Coastal and inland waters ecosystems are ecologically, culturally, and economically important. Monitoring these environments is therefore essential to understand ecosystem functioning, how to ensure sustainable practices and assess the impact of human activities. Among the large diversity of measurement techniques, optical remote sensing presents some clear advantages. Indeed, earth observation satellites nowadays allow to monitor the spatial variability of water quality parameters over large areas and with relatively short revisiting times. In water and above water radiometers, have a great potential for ecosystem monitoring, especially if they are integrated into autonomous measurement systems providing high temporal resolution data, or if they have a high spectral resolution opening the door to new environmental products based on fine spectral features. However, retrieving relevant information on water constituents from radiometric data in optically complex waters is still challenging. Indeed, although in clear, case-1, waters most of the bio-optic parameters are dependent of the chlorophyll-a concentration, in coastal and inland waters (i.e. case-2 waters) light absorption and scattering is affected by terrestrial inputs of sediments and/or dissolved organic carbon which can make the retrieval of simple parameters such as the chlorophyll-a concentration very complicated. In addition, atmospheric correction algorithms are more challenging because of potentially extreme optical water properties and the proximity with the coast or surrounding land. This session is open to all contributions presenting novel applications of inland and coastal aquatic monitoring based on visible and NIR radiometric remote sensing data either from satellite or in situ sensors.
Lead Organizer: Héloïse Lavigne, Royal Belgium Intistute of Natural Sciences (hlavigne@naturalsciences.be)
Co-organizers:
Clémence Goyens, Royal Belgium Institute of Natural Sciences (cgoyens@naturalsciences.be)
Pierre Gernez, Nantes Université (pierre.gernez@univ-nantes.fr)
David Doxaran, Laboratoire D'Oceanographie de Villfrenche, CNRS (david.doxaran@imev-mer.fr)
Evangelos Spyrakos, University of Stirling (evangelos.spyrakos@stir.ac.uk)
Presentations
06:30 PM
EXPLOITATION OF HYPERSPECTRAL PRISMA DATA FOR WATER QUALITY MAPPING (5159)
Primary Presenter: Monica Pinardi, National Research Council of Italy (pinardi.m@irea.cnr.it)
Nowadays, waterbodies have been seriously threatened by climate change: in this context, new-generation satellite hyperspectral sensors are contributing to the water resources studies. This work shows the main goals achieved by the exploitation of PRISMA data for aquatic ecosystems mapping in the framework of the ASI-PRISCAV, PANDA-WATER and PRIMEWATER projects. The suitability of PRISMA radiance and reflectance products was demonstrated (Giardino et al. 2020; Braga et al. 2022) through comparison with reference data: Sentinel-2, Sentinel-3 and in-situ measurements obtained through ad-hoc campaigns, where reflectance and water quality data are collected simultaneously. To demonstrate the PRISMA water quality mapping two approaches were tested: the bio-optical model inversion with the BOMBER code and adaptive semi-empirical algorithms. Bottom substrate (BS) maps were generated by running BOMBER, Total Suspended Matter (TSM) maps with the semi-empirical algorithms and Chlorophyll-a (Chl-a) maps with both approaches. The validation of the water quality products was performed by comparison with in-situ data. The maps obtained with BOMBER showed an accuracy of 80% for the characterization of the BS and RMSE=2.0 mgm-3 for Chl-a retrieval. The maps obtained with the semi-empirical algorithms showed the following results: RMSE=1.9 gm-3 for TSM retrieval and RMSE=3.1 mgm-3 for Chl-a retrieval. Despite the need of further analysis, PRISMA is providing valuable information and - in synergy with multispectral missions - is offering support to water management activities.
