Detection of Phytoplankton Temporal Anomalies Based on Satellite Inherent Optical Properties: A Tool for Monitoring Phytoplankton Blooms

[EN] The baseline of a specific variable defines the average behavior of that variable and it must be built from long data series that represent its spatial and temporal variability. In coastal and marine waters, phytoplankton can produce blooms characterized by a wide range of total cells number or chlorophyll a concentration. Classifying a phytoplankton abundance increase as a bloom depends on the species, the study area and the season. The objective of this study was to define the baseline of satellite absorption coefficients in Todos Santos Bay (Baja California, Mexico) to determine the presence of phytoplankton blooms based on the satellite inherent optical properties index (satellite IOP index). Two field points were selected according to historical bloom reports. To build the baseline, the data of phytoplankton absorption coefficients (aphy,GIOP ) and detritus plus colored dissolved organic matter (CDOM) (adCDOM,GIOP ) from the generalized inherent optical property (GIOP) satellite model of the NASA moderate resolution imaging spectroradiometer (MODIS-Aqua) sensor was studied for the period 2003 to 2016. Field data taken during a phytoplankton bloom event on June 2017 was used to validate the use of satellite products. The association between field and satellite data had a significant positive correlation. The satellite baseline detected a trend change from high values to low values of the satellite IOP index since 2010. Improved wastewater treatment to waters discharged into the Bay, and increased aquaculture of filter-feeding mollusks could have been the cause. The methodology proposed in this study can be a supplementary tool for permanent in situ monitoring programs. This methodology offers several advantages: A complete spatial coverage of the specific coastal area under study, appropriate temporal resolution and a tool for building an objective baseline to detect deviation from average conditions during phytoplankton bloom events.This research was funded by the Council of Science and Technology of Mexico (CONACYT by its acronym in Spanish) with a doctorate scholarship to J.A.A.-M., with the announcement number 291025 in 2015. Also, it was funded by the Spanish Ministry of Education Culture and Sports with a post-doctoral research grant to M.T.S.-F., number CAS18/00107, in support of her stay at the Universidad Autonoma de Baja California (Mexico). The APC was funded by the Secretariat of Public Education of Mexico (SEP) under the Program for Professional Development Teacher.Aguilar-Maldonado, J.; Santamaria-Del-Angel, E.; González-Silvera, A.; Sebastiá-Frasquet, M. (2019). Detection of Phytoplankton Temporal Anomalies Based on Satellite Inherent Optical Properties: A Tool for Monitoring Phytoplankton Blooms. Sensors. 19(15). https://doi.org/10.3390/s19153339S1915Carbonel H., C. A. A., & Valentin, J. L. (1999). Numerical modelling of phytoplankton bloom in the upwelling ecosystem of Cabo Frio (Brazil). Ecological Modelling, 116(2-3), 135-148. doi:10.1016/s0304-3800(98)00201-4Dore, J. E., Letelier, R. M., Church, M. J., Lukas, R., & Karl, D. M. (2008). Summer phytoplankton blooms in the oligotrophic North Pacific Subtropical Gyre: Historical perspective and recent observations. Progress in Oceanography, 76(1), 2-38. doi:10.1016/j.pocean.2007.10.002Cox, R. F., Issa, R. R. A., & Ahrens, D. (2003). Management’s Perception of Key Performance Indicators for Construction. Journal of Construction Engineering and Management, 129(2), 142-151. doi:10.1061/(asce)0733-9364(2003)129:2(142)Zheng, G., & DiGiacomo, P. M. (2017). Remote sensing of chlorophyll-a in coastal waters based on the light absorption coefficient of phytoplankton. Remote Sensing of Environment, 201, 331-341. doi:10.1016/j.rse.2017.09.008Cao, F., Tzortziou, M., Hu, C., Mannino, A., Fichot, C. G., Del Vecchio, R., … Novak, M. (2018). Remote sensing retrievals of colored dissolved organic matter and dissolved organic carbon dynamics in North American estuaries and their margins. Remote Sensing of Environment, 205, 151-165. doi:10.1016/j.rse.2017.11.014Blondeau-Patissier, D., Gower, J. F. R., Dekker, A. G., Phinn, S. R., & Brando, V. E. (2014). A review of ocean color remote sensing methods and statistical techniques for the detection, mapping and analysis of phytoplankton blooms in coastal and open oceans. Progress in Oceanography, 123, 123-144. doi:10.1016/j.pocean.2013.12.008Garver, S. A., & Siegel, D. A. (1997). Inherent optical property inversion of ocean color spectra and its biogeochemical interpretation: 1. Time series from the Sargasso Sea. Journal of Geophysical Research: Oceans, 102(C8), 18607-18625. doi:10.1029/96jc03243Kahru, M., Lee, Z., Kudela, R. M., Manzano-Sarabia, M., & Greg Mitchell, B. (2015). Multi-satellite time series of inherent optical properties in the California Current. Deep Sea Research Part II: Topical Studies in Oceanography, 112, 91-106. doi:10.1016/j.dsr2.2013.07.023Kratzer, S., & Moore, G. (2018). Inherent Optical Properties of the Baltic Sea in Comparison to Other Seas and Oceans. Remote Sensing, 10(3), 418. doi:10.3390/rs10030418Werdell, P. J., McKinna, L. I. W., Boss, E., Ackleson, S. G., Craig, S. E., Gregg, W. W., … Zhang, X. (2018). An overview of approaches and challenges for retrieving marine inherent optical properties from ocean color remote sensing. Progress in Oceanography, 160, 186-212. doi:10.1016/j.pocean.2018.01.001Costa Goela, P., Icely, J., Cristina, S., Newton, A., Moore, G., & Cordeiro, C. (2013). Specific absorption coefficient of phytoplankton off the Southwest coast of the Iberian Peninsula: A contribution to algorithm development for ocean colour remote sensing. Continental Shelf Research, 52, 119-132. doi:10.1016/j.csr.2012.11.009Soja-Woźniak, M., Craig, S., Kratzer, S., Wojtasiewicz, B., Darecki, M., & Jones, C. (2017). A