Empirical Investigation of Noise Pollution from Vessel Traffic on Marine Biodiversity in the Bight of Biafra

Underwater noise generated by vessel traffic represents an increasingly recognised form of marine pollution with demonstrated effects on marine mammal communication, fish behaviour, and invertebrate physiology. This study empirically investigates the characteristics of underwater noise generated by commercial vessel traffic in the Bight of Biafra, with analysis of potential impacts on documented marine biodiversity in the region including Atlantic humpback dolphins and other cetaceans. An empirical measurement methodology was employed, using calibrated hydrophones deployed at six monitoring stations in the Bight of Biafra to record ambient noise levels before, during, and after periods of peak vessel traffic. Vessel traffic density data from automatic identification system records were integrated with acoustic measurements. Noise levels are characterised in terms of frequency, intensity, and spectral composition, and compared against established biological significance thresholds for key species of conservation concern. Results reveal that peak vessel traffic periods produce broadband noise levels exceeding the recommended threshold for cetacean behavioural disturbance at all six monitoring stations, with the highest levels recorded on shipping lanes between Calabar and Equatorial Guinea. A statistically significant positive correlation between vessel traffic density and ambient noise level is confirmed. The study contributes novel empirical acoustic data for this undermonitored region and fills a critical knowledge gap in Nigerian marine environmental monitoring. Keywords: underwater noise pollution, vessel traffic, Bight of Biafra, marine biodiversity, cetaceans