06:30 PM
RESSBIO first results (7442)
Primary Presenter: Xavier Sòria Perpinyà, Universitat de València (javier.soria-perpina@uv.es)
Remote Sensing Spectroscopy for wetlands BIOdiversity (RESSBIO) project aim is to investigate and exploit the capabilities of new Earth Observation satellite missions, equipped with hyperspectral sensors, in the assessment and monitoring of the ecological status of lentic aquatic systems. The new hyperspectral missions already in orbit (PRISMA and EnMAP) offer the possibility of studying the organic matter and phytoplankton composition, separating groups indicators of ecological status (diatoms, chlorophyceae, cyanobacteria, dinoflagellates), as well as the organic matter composition (dissolved and particulate). During the first months of RESSBIO project, field samplings in Albufera de València and Bellús and Beniarrés reservoirs have been carried out, coinciding with PRISMA images acquisition to obtain in situ radiometry and several limnological variables. First, the atmospheric correction of PRISMA L2D images has been validated in our study area (hypertrophic waters), comparing the image remote sensing reflectance (Rrs) with the in situ Rrs convoluted according to the PRISMA image spectral response functions. On the other hand, with the in situ limnological variables data, the accuracy of some algorithms calibrated and validated in the study area were tested in PRISMA images. The good response regarding the algorithms applied with this pre-test is an indication that our hypothesis was correct, and we can obtain algorithms to distinguish both organic matter and phytoplankton composition with hyperspectral sensors.
06:30 PM
PANDA-WATER: PRISMA Products and Applications for inland and coastal WATER (7392)
Primary Presenter: Federica Braga, CNR-ISMAR (f.braga@ismar.cnr.it)
The PANDA-WATER project, funded by the Italian Space Agency (ASI), aims to provide a set of innovative products from PRISMA hyperspectral imagery over inland, transitional, and coastal waters, and to assess its suitability for addressing challenges in aquatic sciences and ecosystem management, exploiting the radiometric sensitivity and the spatial and spectral resolutions. These products will focus on: i) accurate estimates of optically active water constituents; ii) advanced water quality parameters (i.e. particle size distribution, suspended and coloured dissolved matter quality); iii) water depth and benthic substrate; iv) natural or artificial floating materials; v) attenuation coefficient and euphotic depth; vi) cyanobacteria and harmful algal blooms. The novelty of PANDA-WATER stems from the application of the state-of-the-art-algorithms adapted to the characteristics of PRISMA, thus resulting in observational capabilities, complementary to the current Copernicus missions. The product development carried out within PANDA-WATER from PRISMA data will also be suitable for upcoming hyperspectral missions (i.e., Copernicus CHIME, NASA’s PACE, and SBG), thus contributing to the global advance in spaceborne imaging spectrometry.
06:30 PM
PRELIMINARY ANALYSIS OF NEAR-COINCIDENT HYPERSPECTRAL AND MULTISPECTRAL IMAGERY ACROSS EUROPEAN WATERS (5488)
Primary Presenter: Kiana Zolfaghari, University of Waterloo (kzolfagh@uwaterloo.ca)
Hyperspectral remote sensing of water quality is anticipated to improve the accuracy of water quality retrievals through differentiating between optical characteristics of various algal pigments and optically active water constituents. This study investigates the challenges of synergistically using hyperspectral and multispectral satellite images for retrieving water optical characteristics (e.g., chlorophyll-a concentration; Chla). PRISMA images, and multispectral satellite datasets from MSI and OLCI onboard Sentinel-2A/B and Sentinel-3A/B, respectively, were acquired over five European water bodies. Chla field data were collected concurrently with the satellite observations. The ACOLITE model was employed to reduce the atmosphere interferences in all images. Mixture Density Networks (MDNs) was applied to ACOLITE-corrected data to estimate Chla concentration. Preliminary results show that ACOLITE-estimated remote sensing reflectance (Rrs) spectra for the three satellites follow similar patterns, while PRISMA Rrs spectra contain noise across the visible/near-infrared bands. In general, Chla derived from both MSI and OLCI better match in situ Chla data than from PRISMA. The next steps include examining the application of the POLYMER atmospheric correction algorithm in combination with MDN in retrieving Chla. A few spectral indices, such as MCI and NDCI, will also be tested in conjunction with POLYMER- and ACOLITE-corrected Rrs data to fully demonstrate opportunities and challenges in merging future global hyperspectral and multispectral satellite observations.
