. Altimeter observations show that mesoscale features such as eddies and large scale circulation cells are ubiquitous phenomena. They have horizontal length scales of order 100 km with vertical scales of over 1000 m and are associated with mean current speeds (over the upper 1000 m) of 15 ± 7 cm s<sup>−1</sup>. Monthly area averaged surface Eddy Kinetic Energy (EKE) has substantial inter-annual variability, which at times can dominate a mean seasonal signal that varies from a maximum in May (74 cm<sup>2</sup> s<sup>−2</sup>) to a minimum in October (52 cm<sup>2</sup> s<sup>−2</sup>) and has increased gradually since 1992 at about 1.1 cm<sup>2</sup> s<sup>−2</sup> per year. A five mo...
Energy Procedia, 2013
To quantify the risk and impact of CO 2 seepage to the marine ecosystem, the Quantifying and Moni... more To quantify the risk and impact of CO 2 seepage to the marine ecosystem, the Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage project is now undergoing in a bay in Scotland. In advance of the field experiment of this project, we conducted the numerical simulation of CO 2 seepage. From this numerical study, we predicted how CO 2 behave in the bay and how the condition of the sea changes.
International Journal of Greenhouse Gas Control, 2015
International Journal of Greenhouse Gas Control, 2015
This work is focused on results from a recent controlled sub-seabed in situ 28 carbon dioxide (CO... more This work is focused on results from a recent controlled sub-seabed in situ 28 carbon dioxide (CO 2) release experiment (QICS: Quantifying and Monitoring 29 Potential Ecosystem Impacts of Geological Carbon Storage) carried out during May-30 October 2012 in Ardmucknish Bay on the Scottish west coast. Three types of pCO 2 31 sensors (fluorescence, NDIR and ISFET-based technologies) were used in 32 combination with multiparameter instruments measuring oxygen, temperature, 33 salinity and currents in the water column at the epicentre of release and further away. 34 It was shown that distribution of seafloor CO 2 emissions features high spatial and 35 temporal heterogeneity. The highest pCO 2 values (~1250 µatm) were detected at low 36 tide around a bubble stream and within centimetres distance from the seafloor. 37 Further up in the water column, 30 to 100 cm above the seabed, the gradients 38 decreased, but continued to indicate elevated pCO 2 at the epicentre of release 39 throughout the injection campaign with the peak values between 400 and 740 µatm. 40 High-frequency parallel measurements from two instruments placed within 1 m from 41 each other, relocation of one of the instruments at the release site and 2D horizontal 42 mapping of the release and control sites confirmed a localized impact from CO 2 43 emissions. Observed effects on the water column were temporary and post-injection 44 recovery took <7 days. 45 A multivariate statistical approach was used to recognize the periods when the 46 system was dominated by natural forcing with strong correlation between variation in 47 pCO 2 and O 2 , and when it was influenced by purposefully released CO 2. 48 Use of a hydrodynamic circulation model, calibrated with in situ data, was 49 crucial to establishing background conditions in this complex and dynamic shallow 50 water system. 51 65 Previous efforts to study controlled CO 2 releases with the focus on environmental 66 impact and detectability were restricted by either small-scale direct injections of 67 liquid CO 2 into the deep water layers or model studies of the fate of released CO 2. 68 Small-scale liquid CO 2 injections were carried out in a series of experiments off the 69 coast of California (Brewer et al., 2003, 2004), which later developed into the FOCE 70
Conductivity, Temperature, Depth (CTD) measurements were obtained with sea-bird SBE-9 vertical pr... more Conductivity, Temperature, Depth (CTD) measurements were obtained with sea-bird SBE-9 vertical profiler, mounted on the Rosette, at 26 CTD stations during the International research cruise R/V POSEIDON, POS 363, in March 2008 in the North-Western shelf area of the Black Sea.