Novel Statistical Approach for Ocean Colour Estimation of Inherent Optical Properties and Cyanobacteria Abundance in Optically Complex Waters. Remote Sensing, 9(4), 343. doi:10.3390/rs9040343Pavlov, A. K., Taskjelle, T., Kauko, H. M., Hamre, B., Hudson, S. R., Assmy, P., … Granskog, M. A. (2017). Altered inherent optical properties and estimates of the underwater light field during an Arctic under-ice bloom of Phaeocystis pouchetii. Journal of Geophysical Research: Oceans, 122(6), 4939-4961. doi:10.1002/2016jc012471Aguilar-Maldonado, J. A., Santamaría-del-Ángel, E., & Sebastiá-Frasquet, M. T. (2017). Reflectances of SPOT multispectral images associated with the turbidity of the Upper Gulf of California. Revista de Teledetección, (50), 1. doi:10.4995/raet.2017.7795Binding, C. E., Greenberg, T. A., McCullough, G., Watson, S. B., & Page, E. (2018). An analysis of satellite-derived chlorophyll and algal bloom indices on Lake Winnipeg. Journal of Great Lakes Research, 44(3), 436-446. doi:10.1016/j.jglr.2018.04.001Aguilar-Maldonado, J., Santamaría-Del-Ángel, E., González-Silvera, A., Cervantes-Rosas, O., & Sebastiá-Frasquet, M.-T. (2018). Mapping Satellite Inherent Optical Properties Index in Coastal Waters of the Yucatán Peninsula (Mexico). Sustainability, 10(6), 1894. doi:10.3390/su10061894Brewin, R. J. W., Sathyendranath, S., Müller, D., Brockmann, C., Deschamps, P.-Y., Devred, E., … White, G. N. (2015). The Ocean Colour Climate Change Initiative: III. A round-robin comparison on in-water bio-optical algorithms. Remote Sensing of Environment, 162, 271-294. doi:10.1016/j.rse.2013.09.016Aguilar-Maldonado, J., Santamaría-del-Ángel, E., González-Silvera, A., Cervantes-Rosas, O., López, L., Gutiérrez-Magness, A., … Sebastiá-Frasquet, M.-T. (2018). Identification of Phytoplankton Blooms under the Index of Inherent Optical Properties (IOP Index) in Optically Complex Waters. Water, 10(2), 129. doi:10.3390/w10020129Cavole, L., Demko, A., Diner, R., Giddings, A., Koester, I., … Franks, P. (2016). Biological Impacts of the 2013–2015 Warm-Water Anomaly in the Northeast Pacific: Winners, Losers, and the Future. Oceanography, 29(2). doi:10.5670/oceanog.2016.32Di Lorenzo, E., & Mantua, N. (2016). Multi-year persistence of the 2014/15 North Pacific marine heatwave. Nature Climate Change, 6(11), 1042-1047. doi:10.1038/nclimate3082Mkrtchyan, F. A., & Varotsos, C. A. (2018). A New Monitoring System for the Surface Marine Anomalies. Water, Air, & Soil Pollution, 229(8). doi:10.1007/s11270-018-3938-3Gan, R., Yang, Y., & Ma, Y. (2018). Modelling the impacts of the Pacific Ocean sea surface temperature anomalies on a drought event in southwestern China with a piecewise-integration method. International Journal of Climatology, 39(2), 799-813. doi:10.1002/joc.5843Yeh, S.-W., Kug, J.-S., Dewitte, B., Kwon, M.-H., Kirtman, B. P., & Jin, F.-F. (2009). El Niño in a changing climate. Nature, 461(7263), 511-514. doi:10.1038/nature08316Peña Manjarrez, J. (2009). Environmental factors influencing the variability of Lingulodinium polyedrum and Scrippsiella trochoidea (Dinophyceae) cyst production. Ciencias Marinas, 35(1), 1-14. doi:10.7773/cm.v35i1.1406Cepeda-Morales, J. (2017). Response of primary producers to the hydrographic variability in the southern region of the California Current System. Ciencias Marinas, 40(2), 123-135. doi:10.7773/cm.v43i2.2752Barocio-Leon, O. (2007). Phytoplankton primary productivity in the euphotic zone of the California Current System estimated from CZCS imagery. Ciencias Marinas, 33(1), 59-72. doi:10.7773/cm.v33i1.1037INEGI 2015 (Instituto Nacional de Estadística y Geografía/National Institute of Statistic and Geography)http://www.beta.inegi.org.mx/programas/intercensal/2015/default.html#TabuladosGutierrez-Mejia, E., Lares, M. L., Huerta-Diaz, M. A., & Delgadillo-Hinojosa, F. (2016). Cadmium and phosphate variability during algal blooms of the dinoflagellate Lingulodinium polyedrum in Todos Santos Bay, Baja California, Mexico. Science of The Total Environment, 541, 865-876. doi:10.1016/j.scitotenv.2015.09.081Mateos, E., Marinone, S. G., & Parés-Sierra, A. (2009). Towards the numerical simulation of the summer circulation in Todos Santos Bay, Ensenada, B.C. Mexico. Ocean Modelling, 27(1-2), 107-112. doi:10.1016/j.ocemod.2008.11.002SOMMER, U., & LENGFELLNER, K. (2008). Climate change and the timing, magnitude, and composition of the phytoplankton spring bloom. Global Change Biology, 14(6), 1199-1208. doi:10.1111/j.1365-2486.2008.01571.xWinder, M., & Sommer, U. (2012). Phytoplankton response to a changing climate. Hydrobiologia, 698(1), 5-16. doi:10.1007/s10750-012-1149-2Orozco-Borbón, M. V., Rico-Mora, R., Weisberg, S. B., Noble, R. T., Dorsey, J. H., Leecaster, M. K., & McGee, C. D. (2006). Bacteriological water quality along the Tijuana–Ensenada, Baja California, México shoreline. Marine Pollution Bulletin, 52(10), 1190-1196. doi:10.1016/j.marpolbul.2006.02.005Gregg, W. W., & Casey, N. W. (2004). Global and regional evaluation of the SeaWiFS chlorophyll data set. Remote Sensing of Environment, 93(4), 463-479. doi:10.1016/j.rse.2003.12.012Sebastiá, M.-T., Rodilla, M., Sanchis, J.-A., Altur, V., Gadea, I., & Falco, S. (2012). Influence of nutrient inputs from a wetland dominated by agriculture on the phytoplankton community in a shallow harbour at the Spanish Mediterranean coast. Agriculture, Ecosystems & Environment, 152, 10-20. doi:10.1016/j.agee.2012.02.006Wilson, C. (2003). Late Summer chlorophyll blooms in the oligotrophic North Pacific Subtropical Gyre. Geophysical Research Letters, 30(18). doi:10.1029/2003gl017770Villareal, T. A., Adornato, L., Wilson, C., & Schoenbaechler, C. A. (2011). Summer blooms of diatom-diazotroph assemblages and surface chlorophyll in the North Pacific gyre: A disconnect. Journal of Geophysical Research, 116(C3). doi:10.1029/2010jc00626