06:30 PM
Application of GOCI-II to monitoring the diurnal variability in the water quality in Korean coastal waters (5285)
Primary Presenter: Jongkuk choi, KIOST (jkchoi@kiost.ac.kr)
The second Geostationary ocean color imager (GOCI-II), succeeding the mission of GOCI, was launched in February 2020 and is currently in regular operation. It focuses on the succession and the expansion of the GOCI mission, and improves specifications over GOCI in terms of spatial, temporal and the spectral resolution. GOCI have effectively monitored water quality around Korean peninsula for the past decade in terms of chlorophyll-a concentrations (CHL), total suspended sediment (TSS), colored dissolved organic matter (CDOM) along with sea surface salinity (SSS). GOCI could get images in hourly base, making it possible to examine the diurnal variability of water quality. Now we have GOCI-II which has advanced spatial resolution (250 m), frequency (10 times a day) and spectral resolution (12 VNIR bands) for the previous one. Thus, we can get enhanced images in terms of time and space for the coastal waters around Korean peninsula and, consequently see more accurate dynamic variability in water quality. Here, we examined the applicability of GOCI-II to monitoring the diurnal variability in the water quality in Korean coastal waters in terms of the fundamental products like remote sensing reflectance (Rrs), chlorophyll-a concentrations (CHL) products by OCx algorithm, and total suspended sediment (TSS), colored dissolved organic matter (CDOM). We verified the algorithm by comparing with in-situ measurement and also with those from GOCI. Although GOCI has completed its mission at the end of March 2021, we have the duplicated times of operating GOCI-I, GOCI-II from February 2020 to March 2021. From this study, we examined and effectively identified the diurnal variability of water quality of Korean coastal waters.
06:30 PM
New Opportunities offered by SuperDove CubeSats for Monitoring Inland Water Quality and Bathymetry (6939)
Primary Presenter: Milad Niroumand-Jadidi, Fondazione Bruno Kessler (mniroumand@fbk.eu)
The recent development of CubeSat constellations (fleets consisting of numerous small satellites) provides an unprecedented opportunity for monitoring spatiotemporal dynamics of inland waters. The meter-scale spatial resolution and daily revisit frequency of the recent SuperDove constellation can potentially take the remote sensing of inland waters to the next level. However, there is a need to assess the radiometric quality of this new source of data for aquatic applications. This study examines the potential of SuperDove imagery in retrieving bathymetric and water constituent information in inland waters. We adopt both physics-based and machine-learning models to derive the biophysical parameters. The radiative transfer inversion model implemented in water color simulator (WASI) processor is parametrized to retrieve the concentration of chlorophyll-a and total suspended matter in Lake Trasimeno (Italy) using level-2 bottom-of-atmosphere SuperDove imagery. The flexibility of WASI in parametrization allowed us to effectively mitigate the atmospheric and sun-glint artifacts that are a severe problem. Furthermore, we leverage a neural network-based (NN) regression model to infer bathymetry of the Colorado River (US) with depths up to 10 m. The NN-based model automatically handles the feature extraction applied to level-1 top-of-atmosphere SuperDove imagery. The results indicate the promising radiometric quality of the SuperDove data that provided robust retrievals of bathymetric and constituent parameters in inland waters based on physical and machine learning models.
