Accurate light measurements are important in the analysis of photosynthetic systems. Many commercial instruments available to determine light; however, comparison estimates between studies is difficult due differences sensor types and their calibrations. The measurement underwater irradiance also complicated by scattering attenuation interactions with particulates, molecules, bottom. Here, three compared evaluate calibration intensity loggers estimate photosynthetically active radiation...

Based on noninvasive eddy correlation measurements at a marine and freshwater site, this study documents the control that current flow light have sediment‐water oxygen fluxes in permeable sediments. The sediment was exposed to tidal‐driven light, flux varied from night day between −29 78 mmol m −2 d −1 . A fitting model, assuming linear increase respiration with flow, photosynthesis‐irradiance curve for light‐controlled production reproduced measured well ( R 2 = 0.992) revealed 4‐fold...

Quantitative studies of coral reefs are challenged by the three-dimensional hard structure and high spatial variability temporal dynamics their metabolism. We used non-invasive eddy correlation technique to examine respiration photosynthesis rates, through O2 fluxes, from reef crests slopes in Florida Keys, USA. assessed how different habitats is controlled light hydrodynamics. Numerous fluxes (over a 0.25 h period) were as 4500 mmol m−2 d−1, which can only be explained efficient utilization...

Abstract A substantial body of research now exists demonstrating sensitivities marine organisms to ocean acidification (OA) in laboratory settings. However, corresponding situ observations species or ecosystem changes that can be unequivocally attributed anthropogenic OA are limited. Challenges remain detecting and attributing effects nature, part because multiple environmental co-occurring with OA, all which have the potential influence responses. Furthermore, change pH since industrial...

Coral reefs are biologically diverse and structurally complex ecosystems, which have been severally affected by human actions. Consequently, there is a need for rapid ecological assessment of coral reefs, but current approaches require time consuming manual analysis, either during dive survey or on images collected survey. Reef structural complexity essential function challenging to measure often relegated simple metrics such as rugosity. Recent advances in computer vision machine learning...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 529:75-90 (2015) - DOI: https://doi.org/10.3354/meps11314 Sub-tropical seagrass ecosystem metabolism measured by eddy covariance Matthew H. Long1,2,*, Peter Berg1, Karen J. McGlathery1, Joseph C. Zieman1 1Department of Environmental Sciences, University Virginia, 291 McCormick Rd, Charlottesville, Virginia...

Abstract Gas ebullition from aquatic systems to the atmosphere represents a potentially important fraction of primary production that goes unquantified by measurements dissolved gas concentrations. Although photosynthetic surfaces has often been observed, it is rarely quantified. The resulting underestimation activity may significantly bias determination ecosystem trophic status and estimated rates biogeochemical cycling in situ measures oxygen. Here, we quantified Zostera marina meadows...

Sediment‐bound phosphorus (P) is a potential nutrient source for P‐limited seagrasses inhabiting carbonate sediments. We explored the role of organic acid (OA) exudation by in liberating mineral P from Organic acids can act to increase available dissolving sediment, competing with binding sites and complexing dissolution end products, also fueling microbial processes that change pore‐water pH. used dialysis tubing placed around individual roots situ quantify dissolved species immediately...

An aquatic eddy covariance (EC) system was developed to measure the exchange of oxygen (O2) and hydrogen ions (H+) across sediment-water interface. The uses O2 optodes a newly micro-flow cell H+ ion selective field effect transistor; these sensors displayed sufficient precision rapid enough response times concentration changes associated with turbulent exchange. Discrete samples total alkalinity dissolved inorganic carbon were used determine background carbonate chemistry water column relate...

Abstract The oxygen concentration in marine ecosystems is influenced by production and consumption the water column fluxes across both atmosphere–water benthic–water boundaries. Each of these has potential to be significant shallow due high low volumes. This study evaluated contributions three budget two contrasting ecosystems, a Zostera marina (eelgrass) meadow Virginia, U.S.A., coral reef Bermuda. Benthic were eddy covariance. Water measured using an automated incubation system....

Abstract The eddy covariance (EC) technique is a powerful tool for measuring atmospheric exchange rates that was recently adapted by biogeochemists to measure aquatic oxygen fluxes. A review of biogeochemical EC literature revealed the majority studies were conducted in shallow waters where waves likely present, and biased sensor turbulence measurements. This identified larger measurement heights shifted lower frequencies, producing spectral gap between wave frequencies. However, some...

Abstract The net ecosystem metabolism of the seagrass Thalassia testudinum was studied across a nutrient and productivity gradient in Florida Bay, Florida, using Eulerian control volume, eddy covariance, biomass addition techniques. In situ oxygen fluxes were determined by triangular volume with sides 250 m long covariance instrumentation at its center. technique evaluated aboveground through added. spatial temporal resolutions, accuracies, applicability each method compared. better resolved...

