No abstract

Although published literature regarding the 5 species of marine turtle found along the continental African east coast has grown substantially over the last decades, a comprehensive synthesis of their status and ecology is lacking. Using a mixed methods approach, which combined an exhaustive literature review and expert elicitation, we assessed the distribution and magnitude of nesting, foraging areas, connectivity, and anthropogenic threats for these species in Somalia, Kenya, Tanzania, Mozambique, and South Africa. A complex pattern of nesting sites, foraging areas, and migration pathways emerged that identified areas of high importance in all 5 countries, although significant data gaps remain, especially for Somalia. Illegal take, bycatch, and loss of foraging and nesting habitat were identified as the most serious anthropogenic threats. Although these threats are broadly similar along most of the coast, robust data that enable quantification of the impacts are scarce. Experts identified regional strengths and opportunities, as well as impediments to turtle conservation. Topics such as legislation and enforcement, collaboration, local stakeholders, and funding are discussed, and future directions suggested. Given the projected growth in human population along the continental African east coast and expected accompanying development, anthropogenic pressures on turtle populations are set to increase. Stronger regional collaboration and coordination within conservation and research efforts are needed if current and future challenges are to be tackled effectively.

Monitoring of nesting beaches is often the only feasible and low-cost approach for assessing sea turtle populations. We investigated spatio-temporal patterns of sea turtle nesting activity monitored over  successive years in the Lamu archipelago, Kenya. Community-based patrols were conducted on  stretches of beach clustered in five major locations. A total of , nests were recorded: , (.%) green turtle Chelonia mydas nests,  (.%) hawksbill Eretmochelys imbricata nests,  (.%) olive ridley Lepidochelys olivacea nests and  (.%) unidentified nests. Nesting occurred year-round, increasing during March-July, when % of nests were recorded. A stable trend in mean annual nesting densities was observed in all locations. Mean clutch sizes were . ± SE  eggs (range -) for green turtles,  ± SE  eggs (range -) for hawksbill turtles, and  ± SE  eggs (range -) for olive ridley turtles. Curved carapace length for green turtles was - cm, and mean annual incubation duration was . ± SE . days. The mean incubation duration for green turtle nests differed significantly between months and seasons but not locations. The hatching success (pooled data) was .% (n = ,) and was higher for in situ nests (. ± SE .%) compared to relocated nests (. ± SE .%). The results highlight the important contribution of community-based monitoring in Kenya to sustaining the sea turtle populations of the Western Indian Ocean region.