06 March 2014

Notes from The Gambia - strandings & sightings

Stranded bottlenose dolphin  and a wake of vultures, Gunjur.

Waiting on the south bank of the Gambia for my research permit to be issued some weeks ago, I tried to make the best use of my time by visiting fish landing sites and interviewing fishermen about sawfishes and shark landings. On February 15th I happened upon a freshly-stranded bottlenose dolphin on the beach between Kartong and Gunjur. It was an adult male dolphin, some 3.25 m in length and with no externally visible signs as to cause of death. Having recorded some basic data from the stranded animal, which I passed on to the Gambian Department of Parks and Wildlife Management (DPWM), I decided to collate the available data on other strandings I knew about in Gambian waters. DPWM research staff were able to add another record to the database - a dwarf sperm whale (Kogia sima). This is a rare species worldwide, known mainly from strandings, and has been previously been reported from Senegalese waters but not, to my knowledge, from The Gambia.
Dwarf sperm whale. Photo by Amie Touray, DPWM.

Strandings recording kits, which include recording forms, tape measures, clipboards and basic species identification guides, have been left with staff in Niumi National Park and at DPWM's Abuko office, in the hope that more strandings will be recorded in the future, providing greater insight into the species present in Gambian waters and any threats they may face there.

Vessel-based surveys over three weeks resulted in a single sighting - a group of six Atlantic humpback dolphins on the north end of Jinack Island, in Senegalese waters! Rough seas prevented the close approaches needed to take photographs that could be used to identify individual dolphins. Nonetheless, every sighting of this little-studied species provides valuable information on their distribution throughout West African waters. From discussions with dolphin-watching tour operators, it seems that the bottlenose dolphins regularly sighted in the River Gambia may be somewhat dispersed at this time of year, and can be more reliably found in the river during the rainy season.

An Atlantic humpback dolphin in choppy seas off Jinack Island.

This research is funded by the Mohammed Bin Zayed Species Conservation Fund and carried out under a research permit issued by the Gambian Department of Parks and Wildlife Management.Many thanks to Lamin Sanyang, Sarjo Manneh and the other rangers in Niumi National Park and to Mawdo Jallow at DPWM.

No comments: