All taxonomic groups were evaluated by specialist groups, who took into consideration the past, ongoing and future impacts leading to species extinctions and agreed on the main causes of decline for freshwater dependant species at the regional level.
At the northern African scale, habitat loss and degradation induced by human activities appeared to be the most important threat, together with pollution. In addition, natural disasters (especially drought and strong high flow events) are known to be severely affecting freshwater species and have a direct effect on populations. These threats are expected to worsen in the future due to the increasing effects of climate change. Other threats of relevance are human disturbance, changes in the native species dynamics, harvesting, invasive alien species and intrinsic factors.
In total, 207 threatened freshwater taxa are at risk of extinction due to habitat loss and degradation in northern Africa - 114 plants, 49 molluscs, 32 fish and 12 odonata. Threatened odonata, such as the Maghrebian endemic Calopteryx exul, are highly endangered due to the alteration of river systems through pollution and dessication of rivers as a result of water over extraction for agricultural and domestic use throughout northern Africa.
Pollution was identified as the second most important cause of freshwater species extinction in the region. In total, more than half of the regionally threatened freshwater fauna and flora assessed. This alteration of freshwater quality is a negative result directly related to uncontrolled waste disposal from agricultural, industrial and domestic human activities that, in the majority of the cases, are also linked to soil pollution.
Droughts are becoming more frequent and their severity and extent are increasing in the region, already the most affected by water scarcity of the entire African continent (UNEP 2006). On the other hand, important flooding episodes are also becoming more common in the region, carrying enormous amounts of sediment and destroy in the aquatic habitats.
Major threats to freshwater species in northern Africa