Browsing by Subject "Transitional waters"
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- PublicationRestrictedEffects of salinity changes on aquatic organisms in a multiple stressor context(The Royal Society, 2019-01-21) Velasco, Josefa; Cayetano Gutiérrez-Cánovas, Cayetano; Botella Cruz, María; Sánchez Fernández, David; Arribas, Paula; Carbonell, José Antonio; Millán, Andrés; Pallarés, Susana; Ecología e HidrologíaUnder global change, the ion concentration of aquatic ecosystems is changing worldwide. Many freshwater ecosystems are being salinized by anthropogenic salt inputs, whereas many naturally saline ones are being diluted by agricultural drainages. This occurs concomitantly with changes in other stressors, which can result in additive, antagonistic or synergistic effects on organisms. We reviewed experimental studies that manipulated salinity and other abiotic stressors, on inland and transitional aquatic habitats, to (i) synthesize their main effects on organisms' performance, (ii) quantify the frequency of joint effect types across studies and (iii) determine the overall individual and joint effects and their variation among salinity–stressor pairs and organism groups using meta-analyses. Additive effects were slightly more frequent (54%) than non-additive ones (46%) across all the studies (n = 105 responses). However, antagonistic effects were dominant for the stressor pair salinity and toxicants (44%, n = 43), transitional habitats (48%, n = 31) and vertebrates (71%, n = 21). Meta-analyses showed detrimental additive joint effects of salinity and other stressors on organism performance and a greater individual impact of salinity than the other stressors. These results were consistent across stressor pairs and organism types. These findings suggest that strategies to mitigate multiple stressor impacts on aquatic ecosystems should prioritize restoring natural salinity concentrations. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
- PublicationRestrictedEutrophication-induced shifts in fish assemblages from a Mediterranean coastal lagoon(Elsevier, 2025-10-24) Zamora López, Antonio; Guerrero Gómez, Adrián; Torralva Forero, María del Mar; Zamora Marín, José Manuel; Oliva Paterna, Francisco José; Zoología y Antropología Física; Facultad de BiologíaEutrophication remains a critical threat affecting estuarine and coastal lagoon ecosystems, largely driven by intensified anthropogenic pressures and exacerbated by climate change. Understanding the impacts of eutrophic processes on biological communities is essential to ensure effective conservation and management of these vulnerable environments. This study investigates the ecological consequences of eutrophication-induced algal blooms and hypoxia-mediated mass mortality events on fish communities in the Mar Menor coastal lagoon (Western Mediterranean Sea). We assessed temporal changes in fish assemblage structure and composition across three different periods: a baseline reference period (2002–2004), an algal bloom period (2018–2019), and a mass mortalities period (2020–2021). For that purpose, multiple community metrics were assessed, including species richness, abundance, biomass, β-diversity, functional guilds, and species dominance. Significant disturbances in fish abundance and biomass in response to critical eutrophic events were found, though species richness remained stable. Community similarity decreased during warmer seasons of eutrophic periods, but β-diversity values remained constant. Species-specific responses highlighted a marked decline of benthic taxa closely associated with bottom habitats, while zooplanktivores and planktivores became dominant, suggesting the emergence of top-down trophic control mechanisms. Additionally, during hypoxic events, large macrobenthivorous species appeared to seek refuge in shallow and more oxygenated areas, thus leading to evident shifts in fish assemblage composition. These findings provide robust evidence of structural and functional disruption in fish assemblages under eutrophic stress conditions. Our study underscores the relevance of long-term biological monitoring and adaptive management strategies in transitional systems, particularly under future climate and nutrient enrichment scenarios.
- PublicationOpen AccessPopulation dynamics of resident fish in a coastal lagoon under eutrophication-mediated habitat changes(Hellenic Centre for Marine Research, 2024-10-09) Guerrero Gómez, Adrián; Zamora López, Antonio; Torralva Forero, María del Mar; Zamora Marín, José Manuel; Guillén Beltrán, Antonio; Oliva Paterna, Francisco José; Zoología y Antropología FísicaCoastal lagoons, as transitional ecosystems, are crucial for providing ecosystem services and preserving fish communities, yet they face increasing pressures from anthropogenic activities. The Mar Menor coastal lagoon in the western Mediterranean exemplifies this challenge, as it suffers from severe eutrophication driven by agricultural and urban influences. In this study, we assess changes in the population dynamics of three resident fish species (Apricaphanius iberus, Pomatoschistus marmoratus, and Syngnathus abaster) in the context of human-induced impacts in the Mar Menor. Using long-term monitoring data (the reference period of 2002-2004 vs. the eutrophication period of 2015-2019), we analyze temporal variations in their population dynamics and their relationships with eutrophication-mediated structural changes in shallow waters. Our results suggest that these resident species, which are closely associated with shallow areas, show population dynamics that reflect habitat alterations, underscoring their potential as indicators of eutrophication impacts. This study enhances our understanding of the dynamics within transitional ecosystems and provides a basis for integrated management strategies aimed at promoting effective fish conservation
- PublicationOpen AccessPopulation dynamics, habitat use and trapping efficiency of the invasive crab Callinectes sapidus in a Mediterranean hypersaline coastal lagoon(Pensoft Publishers, 2025-10-07) Herrero Reyes, Antonio A.; Guerrero Gómez, Adrián; Zamora López, Antonio; Torralva, Mar; Zamora Marín, José Manuel; Oliva Paterna, Francisco José; Zoología y Antropología FísicaThe blue crab (Callinectes sapidus) has rapidly invaded several coastal lagoons along the Western Mediterranean. However, there are still no comprehensive assessments of its population biology, habitat use and trapping efficiency in critical habitats. A two-year study (November 2021 – September 2023) was conducted in a natural corridor zone placed between the hypersaline Mar Menor coastal lagoon and the Mediterranean Sea. Our main goal was to assess the population structure, habitat use and trapping efficiency (four types of traps) of the blue crab. The blue crab shows a population dynamic and structure that reflects its full settlement and reproductive movements across the study area. Most captures corresponded to adults and subadults, peaking in summer, and largest crabs were recorded in November. A significant relationship was found between crab size, habitat type (Cymodocea nodosa meadows, Caulerpa prolifera meadows and bare substrates) and trap effectiveness. Trapping efficiency varied with both habitat characteristics and crab size, showing a positive relationship of juveniles and adults with muddy substrates, while water depth had a negative influence on juveniles and subadults. However, results supported great plasticity at the microhabitat scale. Fyke nets were identified as the most effective trapping method. Trap type significantly affected the number of captures as a function of crab size and sex, with subadults and females being predominantly captured in fyke nets. These findings provide novel insights into the species’ population biology in invaded regions and cost-efficient control methods, enabling the design of priority management strategies in shallow waters to minimize impacts from crab invasions and to ensure ecological integrity.