Sentinel 2 Analysis of Turbidity Patterns in a Coastal Lagoon

[EN] Coastal lagoons are transitional ecosystems with complex spatial and temporal variability. Remote sensing tools are essential for monitoring and unveiling their variability. Turbidity is a water quality parameter used for studying eutrophication and sediment transport. The objective of this research is to analyze the monthly turbidity pattern in a shallow coastal lagoon along two years with different precipitation regimes. The selected study area is the Albufera de Valencia lagoon (Spain). For this purpose, we used Sentinel 2 images and in situ data from the monitoring program of the Environment General Subdivision of the regional government. We obtained Sentinel 2A and 2B images for years 2017 and 2018 and processed them with SNAP software. The results of the correlation analysis between satellite and in situ data, corroborate that the reflectance of band 5 (705 nm) is suitable for the analysis of turbidity patterns in shallow lagoons (average depth 1 m), such as the Albufera lagoon, even in eutrophic conditions. Turbidity patterns in the Albufera lagoon show a similar trend in wet and dry years, which is mainly linked to the irrigation practice of rice paddies. High turbidity periods are linked to higher water residence time and closed floodgates. However, precipitation and wind also play an important role in the spatial distribution of turbidity. During storm events, phytoplankton and sediments are discharged to the sea, if the floodgates remain open. Fortunately, the rice harvesting season, when the floodgates are open, coincides with the beginning of the rainy period. Nevertheless, this is a lucky coincidence. It is important to develop conscious management of floodgates, because having them closed during rain events can have several negative effects both for the lagoon and for the receiving coastal waters and ecosystem. Non-discharged solids may accumulate in the lagoon worsening the clogging problems, and the beaches next to the receiving coastal waters will not receive an important load of solids to nourish them.Maria-Teresa Sebastia-Frasquet was a beneficiary of the CAS18/00107 post-doctoral research grant, supported by the Spanish Ministry of Education Culture and Sports during her stay at the Universidad Autonoma de Baja California (Mexico); image processing was developed partially during her stay. J.A.A.-M. was a beneficiary of the doctorate scholarship with the announcement number 291025, supported by the Council of Science and Technology of Mexico (CONACYT by its acronym in Spanish).Sebastiá-Frasquet, M.; Aguilar-Maldonado, JA.; Santamaría-Del-Ángel, E.; Estornell Cremades, J. (2019). Sentinel 2 Analysis of Turbidity Patterns in a Coastal Lagoon. Remote Sensing. 11(24):1-17. https://doi.org/10.3390/rs11242926S1171124Riera, R., Tuset, V. M., Betancur-R, R., Lombarte, A., Marcos, C., & Pérez-Ruzafa, A. (2018). Modelling alpha-diversities of coastal lagoon fish assemblages from the Mediterranean Sea. Progress in Oceanography, 165, 100-109. doi:10.1016/j.pocean.2018.05.003Sebastiá-Frasquet, M.-T., Altur, V., & Sanchis, J.-A. (2014). Wetland Planning: Current Problems and Environmental Management Proposals at Supra-Municipal Scale (Spanish Mediterranean Coast). Water, 6(3), 620-641. doi:10.3390/w6030620Doña, C., Chang, N.-B., Caselles, V., Sánchez, J. M., Camacho, A., Delegido, J., & Vannah, B. W. (2015). Integrated satellite data fusion and mining for monitoring lake water quality status of the Albufera de Valencia in Spain. Journal of Environmental Management, 151, 416-426. doi:10.1016/j.jenvman.2014.12.003Gernez, P., Lafon, V., Lerouxel, A., Curti, C., Lubac, B., Cerisier, S., & Barillé, L. (2015). Toward Sentinel-2 High Resolution Remote Sensing of Suspended Particulate Matter in Very Turbid Waters: SPOT4 (Take5) Experiment in the Loire and Gironde Estuaries. Remote Sensing, 7(8), 9507-9528. doi:10.3390/rs70809507Caballero, I., Navarro, G., & Ruiz, J. (2018). Multi-platform assessment of turbidity plumes during dredging operations in a major estuarine system. International Journal of Applied Earth Observation and Geoinformation, 68, 31-41. doi:10.1016/j.jag.2018.01.014Onandia, G., Gudimov, A., Miracle, M. R., & Arhonditsis, G. (2015). Towards the development of a biogeochemical model for addressing the eutrophication problems in the shallow hypertrophic lagoon of Albufera de Valencia, Spain. Ecological Informatics, 26, 70-89. doi:10.1016/j.ecoinf.2015.01.004Sòria-Perpinyà, X., Vicente, E., Urrego, P., Pereira-Sandoval, M., Ruíz-Verdú, A., Delegido, J., … Moreno, J. (2020). Remote