The slender-snouted crocodile is listed as “Critically Endangered” due to exploitation, habitat alteration, human encroachment, invasive species, and population reductions of 50-80%.
In 1996, there was not enough information on the Slender-snouted Crocodile. Some research in the early 1990’s suggested that slender-snouted crocodiles were severely depleted in West Africa, while a separate study in 2003 indicated that they were quite abundant in some parts of Gabon. As such, it was last assessed as Data Deficient on the 1996 International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species.
Since that time, particularly in the last six years, sufficient information has been collected to review its status. As such, an updated assessment was the highest priority recommendation for this species in the 2010 IUCN SSC Crocodile Specialist Group Action Plan update.
The two regions, West and Central Africa, are completely isolated from each other underpinning the impending species split in this taxon. Central African habitats and populations do not seem to be fragmented despite some evidence for genetic isolation between major basins. In contrast, West African populations are highly fragmented due to a combination of severely fragmented forest habitats and the geology of the region and species-specific habitat use. For example, most major forested waterways throughout West Africa, especially in the Upper Guinea forest region, run north to south and show virtually no longitudinal communication except through the ocean which does not seem to be frequented by the slender-snouted Crocodile.
The slender-snouted Crocodile, particularly throughout West Africa, is incredibly shy and susceptible to human disturbance. As human populations throughout its distribution grow and occupy what were previously gallery forests and other forested wetland habitats this species is pushed out or hunted to local extinctions. In West Africa the extent of occurrence in the north of this species range has already declined drastically due to aridification and human settlement. It is projected that this species will likely be lost from the non-true forested areas, such as the wooded, gallery savanna areas in the north of its West African range in the next 10–20 years if it currently still exists in these northern extremes. Additionally, surveys prior to 2005 already suggested that the slender-snouted Crocodile may no longer occur in the Lake Mweru basin or throughout Lake Tanganyika. While very little historic survey data exists, that which does and can be compared to contemporary surveys show that populations are declining.
Based on known extensive trade in crocodile skins and other products, as well as habitat alteration and human encroachment since 1938, the slender-snouted crocodile meets the criteria for listing as Critically Endangered as it is inferred to have undergone a past population reduction of between 50-80% based on direct observation, loss of range and suitable habitat, direct exploitation and the impacts of introduced species. The reduction is closer to 50–60% for Central Africa and 70–90% for West Africa.