Cetacean strandings on the Scottish coast: coastal accessibility factors lead to underreporting

Sammanfattning

Introduction Cetaceans are abundant in the waters surrounding Scotland. These animals are occasionally found stranded along the coastline, and data recording the locations of these stranding events has been collected over the past several decades. There are many factors which may influence the location in which an animal is reported to have stranded. Some of these factors are environmental and influence the location of a stranding. Others relate to human activity and influence the likelihood of the event being reported. This study examines whether stranding reports are influenced by human accessibility, thereby leading to an incomplete understanding of the true prevalence of strandings. Research aims Three central research questions are posed, exploring whether areas with limited coastal access may have underreported strandings. The questions relate to whether the frequency of reported strandings is impacted by: human population density, road networks, cliff height. Methods Each hypothesis is initially examined using visual data analysis to compare maps of stranding locations with the variables of interest. Geographically weighted regression modelling is then carried out with various combinations of the variables. The results of each model run are examined to determine which combination of variables best describes the stranding locations. Key Findings The results suggest that there is a relationship between reported strandings and road network density. Areas with greater road access exhibit higher reported stranding densities, which may suggest that strandings are underreported in regions with poor road access. Human population density and – to a lesser extent – coastal topography also showed a visual relationship with strandings density. However, these factors did not significantly improve model fit. Therefore, the results of the study do not support a strong relationship between these factors and strandings density. Implications for Conservation These findings suggest that the current data on cetacean strandings may be subject to underreporting in areas with sparse road networks. Addressing this bias could improve the accuracy of stranding records, leading to a more comprehensive understanding. This can inform conservation strategies and aid efforts to protect these mammals and their habitats.