sensing of cyanobacterial blooms in a hypertrophic lagoon (Albufera of València, Eastern Iberian Peninsula) using multitemporal Sentinel-2 images. Science of The Total Environment, 698, 134305. doi:10.1016/j.scitotenv.2019.134305Güttler, F. N., Niculescu, S., & Gohin, F. (2013). Turbidity retrieval and monitoring of Danube Delta waters using multi-sensor optical remote sensing data: An integrated view from the delta plain lakes to the western–northwestern Black Sea coastal zone. Remote Sensing of Environment, 132, 86-101. doi:10.1016/j.rse.2013.01.009Quang, N., Sasaki, J., Higa, H., & Huan, N. (2017). Spatiotemporal Variation of Turbidity Based on Landsat 8 OLI in Cam Ranh Bay and Thuy Trieu Lagoon, Vietnam. Water, 9(8), 570. doi:10.3390/w9080570Kari, E., Kratzer, S., Beltrán-Abaunza, J. M., Harvey, E. T., & Vaičiūtė, D. (2016). Retrieval of suspended particulate matter from turbidity – model development, validation, and application to MERIS data over the Baltic Sea. International Journal of Remote Sensing, 38(7), 1983-2003. doi:10.1080/01431161.2016.1230289Kuhn, C., de Matos Valerio, A., Ward, N., Loken, L., Sawakuchi, H. O., Kampel, M., … Butman, D. (2019). Performance of Landsat-8 and Sentinel-2 surface reflectance products for river remote sensing retrievals of chlorophyll-a and turbidity. Remote Sensing of Environment, 224, 104-118. doi:10.1016/j.rse.2019.01.023Liu, H., Li, Q., Shi, T., Hu, S., Wu, G., & Zhou, Q. (2017). Application of Sentinel 2 MSI Images to Retrieve Suspended Particulate Matter Concentrations in Poyang Lake. Remote Sensing, 9(7), 761. doi:10.3390/rs9070761Erena, Domínguez, Aguado, Soria, & García-Galiano. (2019). Monitoring Coastal Lagoon Water Quality Through Remote Sensing: The Mar Menor as a Case Study. Water, 11(7), 1468. doi:10.3390/w11071468Caballero, I., Stumpf, R., & Meredith, A. (2019). Preliminary Assessment of Turbidity and Chlorophyll Impact on Bathymetry Derived from Sentinel-2A and Sentinel-3A Satellites in South Florida. Remote Sensing, 11(6), 645. doi:10.3390/rs11060645Toming, K., Kutser, T., Laas, A., Sepp, M., Paavel, B., & Nõges, T. (2016). First Experiences in Mapping Lake Water Quality Parameters with Sentinel-2 MSI Imagery. Remote Sensing, 8(8), 640. doi:10.3390/rs8080640Usaquén Perilla, O. L., Gómez, A. G., Gómez, A. G., Díaz, C. Á., & Cortezón, J. A. R. (2012). Methodology to assess sustainable management of water resources in coastal lagoons with agricultural uses: An application to the Albufera lagoon of Valencia (Eastern Spain). Ecological Indicators, 13(1), 129-143. doi:10.1016/j.ecolind.2011.05.019Soria, J. M., Vicente, E., & Miracle, M. R. (2000). The influence of flash floods on the limnology of the Albufera of Valencia lagoon (Spain). SIL Proceedings, 1922-2010, 27(4), 2232-2235. doi:10.1080/03680770.1998.11901635Wang, S., Lee, Z., Shang, S., Li, J., Zhang, B., & Lin, G. (2019). Deriving inherent optical properties from classical water color measurements: Forel-Ule index and Secchi disk depth. Optics Express, 27(5), 7642. doi:10.1364/oe.27.007642Wernand, M. R. (2010). On the history of the Secchi disc. Journal of the European Optical Society: Rapid Publications, 5. doi:10.2971/jeos.2010.10013sAguilar-Maldonado, J. A., Santamaría-del-Ángel, E., Gonzalez-Silvera, A., & Sebastiá-Frasquet, M. T. (2019). Detection of Phytoplankton Temporal Anomalies Based on Satellite Inherent Optical Properties: A Tool for Monitoring Phytoplankton Blooms. Sensors, 19(15), 3339. doi:10.3390/s19153339Pereira-Sandoval, M., Ruescas, A., Urrego, P., Ruiz-Verdú, A., Delegido, J., Tenjo, C., … Moreno, J. (2019). Evaluation of Atmospheric Correction Algorithms over Spanish Inland Waters for Sentinel-2 Multi Spectral Imagery Data. Remote Sensing, 11(12), 1469. doi:10.3390/rs11121469Sòria-Perpinyà, X., Miracle, M. R., Soria, J., Delegido, J., & Vicente, E. (2018). Remote sensing application for the study of rapid flushing to remediate eutrophication in shallow lagoons (Albufera of Valencia). Hydrobiologia, 829(1), 125-132. doi:10.1007/s10750-018-3741-6Rodrigo, M. A., & Alonso-Guillén, J. L. (2013). Assessing the potential of Albufera de València Lagoon sediments for the restoration of charophyte meadows. Ecological Engineering, 60, 445-452. doi:10.1016/j.ecoleng.2013.09.041Martín, M., Oliver, N., Hernández-Crespo, C., Gargallo, S., & Regidor, M. C. (2013). The use of free water surface constructed wetland to treat the eutrophicated waters of lake L’Albufera de Valencia (Spain). Ecological Engineering, 50, 52-61. doi:10.1016/j.ecoleng.2012.04.02

