29 December 2012

Searching for the elusive Sousa & the mythical sawfish – Part III.

The only archipelago in West Africa's coastal waters, shallow turquoise waters teeming with fish, only small-scale local fishing..... Guinea-Bissau and the Bijagos Islands sounded like a tropical paradise for coastal dolphins, and for several years I have been plotting a way to get there and find out for myself. Never mind the drug smuggling for which the islands are a hotspot; never mind the lack of development and the political instability which explain why so little research has been done here to-date.Guinea-Bissau had the potential to be a key habitat for Atlantic humpback dolphins, or Sousa, as they are often called. And I wanted to find out.

Sousa are a species of conservation concern, as I have mentioned in previous posts, because they live very close to the coast (often right in the surf zone) and are regularly caught in fishing nets. Any coastal development or pollution also directly affects this species, and throughout West Africa, numbers of Sousa are thought to be declining. This is a unique species, found only along Africa's west coast between Morocco in the north and Angola in the south. There is no estimate of the total population size or even of regional populations, so it is difficult to know just how endangered they are. Were this happening in Europe or North America, there would be outcry from conservation groups to protect this unique species, and government would be under pressure to put monitoring and conservation measures in place. But this is Africa, resources are limited, many species and habitats are under threat and no one has shouted loud enough about the little humpback dolphin

Bottlenose dolphins, Bijagos Archipelago. Photo by R. Leeney.
My plans for a month of dolphin surveys soon dissolved as the sawfish work took over. I managed one dedicated boat survey, around part of the Bijagos Archipelago, but that one survey told me all I needed to know. Two hours into the survey, three humpback dolphins surfaced a little way off from us. I scarcely believed my eyes but then there they were, again; the skipper shouting in agreement! With the bright sun behind them, the 'hump' below each dorsal fin was obvious. We never got close enough for photographs, but it was enough to confirm the presence of Sousa in this little-studied region.

Not-so-elusive, bottlenose dolphins also made several boisterous appearances, during that survey as well as on the trip back from the island of Orango, in the south of the Archipelago, to Bubaque. And while I wandered close to the harbour of Cacine, close to Guinea-Bissau's border with Guinea-Conakry, fishermen mending their nets on the bank of the Rio Cacine shouted 'golfinho' at me and pointed towards a group of bottlenose dolphins which were making their way upriver. I guess everyone in town knew what I was there for. 

Bottlenose dolphins in the River Buba. Photo by A. Torres.
I did manage to collect some data relating to dolphins from the interviews conducted with fishermen throughout the country. This gave me an insight into the attitudes of fishermen to dolphins. In many West African coastal nations, dolphins are seen as a source of food, but in Guinea-Bissau very few fishermen appeared to have this attitude. Some admitted that occasionally, dolphins get entangled in fishing nets, but this does not appear to happen on purpose. The costs to the fisherman - a day's fishing lost and considerable time spent repairing nets - seems to outweigh any gains. The dolphin is consumed in these cases, but seemingly more because it would be wasteful to discard it than out of any specific demand for dolphin meat. 

Guinea-Bissau is probably still a haven for coastal dolphins, relatively speaking, but change will come, eventually. Guinea-Bissau's communities are linked closely to their local environment and thus rely on healthy mangroves, rivers and seas for food, cultivation areas, protection from coastal erosion. What better a mascot for protecting these ecosystems than this most West African of dolphins, Sousa?

This work was funded by the Mohammed Bin Zayed Species Conservation Fund and facilitated by Noé Conservation.

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