A low‐cost self‐contained underwater particle image velocimetry (UWPIV) system has been developed to measure small‐scale turbulent flow structures in situ. The UWPIV employs a compact continuous‐wave laser and an optical scanner deliver light sheet that illuminates naturally occurring particles. Particle images are taken by CCD camera along with ultra‐compact PC. nontethered design can be fit two small housings all components powered batteries: ideal for variety of situ deployments....

Abstract Dissolution of calcite in deep ocean sediments, which is required to balance global marine CaCO 3 production and burial fluxes, still a poorly understood process. In order assess the mechanisms dissolution we analyzed four multicore tops taken along depth transect on Ontong‐Java Plateau. These cores were directly equator, span water column saturation states from ∼0.93 ∼0.74, allowing us effect carbonate sediment composition. The top 2 cm each was sectioned sieved separate coccolith...

Abstract We present a new approach to quantifying air‐water flux and gas transfer velocity ( k 600 ) from underwater eddy covariance (EC) of dissolved oxygen. EC fluxes were measured 35 cm below the interface using an acoustic Doppler velocimeter (ADV) coupled with fast‐responding oxygen optode probe, integrated on floating platform. A micro‐electro‐mechanical system (MEMS)‐based inertial motion unit ADV enabled compensation velocities for platform changing sensor orientation. Deployments 16...

We detected a controlled release of CO2 (g) with pH eddy covariance. quantified emission using measurements water velocity and in the plume aqueous generated by bubble streams, model predictions vertical dissolution its dispersion downstream. was injected 3 m below floor North Sea at rates 5.7–143 kg d − 1. Instruments were 2.6 from center streams. In absence CO2, covariance proton flux due to naturally-occurring benthic organic matter mineralization (equivalent dissolved inorganic carbon...

Abstract Coastal nutrient pollution, or eutrophication, is commonly linked to anthropogenic influences in terrestrial watersheds, where land-use changes often degrade water quality over time. Due gradual changes, the management and monitoring of estuarine systems lag environmental degradation. One example can be found at Waquoit Bay National Estuarine Research Reserve, we developed an analysis framework standardize analyze long-term trends submerged vegetation data from programs that began...

International climate goals require over 5 gigatons/year (Gt/year) of CO2 to be removed from the atmosphere by midcentury. Macroalgae mariculture has been proposed as a strategy for such carbon dioxide removal (CDR). However, global potential seaweed cultivation not assessed in detail. Here, we develop and use dynamic growth model, Global MacroAlgae Cultivation MODeling System (G-MACMODS), estimate yields four different types worldwide, test sensitivity these estimates uncertain biophysical...

Abstract Coral reefs are known to have extremely high rates of primary production. However, common geochemical methods for determining bulk reef metabolism cannot distinguish which organisms responsible Here we used a “bottom‐up” approach estimate the contribution diverse producers including hard corals, octocorals, and algae gross production on coral by scaling up taxon‐specific abundance those taxa in environment. Chamber‐based dominant were obtained as function irradiance, short‐term...

Abstract Multiple methods exist to measure the benthic flux of dissolved oxygen (DO), but many are limited by short deployments and provide only a snapshot processes occurring at sediment–water interface. The gradient (GF) method measures near bed gradients DO estimates eddy diffusivity from existing turbulence closure solve for flux. This study compares measurements seagrass, reef, sand environment with two other methods, covariance chambers, highlight strengths, weaknesses, uncertainty...

Abstract Pelagic photosynthesis and respiration serve critical roles in controlling the dissolved oxygen (DO) concentration seawater. The consumption production via pelagic primary are of particular importance surface ocean freshwater ecosystems where photosynthetically active radiation is abundant. However, dynamic nature large degree heterogeneity these pose substantial challenges for providing accurate estimates marine metabolic state. resulting lack higher‐resolution data systems hinders...

Abstract Movement and migration of fish are critical for sustaining riverine populations. Water resource development alters natural flow regimes can disconnect habitats interfere with hydrological cues movement. Environmental releases counter these impacts, but to be effective they must based on quantitative flow–biota relationships. We used radio‐telemetry investigate the association between movement Tandanus bostocki , a plotosid endemic south‐western Australia. was assessed 15 adult at...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 550:111-119 (2016) - DOI: https://doi.org/10.3354/meps11737 Extreme low oxygen and decreased pH conditions naturally occur within developing squid egg capsules Matthew H. Long1,*, T. Aran Mooney2, Casey Zakroff2,3 1Marine Chemistry Geochemistry Department, Woods Hole Oceanographic Institution, 266 Road, Hole,...

Net-zero greenhouse gas emissions targets are driving interest in opportunities for biomass-based negative and bioenergy, including from marine sources such as seaweed. Yet the biophysical economic limits to farming seaweed at scales relevant global carbon budget have not been assessed detail. We use coupled growth technoeconomic models estimate costs of production related climate benefits, systematically testing relative importance model parameters. Under our most optimistic assumptions,...