10.15468/hsqufs 8e2dff47-ef84-4545-8174-217b17a5e8eb https://ipt.medobis.eu/resource?r=mammeria Hadjer HAMZA Laboratory of Applied Neuroendocrinology, Department of Biology, Faculty of Sciences, Badji Mokhtar University, Annaba 23000, Algeria PhD student

ALGERIA

Rutger De Wit "MARBEC, University of Montpellier, CNRS, IRD, Ifremer, INRAE, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France " Dr

FRANCE

Aicha Beya Mammeria University Algiers 1, Algeria Professor

ALGERIA

ab.mammeria@gmail.com 2026-05-01 ENGLISH This dataset is the main part of a study conducted monthly throughout 2019 at three stations selected due to their combined continental and marine influences. The study aimed to assess the health status of the El Mellah lagoon. The analysis of the spatio-temporal variation of angiosperms reveals significant changes in their distribution within the lagoon, which appear to be linked to fluctuations in the environmental conditions of El Mellah. It is observed that Zostera noltei (Hornemann, 1832) dominates the stations influenced by freshwater, while Ruppia maritima (Linnaeus, 1753) dominates the northern part of the lagoon, where the influence of marine waters is more pronounced. The invasive species Arcuatula senhousia, which was first observed in June 2019 in El Mellah, has been found attached to the leaves and rhizomes of Zostera noltei, and to a lesser extent, on the empty shells of the bivalve Cerastoderma glaucum. Since its introduction, it has dominated the bivalve community in El Mellah with a maximum density of 1321 ± 1167 ind.m-2. This phenomenon can lead to a decline in the biodiversity of the lagoon, particularly affecting the Zostera noltei seagrass and the threatened Cerastoderma glaucum species. It is necessary to conduct comprehensive studies to assess the impact of Arcuatula senhousia in the El Mellah lagoon to implement appropriate conservation and restoration measures to preserve the integrity of the ecosystem." Climate Change none Occurrence GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml Algerian coast coastal lagoon https://marineregions.org/gazetteer.php?p=details&id=14845 invasive species none This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License . Creative Commons Attribution 4.0 International https://spdx.org/licenses/CC-BY-4.0.html CC-BY-4.0 https://ipt.medobis.eu/archive.do?r=mammeria Station1 : 36.877220N; 8.330830E Station2 : 36.887220N; 8.314440E Station3 36.909440N; 8.314440E 8.282 8.37 36.955 36.847 2019-02-20 2019-12-20 Phylum Mollusca Phylum Tracheophyta unkown Aicha Beya Mammeria University Algiers 1, Algeria Professor

ALGERIA

ab.mammeria@gmail.com none El Mellah Lagoon, Algeria Samples were collected monthly in the shallow subtidal (0.3 m to 0.5 m depth) at three stations in El Mellah Lagoon from February to December 2019. The taxonomy mapped to WoRMS; while for locations the coordinateUncertaintyInMeters was added for the Station 1 and station 3 because the coordinates were on the land. This can be justified by the fact that the lagoon surface periodically changes. Since 1964, various coastal ecosystems in the Mediterranean Sea (i.e., coastal lagoons, river deltas and harbours) have been invaded by the Asian date mussel A. senhousia. The dataset is part of the study that represents a new record of this invasive species in El Mellah Lagoon, representing the first report from coastal systems on the southern coast of the Algerian Basin (Western Mediterranean). This project was partly funded by the MARBEC research centre through its IRD-supported “North-South Partnership” funding programme. El Mellah Lagoon is the only shallow, brackish coastal lagoon in Algeria and is located in the El-Kala National Park (UNESCO biosphere reserve) in north-eastern Algeria (36.89290N; 8.32623E). This lagoon is only connected to the Mediterranean Sea through a single long (900 m) and narrow (10–20 m) inlet. Benthic samples were collected monthly in the shallow subtidal (0.3 m to 0.5 m depth) at three stations in El Mellah Lagoon from February to December 2019. 2026-05-10T00:00:00Z HAMZA H, De Wit R, Mammeria A B (2026). Seagrass meadow and macrofauna communities in Southern coast of Algerian Basin (El Mellah Lagoon), 2019. Version 1.17. Hellenic Center for Marine Research. Sampling event dataset https://doi.org/10.15468/hsqufs accessed via GBIF.org on 2026-05-10. Hamza Hadjer, Beya Mammeria Aicha, Bain Abdelmadjid, de Wit Rutger, Klein Judith (2022). First record of the invasive Asian date mussel Arcuatula senhousia (Benson, 1842) in El Mellah Lagoon (Southern coast of Algerian Basin, Western Mediterranean). Bioinvasions Records. 11 (3). 686-699. https://archimer.ifremer.fr/doc/00788/90034/