Population dynamics and secondary production of Cerastoderma edule (Linnaeus, 1758) near its southern border: A baseline study in the Oualidia lagoon, Morocco

Bivalvia Growth Recruitment Production

Authors

  • Nazik Alfeddy Laboratory of Biodiversity, Ecology and Genome, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco.
  • Aicha Hamid Laboratory of Biodiversity, Ecology and Genome, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco.
  • Reda El Kamcha Laboratory of Biodiversity, Ecology and Genome, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco.
  • Mohammed Selfati Laboratoire Santé et Environnement, Faculté des Sciences Aïn Chock, Hassan II University of Casablanca, Casablanca, Morocco.
  • Hocein Bazairi 1Mohammed V University in Rabat, Faculty of Sciences, Laboratory of Biodiversity, Ecology and Genome, 4 Avenue Ibn Battouta, B.P. 1014 RP, Rabat, Morocco; 3Natural Sciences and Environment Research Hub, University of Gibraltar, Europa Point Campus, Gibraltar.
December 25, 2024

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The edible cockle, Cerastoderma edule (Mollusca: Bivalvia), is a key species in many semi-enclosed coastal systems, such as lagoons and estuaries, along the northeastern Atlantic. The present study, based on a two-year sampling (2009-2010) performed at two stations (upstream and downstream), aims to explore the population dynamics and secondary production of C. edule in the Oualidia lagoon (Atlantic coast, Morocco). The results showed spatial and temporal variations between upstream and downstream stations. Downstream population showed higher L? (36 mm) and a lower instantaneous growth rate (K = 0.83 yr-1), while upstream populations exhibited a higher growth rate (K = 1.95 yr-1) with a slightly lower L? (32.5 mm). This disparity may be linked to differences in temperature and salinity gradients. The mortality was higher upstream (Z = 9.18), probably due to ecological and anthropogenic stresses. Recruitment was seasonal at both sites, with temperature apparently playing a role in triggering the phenomenon. Moreover, secondary production was higher upstream, with an annual production of 96.342 gDW.m² in 2009 and 46.114 gDW.m² in 2010, highlighting optimal conditions for cockle development. These results provide baseline data for forthcoming ecological monitoring of the effects of global change, including climate change, on the fitness of the edible cockle C. edule in the Oualidia Lagoon, near the southern limit of the geographical distribution of the species.