Agriculture can be pervasive in its effect on wild nature, affecting various types of natural habitats, including lotic ecosystems. Here, we assess the extent of agricultural expansion on lotic systems in Northern Africa (Algeria, Tunisia, and Morocco) and document its overlap with the distribution of an endemic damselfly, Platycnemis subdilatata Selys, using species distribution modeling. We found that agricultural land cover increased by 321% in the region between 1992 and 2005, and, in particular, the main watercourses experienced an increase in agricultural land cover from 21.4% in 1992 to 78.1% in 2005, together with an increase in the intensity of 226% in agricultural practices. We used capture–mark–recapture (CMR) surveys in terrestrial habitats surrounding a stream bordered by grassland and cropland in northeastern Algeria to determine demographic parameters and population size, as well as cropland occupancy. CMR modeling showed that the recapture and survival probabilities had an average of 0.14 (95%CI: 0.14–0.17) and 0.86 (0.85–0.87), respectively. We estimated a relatively large population of P. subdilatata (~1750 individuals) in terrestrial habitats. The occupancy of terrestrial habitats by adults was spatially structured by age. Our data suggest that P. subdilatata has survived agricultural expansion and intensification better than other local odonate species, mainly because it can occupy transformed landscapes, such as croplands and grasslands.

The Seybouse is the second largest river basin in Algeria, hosting an important biodiversity and providing various ecosystem services. This watershed is highly influenced by agricultural and industrial activities, which threaten its biodiversity and ecosystem integrity. The use of benthic macroinvertebrates as biological indicators has a long tradition in developed countries and integrated into all assessments of the ecological quality of river systems. However, the macroinvertebrates of many North African regions are still not well studied, including those of the Seybouse river. The aim of this study is to assess the inventory and ecological role of benthic macroinvertebrates in inland waters of the Seybouse River and determine the impact of pollution on their spatial distributions. We sampled the benthic macrofauna of Wadi Seybouse and its affluents using regular surveys in three sites, of which one was in the upper Seybouse Bouhamdane in Medjez Amar and two in the middle Seybouse. Between December 2019 and May 2020, 10 physico-chemical parameters (pH, EC, OD, water speed, NO3, Salinity, NO2, MES, turbidity, depth) were measured in order to establish a health state diagnosis of these aquatic ecosystems. The complementary biological approach by the analysis of populations of macroinvertebrates identified 7482 individuals and 40 taxa divided into five classes: Crustaceans which were the most dominant, insects with the main orders (Ephemeroptera, Diptera, Trichoptera, Heteroptera and Odonata), Molluscs, Nematodes and Annelids. The physico-chemical analyzes and the application of the organic pollution indices indicated a strong to excessive pollution for all sites, especially in Seybouse upstream

The theme is based on the determination and the impact of pollution on the aquatic fauna of Seybouse river in the wilaya of Guelma. This study aimed to evaluate the physicochemical properties of water, to determine the macro-benthic invertebrates of this ecosystem. The money samples of water are taken (November - May) at three stations at different depths, including a very polluted one at downstream of the Wadi. Several physico-chemical parameters were measured (pH, electrical conductivity, turbidity, BOD5 MES, water temperature and salinity). The Bi-monthly sampling of macro invertebrates revealed the existence of 40 taxa, divided into 4 branches (amphibians, molluscs, arthropods, annelids), made up of 2344 identified individuals, and distributed according to the bathymetry, where the majority are Arthropods with 95.38%. The annelids represent 3.71%, collected mainly at the level of the strongly anthropized site C. Therefore, the distribution of the macrobenthic fauna, depends on the physico-chemical parameters, on the geographical position.Maintaining a standard water quality in this aquatic ecosystem requires continuous monitoring of its physicochemical characteristics.

Aquatic macroinvertebrates are integral parts of functioning wetlands, inhabiting a diversity of aquatic ecosystems where communities are spatially structured. Macroinvertebrates of some Mediterranean regions such as North Africa are still not well studied. Here, we study the community structure of benthic macroinvertebrates in four different types of lotic and lentic wetlands in the semiarid Haut Plateaux of Northeast Algeria. Macroinvertebrates and 06 physicochemical parameters were sampled in 12 sites belonging to four types of habitats (lotic river, lentic river, dams, and sebkha [saline lentic water body]) during January-December 2021. Eventually, the character lentic-lotic was the most important variable affecting the affecting invertebrate communities in the Mediterranean region. The results revealed that sebkha and dams had a lower Shannon index than lentic and lotic rivers. Non-metric multidimensional scaling analysis showed a strong overlap between the community composition in lotic and lentic sites . Howeverin the three types of aquatic groups lentic river, dam and lotic habitats showed a strong overlap between the community whereas sebkha was markedly separated. Redundancy analysis showed that water velocity and pH, were the main drivers of community structure of macroinvertebrates, revealed a strong effect with pH (F1,8=4.15, P = 0.001) and water velocity (F1,8= 3.22, P = 0.002) , separating lotic communities from those that inhabited dams, lentic rivers, and sebkhas. As conclusion, this study contributes to the better understanding of the community structure of macroinvertebrates in semiarid North Africa where wetlands have been experiencing high anthropogenic disturbance.

Understanding the spatial and temporal niche of waterfowl is essential for effective management and conservation. To determine the ecology and phenology of Anatidae in North Africa, we carried out a 12–month study (2019–2020) in three wetlands that constitute a winter refuge for waterbirds in the Souk–Ahras region in north–east Algeria. We surveyed species richness, the seasonal pattern of the number of Anatidae, and their wintering diurnal behavior using regular counts and scans. We recorded thirteen species: six wintering species (Anas clypeata, Anas penelope, Anas strepera, Tadorna tadorna, Aythya ferina, and Anas crecca crecca) and three sedentary nesting species (Anas platyrhynchos, Oxyura leucocephala, and Aythya nyroca), the latter two having national and international protection status. The survey showed that the wintering behavior of all these species is dominated by sleep, which on average accounts for almost half of the total time (48.91 %). Our results indicate that the three wetlands host a complex waterfowl community that includes species of conservation concern and that these sites likely play an essential role in providing the essential resources for wintering. Dataset published through GBIF (Doi: 10.15470/fozdot)

A preliminary inventory of macroinvertebrate communities and a regular physicochemical analysis of groundwater were carried out in the Souk Ahras region (north-eastern Algeria). It aims to study and analyze the structure and distribution of underground aquatic species, thus determining the relationship that may exist between the quality of water in wells and springs with the diversity of aquatic fauna present in the habitats. Through 2018, 14 stations (10 wells and 4 springs) were monitored on a monthly basis, while water and aquatic fauna samples were taken. A principal component analysis (PCA) of the physicochemical quality parameters was carried out from the average values of each parameter. It has been observed that the waters are highly mineralized, due to the high values of total hardness, salinity, and sulfate levels in certain stations. The sources of contamination are mainly due to the raw wastewater circulating in the small canals. Also “seguias” are used either to evacuate wastewater or for irrigation, which seeps down to the water table. The collected aquatic fauna in all the 14 stations is diversified and contains 29 families which correspond to 4 taxa.