Coasts and oceans
Key Messages
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Coasts and oceans are interconnected natural systems that play a vital role in supporting biodiversity, regulating climate, and sustaining human livelihoods. Coasts are the dynamic zones where land meets the ocean, shaped by tides, waves, and weather. Oceans are vast bodies of saltwater that cover about 70% of the Earth's surface. Coasts and oceans provide essential resources such as fisheries, tourism, and coastal protection.
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Oceans play a vital role in regulating global climate systems, effectively mitigating the rate of warming on land and sea surfaces. Sea surface temperatures around Queensland, particularly in the Coral Sea and Gulf of Carpentaria, are key indicators of tropical cyclones and low formations on the east coast. Warmer than average sea surface temperatures favour the development of these weather systems which often bring flood-producing rainfall, and damaging wind and storm surges, particularly to coastal and near-coastal parts of Queensland. While recent change in mean sea level is not significant, sea level rise over the historical tide gauge record is discernible.
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Coastal hazards impact on both the natural environment and human settlements. Coastal erosion and storm tide inundation are part of normal coastal processes, albeit at the extreme end of natural fluctuations. For the natural environment, they are the high energy drivers of endless change which has formed the coast we see today. For human settlements however, we consider them destructive and a risk to life and property. Understanding the risks can improve decision-making for both management of the natural environment and new urban development and help build resilience for existing developments exposed to these hazards.
Key Facts
State
- Sea surface temperature
Oceans play a significant role in regulating global climate systems. Average sea surface temperatures have continued to increase over the past ten years. For the Coral Sea region, which is representative of conditions near Queensland, the average sea-surface temperature from 2014 to 2023 was the warmest on record.
- Southern Oscillation Index
La Niña conditions prevailed from late 2020 to early 2023, followed by El Niño from late 2023 through early 2024. La Niña often shifts tropical weather systems closer to Queensland, increasing the likelihood of above-average summer rainfall, floods and tropical cyclones. El Niño is usually, but not always, associated with below-average rainfall.
- Sea level
According to historical Queensland tide gauge records, Queensland’s sea levels are rising by 3.0 mm/year. This trend aligns with the global long-term trend.
- Storm tide inundation incidences
In the last five years, two major events, Severe Tropical Cyclone Megan and Tropical Cyclone Seth, caused significant storm tide inundations. Most notably, a new tidal channel cut through the northern end of Bribie Island, creating a new entrance to the Pumicestone Passage from Moreton Bay.
Pressure
- Coastal hazard erosion-prone area
Mainland beaches and coastlines from Cape York to Bundaberg remain in good condition. Coastlines across the state are dynamic. Within the Great Barrier Reef Region observed changes over recent years likely reflect natural variations in climatic and oceanic influences predominantly. However, sea-level rise is expected to increase erosion rates, recession and inundation in the coming decades.