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Food availability is a crucial factor influencing the behavioral responses, development and physiology of bivalve’s larvae. In this study, we investigated the effects of two feeding strategies (Fv: number of microalgae cells per volume and Fb: number of microalgae cells per biomass) on Mytilus galloprovincialis larvae reared at three different stocking densities (D5: 5 larvae/ml, D15: 15 larvae/ml and D30: 30 larvae/ml). The results showed that larvae fed per volume (Fv) exhibited the highest survival rates across all tested densities (59%, 53% and 39% for D5, D15and D30 respectively), compared to larvae fed per biomass (Fb) (40%, 39% and 32% for, D15, D30 and D5 respectively). Conversely, feeding per biomass led to a significant increase in cumulative shell length gain (D5: 211.4 µm; D15: 214.99 µm and D30: 208.11µm) compared to feeding per volume (D5: 201.12 µm; D15: 166.23 µm and D30:130.09 µm). Statistical analysis revealed that food availability significantly influenced survival only at low larvae density (D5: F=20.13; P

Larval rearing is a critical phase in bivalve hatchery production and plays a crucial role in the success of spat production. Therefore, understanding the effect of density on larval performance and post-larvae settlement is crucial for optimizing and improving the success of bivalve hatchery production. This study aimed to evaluate the effect of different stocking density on larval performances and settlement rate of clams Ruditapes decussatus. Three different larval rearing densities (10, 20, and 40 larvae/mL) and four settlement densities (35, 70, 100, and 140 larvae/cm²) were studied. The results regarding larval performance showed that high density resulted in low larval survival (18% for D40) compared to low and moderate densities (23% for D10 and 26% for D20, respectively). In terms of post-larvae settlement, a density of 35 larvae/cm² exhibited the highest fixation rate (36%) compared to 33%, 18%, and 9% at 70, 100, and 140 larvae/cm², respectively. Statistical analysis revealed a significant effect of larval density on both survival and growth (F = 11.79, p < 0.05; F = 18.63, p < 0.05, respectively), as well as a highly significant effect on settlement (F = 14.88, p < 0.001). Overall, it is advisable to maintain moderate densities during both larval performance and post-larvae settlement for seed production of R. decussatus in the hatchery.

In mussel hatchery systems, the settlement process is a crucial element influencing seed yield. The current study assayed the influence of five densities of competent pediveliger larvae on settlement success and post-larvae production. We showed an inverse relationship between density and settlement efficiency, e.g., an attachment success of 99.4% at the lowest density (35 larvae/cm2) but only 9% at the highest density (210 larvae/cm2). However, post-larvae production was higher at intermediate larvae densities (70 larvae/cm2). The reimplementation of treatments upon post-larvae density after 6 weeks post settlement showed that the lowest-density groups bore both the highest post-larvae growth rate (22.24 ± 4.60 µm/day) and the largest head batch (48% of the size distribution), as compared to the higher-post-larvae-density groups. These results highlight the importance of optimizing both pediveliger larvae density and post-larvae density, to maximize high-quality seed yield in local hatcheries. Current rearing technologies would assure a timely commercial seed production to protect natural sea rocky beds in Alboran Sea coasts.

The Mediterranean mussel Mytilus galloprovincialis is distributed in both hemispheres either natively or introduced. The updated population genetic distribution of this species provides a useful knowledge against which future distribution shifts could be assessed. This study, performed with seven microsatellite markers and three reference species (M. edulis, M. chilensis and M. trossulus), aimed to determine the scenario of genetic divergence between 15 samples of M. galloprovincialis from 10 localities in Europe, Africa, Asia, Australia, North America and South America. In agreement with previous data, M. trossulus was the most divergent taxon of the genus, but M. chilensis appeared as an intermediate taxon between M. edulis and M. galloprovincialis, though closer to this latter. M. galloprovincialis from the Atlantic Northeast appears as the most likely source of worldwide exotic settlements instead of the previously thought Mediterranean population. The successful worldwide establishment of M. galloprovincialis suggests it is a flexible evolutionary species (FES), i.e., a species or population whose genetic background allows it to rapidly adapt to changing environments. This natural endowed plastic adaptation makes it a candidate resilient species amidst the ongoing climatic change.

Investigating habitat selection and ecological factors trade-offs is a major avian ecology topic which is closely implicated for conservation purposes. Studies dealing with the impacts of ecological factors on wintering Spoonbills are overall scarce. Here, we used Principal Component Analyses (PCA) and Generalized Linear Mixed Models (GLMM) to test the relevance of geographical, environmental and anthropogenic factors in predicting the occupancy and abundance of the Eurasian spoonbills (Platalea leucorodia) during 2008-2011 within 28 Moroccan wetlands. The Eurasian Spoonbill mean annual occurrence was 59.2% (± 1.5% SE; 95%CI: 56.3%-62.1%). Among the occupied wetlands, 15 (83.3%) were regularly occupied. We found that the Eurasian spoonbill occurrence was negatively related to distance to coastline, altitude and human presence, whereas its abundance increased significantly with increasing mudflat areas. These findings highlight the significant effect of human presence in selecting wintering sites, but not in the prediction of abundance. Management strategies should therefore address specific attributes of coastal wetlands and should carefully consider the effects of habitat use especially those related to mudflats. We further suggest guidelines for future studies to understand the dynamic of Eurasian spoonbills wintering in the region.