Geophysical Research Letters, 2006
Whether the North Atlantic Ocean is warming or cooling is an important question both in physical ... more Whether the North Atlantic Ocean is warming or cooling is an important question both in physical oceanography and climate change. The Argo profiling buoys provide an accurate and stable instrument for determining the tendencies in heat content from the surface to 2000 m from 1999 to 2005. To calculate temperature and heat content anomalies two reference climatologies are used. These are the well known WOA2001 climatology (Stephens et al., 2002), and a new WOCE Global Hydrographic climatology (Gouretski and Koltermann, 2004). The former climatology is used for our main results, and the latter is used for evaluating the sensitivity of our results to the climatology. Our scheme allows us to estimate the anomaly of heat content (AHC) in the North Atlantic and its smaller sub-domains (i.e. 10°b oxes) for the period 1999-2005. We have found a dipole structure in the time averaged AHC: negative values are concentrated in the southern and middle latitudes of the North Atlantic whilst positive values are found north of 50°N. The upper 1500 m of the North Atlantic is warming throughout the period 1999 to 2005. Citation: Ivchenko,
Scientific Reports
Developments in animal electronic tagging and tracking have transformed the field of movement eco... more Developments in animal electronic tagging and tracking have transformed the field of movement ecology, but interest is also growing in the contributions of tagged animals to oceanography. Animal-borne sensors can address data gaps, improve ocean model skill and support model validation, but previous studies in this area have focused almost exclusively on satellite-telemetered seabirds and seals. Here, for the first time, we develop the use of benthic species as animal oceanographers by combining archival (depth and temperature) data from animal-borne tags, passive acoustic telemetry and citizen-science mark-recapture records from 2016–17 for the Critically Endangered flapper skate (Dipturus intermedius) in Scotland. By comparing temperature observations to predictions from the West Scotland Coastal Ocean Modelling System, we quantify model skill and empirically validate an independent model update. The results from bottom-temperature and temperature-depth profile validation (5,324 o...
Shapefile showing management areas for the Scottish west coast region, as recommended by the anal... more Shapefile showing management areas for the Scottish west coast region, as recommended by the analysis of connectivity estimates generated using a hydrodynamic model. The methods used to generate the layout are described by Adams et al. (2016); a threshold connection probability of 0.01 (weak: in either direction) between individual farm sites contained within each area was applied.<br>
Scientific Reports, 2018
A correction to this article has been published and is linked from the HTML and PDF versions of t... more A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celti... more Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celtic Sea is analysed using observational data and numerical modelling. In a deep layer (500-800m) in the centre of the canyon shear variance was elevated by an order of magnitude. Corresponding large vertical oscillations of deep isotherms, and a local maximum of horizontal velocity were replicated numerically using the MITgcm. The elevated internal tidal activity in the deep part of the canyon is explained in terms of the downward propagation and focusing of multiple internal tidal beams generated at the shelf break. The near-circular shape of the canyon head and steep bottom topography throughout the canyon (steeper than the tidal beam) create favourable conditions for the lens-like focusing of tidal energy in the canyon's centre. Observations and modeling show that the energy focusing greatly intensifies local diapycnal mixing, that leads to local formation of a baroclinic eddy.
Journal of Applied Ecology, 2021
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Environmental Management of Marine Ecosystems, 2018
Frontiers in Marine Science, 2019
The northwest shelf of the Black Sea has suffered well-documented declines in biodiversity since ... more The northwest shelf of the Black Sea has suffered well-documented declines in biodiversity since the 1960s, and by the 1990s was considered a dead zone with virtually no sign of macroscopic epibenthic life. It was characterised by high levels of anthropogenic input, massive phytoplankton blooms, and periodically hypoxic to anoxic bottom waters. An important contributor to primary production on the northwest shelf is the red alga Phyllophora spp. growing in waters to 70 m depth. Phyllophora is a habitat forming taxon supporting complex assemblages of bivalves, sponges, and ascidians, with an associated rich fish fauna. From 1990 on, nutrient loads entering the system plummeted and the severity of algal blooms decreased. Changes to benthic communities, however, were far less rapid, and the trajectory and rate of any recovery of the dead zone, in particular Zernov's Phyllophora Field, is far from certain. This study used towed underwater video imagery from research cruises in summer 2006 and spring 2008 to classify and map macro-epibenthic assemblage structure, and related this to putative physical, chemical and spatial drivers. Distinct and relatively stable benthic communities were in evidence across the northwest shelf at that time. These communities were largely structured by substrate type and depth, but there is some evidence that nutrients continued to play a role. Phyllophora spp. was present across much, but not all, of its former range, but at far lower percent cover than previously. The pattern of abundance of Phyllophora in 2006-2008 did not correlate with the documented pre-eutrophication pattern from 1966. There is some evidence that fastergrowing opportunistic species have hindered recovery. We conclude that while there was evidence of sustained recovery, by 2008 the macro-epibenthic communities of the northwest shelf of the Black Sea were far from their pre-eutrophication state.