Reflectancias de imágenes multiespectrales de SPOT asociadas a la turbidez en el Alto Golfo de California

[EN] The use of satellite images for the observation and measurement of marine turbidity has been developed mainly with ocean colour sensors, such as MODIS. These images have a maximum spatial resolution of 250 m in their visible and infrared bands. In this research, images of the SPOT sensors were chosen as an alternative to overcome this limited spatial resolution. The objective was to prove the suitability of SPOT to measure turbidity in areas with great spatial variability. As a first step, all the images were standardized and the SPOT wavelength that had the largest association in the Principal Component Analysis was chosen (PCA). The results show that the bands of a SPOT multispectral image are highly redundant. The wavelength of the 610-680 nm (S2610-680) obtained the best association in 89% of the 73 images analysed. The SPOT reflectance (Rrs) (S2610-680) was compared with MODIS 620-670 nm (M1620-670), which has already been tested in other research and has proved to be adequate for measuring turbidity. Both sensors performance was similar for low and moderate reflectance but for high reflectance, SPOT (S2610-680) had a better performance than MODIS (M1620-670). Additionally, the SPOT Rrs (S2610-680) was associated with standardized Secchi disk depth data, which were measured in situ, to check SPOT suitability. SPOT Rrs (S2610-680)images were classified into: 1) cold or warm season, 2) spring tide or neap tide and 3) water flux or reflux. These constructed scenarios allowed to see the result of the Standardized Space Anomalies, which showed the continuous presence of low and medium values in the most oceanic region of the Upper Gulf of California (UGC) and very high values in all the scenarios in the intertidal zone. This research has shown that SPOT Rrs (S2610-680) is useful for observing, differentiating and measuring turbidity patterns in areas with very high spatial variability.[ES] El uso de imágenes de satélite para la observación y medida de la turbidez marina se ha desarrollado principalmente con sensores de color del océano como MODIS. Estas imágenes tienen una resolución espacial máxima de 250 m en las bandas visible e infrarroja. En esta investigación, se eligieron imágenes del sensor SPOT como alternativa para superar esta limitada resolución espacial. El objetivo es probar la validez de SPOT para medir turbidez en áreas con gran variabilidad espacial. Como primer paso se normalizaron todas las imágenes y se eligió la longitud de onda de SPOT que mejor ajuste obtuvo a partir del Análisis de Componentes Principales (ACP). Los resultados mostraron que las bandas de una imagen multiespectral SPOT tienen una alta redundancia (buena correlación) entre sí. La longitud de onda de los 610-680 nm (S2610-680) fue la que obtuvo el mejor ajuste en 89% de las 73 imágenes analizadas. Esta reflectancia (Rrs) (S2610-680) de SPOT fue comparada con MODIS (M1620-670). El comportamiento de ambos sensores fue similar para reflectancias bajas y medias, pero para altas reflectancias SPOT Rrs (S2610-680) tuvo un mejor rendimiento que MODIS. Además, la Rrs (S2610-680) de SPOT fue asociada con datos in situ normalizados de profundidad del disco de Secchi para comprobar la idoneidad del sensor SPOT. Las imágenes Rrs (S2610-680) de SPOT fueron clasificadas en: 1) época fría o cálida, 2) marea viva o muerta, y 3) flujo o reflujo de las aguas. Estos escenarios seleccionados permitieron ver el resultado de las Anomalías Espaciales Normalizadas, que dejaron ver la continua presencia de valores bajos y medios en la región más oceánica del Alto Golfo de California (AGC) y valores muy altos en todos los escenarios en la zona intermareal del AGC. El trabajo realizado permite concluir que la reflectancia Rrs (S2610-680) de SPOT es válida para observar, diferenciar y medir patrones de turbidez en áreas con una elevada variabilidad espacial.Aguilar-Maldonado, JA.; Santamaría-Del-Ángel, E.; Sebastiá-Frasquet, MT. (2017). Reflectances of SPOT multispectral images associated with the turbidity of the Upper Gulf of California. Revista de Teledetección. (50):1-16. doi:10.4995/raet.2017.7795SWORD1165

Cooperation in the Campo de Gibraltar after Brexit. New framework for frontier workers

Brexit has directly impacted Spain’s relationship with the UK due to the Gibraltar issue. The British withdrawal from the EU has forced the redefinition of the European statute of Gibraltar, and its relations with Spain and the European Union, in institutional, legal and economic terms. In this context, novel mechanisms have also been devised to regulate the treatment of cross-border cooperation with Gibraltar, which has had intermittent phases in its evolution over time. Within the framework of the British exit process, a new model has been agreed in successive EU-UK agreements that combine Hard Law (Primary EU Law) with Soft Law (Memoranda of Understanding–MOU). This regulation has required a specific prior BritishSpanish negotiation. We will especially highlight the UK-EU Withdrawal Treaty of 2019, which has formed an authentic system of crossborder cooperation involving the UK, the EU, Gibraltar and Spain, through a series of Spanish-British bilateral Memoranda interconnected with the Protocol on Gibraltar of the Treaty, which in turn refers to the Tax Treaty. It is a new system of concrete cooperation on the rights of citizens and border workers, among other matter

Turbidity patterns in the Albufera lake, Spain, and their relation to irrigation cycles