06:30 PM
VALIDATION OF ATMOSPHERIC CORRECTION PROCESSORS IN INLAND AND COASTAL WATERS OF IBERIAN PENINSULA APPLIED TO OLCI-SENTINEL-3 IMAGES (5741)
Primary Presenter: Patricia Urrego, Image Processing Laboratory (IPL), University of Valencia (patricia.urrego@uv.es)
Atmospheric correction (AC) of satellite images is fundamental for water quality studies due to the low reflectance of water in the VIS-NIR region of the spectrum, which rarely exceeds 20%, and then the dominant contribution of atmosphere to the radiance signal measured by satellites in such spectral region. This presents a challenge, especially in inland waters, where the content of different optically active components, such as phytoplankton, organic matter, non-algal particles, increase the reflectance values in the NIR region compared to oceanic water. This hampers the application of usual AC algorithms, where water bodies are assumed to have reflectances values close to zero in the NIR region. In this work, four AC algorithms specially developed for application in water bodies (C2RCC, ACOLITE, Polymer and Level-2 OLCI product) were evaluated using the Sentinel-3-OLCI sensor (S3-OLCI) images, a multispectral radiometer specifically designed for use over water bodies. The reflectance spectra obtained from the processors were validated with in-situ remote sensing reflectance (Rrs) data measured during field campaigns carried out in reservoirs and coastal water of the Iberian Peninsula (Spain) with different trophic states, between 2018 and 2023. For this purpose, 27 images of S3-OLCI coinciding (±1 day) with dates of the field radiometry measurements, were atmospherically corrected using the four AC algorithms. The Rrs obtained from each pixel band coinciding with the sampling points were statistically filtered, and the resulting dataset was validated with the in-situ radiometry data.
06:30 PM
Tracing two origins of Sargassum bloom in the Yellow Sea and East China Sea using Sentinel-2 and GOCI data (5571)
Primary Presenter: Young Baek Son, Korea Institute of Ocean Science and Technology(KIOST) (sonyb@kiost.ac.kr)
The Yellow Sea (YS) and East China Sea (ECS) have the world’s largest supply of floating macroalgae. The golden tides (Sargassum horneri) appear mainly in the YS and ECS, but become entangled as they drift. The floating harmful macroalgae blooms (HMBs) obstructs navigation and is a huge socioeconomic problem in the vicinity of coastal areas. However, the annual pattern of Sargassum bloom is not well known due to changing air-sea interaction conditions. To determine the spatio-temporal distribution and variation of the golden tide in the YS and ECS, the multi-satellite sensor data (e.g. Sentinel-2 and GOCI) was used to detect the floating macroalgae patch using the Alternative Floating Algae Index and mapped over the study area using a 15-year data. The floating patches detected by both satellite data were overlapped to make the annual pattern maps. The Sargassum blooms were generally found on spring in the YS and ECS. The Sargassum blooms was proceeded in the waters near the Yangtze River and Zhejiang Province, China and then floating into the east and north-east ward influenced by the Tsushima warm current or Kuroshio. The Sargassum blooms were build-up in the middle of the ECS and pile-up in the coast of Korea from March to May. Recently, the Sargassum blooms were temporally expanded from to May from 2019 to 2022 and spatially raised in the YS and ECS. The initiated drifting blooms were detected in the Bohai Bay and Shandong Peninsula from September to October and then expanded in a southward direction from the central YS to Jeju Island, Korea during November to March. The blooms lasted 5-6 months in the YS and ECS. The second onset blooms were found near the mouth of the Yangtze River and Zhejiang Province from January to February and expanded in an east- or north-ward direction from March to May (or June). From the annual pattern maps of the golden tide blooms, we suggested two origins with tracing the temporal and spatial distribution and development. The first blooms were onset on fall around the Bohai Bay and/or Shandong Peninsula and southward controlled by the local wind and sea surface temperature condition on winter. The second blooms were initiated on winter near the Zhejiang Province, China and east- and northward affected by the local current and wind condition.