The Proceedings of the National Symposium on Power and Energy Systems, 2013
To quantify the risk and impact of CO2 seepage to the marine ecosystem ， the Quantifying and Moni... more To quantify the risk and impact of CO2 seepage to the marine ecosystem ， the Quantifying and Monitoring Potential Ecosystem lmpacts ofGeological Carbon Storage project is now undergoing in a bay in Scotland． In advance of the field expcriment of this pr〔) jec も we conducted the numerical simulatien of CO2 seepage， From
Aquaculture Environment Interactions, 2016
In modern large-scale salmon aquaculture, sites are managed within spatial units. In Scottish wat... more In modern large-scale salmon aquaculture, sites are managed within spatial units. In Scottish waters, several different definitions are used: operator-defined 'Farm Management Areas' (FMAs), regulator-defined 'Disease Management Areas' (DMAs) and 'Fish Health Management Reporting areas' (FHMRAs). FMAs balance many operational requirements, while the sole purpose of DMAs is to limit the spread of disease. FHMRAs are based on historical wild fish monitoring areas. One objective of these units is to monitor and limit the spread of water-borne agents such as infectious salmon anaemia and parasites such as sea lice, which present a perennial economic and ecological challenge. However, unit boundaries are either based on simplified hydrodynamic assumptions, or do not incorporate such information. Their effectiveness for infection control is therefore unclear. We used the latest developments in hydrodynamic modelling to predict population connectivity of sea lice between all current operational salmon aquaculture sites in the complex west coast of Scotland region over 1 yr (June 2013 to June 2014). Aggregating site connectivity matrices by management units, we identified the extent to which units supplied lice to (or received lice from) other units, and their effectiveness for infection control. Total estimated connectivity varied over time by a factor of 2. A general northward movement of simulated larvae was observed. Even the smallest management units reduced external infection by around 75% versus individually managed sites. Larger management units reduced estimated connectivity further. Optimised units derived by applying thresholds to site matrices suggested that management within water bodies at the scale of 50 to 100 km would be most effective.
Journal of Geophysical Research: Oceans, 2016
Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-b... more Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-break, in the vicinity of Whittard Canyon. The presence of this upwelling appears to be tied to the direction and strength of the local slope current, which is in itself highly variable. During typical summer time equatorward flow, an unbalanced pressure gradient force and the resulting disruption of geostrophic flow can lead to upwelling along the main axis of two small shelf break canyons. As the slope current reverts to poleward flow, the upwelling stops and the remnants of the upwelled features are mixed into the local shelf water or advected away from the region. The upwelled features are identified by the presence of subpycnocline high salinity water on the shelf, and are upwelled from a depth of 300 m on the slope, thus providing a mechanism for the transport of nutrients across the shelf break onto the shelf.
Journal of Geophysical Research: Oceans, 2016
Key points: Generation of internal tide in a circular canyon; Focusing of baroclinic tidal energy... more Key points: Generation of internal tide in a circular canyon; Focusing of baroclinic tidal energy in the canyon centre; Generation of a baroclinic eddy due to diapicnal mixing. Strong three dimensional focusing of internal tidal energy in the Petite Sole Canyon in the Celtic Sea is analysed using observational data and numerical modelling. In a deep layer (500-800 m) in the centre of the canyon shear variance was elevated by an order of magnitude. Corresponding large vertical oscillations of deep isotherms, and a local maximum of horizontal velocity were replicated numerically using the MITgcm. The elevated internal tidal activity in the deep part of the canyon is explained in terms of the downward propagation and focusing of multiple internal tidal beams generated at the shelf break. The near-circular shape of the canyon head and steep bottom topography throughout the canyon (steeper than the tidal beam) create favourable conditions for the lens-like focusing of tidal energy in the canyon's centre. Observations and modeling show that the energy focusing greatly intensifies local diapycnal mixing, that leads to local formation of a baroclinic eddy.
