Kia ora MARMAM community,

My colleagues and I are very happy to share the publication of our new paper:

‘Dredging activity in a highly urbanised estuary did not affect the long-term occurrence of Indo-Pacific bottlenose dolphins and long-nosed fur seals’ in Marine Pollution Bulletin.

Citation: M. I. Bossley, A. Steiner, G. J. Parra, F. Saltré and K. J. Peters (2022). Dredging activity in a highly urbanized estuary did not affect the long-term occurrence of Indo-Pacific bottlenose dolphins and long-nosed fur seals. Marine Pollution Bulletin 114183

Abstract: Dredging is an excavation activity used worldwide in marine and freshwater environments to create, deepen, and maintain waterways, harbours, channels, locks, docks, berths, river entrances, and approaches to ports and boat ramps. However, dredging impacts on marine life, including marine mammals (cetaceans, pinnipeds, and sirenians), remain largely unknown. Here we quantified the effect of dredging operations in 2005 and 2019 on the occurrence of Indo-Pacific bottlenose dolphins (Tursiops aduncus) and long-nosed fur seals (Arctocephalus forsteri) in the Port River estuary, a highly urbanized estuary in Adelaide, South Australia. We applied generalised linear models to two long-term sighting datasets (dolphins: 1992–2020, fur seals: 2010–2020), to analyse changes in sighting rates as a function of dredging operations, season, rainfall, and sea surface temperature. We showed that the fluctuations in both dolphin and fur seal occurrences were not correlated with dredging operations, whereas sea surface temperature and season were stronger predictors of both species sighting rates (with seals more prevalent during the colder months, and dolphins in summer). Given the highly industrial environment of the Port River estuary, it is possible that animals in this area are habituated to high noise levels and therefore were not disturbed by dredging operations. Future research would benefit from analysing short-term effects of dredging operations on behaviour, movement patterns and habitat use to determine effects of possible habitat alteration caused by dredging.

Available open-access at https://www.sciencedirect.com/science/article/pii/S0025326X22008657

Ngā mihi,

Katharina

Katharina J. Peters, PhD

Postdoctoral Researcher

Te Kura Aronukurangi | School of Earth and Environment

Te Whare Wānanga o Waitaha | University of Canterbury

Ōtautahi, Aotearoa | Christchurch, NZ