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 Río Nuñez estuary, we propose a single 'Guineas stock', combining the former 'Rio do Jêba-Bijagos' and South Guinea stocks.

The clinical and epidemiological features of tattoo skin disease (TSD), caused by cetacean poxviruses, are reported in 257 common bottlenose dolphins (Tursiops truncatus) held in 31 facilities in the USA and Europe. Photographs and biological data of 146 females and 111 males were analyzed. Dolphins were classified into three age classes (0-3; 4-8; over 9 years), approximating the life stages of 'calves and young juveniles', 'juveniles and sub-adults' and 'adults'. The youngest dolphins with tattoos were 14 and 15 months old. Minimal TSD persistence varied between 4 and 65 months in 30 dolphins and was over 22 months in those with very large lesions (> 115 mm). In 2012-2014, 20.6% of the 257 dolphins had TSD. Prevalence varied between facilities from 5.6% (n= 18) to 60% (n= 20), possibly reflecting variation in environmental conditions. Prevalence was significantly higher in males (31.5%) than in females (12.3%), a pattern which departs from that observed in free-ranging Delphinidae where there is no gender bias. As with free-ranging Delphinidae, TSD prevalence in captive females varied with age category, being the highest in the 4 to 8 year old. By contrast, prevalence levels in males were high in all age classes. Prevalence of very large tattoos was also higher in males (28.6%, n= 35) than in females (11.1%, n= 18). Combined, these data suggest that captive male T. truncatus are more vulnerable to TSD than females possibly because of differences in immune response and because males may be more susceptible to captivity-related stress than females.

Small-boat and shore-based surveys in 2017 confirm that Atlantic humpback (Sousa teuszii) and common bottlenose dolphins (Tursiops truncatus) are resident in shallow neritic waters surrounding the protected MPA Tristao Islands in northern Guinea. Inshore-type T. truncatus were encountered also between Conakry and Kayar. First documented in 2012, dolphin bycatches in local fisheries continue to occur. The frequency of beach-cast remains suggests a significant conservation issue. Both multi- and monofilament gillnets are widely deployed, but it remains unclear which gear is the main cause of mortality. Forensic evidence shows that captured dolphins are often utilized for local consumption. Marine bushmeat of cetaceans is documented in many coastal nations in West and Central Africa. In Tristao Islands their use is synchronous with and thought related to declining fish stocks. Significant anthropogenic mortality relative to their low abundance, besides suspected pressures such as prey competition with fisheries and habitat deterioration from coastal development, raise concern for the future of coastal dolphins, in particular endangered S. teuszii, even in this formally protected MPA. Conservation measures need to be re-evaluated for improved efficiency while surveys to monitor trends should be annual.