[EN] The Albufera Natural Park (Valencia, Spain) is one of the most representative coastal wetlands in the Mediterranean basin. It holds several protection designations at national and international level, such as Spanish Natural Park, Special Protection Areas (SPAs) for birds, Sites of Community Importance (SCIs) and Ramsar Site. Both the park and its main lake, Albufera¿s lake, face several environmental problems. One of them is reduced transparency and lake clogging. The lake is highly dependent on the rice cycle and on irrigation returns, mainly from the Acequia Real. In this study, we analyse the monthly transparency and turbidity patterns during year 2018, and we relate them to irrigation cycles. We used Sentinel 2A satellite images from the European Space Agency, which have an atmospheric correction. Remote sensing results were compared with in situ data from the monitoring program of the Environment General Subdivision of the regional government. This monitoring program samples five points on a monthly basis, and analyses Secchi disk depth, suspended solids and chlorophyll a. Our results show the temporal and spatial pattern of turbidity in the Albufera lake which offers relevant information for water resources management.María-Teresa Sebastiá-Frasquet was beneficiary of the CAS18/00107 post-doctoral research grant, supported by the Spanish Ministry of Education Culture and Sports during her stay at the Universidad Autónoma de Baja California (Mexico), image processing was partially developed during the staySebastiá-Frasquet, M.; Aguilar-Maldonado, JA.; Santamaría-Del-Ángel, E.; Altur Grau, VJ. (2019). Turbidity patterns in the Albufera lake, Spain, and their relation to irrigation cycles. WIT Transactions on Ecology and the Environment (Online). 239:173-180. https://doi.org/10.2495/WS190151S17318023

Mapping Satellite Inherent Optical Properties Index in Coastal Waters of the Yucatán Peninsula (Mexico)

