Challenges and priorities for the conservation of the Vulnerable Atlantic humpback dolphin (Sousa teuszii), with a case study from Namibe Province, Angola
Weir, C.R.; Van Waerebeek, K.; Jefferson, T.A.; Collins, T. (2010). Challenges and priorities for the conservation of the Vulnerable Atlantic humpback dolphin (Sousa teuszii), with a case study from Namibe Province, Angola. International Whaling Commission: Agadir. 17 pp.
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| Keywords |
Sousa teuszii (Kükenthal, 1892) [WoRMS]
Marine/Coastal |
| Author keywords |
ATLANTIC HUMPBACK DOLPHIN, CONSERVATION, MONITORING, INCIDENTAL CATCHES, ATLANTIC OCEAN, AFRICA |
| Authors | | Top |
- Weir, C.R.
- Van Waerebeek, K., more
- Jefferson, T.A.
- Collins, T.
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| Abstract |
Atlantic humpback dolphins (Sousa teuszii) are endemic to tropical coastal waters between Western Sahara and Angola, West Africa. They are classified as Vulnerable by the IUCN due to their restricted geographic range, low abundance and declining status. Seventy-one Atlantic humpback dolphin sightings were recorded along 55km of coast in Namibe Province, Angola, during two three-week periods in the summer and winter of 2008. Photo-identification documented 10 individuals, indicating low abundance of the Angola Management Stock. Most sightings (n=46, 65%) occurred in a restricted niche within 300m of shore rendering dolphins highly susceptible to anthropogenic impacts. Nearshore (<1km from the coast) anthropogenic activity was highest (4.8 fishing boats and 2.0 gillnets per km in sector 10) in the southernmost sectors of the study area where no dolphins were sighted. In Namibe Province, as throughout their range, bycatch (incidental capture) in gillnets is the greatest likely cause of mortality, with directed capture, habitat degradation and over-fishing also potential impacts. Other threats include marine pollution, climate change and anthropogenic sound. Low abundance, fragmentation of populations and low genetic variation may increase the vulnerability of the species to stochastic processes. Conservation challenges include a paucity of biological data, absence of education programmes, and widespread poverty amongst coastal communities which rely heavily on artisanal fisheries for subsistence. Recommended priorities for Atlantic humpback dolphin conservation include: (i) distribution and abundance surveys; (ii) bycatch monitoring programmes; (iii) awareness schemes; (iv) protected areas where healthy populations remain; and (iv) reduction/elimination of nearshore gillnet use within core habitat. |
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