Pinniped hearing tests reveal noise sensitivity

Researchers in Australia have evaluated the auditory capabilities of seals and sea lions to explore how artificial sounds affect these marine creatures. The peer-reviewed investigation aimed to establish baseline acoustic data following concerns over rising noise pollution.

Staff members at Taronga Zoo in Sydney conditioned two fur seals alongside two sea lions to participate in hearing trials. During the sessions, the animals were taught to press a paddle whenever an acoustic tone was played, receiving fish rewards for accurate responses.

The gathered data indicated that the pinnipeds exhibited the greatest sensitivity to tones near 3.2 kilohertz. Lead scientist Christine Erbe, a professor at Curtin University, explained that determining what sounds an animal can perceive is essential before evaluating potential acoustic disruption.

According to Erbe, establishing this baseline enables scientists to examine the consequences of sounds produced by vessels, airplanes, and coastal building projects. She emphasized that the findings hold special value for the endangered Australian sea lion, a species numbering roughly 12,000 individuals that depends on acoustic cues to navigate, locate prey, communicate, and notice danger.

Man-made noise is recognized for harming wildlife, with earlier studies noting worldwide behavioral changes in birds, including disruptions to mating calls and foraging. Behavioral biologist Benjamin Pitcher from Taronga Conservation Society Australia noted that the pinniped results offer practical value for conservation strategies.

Pitcher indicated that these conclusions can support assessments of environmental impacts and guide noise regulation policies as maritime shipping, offshore operations, and coastal work grow. He added that while in-air auditory thresholds are now documented, future investigations will focus on underwater impacts.