06:30 PM
MONITORING EELGRASS (MARINE PLANTS) IN LA ROMAINE ESTUARY, QUÉBEC, CANADA (6844)
Primary Presenter: Alain Tremblay, Hydro-Québec (tremblay.alain.claude@gmail.com)
From 2014 to 2021, four generating stations were commissioned on La Romaine River, on North shore of St Lawrence River. A specific monitoring program was carried out in summers 2013, 2015, 2017, 2019 and 2021 to follow-up change in eelgrass beds. It involved documenting the eelgrass bed surface area as well as abundance of the eelgrass beds. High resolution satellite images were taken at low tide to characterize bed surface and abundance. Ground truthing was performed to validate the presence or absence of eelgrass plants and to calibrate satellite images. Our results indicate that there are modifications of both surface area and abundance, with years showing increase of surface area and some years indicating a decrease in surface area, especially in the margins of eelgrass beds which are more exposed to waves, tides and currents. Moreover, the results suggest that eelgrass beds persist, and their central part expand. Similar changes over time are also observed in reference sites indicating that these changes are more related to natural variability than the effect of the flooding and operating of Romaine complex.
06:30 PM
Assessing Seasonal Variations in Freshwater Grass Distribution and Biomass on Susquehanna Flats Through High-Resolution Planet Satellite Imagery. (6917)
Primary Presenter: Kylie Harrison, Old Dominion University (keharrison01@gmail.com)
Susquehanna Flats, located at the mouth of the Susquehanna River in Maryland, is a large, shallow mud flat covered with dense populations of freshwater grasses, including wild celery (Vallisneria americana) and water stargrass (Heteranthera dubia). This dynamic ecosystem has long been a popular destination for both fishermen and tourists. Since the 1980s, annual mapping of Susquehanna Flats has been undertaken from aerial photography. However, these once-yearly observations overlook the dramatic seasonal changes in both extent and biomass of the vegetation. In this study we investigated patterns of seasonality on Susquehanna Flats from 2016 to 2023 using imagery from Planet, a commercial satellite company, providing daily coverage of terrestrial and coastal ecosystems at 3 m spatial resolution. We found that grasses on the flats experience a significant die-off during winter months, with aerial coverage reducing from approximately 50 km² in August to 6 km² in December. Estimated above ground carbon biomass in the summer reached as high as 3.5 Gg carbon, declining to less than 0.3 Gg C in the winter, pointing towards a potential carbon export from the flats of ~3 Gg carbon per year. Understanding the seasonal cycle of growth on the flats has important implications for the management and conservation strategies for this unique habitat.
06:30 PM
Using Hyperspectral remote sensing in situ data in conjunction with Sentinel-2 images to monitor water quality in drinking water reservoirs (5612)
Primary Presenter: Clemence Goyens, RBINS (cgoyens@naturalsciences.be)
In the past decade, severe algal blooms have been occurring in the Blankaart (Belgium) and La Loggia (Italy), two surface water reservoirs acting as a first biologic treatment step before further processing to drinking water. Since these algal blooms hamper the water production, strategies (e.g., injection of algaecide) have been looked at to prevent these from happening or try to control them. In this context, the HYperspectral Pointable System for Terrestrial and Aquatic Radiometry (HYPSTAR), installed since early 2021, helps in monitoring the effectiveness of these strategies. Indeed the HYPSTAR provides, at a very high temporal resolution, bio-optical parameters related to the water quality, i.e., Chlorophyll-a (Chla) concentrations and Suspended Particulate Matter (SPM). In addition, to catch the spatial variability of the water quality, we investigated the potential to provide more advanced water quality maps using Sentinel-2 MSI images. The optimized atmospheric correction method, ACOLITE-GLAD, taking into account adjacency effect and sunglint, was therefore used together with improved algorithms for water quality products, e.g., semi-empirical, semi-analytical, and, neural network based approaches. In the frame of the H2020-CALLISTO project, the resulting water quality data is ingested in a data portal allowing managers of drinking water reservoirs to access continuous and accurate water quality assessment.
