Ichkeul National Park

Poaching was considered a threat in 2004 and (to a lesser degree) in 2008. In 2008, hunting was permitted in the periphery of the site and illegal fishing was considered a significant but manageable problem (GOPA, 2006; UNEP-WCMC, 2012). Since 2011, day and night poaching inside the park has steadily increased and a lack of capacity of park management and surveillance teams, in particular the lack of specially trained personnel in anti-poaching, means that this is a growing problem for the birdlife that frequents the park. Poaching inside the park includes a Greylag Goose from Hungary tracked via GPS (IUCN Consultation, 2020). There are concerns that insufficient fishing management has disturbed the balance of the lake's ichthyofauna and diminished the food resources of piscivorous species, especially water birds (IUCN Consultation, 2020).

From 1996 to 2006, the site was included on the List of World Heritage in Danger because of damming, resulting in salinization and consequent degradation of vegetation (World Heritage Committee, 1996, 2006). Reduction of water inflow, from 350 to 230-270 million m3 following dam construction causing salinity to increase to 73 g/l, lead to a shift in vegetation to halophytes and a dramatic reduction in waterbird numbers (Baccar et al., 2000; Hamdi et al., 2008; Hamdi et al., 2012). Exceptionally abundant rainfall in 2002/03-2004/05 winters replenished the water resources of the lake and contributed to desalinization to acceptable levels (Skinner et al., 2006). This replenished the water table and reduced salinity to 5-6 g/l, resulting in partial ecosystem recovery, but the threat from potentially insufficient water input remained. A positive trend was maintained through downstream flow regulations by Tinja sluice management since 2003/04 (UNESCO, 2007, 2008). In response to this positive trend, the site was removed from the List of World Heritage in Danger in 2006. Nevertheless, from 2002/03 to 2008/09, the site experienced highly fluctuating total water inflow between 59 and 535 million m3 (average 257 millions m3), the contribution of dam releases to these inflows having itself fluctuated between 6 and 345 million m3 (average 140 million m3) (UNESCO, 2010; IUCN Consultation, 2020). Declining water levels during dry years threatens aquatic fauna, including the European eel (Daly-Hassen, 2017). Between the hydrological years 1999/2000 and 2016/17, the total storage capacity of the dams increased from 279 to 383 Mm3, representing a 37% increase. However, over the same period this growth in capacity was accompanied by a 149% rise in local water demand (drinking water for the supply and distribution of water of Bizerte, water for the irrigated area of the basin, and water destined for transfer outside the Ichkeul basin). The reduced inflows to the dams (particularly in the seasons 2015/16 and 2016/17, which was 89 Mm3 and 124 Mm3, respectively) combined with an apparently irrepressible demand for water in the south meant almost no releases were made into Lake Ichkeul (2.4 Mm3 in 2015/16 and 1.7Mm3 in 2016/17, which were in fact leaks). This led to a dramatic imbalance in the lake’s ecosystem (Ben Fraj et al., 2019). Ichthyofauna production in the lake has dropped drastically (from an average of 158 tons in 1962–1994 to an average of 77 tons in 1995–2020), which coincided with the dam construction and increasing salinity (Sahbani et al., 2022).

Industrial waste, domestic sewage as well as farmland runoffs and effluents from fisheries and aquaculture practices threaten biodiversity values of the property (Sahbani et al., 2022). Organochlorine pesticides from adjacent agricultural areas as well as polycyclic aromatic hydrocarbons have been reported in lake sediments, with seasonal fluctuations according to changes in the hydrological regimes (Ben Salem et al., 2017).

The high livestock load of the inhabitants (sheep and cattle) has contributed to the reduction of green grass especially during autumn. This activity can lead to contamination if there is a contagious disease, which can also influence the genetic character of buffalos (IUCN Consultation, 2025).