What’s behind the recent shark incidents on Sydney’s Northern Beaches - and what it means for our oceans
In recent days, Sydney’s Northern Beaches and harbour waters have been at the centre of public attention following a cluster of shark-related incidents, including several unprovoked bites and multiple confirmed sightings. Beach closures and safety warnings have understandably sparked fear, concern and a lot of questions within our coastal communities.
At Living Ocean, our role is to help people understand what’s happening beneath the surface - using science, context and long-term ecological thinking - while also connecting individual events like these to broader changes unfolding in our oceans, including climate change.
What Happened?
Over a short 48-hour period, multiple shark encounters were reported across the NSW east coast, including at Sydney’s Northern Beaches. Several beaches were temporarily closed as lifeguards and authorities responded to active sightings.
Importantly, these incidents occurred following significant rainfall and storm activity, which dramatically changed coastal water conditions - particularly in estuaries, harbour entrances and nearshore zones.
The science behind shark behaviour
While shark encounters are confronting, they are rarely random. Several well-understood environmental factors help explain why sharks were closer to shore at this time.
1. Murky Water and Heavy Rainfall
Recent rainfall caused increased run-off into coastal waters, making conditions turbid and low-visibility. This kind of environment attracts baitfish and other prey species, which in turn draws larger predators.
Bull sharks - a species commonly involved in near-shore incidents - are particularly comfortable in murky and brackish water. They rely less on vision and more on sensory cues such as sound and electrical signals, which can increase the risk of mistaken identity in poor visibility conditions.
2. Warmer Waters and Longer Seasons
Over the longer term, warming ocean temperatures are influencing when and where sharks are active. Research along Australia’s east coast shows that species like bull sharks are staying further south, and for longer periods, as water temperatures remain warmer later into the year.
This doesn’t mean sharks are becoming more aggressive but it does mean that the window of overlap between humans and sharks is expanding, simply because the environmental conditions that support shark activity are persisting for longer.
3. Shark Bites Remain Rare
Despite heightened media coverage, shark bite incidents remain statistically rare. Most interactions are cases of mistaken identity, and the overall risk to water users remains low when safety advice and closures are followed.
Why This Matters to Living Ocean
For Living Ocean, these events are not just about sharks - they are about ecosystems under pressure.
The same environmental changes influencing shark behaviour are also affecting whales, dolphins and entire marine food webs.
Our ongoing research into whale movements, acoustic environments and climate impacts shows that warming waters and shifting currents are already changing:
where whales migrate
where they feed and breed
how they use sound to navigate and communicate
These changes ripple through the ocean system. When prey species move, predators follow. When temperatures shift, ecosystems reorganise. Shark encounters, whale strandings, altered migration timing - these are not isolated issues. They are all signals of a rapidly changing ocean.
By studying and monitoring these patterns, Living Ocean aims to build understanding that supports coexistence, conservation and informed decision-making - rather than fear-based responses.
Staying Safe in the Water
While sharks are a natural and important part of healthy oceans, there are steps we can all take to reduce risk:
Avoid swimming or surfing in murky water, especially after heavy rain
Heed beach closures and swim between the flags
Stay informed using local safety updates and shark-monitoring tools
A Bigger Picture
Shark encounters remind us that the ocean is not static - it is dynamic, powerful and deeply interconnected. By investing in science, supporting marine research, and addressing the root causes of ocean change, particularly climate change, we can protect both people and marine life.
To learn more about how Living Ocean is studying whales, ocean soundscapes and climate impacts, explore our latest research update here.