06:30 PM
Monitoring Harmful Algal Blooms with autonomous hyperspectral radiometry systems (PANTHYR and HYPSTAR) in coastal and in inland waters (5700)
Primary Presenter: Héloïse Lavigne, Royal Belgium Institute of Natural Sciences (hlavigne@naturalsciences.be)
Harmful algal blooms (HAB), defined by the rapid development of a toxic or non desirable phytoplankton species in a water body, impact both economy and water environment. Their monitoring is then one of the main duty of water quality managers. HAB monitoring is generally based on punctual water sampling and analysis which is time consuming. To support HAB monitoring, optical remote sensing as been used, providing information on total phytoplankton biomass with chlorophyll-a concentration (Chl-a). However, Chla is only partially informative as it does not allow to distinguish between phytoplankton species. Here, we show that the newly developed autonomous hyperspectral radiometry systems (PANTHYR and HYPSTAR) primary dedicated to the validation of water reflectance data from satellite can be very useful for HAB monitoring. On a first example, we show how Phaeocystis globosa bloom can be monitored with a PANTHYR system in the Southern North Sea. Although not toxic, this specie produces foam which accumulates on the beach impacting touristic and economical activities. On a second example, toxic cyanobacteria blooms are monitored in a water reservoir at Blankaart (Belgium). In both cases, HAB indexes are developed based on the specificity of pigment composition of the harmful phytoplankton species compared to other local species using the analysis of second derivatives of the water reflectance spectra. We hence show that HYPSTAR and PANTHYR technology associated with local HAB indexes will allow for an improvement of HAB monitoring with real time alerts at daily scale.
06:30 PM
Combining modelling and automated monitoring in reservoirs to track water quality: A management point of view (7365)
Primary Presenter: Javier Vidal Hurtado, EDF (javier.vidal-hurtado@edf.fr)
In the recent years, a growing amount of plans to preserve and manage the water resources has developed all around the globe. Water quality monitoring and assessment programs are used to characterize waters, identify trends over time, recognize emerging problems, and determine effectiveness of water management programs. Complemented by remote sensing, the in-situ data from automated buoys represent an important dataset to model the ecosystem, and subsequently predict water quality. Eutrophication, cyanobacteria blooms and anoxia determine, to a large extend, the water quality issues in reservoirs. In the hydroelectric reservoir of Eguzon (France), an on-going survey has been lunched to predict water quality at short term and its evolution under climate change. An automated buoy measuring meteorological, hydro-physical and biogeochemical parameters (temperature, conductivity, turbidity, oxygen, chlorophyll a, phycocyanin) has been deployed and complemented with bi-weekly in-situ measurements in the reservoir, upstream and downstream. In addition, the coupled hydrodynamic-biogeochemical model GLM-AED2 is being implemented for the reservoir of Eguzon. The reservoir modelling will be integrated in a broader watershed model. The goal of the on-going collaborative research site of Eguzon is to bring together both researchers and stakeholders to progress in the metrology, knowledge and modelling of the water quality of reservoirs.
06:30 PM
OPTICAL CHARACTERIZATION OF ESTUARINE AND COASTAL WATERS AROUND THE SITE AERONET-OC BAHÍA BLANCA, SW ATLANTIC (5938)
Primary Presenter: Paula Pratolongo, CONSEJO NACIONAL DE INVESTIGACIONES CIENTÍFICAS Y TÉCNICAS (CONICET) (ppratolongo@gmail.com)
The site Bahía Blanca (AERONET-OC, NASA) was established in 2020 at the mouth of the main channel of the Bahía Blanca Estuary, a coastal system characterized by high suspended loads and turbidity. We present remote sensing reflectance (Rs) spectra obtained with a hand-held spectroradiometer and data from intensive field water sampling including measurements of turbidity (T, FNU), chlorophyll a (Chla, μg l−1), suspended particulate matter (SPM, mg l−1), phytoplankton absorption (aphy) and the total particulate matter absorption (ap). According to the Rs spectra, waters within the channel showed relatively low values in the blue and green part of the visible spectrum, maximum Rs values occurred around 570 nm, and remained high in the red, with no clear fluorescence peak. Estuarine waters presented the highest suspended loads (5.1 to 140.6 mg l-1) and T values (8.4 to 147.7 FNU). Chla ranged 0.83 to 6.08 μg l−1 and values were not correlated with T. In the coastal zone out of the estuary, the Rs spectra displayed a relative strong peak around 570 nm as well as a secondary peak at 687 nm. SPM (5.1 to 50.1 mg l-1) and T (5.6 and 43.7 FNU) diminished. Chla ranged 0.78 to 3.74 μg l−1 and the strong correlation between T, Chla, aphy, and ap suggest that the SPM includes a relative high proportion of detrital material and phytoplankton cells. The AERONET site is in the transition between these contrasting estuarine vs coastal water types, and the relative contribution of organic and inorganic compounds to the suspended material would be mostly related with the prevalence of NW winds.