[EN] The Yucatan Peninsula hosts worldwide-known tourism destinations that concentrate most of the Mexico tourism activity. In this region, tourism has exponentially increased over the last years, including wildlife oriented tourism. Rapid tourism development, involving the consequent construction of hotels and tourist commodities, is associated with domestic sewage discharges from septic tanks. In this karstic environment, submarine groundwater discharges are very important and highly vulnerable to anthropogenic pollution. Nutrient loadings are linked to harmful algal blooms, which are an issue of concern to local and federal authorities due to their recurrence and socioeconomic and human health costs. In this study, we used satellite products from MODIS (Moderate Resolution Imaging Spectroradiometer) to calculate and map the satellite Inherent Optical Properties (IOP) Index. We worked with different scenarios considering both holiday and hydrological seasons. Our results showed that the satellite IOP Index allows one to build baseline information in a sustainable mid-term or long-term basis which is key for ecosystem-based management.This research was funded by CONACYT with a doctorate scholarship to Jesús A. Aguilar-Maldonado,with the announcement number 251025 in 2015. María-Teresa Sebastiá-Frasquet was a beneficiary of the BEST/2017/217 post-doctoral research grant, supported by the Valencian Conselleria d’Educació, Investigació,Cultura i Esport (Spain) during her stay at the Universidad Autónoma de Baja California (Mexico). The Secretariat of Public Education of Mexico (SEP) under the Program for Professional Development Teacher, covered the costs of publication in open access.Aguilar-Maldonado, J.; Santamaría-Del-Ángel, E.; González-Silvera, A.; Cervantes-Rosas, OD.; Sebastiá-Frasquet, M. (2018). Mapping Satellite Inherent Optical Properties Index in Coastal Waters of the Yucatán Peninsula (Mexico). Sustainability. 10(6). https://doi.org/10.3390/su10061894S1894106Bentz, J., Lopes, F., Calado, H., & Dearden, P. (2016). Sustaining marine wildlife tourism through linking Limits of Acceptable Change and zoning in the Wildlife Tourism Model. Marine Policy, 68, 100-107. doi:10.1016/j.marpol.2016.02.016Jarvis, D., Stoeckl, N., & Liu, H.-B. (2016). The impact of economic, social and environmental factors on trip satisfaction and the likelihood of visitors returning. Tourism Management, 52, 1-18. doi:10.1016/j.tourman.2015.06.003Ziegler, J., Dearden, P., & Rollins, R. (2012). But are tourists satisfied? Importance-performance analysis of the whale shark tourism industry on Isla Holbox, Mexico. Tourism Management, 33(3), 692-701. doi:10.1016/j.tourman.2011.08.004Duffus, D. A., & Dearden, P. (1990). Non-consumptive wildlife-oriented recreation: A conceptual framework. Biological Conservation, 53(3), 213-231. doi:10.1016/0006-3207(90)90087-6Aguilar-Trujillo, A. C., Okolodkov, Y. B., Herrera-Silveira, J. A., Merino-Virgilio, F. del C., & Galicia-García, C. (2017). Taxocoenosis of epibenthic dinoflagellates in the coastal waters of the northern Yucatan Peninsula before and after the harmful algal bloom event in 2011–2012. Marine Pollution Bulletin, 119(1), 396-406. doi:10.1016/j.marpolbul.2017.02.074Ulloa, M. J., Álvarez-Torres, P., Horak-Romo, K. P., & Ortega-Izaguirre, R. (2017). Harmful algal blooms and eutrophication along the mexican coast of the Gulf of Mexico large marine ecosystem. Environmental Development, 22, 120-128. doi:10.1016/j.envdev.2016.10.007Henrichs, D. W., Hetland, R. D., & Campbell, L. (2015). Identifying bloom origins of the toxic dinoflagellate Karenia brevis in the western Gulf of Mexico using a spatially explicit individual-based model. Ecological Modelling, 313, 251-258. doi:10.1016/j.ecolmodel.2015.06.038Murray, G. (2007). Constructing Paradise: The Impacts of Big Tourism in the Mexican Coastal Zone. 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L. (2015). Biophysical modeling assessment of the drivers for plankton dynamics in dreissenid-colonized western Lake Erie. Ecological Modelling, 308, 18-33. doi:10.1016/j.ecolmodel.2015.04.004Aguilar-Maldonado, J., Santamaría-del-Ángel, E., González-Silvera, A., Cervantes-Rosas, O., López, L., Gutiérrez-Magness, A., … Sebastiá-Frasquet, M.-T. (2018). Identification of Phytoplankton Blooms under the Index of Inherent Optical Properties (IOP Index) in Optically Complex Waters. Water, 10(2), 129. doi:10.3390/w10020129Wei, G., Tang, D., & Wang, S. (2008). Distribution of chlorophyll and harmful algal blooms (HABs): A review on space based studies in the coastal environments of Chinese marginal seas. Advances in Space Research, 41(1), 12-19. doi:10.1016/j.asr.2007.01.037Urquhart, E. A., Schaeffer, B. A., Stumpf, R. P., Loftin, K. A., & Werdell, P. J. (2017). A method for examining temporal changes in cyanobacterial harmful algal bloom spatial extent using satellite remote sensing. Harmful Algae, 67, 144-152. doi:10.1016/j.hal.2017.06.001Harvey, E. T., Kratzer, S., & Philipson, P. (2015). Satellite-based water quality monitoring for improved spatial and temporal retrieval of chlorophyll-a in coastal waters. Remote Sensing of Environment, 158, 417-430. doi:10.1016/j.rse.2014.11.017Malthus, T. J., & Mumby, P. J. (2003). Remote sensing of the coastal zone: An overview and priorities for future research. International Journal of Remote Sensing, 24(13), 2805-2815. doi:10.1080/0143116031000066954Matthews, M. W. (2011). A current review of empirical procedures of remote sensing in inland and near-coastal transitional waters. International Journal of Remote Sensing, 32(21), 6855-6899. doi:10.1080/01431161.2010.512947Miller, R. L., & McKee, B. A. (2004). Using MODIS Terra 250 m imagery to map concentrations of total suspended matter in coastal waters. Remote Sensing of Environment, 93(1-2), 259-266. doi:10.1016/j.rse.2004.07.012Loisel, H., Vantrepotte, V., Norkvist, K., Mériaux, X., Kheireddine, M., Ras, J., … Moutin, T. (2011). Characterization of the bio-optical anomaly and diurnal variability of particulate matter, as seen from scattering and backscattering coefficients, in ultra-oligotrophic eddies of the Mediterranean Sea. Biogeosciences, 8(11), 3295-3317. doi:10.5194/bg-8-3295-2011Werdell, P. J., Franz, B. A., Bailey, S. W., Feldman, G. C., Boss, E., Brando, V. E., … Mangin, A. (2013). Generalized ocean color inversion model for retrieving marine inherent optical properties. Applied Optics, 52(10), 2019. doi:10.1364/ao.52.002019Brezonik, P. L., Olmanson, L. G., Finlay, J. C., & Bauer, M. E. (2015). Factors affecting the measurement of CDOM by remote sensing of optically complex inland waters. Remote Sensing of Environment, 157, 199-215. doi:10.1016/j.rse.2014.04.033Odermatt, D., Gitelson, A., Brando, V. E., & Schaepman, M. (2012). Review of constituent retrieval in optically deep and complex waters from satellite imagery. Remote Sensing of Environment, 118, 116-126. doi:10.1016/j.rse.2011.11.013Enriquez, C., Mariño-Tapia, I., Jeronimo, G., & Capurro-Filograsso, L. (2013). Thermohaline processes in a tropical coastal zone. Continental Shelf Research, 69, 101-109. doi:10.1016/j.csr.2013.08.018Estadísticas del Agua en México. Secretaría de Medio Ambiente y Recursos Naturaleshttp://201.116.60.25/publicaciones/EAM_2016.pdfArcega-Cabrera, F., Garza-Pérez, R., Noreña-Barroso, E., & Oceguera-Vargas, I. (2014). Impacts of Geochemical and Environmental Factors on Seasonal Variation of Heavy Metals in a Coastal Lagoon Yucatan, Mexico. Bulletin of Environmental Contamination and Toxicology, 94(1), 58-65. doi:10.1007/s00128-014-1416-1Lopez-Maldonado, Y., Batllori-Sampedro, E., Binder, C. R., & Fath, B. D. (2017). Local groundwater balance model: stakeholders’ efforts to address groundwater monitoring and literacy. Hydrological Sciences Journal, 62(14), 2297-2312. doi:10.1080/02626667.2017.1372857Derrien, M., Cabrera, F. A., Tavera, N. L. V., Kantún Manzano, C. A., & Vizcaino, S. C. (2015). Sources and distribution of organic matter along the Ring of Cenotes, Yucatan, Mexico: Sterol markers and statistical approaches. Science of The Total Environment, 511, 223-229. doi:10.1016/j.scitotenv.2014.12.053INEGIhttp://www.beta.inegi.org.mx/temas/agua/Ramírez, R., Seeliger, L., & Di Pietro, F. (2016). Price, Virtues, Principles: How to Discern What Inspires Best Practices in Water Management? A Case Study about Small Farmers in the Yucatan Peninsula of Mexico. Sustainability, 8(4), 385. doi:10.3390/su8040385Null, K. A., Knee, K. L., Crook, E. D., de Sieyes, N. R., Rebolledo-Vieyra, M., Hernández-Terrones, L., & Paytan, A. (2014). Composition and fluxes of submarine groundwater along the Caribbean coast of the Yucatan Peninsula. 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J., & Herrera-Silveira, J. A. (2010). Dispersion in the Yucatan coastal zone: Implications for red tide events. Continental Shelf Research, 30(2), 127-137. doi:10.1016/j.csr.2009.10.00

