Scientist in Residence
A multidisciplinary approach to assess the impacts of anthropogenic noise on Australian fur seals (Arctocephalus pusillus doriferus): soundscape, behaviour, and stress hormone concentrations as key factors.
Dr Rachael Gray (University of Sydney), Dr Rebecca McIntosh (Phillip Island Nature Parks), Dr Isabelle Charrier (Universite de Paris-Saclay & CNRS)
Who am I?
Hi, I’m Jess Taylor. I’m doing my PhD at the University of Sydney, in collaboration with Phillip Island Nature Parks and the University of Paris-Saclay. My project is looking at the effects of human-generated (anthropogenic) noise on the Australian fur seal breeding colony at Seal Rocks. This project is supported by the Penguin Foundation, Holsworth Wildlife Research Endowment at the Ecological Society of Australia, and the Foundation for Australia’s Most Endangered Species (FAME).
Brief project description
Anthropogenic noise pollution has become a widespread issue in the world’s oceans, affecting many marine species. Little is known of its impact on Australian fur seals, but there is some evidence that loud boat noise can disrupt normal behaviour and vocal communication, which can negatively impact health and survival.
Seal Rocks is the largest Australian fur seal breeding colony and a key tourism destination. Visitation peaks during the pupping/breeding season, a time in which the colony is particularly vulnerable to disturbance. In addition, there are regular breaches of the minimum approach distances, which are 60 m for boats (with the exception of authorised tour and research vessels) and 260 m for jet-skis. Despite this, the level of noise produced by visitation and its impact on the colony remains unknown. The main aim of my project is therefore to determine the impact of anthropogenic noise, specifically boat noise, on the Seal Rocks colony, and to assess whether the current management strategy at the site is adequate.
To address this, we are taking a multidisciplinary approach to create an acoustic impact model of visitation at Seal Rocks. The model will be based on data from underwater acoustic and visual monitoring of boats approaching Seal Rocks, pup health, physiological indicators of stress, and behavioural response to controlled boat noise exposure. All data will be collected during high visitation (summer) and low visitation (autumn/winter) for two consecutive years to facilitate comparisons between season and between year.
The outcomes of my project will be communicated to key stakeholders to inform management regulations at Seal Rocks. In addition, the developed acoustic impact model will be adaptable to other Australian fur seal colonies, and to other seal and marine mammal species, with the goal of promoting best-practice guidelines for ecotourism at sensitive marine sites.
OBSERVATIONS FROM THE NOBBIES
What will I be doing?
For up to 10 days at a time in December and January, I will be stationed on the boardwalk at The Nobbies to record boats approaching Seal Rocks as part of the acoustic and visual monitoring aspect of my project. Every 15 minutes from 8:30-13:30, I will count the number and type (e.g., small, medium, large, jet-ski) of vessels around Seal Rocks, note their position using a long-distance rangefinder and map of Seal Rocks, and categorise their speed (e.g., stationary, slow, medium, fast) and direction.
Why is this important?
The data collected during these observations has a dual purpose. First, it will be used to validate the underwater acoustic recordings (which will be happening concurrently), by providing reference points in space and time. Second, by visually cataloguing and quantifying visitation at Seal Rocks, we can identify visitation hotspots. Then, when we’re assessing pup health and stress, we can see if and how this varies in parts of the colony with differing exposure to visitation.
Long-distance rangefinder: Vortex Razor HD 4000. Will be used to record the location of boats relative to the observer (me), then using the location of known landmarks, we can calculate the distance of boats from Seal Rocks. This particular rangefinder is necessary as it can detect ranges up to 3,658 m.
Spotting scope: Bushnell Spotting Scope (48x50). Will be used to observe behaviour of seals on Seal Rocks from The Nobbies.
Underwater passive acoustic recorders: JASON Highblue Signal Acquisition System. Up to four underwater soundrecorders will be positioned near Seal Rocks to continuously record boat noise and visitation for one month at a time.
Image by Holly Baird IG: @hollybaird79
For more information on minimum approach distances:
Victorian government marine mammal regulations are found here:
To see the detailed boundaries for the Victorian seal breeding colonies, view the “Victorian Government Gazette: No. S470 Thursday 21 November 2019” of the Wildlife Act 1975; Seal Rocks is on pg 9. https://www.reglii.com/aus/VGG/2019/VGG.2019.11.21.S470
Get in touch!
My twitter: @taylor_jessalyn
Sydney School of Veterinary Science
Web: https://www.sydney.edu.au/science/schools/sydney-school-of-veterinary-science.html | Twitter: @Sydney_Vet
These are raw sound clips we have collected with the underwater recorders during the testing phase.
Underwater images by Holly Baird IG: @hollybaird79