Banc d'Arguin National Park

Reduction in catch following overfishing by external poachers made local fishermen use unsustainable fishing methods (UNEP-WCMC, 2012). Illegal fishing within PNBA strongly reduced by 2009, owing to agreements with local Imraguen fishermen, improved patrolling capacity and an effective surveillance scheme. However, the results of maritime surveillance show that trawler pressure remains strong in the northern and southern parts of the PNBA and, on the other hand, that sail-lines represent an increasing internal pressure in 2022 and 2023 on fishery resources, particularly through the use of monofilament nets, prohibited by law (State Party of Mauritania, 2024). Artisanal fishing is becoming increasingly commercial, and the increasing number of non-Imraguen fishermen in the park, as well as the increasing targeted fishing of sharks and rays, which reaches up to an estimated 1,000 tonnes per year since 2014, are a significant concern (State Party of Mauritania, 2019, 2022, 2024). Catches of elasmobranchs outside the property, while showing a significant decrease, still remain high (from 13,000 tonnes in 2019 to less than 2,000 tonnes in 2023) (State Party of Mauritania, 2024). Fisheries also affect the Mediterranean Monk Seal (outside the site), reduce habitat, and abandoned nets cause seal and turtle mortality (IUCN, 2008; Hama et al., 2019). Increasing fishing practices and the still important catches of sharks and rays remain a real concern (UNESCO / IUCN Mission Report, 2014; Trégarot et al., 2018; Dia et al. 2023). The overexploitation of top predators can have serious impact on the trophic web, including on birds (Trégarot et al., 2018).

Fishing outside the PNBA further increases pressure on the marine resources around and inside the site. There are strong pressures from international (including European) fleets – in 2012, 334 foreign trawlers were licensed to fish in waters surrounding PNBA (UNEP-WCMC, 2012) and have continuously increased since then (Global Fishing Watch, 2020). Artisanal fishing catch in the immediate vicinity of the property has also increased by more than a factor of ten between 1994 and 2010. In addition the development of commercial fishing ports at Nouadhibou and Tanit (respectively 20 km NW and 50 km south of the PNBA), further accentuates pressure on the marine resources around and inside the site. The pollution of water by boats and the fishing gear wastes impact negatively the PNBA, leading for instance to sea turtles stranding events in the PNBA (Hama et al., 2019).

The external fishing effects on PNBA's food webs and ecosystems remain unclear as the importance of areas outside park for lifecycle stages of most fish is not known, however, significant impacts on the OUV of the property are likely according to the strong dependence of fisheries to the PNBA (UNESCO/IUCN, 2010; Meissa et al. 2018).

Agricultural runoff from the Senegal River only slightly affects the property given the distance and currents (UNESCO, 2008). The Taziast gold mine located 60 km from the site uses water from important underground watersheds connected to the park. Although water pollution may be limited as the mine is reported to use a closed water loop (State Party of Mauritania, 2019), there are concerns over the transport of mercury by wind (IUCN Consultation, 2025). Significant water pollution with high concentrations of cadmium as well as an unacceptable amount of plastic and other waste have been confirmed (UNESCO & IUCN, 2014; Salim & Abdulhalim, 2016; Trégarot et al., 2018). Plastic waste has increased due to the development of Chami, as well as coming from Mamghar and Nouadhibou. However, the most significant source of plastic pollution comes from the sea due to discarded fishing gear, bottles and buoys (IUCN Consultation, 2025). The disintegration into microplastics, when ingested by marine organisms, cause chemical and physical damage to a wide range of marine organisms representing different trophic levels (Hollman et al., 2013; Setälä et al., 2016). Between the villages of Teichott and R'Gueiba there is an enormous amount of plastic waste, coming from land sources as well as brought in directly from the ocean, which extends over several kilometres (Serrao, 2018; IUCN Consultation, 2025).

The 2014 UNESCO / IUCN mission encountered two rallies during its 7-day visit to the park, noting that the property is riddled with off-road tracks with no signage informing drivers that they are in a National Park. Tourism-related trash was also observed, and concern for increased beach tourism demand as the new city of Chami developed was also a concern (UNESCO & IUCN, 2014). The 2016 technical mission to PNBA provided updated information on ecotourism in the Park, and developed a set of recommendations to support local livelihoods through encouraging local infrastructure and training of women in the field of ecotourism (Salim and Abdulhalim, 2016). Between 2017 and 2018, the CSBA examined two requests for the installation of tourist infrastructure inside the PNBA: one concerning the construction of an airfield and the other the construction of a beach (Chami Beach). The CSBA issued an unfavorable opinion each time. This means that the PNBA is under strong pressure from tourism operators. Since tourism is still poorly developed in the PNBA, its impact on the local environment is therefore limited (Boide et al., 2018). However, over-frequentation during week-ends; additional pressure on fish populations by amateur fishing; degradation of coastal dunes due to non-organized 4x4 traffic and noise pollution affecting the avifauna; degradation of coastal vegetation; over-consumption of freshwater and the management of tourism waste (inexistant in the PNBA) are all additional pressures on the site that need to be controlled.

Three marine alien species were identified during a scientific survey around Ejewir (Serrao, 2018). The green alga Caulerpa taxifolia, a highly invasive species that could compete with local seagrass, was collected and fishermen reported finding it in their fishing nets, together with an invasive ascidian tunicate (Botrylloides diegensis). An unidentified red alga were also observed.

Ongoing climate change already impacts the PNBA (CSE, 2024). Landscape changes triggered by climate change may affect food webs and ecosystem functioning (IPCC, 2019). Sea level rise and erosion are modifying the flat and sandy coastlines and impact marine and terrestrial ecosystems (e.g. El-Hacen et al., 2018). Up to 70m of recent coastal retreat has been observed near Iwik (Trégarot et al., 2018). Areas rarely flooded before are at present flooded, frequently destroying breeding colonies of seabirds. A number of bird species, certain herbaceous species such as Stipagrostis and Heliothropium, as well as reptiles are highly sensitive to climatic hazards (CSE, 2024). For the local subspecies of Eurasian spoonbill, the threat is very high and park management has artificially raised their nesting sites on the island of Nair to provide refuge. Some areas, for example Neroumi island, have been flooded almost permanently. Submersion of islands and islets leads to the loss of suitable habitat areas for some species (IUCN Consultation, 2025). A decline in the reproductive success of the Eurasian spoonbill has been recorded in the past, which may be related to a rising sea level (UNESCO & IUCN, 2014), although in recent years a stabilisation has been observed (State Party of Mauritania, 2024). Climate change also impacts staging sites of migratory birds outside the PNBA (in the Arctic for instance), modifying their displacements and thus their presence in the PNBA (Rakhimberdiev et al., 2018). Worryingly and partially due to climate change, the total number of birds within the PNBA decreased from 2.3 to 2 million since 1980 (PNBA, 2018; Oudman et al. 2020). PNBA marine ecosystems crucially depend on climate-sensitive East Atlantic upwelling, wind and marine currents and water temperature, but the exact response of these parameters to future climate change is unknown. Coastal ecosystems play an important role of protection from marine storms and cyclones that could be limited in the future (Trégarot et al., 2018, Vousdoukas et al., 2020). In contrast, sea level rise creates new intertidal ecosystems on low-lying lands, that could be future hotspots of biodiversity (Trégarot et al., 2018). A breach made by the ocean in the dune cord has been observed at Bellaât (Cap Sainte-Anne) since 2013. This breach has created an important permanent lagoon which hosts a great biodiversity (reports by the Scientific Council of Banc d 'Arguin in State Party of Mauritania, 2019).