Is the Cooling Vest an Ergogenic Tool for Physically Active Individuals? Assessment of Perceptual Response, Thermo-Physiological Behavior, and Sports Performance: A Systematic Review and Meta-Analysis

[EN] Exercise capacity is limited by environmental heat stress because thermoregulatory systems are altered and cannot prevent the elevation of body temperature due to a complex interplay of physiological, physical, and perceptual alterations. Cooling is an effective strategy to attenuate the temperature rise. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the PEDro scale for assessing methodological quality, we systematically reviewed studies indexed in Medline, Web of Science, EMBASE, Science Direct, Sportdiscus, and Scopus, to evaluate the effects of the cooling vest (CVs) on perceptual response, physiological behavior, and sports performance in adult physical activity practitioners under heat stress conditions. Among the 711 studies identified in the search, 10 studies for the systematic review and eight for the meta-analysis met the inclusion and exclusion criteria. Overall, the use of CVs showed improvements in certain sports performance indicators, being significant (p < 0.05) in test time and substantial in peak power that could be influenced directly by the significant reduction (p < 0.05) in skin temperature and indirectly by the significant improvement (p < 0.05) in thermal and exertional perceptual responses, without the involvement of core temperature. In conclusion, the use of CVs is a cooling technique that influences perceptual response, thermo-physiological behavior, and sports performance. However, further studies are needed to elucidate the relevance of its application to CVs.S

Seed Morphology in the Vitaceae Based on Geometric Models

16 páginas, 8 figuras, 6 tablasMorphometric methods based on artificial vision algorithms provide measurements for magnitudes descriptive of seed images (i.e., the length, width, area, and surface circularity index). Nevertheless, their results frequently omit the resemblance of the images to geometric figures that may be used as models. A complementary method based on the comparison of seed images with geometric models is applied to seeds of Vitis spp. The J index gives the percentage of similarity between a seed image and the model. Seven new geometric models are described based on the heart-shaped and piriform curves. Seeds of different species, subspecies and cultivars of Vitis adjust to different models. Models 1 and 3, the heart curve and the water drop, adjust better to seeds of V. amurensis, V. labrusca and V. rupestris than to V. vinifera. Model 6, the Fibonacci’s pear, adjusts well to seeds of V. vinifera, in general, and better to V. vinifera ssp. vinifera than to V. vinifera ssp. sylvestris. Seed morphology in species of Cissus and Parthenocissus, two relatives of Vitis in the Vitaceae, is also analysed. Geometric models are a tool for the description and identification of species and lower taxonomic levels complementing the results of morphometric analysis.This research was funded by Universidad de Salamanca (Programa XIII para la financiación de grupos GIR)Peer reviewe

La cooperación en el Campo de Gibraltar tras el Brexit. Nuevo marco para trabajadores fronterizos

El Brexit ha impactado directamente en la relación de España con el Reino Unido (RU) por la cuestión de Gibraltar. La salida británica ha obligado a redefinir el estatuto europeo de Gibraltar, y sus relaciones con España y la Unión Europea (UE), en términos institucionales, jurídicos y económicos. En este contexto, también se han ideado unos mecanismos novedosos para regular y encauzar el tratamiento de la cooperación transfronteriza con Gibraltar, que ha tenido variadas e intermitentes fases en su planteamiento y evolución en el tiempo. En el marco del proceso de salida del RU de la UE se ha acordado un nuevo modelo en los sucesivos Tratados y acuerdos UE-RU que combinan Hard Law de Derecho originario con Soft Law de Memorandos de Entendimiento (Memorandum of Understanding- MoU). Esta regulación ha requerido de una negociación específica previa británico-española. Destacaremos especialmente el primer Tratado de Retirada RU-UE de 2019, que ha conformado un auténtico sistema de cooperación transfronteriza que involucra al RU, la UE, Gibraltar y España, mediante una serie de Memorandos bilaterales hispano-británicos interconectados con el Protocolo sobre Gibraltar del Tratado, que a su vez reenvía al Tratado fiscal. Se trata de un nuevo sistema de cooperación concreta sobre derechos de los ciudadanos y trabajadores fronterizos, entre otras materias

Growth and accessory pigments to chlorophyll a ratios of Thalassiosira pseudonana (Bacillariophyceae) cultured under different irradiances.

This study investigated how different light conditions affect the growth and accessory pigment to chlorophyll a ratios in Thalassiosira pseudonana. The microalga was grown for five days under four irradiances (50, 150, 300 and 750 µmol quanta m-2 s-1) with f/2 medium. Daily growth and pigment composition were determined for each treatment. Initial mean cellular density for all treatment was 1.15 ± 0.057 × 105 cell ml-1, which increased the first two days of culture to 1.21 ± 0.012 x 106 cell ml-1 on average and did not show significant changes among irradiances. Growth rates decreased with the final cell numbers being similar among treatments except for the lowest irradiance, which increased their cellular density. Chlorophyll a and fucoxanthin concentrations showed statistically significant differences (p &lt; 0.001) among the different levels of light. These concentrations were always higher at low than at high irradiances. For diadinoxanthin the concentrations decreased as the irradiance increased, which was contrary to what occurred with diatoxanthin. Fucoxanthin to chlorophyll a ratio was not significantly affected by the irradiance level (p = 0.444), but did change during time under culture (p = 0.003). Diatoxanthin to chlorophyll a ratios increased among different irradiances and with time, with higher values at high irradiances, whereas, diadinoxanthin to chlorophyll a ratios only increased at 750 µmol quanta m-2 s-1. It is concluded that variations in light intensity did not change the cellular densities of T. pseudonana but did have significant effects on accessory pigment to chlorophyll a ratios