06:30 PM
PANTHYR, AN AUTOMATED ABOVE-WATER MEASUREMENT SYSTEM INSTALLED ON C-POWER: HYPERSPECTRAL WATER REFLECTANCE DATA FOR SATELLITE VALIDATION AND MONITORING OF BELGIAN COASTAL WATER (6725)
Primary Presenter: Francesca Ortenzio, RBINS (fortenzio@naturalsciences.be)
Satellite optical remote sensing is used to monitor coastal and inland water quality, providing data for port and coastal management by measuring parameters such as chlorophyll-a and suspended particulate matter. The quality of this satellite operational data depends on intermediate processing, supported by in situ measurements of water reflectance. PANTHYR, a “PAN-and-Tilt HYperspectral Radiometer system” is part of WATERHYPERNET, an international network of automated radiometers on zenith- and azimuth- pointing systems, that will provide hyperspectral validation covering a spectral range of 400-900 nm, sufficient for all visible and near infrared bands of current deployed satellite platforms. The network is built on the experience gained from AERONET-OC, a multispectral network existing for more than 20 years. The Panthyr collects data every 20 minutes from sunrise till sunset and the main application will be to provide data for satellite validation. Nonetheless, the availability of high frequency and long-term hyperspectral water reflectance measurements can be useful for many other applications related to Belgian water monitoring, such as phytoplankton, turbidity dynamics, diatoms blooming. A Panthyr is being installed on the C-Power Windfarm OTS Platform, in the North Sea 30 km off the Belgian coastline. On the same platform is already running a CIMEL from the AERONET-OC, allowing for comparison between the two sensors, multi- and hyperspectral. We will present here the first results of the Panthyr installation on C-Power.
06:30 PM
BIOLUMINESCENCE OF THE CTENIOPHORE MNEMIOPSIS LEIDYI: FIRST FLASH KINETICS (7204)
Primary Presenter: Abigail Blackburn, HBOI FAU (ablackburn2021@fau.edu)
The ctenophore <em>Mnemiopsis leidyi</em> is a coastal and opportunistic species that can be abundant and invasive in many parts of the world causing fishery crashes and altering ecosystems. This species is well known for its bright bioluminescence, but its light emission response to flow stimulation has not been previously quantified. The objective of this study is to determine the luminescent response of <em>M. leidyi</em> to several types of mechanical stimuli, including fully characterized laminar pipe flow, an impeller pump with the UBAT bathyphotometer, grid stimulated pipe flow, and stirring as the stimulus within an integrating sphere. For all conditions, the light intensity and temporal kinetics of the flash responses were determined such as total flash duration, rise time, exponential decay, and max intensity of the most prominent peak. For the UBAT, max intensity of the most prominent peak was 2.5e10 photons/s with an average rise time of 0.0798s and a median flash duration of 0.48s. For pipe flow, the response threshold was assessed as a function of fluid shear stress, the threshold was found to be 0.06Pa. Tests with different ages and sizes of cydippids determine how the bioluminescent responses differ with developmental stage, as the flashes of older and larger individuals are higher in intensity and longer. This study provides a well-defined baseline of cydippid flash responses, which can be used for interpreting field measurements made with bathyphotometers and determining their contribution to the bioluminescence potential of waters where they are present.
SS102P Inland and Coastal Aquatic Ecosystems Monitoring from In Situ and Satellite Radiometric Measurements
Description
Time: 6:30 PM
Date: 8/6/2023
Room: Mezzanine