In terms of the nutritional needs, the choice of the appropriate phytoplankton strain is the main criterion during bivalves breeding improvement in captivity. Seven nutritional diets based on tree microalgae species (Chaetoceros calcitrans, Tetraselmis suecica and Pavlova lutheri), and seven feeding rations (0%, 1%, 2%, 3%, 4%, 5% and 6%) were used to assess the nutritional pattern of Ruditapes decussatus during conditioning practices. All regimes have shown the highest ingestion rate at low food availability (1% to 3%) with a leaning to diets based on C. Calcitrans followed by T. suecica and P. lutheri respectively.A significant influence of diets quality on absorption efficiency of phytoplankton was observed for both monospecific and bispecific diets (F = 21.78, p =3.2 10-7 *** and F = 250.09, p= 2.2 10-16 ***respectively). Whereas, low influence of food availability on absorption efficiency among all used rations has been revealed by clams reared under mono, bi and trispecific diets respectively (F = 11,19, p= 1.9 10-7 ***; F = 16,63, p= 1.03 10-9 *** and F = 2.78, p=0.0534ns). Consequently, this study could be handled as a standard protocol for conditioning process in furtherance of yield maximizing and cost minimizing during spat production of bivalves in hatcheries.

Three diets based on three microalgae species (Tetraselmi ssuecica, Isochrysis galbana, and Chaetoceros calcitrans) and three feeding rations (1%, 2%, and 3%) were used to understand the ecophysiology of the Mediterranean mussel Mytilus galloprovincialis during Broodstock conditioning. Generally, mussels increase their consumption regarding food availability for all diets, and it is evident that the highest consumption was recorded with a feed ratio of 3%. During the study, I. galbana and C. calcitrans strains show the high consumption (1.58 µg. g-1. h–1 ±0.00) and (1.58µg. g-1. h–1 ±0.00) compared with T. suecica (1.542 µg. g-1. h–1 ±0.023) recorded at 3% food ration of monospecific diets. Same results were recorded for ingestion but with great learning for I. galbana in triscpecific diet (0.70 µg. g-1. h–1 ±0.052) compared to C. calcitrans(0.36 µg. g-1. h–1 ±0.037) and T. suecica (0.25 µg. g-1. h–1 ±0.126), respectively.The analysis of ANOVA has shown that both diet and food availability affect significantly the ingestion (F = 30.9, df = 2, p < 0.001 and F = 4.4, df = 6, p < 0.001) during mussel conditioning.

Spat supply for mussel farming in Morocco is essentially based on seed capture and collection from natural beds. However, natural irregularity recruitment in exploited areas and encountered difficulties during spat collection operations have led to develop and improve reproduction techniques under controlled conditions in hatcheries. The present study focused on the larvae phase aiming at assessing growth rate varies between different development stages. Trocophore larva stage had a size of 63.25 μm and reached the pedivilegere stage with a size of 272.56 μm in 18 culture days. Length growth was more significant than width growth for both H-batch and T-batch. For instance, larvae grew in terms of length quickly in H-batch than T-batch (11.10± 1.30 and 9.67 ± 1.17 μm day-1), and the same pattern was observed for T-batch larvae. Inversely, the total biomass consumed was higher during T-batch larvae rearing than H-batch ones. In contrast, the effect of feeding on growth was observed more significantly for H-batch larvae (t=7.55, df=23, p

COVID-19 pandemic has had huge impacts on multiple industries and sectors, not just ecotourism and wildlife protection in Morocco. Ecological health and wildlife are a critical resource for the country’s tourism sector recovery. Conservation is considered as one of the industries that are hit hard by the COVID-19 pandemic. Many of the threats facing biodiversity and protected areas have been exacerbated during and following, the outbreak with practices such as poaching, wildlife trafficking, and forest logging activities resumed due to the country lockdown and ecotourism collapse. Conservationists should take emergency actions in the short-term to help rural communities and grassroots organizations and review waysto achieve conservation and sustainability goals in the post-pandemic era.

The population of the African continent is significantly increasing which has given rise to societal, economic and environmental changes. This will generate an increase in demand for food, water and energy. Thus, strategies for sustainable management of natural resources need to be adopted urgently in order to match the future needs and to ensure sustainable development on the continent. The Water Energy Food (WEF) nexus is one the avenues for studying the current and future interactions and interdependencies of the WEF sectors under different scenarios and challenges in the effort towards establishing sustainable use of natural resources. Policies around the nexus approach are few or absent at the continental and countrylevels. This paper is a first review on the adoption of the Nexus in two model African countries, Morocco and South Africa. The review compares the water, energy and food sectors and the related national policies, plans and frameworks. The data related to the WEF Nexus revealed key difficulties of availability in both countries. A comparative analysis of the situation in both countries demonstrated differences in policies relating to the WEF Nexus across the sectors: water, energy, and agriculture. Additionally, the paper explores the relevance of technology-assisted frameworks for the WEF nexus and also analyzed risks to agriculture and food security in the context of the reviewed countries.