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Occurrence of the invasive brown seaweed Rugulopteryx okamurae in Morocco (Mediterranean Sea)

Authors:
  • Instituto Universitario de Sanidad Animal y Seguridad Alimentaria
  • National Institute of Fisheries Research

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Rugulopteryx okamurae, a brown alga native to the temperate western Pacific Ocean, was discovered for the first time in the Mediterranean Sea in 2002, in the Thau Lagoon (France). A new population of R. okamuraewas discovered in Belyounech Beach with the observation of some specimens fixed near the harbour of Tanger (Strait of Gibraltar-Morocco). As well as, the remarkable record of this alga stranded in M’diq beach (Alboran Sea-Morocco).Since its introduction R. okamurae has established in the Thau Lagoon (France), self-sustaining populations without displaying an invasive behaviour. On the contrary,the newly discovered population in Morocco would be classified as invasive. This new record gives the range extension of this invasive alga, from the southwest of Alboran Sea to the southwestern limit of Gibraltar.The presence of this invasive seaweed in the area may affect the native alga, seagrass and native fauna including fish community negatively (PDF) Occurrence of the invasive brown seaweed Rugulopteryx okamurae in Morocco (Mediterranean Sea). Available from: https://www.researchgate.net/publication/325467091_Occurrence_of_the_invasive_brown_seaweed_Rugulopteryx_okamurae_in_Morocco_Mediterranean_Sea [accessed Mar 18 2019].
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... This brown macroalga, originated from the northwest of Asia (Hwang et al., 2009), has been systematically reported on the coasts of the Strait of Gibraltar since 2015 (see Altamirano-Jeschke et al., 2016), when more than 5,000 tons of wracks were extracted from the beaches of its south coasts, in the city of Ceuta (North-Africa) (Ocaña et al., 2016). The rocky bottoms of The Jbel Moussa Site of Biological and Ecological Interest (SIBE) (El Aamri et al., 2018) and the eastern littoral of El Estrecho Natural Park (PNE) firstly represented the northern and southern scenarios of R. okamurae expansion in the Strait of Gibraltar. Until date, these areas constitute the most intensely affected by the brown alga, which continues its westward and eastward directionality of expansion Figueroa et al., 2020) with trend to monopolize the sea rocky bottom in detriment of the photophilous resident biota (García-Gómez et al., 2020b). ...
... It is urgent to carry out studies on the distribution, ecology and impacts of R. okamurae in the Mediterranean and the Atlantic coasts, as well as the implementation of management measures. However, few studies have been carried out on R. okamurae distribution (e.g., Altamirano-Jeschke et al., 2016;Ocaña et al., 2016;El Aamri et al., 2018;Altamirano et al., 2019) and its derived impacts on the recipient sessile , 2020bSempere-Valverde et al., 2020) and mobile associated biota (Navarro-Barranco et al., 2019). In this regard, there is only one published study monitoring the temporal dynamic of the invasion since the first apparition of the species in the Strait waters (see García-Gómez et al., 2020b) by the utilization of Sessile Bioindicators in Permanent Quadrats (SBPQ). ...
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