Broad-scale impacts of coastal mega-infrastructure project on obligatory inshore delphinids: A cautionary tale from Hong Kong.

Inshore marine habitats experience considerable anthropogenic pressure, as this is where many adverse effects of human activities concentrate. In the rapidly-changing seascape of the Anthropocene, Hong Kong waters at the heart of world's fastest developing coastal region can serve as a preview-window into coastal seas of the future, with ever-growing anthropogenic footprint. Here, we quantify how large-scale coastal infrastructure projects can affect obligatory inshore cetaceans, bringing about population-level consequences that may compromise their long-term demographic viability. As a case in point, we look at the construction of world's longest sea crossing system and broad-scale demographic, social and spatial responses it has caused in a shallow-water delphinid, the Indo-Pacific humpback dolphin (Sousa chinensis). Soon after the infrastructure project began, dolphins markedly altered their home range near construction sites such that these waters no longer functioned as dolphin core areas despite the apparent presence of prey, indicating that anthropogenic impacts outweighed foraging benefits. The contraction of key habitats has in turn led individuals to interact over spatially more constricted area, reshaping their group dynamics and social network. Although there was no apparent decline in dolphin numbers that could be detected with mark-recapture estimates, adult survival rates decreased drastically from 0.960 to 0.904, the lowest estimate for these animals anywhere across the region to date, notably below the previously estimated demographic threshold of their long-term persistence (0.955). It is apparent that during an advanced stage of this coastal infrastructure project, dolphins were under a major anthropogenic pressure that, if sustained, could be detrimental to their long-term persistence as a viable demographic unit. As effective conservation of species and habitats depends on informed management decisions, this study offers a valuable lesson in environmental risk assessment, underscoring the implications of human-induced rapid environmental change on obligatory inshore delphinids-sentinels of coastal habitats that are increasingly degraded in fast-changing coastal seas.

The role of African buffalo in the epidemiology of foot-and-mouth disease in sympatric cattle and buffalo populations in Kenya.

Quantitative knowledge on the contribution of African buffalo to the epidemiology of foot-and-mouth disease virus (FMDV) in East Africa is lacking, and this information is essential for the design of control programs in the region. The objective of this study was to investigate the epidemiology of FMDV in buffalo, including the role of buffalo in the circulation of FMDV in livestock populations. We collected blood and oropharyngeal fluids from 92 wild buffalo and 98 sympatric cattle in central Kenya and sequenced the virus' VP1 coding region. We show that FMDV has a high seroprevalence in buffalo (~77%) and targeted cattle (~93%). In addition, we recovered 80 FMDV sequences from buffalo, all of which were serotype SAT1 and SAT2, and four serotype O and A sequences from sympatric cattle. Notably, six individual buffalo were co-infected with both SAT1 and SAT2. Amongst sympatric buffalo and cattle, the fact that no SAT1 or 2 sequences were found in cattle suggests that transmission of FMDV from buffalo to sympatric cattle is rare. Similarly, there was no evidence that serotype O and A sequences found in cattle were transmitted to buffalo. However, viruses from FMDV outbreaks in cattle elsewhere in Kenya were closely related to SAT1 and SAT2 viruses found in buffalo in this study, suggesting that FMDV in cattle and buffalo do not constitute independently evolving populations. We also show that fine-scale geographic features, such as rivers, influence the circulation of FMDV in buffalo and that social segregation amongst sympatric herds may limit between-herd transmission. These results significantly advance our understanding of the ecology and molecular epidemiology of FMDV at wildlife-livestock interfaces in East Africa and will help to inform the design of control and surveillance strategies for this disease in the region.