Long-term soundscape monitoring in the Ross Sea and its marine protected area

Abstract

The Ross Sea is one of the most isolated and pristine environments on the planet but is also home to a commercial fishery for Antarctic toothfish. In 2017, the world's largest marine protected area (MPA) was established here, covering some 1.55 million square kilometers of water. As part of a New Zealand program that aims to establish the conservation value of the Ross Sea region MPA, we deployed three passive acoustic recorders to study the seasonal occurrence of sperm whales and understand ecological connectivity between toothfish and sperm whales. Our study also presented an opportunity to more broadly study the soundscape of the Ross Sea and its changes under climate variability. The moorings were deployed in February 2018 and refurbished in February 2019. Ambient noise levels were measured to investigate their variation throughout the year and among locations. Preliminary data show the presence of baleen and sperm whales, as well as odontocetes and leopard seals. We outline plans for using the acoustic information collected in the next five years of this project to understand how climate variability and change affect the soundscape of the region and provide information on key predators in the region.