High frequency monitoring reveals fine scale spatial and temporal dynamics of the deep chlorophyll maximum of a stratified coastal lagoon

Eyto, Elvira de; Kelly, Sean D.; Ryder, Elizabeth F.; Dillane, Mary; Archer, Lorraine; O'Cathain, Donncha; Daly, S.A.; Lyons, Kieran; Obrador, Biel; Brentrup, Jennifer A.; Naumoski, Andreja; Poole, Russell; Lucy, Frances E.; Jennings, Eleanor

doi:10.1016/j.ecss.2018.12.010

Cited by 9 publications

(7 citation statements)

References 93 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Long residence times (compared to the rapidly flushed surface layer) and the spring‐neap modulation of influx may also have biological implications in systems with spring‐neap modulated volume fluxes such as Furnace. The subsurface chlorophyll maxima was found to occupy this intermediate depth zone below the upper halocline (de Eyto et al 2019) and pelagic productivity in this stable region could potentially be influenced by fortnightly variability in tidal fluxes.…”

Section: Discussionmentioning

confidence: 98%

“…Lough Furnace represents an ideal natural laboratory for investigating hydrodynamical processes relevant to larger‐scale stratified estuarine basins. Furnace has also served as a model system for important ecologically motivated research including the population dynamics of euryhaline invertebrates (Parker and West 1979), a paleolimnological reconstruction of its evolution toward anoxic conditions, which appears to have occurred at about 3400 calendar years before present (Cassina et al 2013), divergent evolution in fish ecotypes (Ravinet et al 2015), biophysical interactions between benthic fish and internal waves (Kelly et al 2018 b ), and dynamics of subsurface chlorophyll maxima (de Eyto et al 2019). Although deoxygenation in open coastal areas and well‐flushed estuaries was reported as being rare in an Irish context (O'Boyle et al 2009), documented examples of other perennially or periodically deoxygenated coastal systems along the Atlantic coast of Ireland include Ardbear Salt Lake (Henry et al 2008) and Lough Hyne (Trowbridge et al 2017).…”

mentioning

confidence: 99%

“…Of particular concern are the potential impacts of releasing toxic hydrogen sulfide (H 2 S) gas, which has accumulated in anoxic deep water, to aquatic life in oxygenated surface waters (Luther et al 2004) or to the atmosphere (Capet et al 2016). In Furnace, deep‐water ventilations have been linked to mass fish kills (Anon 1995) and phytoplankton population dynamics (de Eyto et al 2019).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Characterizing ventilation events in an anoxic coastal basin: Observed dynamics and the role of climatic drivers

Kelly

Eyto

Dillane

et al. 2020

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

Restricted horizontal exchange and vertical stratification restrict ventilation of bottom waters in many coastal systems, leading to stagnant basin water conditions. Dense inflows from oceanic sources can lead to dramatic changes in basin-scale properties over very short timescales. Here, we used a semi-enclosed coastal basin with deep-anoxia (Lough Furnace) as a test bed, in order to discern estuary-ocean exchange dynamics that lead to irregular and ephemeral deep-water ventilations. Measured densities and current profiler-based estimates of volume fluxes were used to compute typical renewal times of individual water masses in the stratified inner basin. Renewal timescales were primarily determined by freshwater flux and the spring-neap tidal cycle. The deployment period culminated with observations of a ventilation of the basin water which had been stagnant for over 2.5 yr. Entrainment of ambient resident water doubled the volume of the dense plume and diluted its oxygen content. Following ventilation, the volumetric extent of anoxia expanded by 20% within several months, owing to uplifting of old basin water and oxygen consumption in the new basin water. Founded on these observations, a predictive model was constructed relying only on freshwater, atmospheric pressure, and wind data and successfully recreated ventilation events over the past decade. Hindcasting the model back multiple decades implied contrasting periods of higher and lower frequency variability in ventilation occurrence. This model offers a diagnostic tool for assessing how climatic change may influence the oxygen climate in systems that experience contrasting regimes of suboxia and ventilation.

show abstract

Section: Discussionmentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Characterizing ventilation events in an anoxic coastal basin: Observed dynamics and the role of climatic drivers

Kelly

Eyto

Dillane

et al. 2020

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

show abstract

“…Flow structure and turbulence in this section is noteworthy, as it sets the composition of fluid entering and leaving Furnace. This has implications for exchange of resident interior water [ 38 ] and influxes of nutrients or planktonic seed populations [ 66 ] and also establishes the initial density of the estuarine outflow, which can influence far field plume dynamics in the coastal ocean [ 67 ]. The development of stratified flow resulted in the dilution of incoming tidal water as it met largely unmixed low salinity surface outflow in the shallow area between MR01 and MR02 (Figs 1 and 7B ); this resulted in only intermediate depth water replacement in the main Furnace basin in the months following the flood event.…”

