The Albufera of Valencia, a Mediterranean coastal lagoon, has been in a turbid state since 1974, with only four episodes of temporary water transparency in spring. Despite its average depth of 1 m and oligohaline waters, excessive turbidity, fish grazing, and toxic compounds have inhibited submerged macrophyte growth. In spring 2018, a significant area of Myriophyllum spicatum emerged and exhibited significant density until its complete disappearance in August 2018. Using Sentinel-2 and Landsat-8 imagery, we monitored water quality variables and vegetation density during these months. Our study revealed the first unique occurrence of M. spicatum in more than 40 years. A period of increased transparency from summer 2017 compared to previous years seems to be the cause of this appearance, while high summer temperatures caused its disappearance. While improving water quality may help restore submerged macrophyte meadows, our results suggest that summer maximum temperatures may inhibit recovery. Remote sensing, particularly the NDVI index, proved successful in monitoring aquatic vegetation and understanding species-environment relationships. This methodology can enhance future monitoring efforts for macrophyte colonization and expand knowledge of their occurrence and causes of disappearance in this and other similar areas.

Waterbirds are key agents of passive dispersal for aquatic invertebrates, particularly through internal transport of their propagules. In this study, we assessed the potential dispersal of invertebrates through endozoochory by two Anatidae species, the mallard and the common shelduck, in Albufera de Valencia Natural Park. We aimed at comparing the hatching success of invertebrate propagules egested by both ducks, under two temperatures, simulating cold (15 °C) and warm (25 °C) conditions. We performed a controlled hatching experiment using faecal samples (30 per species) collected from the roosting areas of both ducks. A total of 34 invertebrate taxa hatched, including rotifers, cladocerans, copepods, ostracods, ciliates, and microturbellarians. Species richness and hatching rates were higher under warm conditions, and shelduck samples showed more diverse assemblages than mallards. Five of the detected taxa are considered invasive non-native to the region. Some of the rotifer and ostracod species found, as well as microturbellarians, represent first records of internal dispersal by waterbirds. Our findings suggest that temperature can influence hatching success and may shape the community composition of colonizing organisms through endozoochory. Moreover, Anatidae can be effective vectors for aquatic invertebrates, including non-native species, with potential implications for metacommunity dynamics and invasions in Mediterranean wetlands.

La Albufera de Valencia presenta graves problemas de eutrofización desde los años 70. Debido a su alto interés, se han hecho multitud de trabajos científicos aplicando la teledetección al estudio de la calidad de sus aguas. Sin embargo, recientes cambios como el gran crecimiento de nuevas especies de fitoplancton o las fuertes inundaciones, requieren la búsqueda de nuevos modelos para el uso de la teledetección en este lago, pues han cambiado sus propiedades ópticas. En este trabajo, utilizando datos de campo obtenidos entre 2016 y 2025, se han calibrado diferentes índices espectrales para la estimación de distintas variables biofísicas de calidad de aguas usando Sentinel-2. Las variables en estudio han sido la concentración de clorofila-a, la ficocianina, los sólidos totales en suspensión, la profundidad del Disco de Secchi y el contenido en fósforo total. Los modelos muestran NRMSE variables entre 15 y 26% y permiten tanto la elaboración de mapas de las diferentes variables como la obtención de series temporales que nos pueden proporcionar un conocimiento más profundo del estado y los cambios de la Albufera.

The Albufera of Valencia (Spain) is a representative case of pressure on water quality, which caused the hypertrophic state of the lake to completely change the ecosystem that once featured crystal clear waters. PerúSAT-1 is the first Peruvian remote sensing satellite developed for natural disaster monitoring. Its high spatial resolution makes it an ideal sensor for capturing highly detailed products, which are useful for a variety of applications. The ability to change its acquisition geometry allows for an increase in revisit time. The main objective of this study is to assess the potential of PerúSAT-1′s multispectral images to develop multi-parameter algorithms to evaluate the ecological state of the Albufera lagoon. During five field campaigns, samples were taken, and measurements of ecological indicators (chlorophyll-a, Secchi disk depth, total suspended matter, and its organic-inorganic fraction) were made. All possible combinations of two bands were obtained and subsequently correlated with the biophysical variables by fitting a linear regression between the field data and the band combinations. The equations for estimating all the water variables result in the following R² values: 0.76 for chlorophyll-a (NRMSE: 16%), 0.75 for Secchi disk depth (NRMSE: 15%), 0.84 for total suspended matter (NRMSE: 11%), 0.76 for the inorganic fraction (NRMSE: 15%), and 0.87 for the organic fraction (NRMSE: 9%). Finally, the equations were applied to the Albufera lagoon images to obtain thematic maps for all variables.

The impacts of climate change in the Mediterranean basin are characterized by the alternation between prolonged droughts and episodes of high-intensity torrential rainfall. These hydrometeorological extremes contribute to severe soil erosion, the extent of which is strongly influenced by the land cover within the catchment area, ultimately affecting the quality of the receiving water body. Taking advantage of the increased availability of hyperspectral imagery in recent years, this study aims to estimate both the concentration and composition of suspended matter in inland waters situated in the eastern Iberian Peninsula. For this purpose, we have relied on 55 in situ samples and their respective reflectance spectra, for 36 sites from the L2D product of the PRISMA mission, and for 19 sites from the L2A product of the EnMAP mission. To obtain algorithms, we first use the ARTMO toolbox to identify the best-performing ones and then determine the same retrieval algorithm for both sensors. For the organic fraction the best algorithm uses the 714 nm band, with a NRMSE of 15% for PRISMA and 10% for EnMAP. For the inorganic fraction, the best-performing algorithm was based on the ratio between the ~705 nm band and the 551 nm band, with a NRMSE of 8% for PRISMA and 5% for EnMAP. Finally, the total suspended matter is the sum of both fractions, with a NRMSE of 9% for PRISMA and 5% for EnMAP.