Tree species include Acacia raddiana , Balanites aegyptiaca , Maerva crassifolia and Capparis decidua . These are the most northerly stands of mangrove on the eastern shore of the Atlantic and represent relicts from the period when the coastal oueds carried fresh water from the Sahara. At least 108 bird species have been recorded, representing both Palaearctic and Afrotropical realms. Wintering shorebirds number over three million and include hundreds of thousands of black tern Chlidonias nigra and flamingo Phoenocopterus ruber , ringed plover Charadrius hiaticula , grey plover Pluvialis squatarola , knot Calidris canutus , redshank Tringa totanus and bar-tailed godwit Limosa lapponica . The area is one of the most important wintering grounds for European spoonbill Platalea leucorodia leucorodia .
Fish are one of the most important components of the fauna.
The local people, the Imraguen or Amrig, relate many of their customs to the natural environment. Even their name literally means 'the ones who gather life'. Imraguen tribesmen still maintain their age-old life styles, based almost exclusively on harvesting the migratory fish populations using traditional sailing boats. Fishing techniques, unchanged since first recorded by 15th century Portuguese explorers, include the unique symbiotic collaboration with wild dolphins to catch schools of grey mullet. The 500 or so Imraguen tribesmen live in seven villages within the park, but are dependent on water supplies collected outside the boundary.