To focus expertise, wisdom and enthusiasm for the benefit of Moreton Bay
These are not occasional visitors passing through the Bay. Australian humpback dolphins (Sousa sahulensis) live here year-round, using Moreton Bay’s shallow coastal waters, channels, river mouths, feeding areas and sheltered habitats as part of their daily lives. In doing so, they also tell us something important about the health of the Bay itself.
A small resident population in a busy bay
The Moreton Bay population of Australian humpback dolphins is small, resident and vulnerable, with previous research estimating only 128–139 individuals. That makes every pressure on their habitat matter.
A recent study by Elizabeth Hawkins and Jessie Good from Dolphin Research Australia drew on 270 vessel-based surveys across Moreton Bay between 2014 and 2022, involving almost 1717 hours of field effort. Across that work, researchers encountered groups of Australian humpback dolphins on 390 occasions, using those sightings to map where dolphins are most often recorded — and where those areas overlap with human pressures across the Bay.
The message is clear: the challenge is not one single threat. It is the combined pressure of many threats occurring in the same places dolphins continue to use.
Where dolphin habitat and human pressure overlap
The study identified 12 key human-related threats to Australian humpback dolphins in Moreton Bay. More than half were ranked as high risk. Pathogens, pollution, habitat degradation and climate change were identified as the highest-ranked threats in terms of consequence, while vessel traffic and illegal provisioning — hand-feeding dolphins — had the highest likelihood scores.
That matters because Australian humpback dolphins in Moreton Bay show strong site fidelity. They are not simply moving away from pressured areas. Some of their core habitats overlap with parts of the Bay where vessel traffic, fishing activity, pollution, habitat degradation, coastal development and other pressures are also concentrated.
In other words, some of the places most important to dolphins are also some of the places where human activity is most intense.
The study’s spatial analysis found exposure hotspots in the northern, western and southern regions of Moreton Bay, with the largest hotspot located in the western Bay near the Port of Brisbane. It also found that 72.5% of core exposure hotspot areas occurred in General Use zones of the Moreton Bay Marine Park — the zone type with the lowest level of protection.
Why this matters for the Marine Park review
This is one of the most important findings for the current State Government review of the Moreton Bay Marine Park, which is now in its information-gathering phase. If threatened species are spending time in places where cumulative risk is high, then protection needs to be designed around the places animals actually use — not simply around lines on an existing zoning map.
The Australian humpback dolphin is listed as Vulnerable under Australia’s national environment law. In Moreton Bay, its vulnerability is intensified by a small resident population, low reproductive output, strong habitat dependence and growing pressure from one of Australia’s fastest-growing urban regions.
The good news is that research like this gives managers, decision-makers and the community better tools. It helps identify where action should be prioritised: improving water quality, reducing pollutant loads, managing vessel disturbance, preventing illegal feeding, reducing fishing-gear interactions, monitoring development impacts and considering dolphin-specific protections in core habitat areas.
Turning affection into stewardship
Everyone loves seeing dolphins in the wild. They stop us in our tracks and remind us why Moreton Bay matters. Around the Bay, groups such as Bribie Island Dolphin Sightings give everyone a way to share that excitement and help keep local dolphins visible and valued.
Curated community observations can support formal survey work, while also building awareness and encouraging stewardship. They can turn people’s natural affection for dolphins into a stronger sense of responsibility for the waters these animals depend on.
Moreton Bay’s cultural, natural and social values are deeply connected. The Bay supports wildlife, livelihoods, recreation, research, tourism and community identity. But those values depend on a healthy living system.
The Australian humpback dolphin gives us a powerful reminder that conservation is not abstract. It is about the real places animals need, the real pressures they face, and the real decisions we make.
On Endangered Species Day, the question is not simply whether we care about threatened species. It is whether we are prepared to protect the places they depend on.
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Help The Moreton Bay Foundation continue its vital evidence-based advocacy work. Your donation will support a collaborative, science-led effort to protect and restore one of Australia’s most valuable coastal and marine ecosystems.