Abstract:Aquatic eddy covariance (AEC) is increasingly being used to study benthic oxygen (O2) flux dynamics, organic carbon cycling, and ecosystem health in marine and freshwater environments. Because it is a noninvasive technique, has a high temporal resolution (∼15 min), and integrates over a large area of the seafloor (typically 10–100 m2), it has provided new insights on the functioning of aquatic ecosystems under naturally varying in situ conditions and has given us more accurate assessments of their metabolism. … Show more
“…The site is located in a tidaldriven, shallow bay where current flow and light attenuation change on an hourly basis. Due to the dynamic nature of the system and the strong effect these changing environmental drivers can have on O 2 fluxes (Berger et al 2020;Berg et al 2022), hourly data from individual days were highly variable and did not show clear trends in respiration. This led to the use of binned values for trend analysis.…”
Accurate daily metabolic estimates of respiration, gross primary production, and net ecosystem metabolism are necessary to assess ecosystem health and blue carbon contributions of vegetated coastal ecosystems. Using our database of 2115 hourly benthic oxygen (O2) fluxes measured by aquatic eddy covariance, we examine how respiration for a Zostera marina seagrass meadow varies through night and day, and how this affects commonly performed metabolic estimates. Respiration decreased linearly by 29% through the night and a corresponding linear increase in daytime respiration coupled with production described by a standard photosynthesis–irradiance curve accurately predicted measured daytime O2 fluxes. Many studies have questioned the widely used assumption in metabolic estimates that nighttime and daytime respiration are constant and equal. However, if respiration can be approximated as we found here by linear relationships, standard means for calculating daily metabolic numbers remain valid if estimates are based on full 24‐h records of flux data.
“…The site is located in a tidaldriven, shallow bay where current flow and light attenuation change on an hourly basis. Due to the dynamic nature of the system and the strong effect these changing environmental drivers can have on O 2 fluxes (Berger et al 2020;Berg et al 2022), hourly data from individual days were highly variable and did not show clear trends in respiration. This led to the use of binned values for trend analysis.…”
Accurate daily metabolic estimates of respiration, gross primary production, and net ecosystem metabolism are necessary to assess ecosystem health and blue carbon contributions of vegetated coastal ecosystems. Using our database of 2115 hourly benthic oxygen (O2) fluxes measured by aquatic eddy covariance, we examine how respiration for a Zostera marina seagrass meadow varies through night and day, and how this affects commonly performed metabolic estimates. Respiration decreased linearly by 29% through the night and a corresponding linear increase in daytime respiration coupled with production described by a standard photosynthesis–irradiance curve accurately predicted measured daytime O2 fluxes. Many studies have questioned the widely used assumption in metabolic estimates that nighttime and daytime respiration are constant and equal. However, if respiration can be approximated as we found here by linear relationships, standard means for calculating daily metabolic numbers remain valid if estimates are based on full 24‐h records of flux data.
“…Aquatic Eddy Covariance). Adoption of these relatively novel methods in seaweed habitats is still not widespread however 52 , possibly due to the their relatively high cost and current inability to be deployed in wave-highly-exposed environments where many seaweeds thrive. Fig.…”
Net primary productivity (NPP) plays a pivotal role in the global carbon balance but estimating the NPP of underwater habitats remains a challenging task. Seaweeds (marine macroalgae) form the largest and most productive underwater vegetated habitat on Earth. Yet, little is known about the distribution of their NPP at large spatial scales, despite more than 70 years of local-scale studies being scattered throughout the literature. We present a global dataset containing NPP records for 246 seaweed taxa at 429 individual sites distributed on all continents from the intertidal to 55 m depth. All records are standardized to annual aerial carbon production (g C m−2 yr−1) and are accompanied by detailed taxonomic and methodological information. The dataset presented here provides a basis for local, regional and global comparative studies of the NPP of underwater vegetation and is pivotal for achieving a better understanding of the role seaweeds play in the global coastal carbon cycle.
“…That organic matter degradation rates inferred from oxygen microprofiles span a wide range (Archer et al, 1989a;Arndt et al, 2013;Wenzhöfer et al, 2016) may be, among other factors, due to the dependency on tidal and other ocean bottom current fluctuations. To adequately capture O 2 consumption rate in sediments, O 2 fluxes should be measured and integrated over a period of time longer than a tidal cycle (Berg et al, 2022).…”
Abstract. We introduce a time-dependent, one-dimensional model of
early diagenesis that we term RADI, an acronym accounting for the main
processes included in the model: chemical reactions, advection, molecular
and bio-diffusion, and bio-irrigation. RADI is targeted for study of
deep-sea sediments, in particular those containing calcium carbonates
(CaCO3). RADI combines CaCO3 dissolution driven by organic matter
degradation with a diffusive boundary layer and integrates state-of-the-art
parameterizations of CaCO3 dissolution kinetics in seawater, thus
serving as a link between mechanistic surface reaction modeling and
global-scale biogeochemical models. RADI also includes CaCO3
precipitation, providing a continuum between CaCO3 dissolution and
precipitation. RADI integrates components rather than individual chemical
species for accessibility and is straightforward to compare against
measurements. RADI is the first diagenetic model implemented in Julia, a
high-performance programming language that is free and open source, and it
is also available in MATLAB/GNU Octave. Here, we first describe the
scientific background behind RADI and its implementations. Following this, we evaluate
its performance in three selected locations and explore other potential
applications, such as the influence of tides and seasonality on early
diagenesis in the deep ocean. RADI is a powerful tool to study the
time-transient and steady-state response of the sedimentary system to
environmental perturbation, such as deep-sea mining, deoxygenation, or
acidification events.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