Ocean Science Discussions, 2014
Mesoscale variability in the central Rockall Trough between about 56 and 58° N has been investiga... more Mesoscale variability in the central Rockall Trough between about 56 and 58° N has been investigated using a combination of ship-borne, underwater glider and gridded satellite altimeter measurements. Altimeter observations show that mesoscale features such as eddies and large scale circulation cells are ubiquitous phenomena. They have horizontal length scales of order 100 km with vertical scales of over 1000 m and are associated with mean current speeds (over the upper 1000 m) of 15 ± 7 cm s<sup>−1</sup>. Monthly area averaged surface Eddy Kinetic Energy (EKE) has substantial inter-annual variability, which at times can dominate a mean seasonal signal that varies from a maximum in May (74 cm<sup>2</sup> s<sup>−2</sup>) to a minimum in October (52 cm<sup>2</sup> s<sup>−2</sup>) and has increased gradually since 1992 at about 1.1 cm<sup>2</sup> s<sup>−2</sup> per year. A five mo...
Energy Procedia, 2013
To quantify the risk and impact of CO 2 seepage to the marine ecosystem, the Quantifying and Moni... more To quantify the risk and impact of CO 2 seepage to the marine ecosystem, the Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage project is now undergoing in a bay in Scotland. In advance of the field experiment of this project, we conducted the numerical simulation of CO 2 seepage. From this numerical study, we predicted how CO 2 behave in the bay and how the condition of the sea changes.
International Journal of Greenhouse Gas Control, 2015
International Journal of Greenhouse Gas Control, 2015
This work is focused on results from a recent controlled sub-seabed in situ 28 carbon dioxide (CO... more This work is focused on results from a recent controlled sub-seabed in situ 28 carbon dioxide (CO 2) release experiment (QICS: Quantifying and Monitoring 29 Potential Ecosystem Impacts of Geological Carbon Storage) carried out during May-30 October 2012 in Ardmucknish Bay on the Scottish west coast. Three types of pCO 2 31 sensors (fluorescence, NDIR and ISFET-based technologies) were used in 32 combination with multiparameter instruments measuring oxygen, temperature, 33 salinity and currents in the water column at the epicentre of release and further away. 34 It was shown that distribution of seafloor CO 2 emissions features high spatial and 35 temporal heterogeneity. The highest pCO 2 values (~1250 µatm) were detected at low 36 tide around a bubble stream and within centimetres distance from the seafloor. 37 Further up in the water column, 30 to 100 cm above the seabed, the gradients 38 decreased, but continued to indicate elevated pCO 2 at the epicentre of release 39 throughout the injection campaign with the peak values between 400 and 740 µatm. 40 High-frequency parallel measurements from two instruments placed within 1 m from 41 each other, relocation of one of the instruments at the release site and 2D horizontal 42 mapping of the release and control sites confirmed a localized impact from CO 2 43 emissions. Observed effects on the water column were temporary and post-injection 44 recovery took <7 days. 45 A multivariate statistical approach was used to recognize the periods when the 46 system was dominated by natural forcing with strong correlation between variation in 47 pCO 2 and O 2 , and when it was influenced by purposefully released CO 2. 48 Use of a hydrodynamic circulation model, calibrated with in situ data, was 49 crucial to establishing background conditions in this complex and dynamic shallow 50 water system. 51 65 Previous efforts to study controlled CO 2 releases with the focus on environmental 66 impact and detectability were restricted by either small-scale direct injections of 67 liquid CO 2 into the deep water layers or model studies of the fate of released CO 2. 68 Small-scale liquid CO 2 injections were carried out in a series of experiments off the 69 coast of California (Brewer et al., 2003, 2004), which later developed into the FOCE 70