Key Biodiversity Areas

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Sierra Leone River Estuary (6834)
Sierra Leone, Africa

Site overview


KBA status: confirmed
Year of last assessment: 2019
National site name: Sierra Leone River Estuary
Central coordinates: Latitude: 8.6167, Longitude: -13.0500
System: terrestrial, marine, freshwater
Elevation (m): 0 to 75
Area of KBA (km2): 558.23228
Protected area coverage (%): 75.84
KBA classification: Regional
Legacy site: Yes

Site details


Site description: This site is the drowned estuary of the Rokel or Seli river. It is bounded to the north by a coastal plain indented by creeks, and to the south by the mountainous Western Area peninsula. At the point of entry into the Atlantic Ocean, the estuary widens to about 11 km and abruptly deepens along its southern shore to form a natural harbour (the third-largest in the world). The estuary is lined by 110 ha of mud and sand foreshore, backed by mangrove, and 1,800 ha of intertidal mudflat and muddy sandflats. The predominant mangrove tree species are <I>Rhizophora</I> sp., <I>Avicennia africana</I>, <I>Laguncularia</I> sp. and <I>Conocarpus </I>sp., and these cover a total of 34,234 ha (19% of the total area of mangrove in Sierra Leone).
Rationale for qualifying as KBA: See Box for key species. A total of 36 wader species have been recorded in the estuary and numbers are known to exceed 20,000 regularly. This is one of the four major sites for wintering waders in the country. Concentrations are usually found along the banks of the Bunce river and Aberdeen Creek, where mangrove provides suitable roosting sites, as well as breeding habitat for such species as <I>Butorides striatus.</I> Less common migrant Palearctic waders (less than 500 individuals) found include <I>Arenaria interpres</I>, <I>Numenius arquata</I>, <I>Tringa stagnatilis </I>and<I> Calidris temminckii</I>.<P>Non-bird biodiversity: None known to BirdLife International.</P>
Manageability of the site: Site identified based on BirdLife International's Important Bird and Biodiversity Areas, under which manageability is strongly recommended but not explicitly documented
Delineation rationale: Digitized from national and continental scale maps of protected areas, lakes and wetlands.

Habitats


IUCN HabitatCoverage %Habitat detail
Wetlands(Inland)2
Artificial - Terrestrial2
Forest90
Marine Neritic2
Marine Intertidal3
Marine Coastal/Supratidal1

Threats


Summary of threats to biodiversity at KBA: There is no official protection for this site. However, there are legal restrictions against fishing activities by large trawlers. Only artisanal fishing by small (2–8 man) canoes with nets or fishing line is permitted. Legislation also exists on the size of the net mesh that can be used, but there is little enforcement. Mangroves along the banks and creeks are being cleared for small-scale farming and they are also cut down and sold for firewood. Dumping of untreated waste from industries in the Freetown area and oil spillage from tankers unloading at the main port threaten the wildlife in the estuary. Although threat levels are thought to be generally low at present, conservation action is needed.
Threat level 1Threat level 2Threat level 3Timing
Residential & commercial developmentHousing & urban areasOngoing

Additional information


References: Schwarz (1992), Taylor and Rose (1994), Tye and Tye (1987).
Contributors: Site identified based on Important Bird and Biodiversity Areas by the BirdLife International Partnership