New records of Atlantic humpback dolphin in Guinea, Nigeria, Cameroon and Togo underscore fisheries pressure and generalised marine bushmeat demand [article]

Koen Van Waerebeek, Michael Uwagbae, Gabriel Segniagbeto, Idrissa L. Bamy, Isidore Ayissi
2015 bioRxiv   pre-print
In northern Guinea, we sighted two groups of Sousa teuszii (n=25; n=40 dolphins) off the Tristao Islands during exploratory small-boat surveys in 2011-12. Based on these and recent (2013) observations in the contiguous Rio Nunez estuary, we propose a single 'Guineas stock', combining the former 'Canal do Jeba-Bijagos' and South Guinea stocks. Significant mortality of S. teuszii from fisheries interactions is widely recognised however not quantifiable as monitoring effort is sporadic. In Guinea,
more » ... catches were documented in 2002 (n=1) and in 2011-12 (n=5). Landed specimens were recorded in Cameroon (n=2) and Nigeria (n=2). All individuals were killed in small-scale coastal fisheries, presumably as accidental net entanglements, though directed takes cannot be excluded. All landed dolphins were butchered for human consumption (marine bushmeat). Nigerian fishers indicated also an alternative use as shark bait. If local markets in cetacean bushmeat and bait develop, as in Ghana, that will exacerbate pressures by encouraging directed takes. Catch records in Nigeria and sightings in Togo authenticate both nations as (long-suspected) range states for S. teuszii, a belated documenting of the primary, historical distribution. The Gulf of Guinea stock ('Cameroon dolphins') extends at least from Togo to southern Cameroon, and probably into Equatorial Guinea. However, rare sightings of small groups point to remnant, not thriving, dolphin communities. We anticipate de novo distribution gaps emerging and consolidating, following decades of fisheries interactions and creeping encroachment on once pristine coastal habitat. Developed coastlines in Ghana and Cote d'Ivoire devoid of records may already constitute such gaps. As the lack or scarcity of records warn about formidable challenges to the long-term survival of S. teuszii, innovative, workable protection measures are needed, soonest. We recommend the implementation of several new border-straddling marine protected areas (cf. Saloum Delta-Niumi National Park Complex) which could bring forth a major conservation effect. Binational involvement bears obvious advantages, from sharing responsibilities and allowing for larger protected areas. Suggested dolphin sanctuary examples could include MPAs straddling borders between Cameroon/Equatorial Guinea and Guinea-Bissau/Guinea-Conakry.
doi:10.1101/035337 fatcat:hkq7cg25grevzhv7hciya72nje