Oued Bouhlou: A new hope for the Moroccan pearl mussel

Abstract

1. The freshwater pearl mussel Margaritifera marocana (Pallary, 1918) is an endemic species of Morocco being listed as critically endangered and it stands among the world 0 s 100 most threatened species. An extensive survey was performed in the Sebou basin (total area of approximately 40,000 km 2 ), covering 26 different sites. Margaritifera marocana was found only in four sites limited to a small tributary (Oued (=River) Bouhlou).2. This population has a very restricted distribution (no more than 4 km of river length) but appears stable with recent recruitment, since small specimens were found.3. Genetic analyses were performed, showing that this population has a similar diversity to that found in the River Laabid (Oum Er Rbia basin), but represents a distinct conservation unit that should be managed independently.4. Although this study adds a new population to the current known distribution of M. marocana, urgent conservation measures (e.g. extension of the Tazzekka National Park; better management of river flow; increase of the riparian vegetation in some stretches; establishment of national and international legislation, and engagement of local citizens) are needed given the species 0 restricted distribution, its rarity, and the numerous threats that impair its future survival. the presence of this species, but only the River ('Oued' in Arabic) Laabid contains a stable and recruiting population. In other rivers surveyed, the species was found to have a very low abundance and restricted spatial distribution (River Oum Er Rbia) or it was not possible to confirm its occurrence, despite earlier studies describing its presence (River Derna; Araujo, Toledo, Van Damme, Ghamizi, & Machordom, 2009).Earlier studies or specimens available in museums also confirm the presence of M. marocana in the Sebou basin. However, most of these studies are outdated and given the number of threats that this species is exposed to (extensively reviewed in Sousa et al., 2016), many of these earlier described populations are possibly now extinct. The aims of this study were: (i) to detect the presence of populations in the Sebou basin; (ii) to assess basic ecological characteristics such as distribution, abundance and population structure; and (iii) to characterize and compare the genetic diversity of the newly discovered population in the Sebou basin with the M. marocana populations previously described in the Oum Er Rbia basin.

Freshwater conservation assessments in (semi-)arid regions: Testing river intermittence and buffer strategies using freshwater mussels (Bivalvia, Unionida) in Morocco

“…The coordinates of each sampling site were recorded using GPS. Distribution data collected during the present study was supplemented by bibliographical data (Araujo et al, 2009(Araujo et al, , 2010(Araujo et al, , 2016Froufe et al, 2016aFroufe et al, , 2016bSousa et al, 2016Sousa et al, , 2018. All collected individuals were morphologically identified on site and a small tissue snip was collected from each specimen following a non-lethal protocol (Naimo et al, 1998) for genetic analyses (Table 1).…”

“…Even though urgent conservation planning is needed, basic data like the diversity and distribution of freshwater mussel species is often outdated or even absent, particularly in North Africa (Graf and Cummings, 2011). Moroccan freshwater mussels have been the focus of some studies during the 20th century (Pallary, 1918(Pallary, , 1928Van Damme, 1984;Mandhal-Barth, 1988;Daget, 1998), but only in the last decade was it possible to start tackling the uncertainties regarding current distributions and taxonomy, mostly due to molecular approaches (Araujo et al, 2009(Araujo et al, , 2010Khalloufi et al, 2011;Froufe et al, 2016aFroufe et al, , 2016bSousa et al, 2016Sousa et al, , 2018. Presently, there are five recognised native freshwater mussel species in Morocco: four from family Unionidae Rafinesque 1820: Anodonta sp.…”

“…With the exception of the Anodonta sp., the taxonomic status of all Moroccan species has been recently tested and validated (Araujo et al, 2009(Araujo et al, , 2016Froufe et al, 2016aFroufe et al, , 2016b. The current distribution of all five species is poorly known and/or outdated, since almost all species have apparently suffered great declines over their range in the last decades (Araujo et al, 2009(Araujo et al, , 2010Froufe et al, 2016aFroufe et al, , 2016bSousa et al, 2016Sousa et al, , 2018.…”

Conservation of freshwater bivalves at the global scale: diversity, threats and research needs

“…While the NT pattern may not be very representative of the ecoregion due to the few assessed species, in AF it reflects the poor knowledge about the NE Not evaluated by the IUCN Red List; and the IUCN Red List categories: DD data deficient, LC least concern, NT near threatened, VU vulnerable, EN endangered, CR critically endangered, CR (PE) critically endangered probably extinct, EX extinct population size and trends. This is due to the lack of research that is being done in the AF, where survey and monitoring studies are almost non-existent (Lopes-Lima et al, 2014;Sousa et al, 2016Sousa et al, , 2017.…”

Captive breeding of Margaritifera auricularia (Spengler, 1793) and its conservation importance

“…Similar methods can be applied to other M. auricularia populations or other endangered freshwater mussels (e.g. M. marocana ) with similar life‐cycle traits (Sousa et al, ; ). These captive programmes and the later release of reared juveniles into natural habitats should only be implemented after the restoration of abiotic and biotic conditions, to allow the successful colonization of M. auricularia and the recovery of their populations in the natural habitat.…”