Section: Discussionmentioning

confidence: 99%

Impacts of a record-breaking storm on physical and biogeochemical regimes along a catchment-to-coast continuum

et al. 2020

Self Cite

View full text Add to dashboard Cite

The impacts of changes in climate are often most readily observed through the effects of extremes in local weather, effects that often propagate through multiple ecosystem levels. Precise effects of any extreme weather event depend not only on the type of event and its timing, but also on the ecosystem affected. Here the cascade of effects following the arrival of an atmospheric river (directed by record-breaking Storm Desmond) across terrestrial, freshwater and coastal zones is quantified, using the Burrishoole system on the Atlantic coast of Ireland as a natural observatory. We used a network of high-frequency in-situ sensors to capture in detail the effects of an unprecedented period of rainfall, high wind speeds and above-average winter air temperatures on catchment and estuarine dynamics. In the main freshwater lake, water clarity decreased and acidity increased during Storm Desmond. Surface heat input, due to a warm and moist above-lake air mass, was rapidly distributed throughout the water column. River discharge into the downstream coastal basin was estimated to be the highest on record (since 1976), increasing the buoyancy flux by an order of magnitude and doubling the water column stratification stability. Entrainment of salt into the outflowing freshwater plume exported resident salt from the inner estuarine basin, resulting in net salt loss. Here, the increased stratification markedly reinforced isolation of the bottom waters, promoting deoxygenation. Measurements of current between the inner estuarine basin and the adjacent coastal waters indicated a 20-fold increase in the volume of seaward flowing low-salinity water, as a result of storm rainfall over the watershed. Storm impacts spanned the full catchment-to-coast continuum and these results provide a glimpse into a potential future for hydrological systems where these severe hydroclimatic events are expected to occur more frequently.

show abstract

“…These sensors can be deployed for a long period and in remote locations and are traditionally used on buoys and gliders to monitor key environmental parameters, at various time scales and for different aquatic systems. They have enabled a better understanding of the trends in the physical and biological variables in these systems and have even provided new insights into ecosystem functioning (de Eyto et al 2019; Trombetta et al 2019). Within the framework of mesocosm experiment, using sensor data to estimate metabolic parameters has several advantages compared to the traditional incubation technique, as the sensors are noninvasive and their use does not introduce bottle or container effects into the measurement, thus avoiding the error propagation associated with incubations (Staehr et al 2010 a ).…”

mentioning

confidence: 99%

A new method to estimate planktonic oxygen metabolism using high‐frequency sensor measurements in mesocosm experiments and considering daytime and nighttime respirations

Soulié

Mas²,

Parin³

et al. 2021

Limnology & Ocean Methods

View full text Add to dashboard Cite

Understanding how aquatic ecosystems respond to perturbations has emerged as a crucial way to predict the future of these ecosystems and to assess their capacity to produce oxygen and store atmospheric carbon. In this context, in situ mesocosm experiments are a useful approach for simulating disturbances and observing changes in planktonic communities over time and under controlled conditions. Within mesocosm experiments, the estimation of fundamental parameters such as gross primary production (GPP), net community production (NCP), and respiration (R) allows the evaluation of planktonic metabolic responses to a perturbation. The continuous estimation of these metabolic parameters in real time and at high frequency is made possible by employing noninvasive automated sensors in the water column. However, some uncertainties and methodological questions about the estimation of daytime respiration remain to be addressed for this method, and notably to address the fact that respiration could be significantly higher during the day than during the night. In this study, data from two in situ mesocosm experiments performed in fall and spring in a coastal Mediterranean area were used to develop a new method of estimating daytime respiration, and in turn daily GPP, R, and NCP, by considering the maximum instantaneous R, and that takes into account the variability of the coupling between day-night and dissolved oxygen cycles. This new method was compared with the Winkler incubation technique and with another existing method. Results showed that using this existing method, daytime R was significantly underestimated relative to estimates obtained with the newly proposed method.

show abstract

High frequency monitoring reveals fine scale spatial and temporal dynamics of the deep chlorophyll maximum of a stratified coastal lagoon

Cited by 9 publications

References 93 publications

Characterizing ventilation events in an anoxic coastal basin: Observed dynamics and the role of climatic drivers

Characterizing ventilation events in an anoxic coastal basin: Observed dynamics and the role of climatic drivers

Impacts of a record-breaking storm on physical and biogeochemical regimes along a catchment-to-coast continuum

A new method to estimate planktonic oxygen metabolism using high‐frequency sensor measurements in mesocosm experiments and considering daytime and nighttime respirations

Contact Info

Product

Resources

About