http://hdl.handle.net/10174/14297 Fri, 03 Apr 2026 22:15:07 GMT 2026-04-03T22:15:07Z http://hdl.handle.net/10174/40752 Title: Preliminary observations of hunting behaviour by a freshwater threatened Leuciscidae Authors: Soares, Marta; Cardoso, S.C.; Anastácio, P.M.; Banha, F. Abstract: Freshwater ecosystems host diverse fish species that employ various foraging strategies, including hunting, a behaviour more commonly documented in marine environments. This study focuses on the threatened Iberian chub, Squalius pyrenaicus, in the Vascão River, Portugal, a species known for its opportunistic feeding. Using an underwater camera, we observed 45 predatory events in which S. pyrenaicus employed two tactics: solitary pursuit and group hunting. In group hunting, individuals coordinated attacks, encircling and taking turns pursuing prey. While all attacks seem unsuccessful, one feeding event was recorded where two S. pyrenaicus individuals interacted to capture a prey fish. Our findings suggest that S. pyrenaicus may rely on rudimentary social behaviors during solitary and group hunting, potentially influenced by environmental factors. This is the first report of such behaviour in this species, underscoring the need for further research into social and cognitive aspects of freshwater fish predation, particularly in light of ecosystem threats like invasive species and climate change. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/40752 2025-01-01T00:00:00Z http://hdl.handle.net/10174/40745 Title: Integrating Ecotoxicological Assessment to Evaluate Agricultural Impacts on Aquatic Ecosystems: A Case Study of the Lage Reservoir (Mediterranean Region) Authors: Catarino, A.; Mourinha, C.; Custódio, M.; Anastácio, P.; Palma, P. Abstract: This study analyzed the use of a toolbox to evaluate the impact of agricultural activity on the water quality/status classification of a hydro-agricultural reservoir (Lage reservoir, Southern Portugal). The framework integrated the quantification of a group of 51 pesticides and ecotoxicological endpoints with organisms from different trophic categories (the bacterium Aliivibrio fischeri, the microalga Pseudokirchneriella subcapitata, and the crustaceans Daphnia magna and Thamnocephalus platyurus) at two sampling points in the reservoir (Lage (L) and Lage S (LS)) between 2018 and 2020. Over the three-year study, we quantified 36 of the 51 pesticides analyzed in the Lage reservoir. Total concentrations increased successively from 0.95 µg L−1 to 1.99 and 2.66 µg L−1. Among these, the pesticides most frequently detected were terbuthylazine (100% of detection) and metolachlor (83% of detection), with maximum concentrations of 115.6 and 85.5 µg L−1, respectively. Samples from the LS site showed higher toxicity, where A. fischeri presented 30 min EC50 values of 39–51%. Microalgae growth was consistently inhibited, correlating with agricultural activity, mainly the application of herbicides and insecticides, while D. magna feeding rates revealed no inhibitory effects in the Lage samples. The results highlight that although the detected pesticide levels were below regulatory limits, they still induced toxic effects in the tested organisms. The potential ecological status of the reservoir was classified as moderate, and the integration of the proposal toolbox allowed refinement of the classification of water status. The results demonstrated that this integrated approach, combining multiple assessment methods, establishes a more robust water quality evaluation methodology, allowing it to be used as a tool complementary to the WFD methodology. This proposal not only identified existing pollution impacts but also enabled (1) early detection of the toxic effects of emerging contaminants to prevent ecological damage; (2) proactive management through specific actions to restore water status; and (3) improved sustainable water use. Keywords: Alqueva project; bioassays; irrigation agriculture; water status classification; Water Framework Directive Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/40745 2025-01-01T00:00:00Z http://hdl.handle.net/10174/40744 Title: Invasions in aquatic systems: Patterns, mechanisms and management Authors: Anastacio, P.; Ribeiro, F.; Chainho, P. Abstract: The 13th NEOBIOTA International Conference on Biological Invasions (NEOBIOTA 2024), held in Lisbon, Portugal, from 3–6 September 2024, brought together 421 participants from 47 countries for one of the most significant global gatherings in invasion science. Notably, this meeting featured the strongest representation of aquatic studies to date, spanning marine and freshwater systems across oral sessions, posters and workshops. This momentum contributed to the creation of a dedicated Special Issue, incorporating contributions from both conference participants and other aquatic researchers. This Special Issue on Invasions in Aquatic Systems comprises 23 papers — original research and reviews — organised into five themes: Responses to Environmental Stressors, Ecological Interactions and Invasion Impacts, Detection and Monitoring Tools, Management and Policy and Global and Regional Syntheses (Fig. 1). Collectively, these papers provide a data-rich snapshot of a rapidly evolving field and the challenges it faces. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/40744 2025-01-01T00:00:00Z http://hdl.handle.net/10174/40740 Title: Effectiveness of legislative tools to stop biological invasions: freshwater turtles’ invasion in Europe as a study case Authors: Rato, J.; Brandão, P.; Gama, M.; Banha, F.; Anastácio, P. Abstract: Invasive species pose significant threats to biodiversity, human health, and economic systems. Freshwater turtles are popular as pets, but when released or allowed to escape into the wild, they can become invasive. A prominent example is the red-eared slider Trachemys scripta, which is recognized as a globally invasive species. Legislative tools, such as the European Union Regulation 1143/2014 on the prevention and management of invasive alien species, aim to combat these threats. This framework includes the implementation of Commission Implementing Regulation 1141/2016, which banned the trade of listed invasive species, including T. scripta. This study evaluates the effectiveness of Regulation 1143/2014 on T. scripta invasion and its consequences on other freshwater turtle invasions, using data from the CITES database and the GBIF platform. While T. scripta imports into the EU ceased after 2016, the species continues to establish and expand in the wild. This suggests that the trade ban had minimal impact on already established populations, highlighting the need for additional measures to reduce and control its spread. Simultaneously, imports and records of other freshwater turtle species have risen, indicating a shift in trade dynamics. These species are increasingly being introduced, potentially exacerbating the biological invasion problem. Despite limitations inherent to CITES and GBIF data, our findings suggest that the current European legislation has not been effective in mitigating T. scripta invasions and may have unintentionally contributed to the introduction of other invasive turtles. We recommend that the European Union develop invasive species lists tailored to each biogeographic regions of Europe to enhance the effectiveness of legislation. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/40740 2025-01-01T00:00:00Z