What does climate change mean for the future of fishing and aquaculture in Australia?

For people working in Australia’s seafood industry, climate change isn’t something that is happening somewhere else or sometime in the future. Ocean temperatures are changing, marine heatwaves are becoming more common, and the fish and other species we rely on are responding.

A study led by CSIRO researcher Dr Stephanie Brodie, has mapped climate change risk across Australia’s entire marine estate, from the Torres Strait to the waters around Macquarie Island.

The researchers looked at a range of changes that could affect seafood production, including warming oceans, marine heatwaves, ocean acidification, changing currents and productivity, and changes in rainfall and extreme heat.

So, what does this mean for fishing?

The study found that every part of Australia’s marine estate is exposed to some form of climate change, but the level of exposure varies from place to place.

Northern Australia, the Great Barrier Reef and Torres Strait are among the areas expected to experience some of the greatest changes. Other areas, including parts of the Southern Ocean, are expected to experience less exposure to some climate hazards.

One of the biggest concerns is marine heatwaves.

Under a future where global temperatures reach 3°C above pre-industrial levels, the researchers estimate that heatwave conditions could last for an additional 237 days per year on average across Australia’s marine estate.

That doesn’t mean every fishing ground will be in a heatwave for 237 days. It means that, across the country, conditions that we currently consider extreme could become much more common and persistent.

The study also found that the amount of biomass available to fisheries is likely to decrease as warming increases. Across Australia’s marine estate, the average decline is estimated at around 2% under 1.5°C warming and 12% under 3°C warming, with some areas potentially experiencing much larger declines.

For a fisherman, these changes could mean different species in familiar fishing grounds, changes in when and where fish are available, lesspredictable seasons, and greater pressure on the businesses and communities that depend on fishing.

Importantly, the researchers aren’t saying that the future of Australian fishing is already decided.

Instead, this assessment gives us information that can help fisheries, industry and governments prepare for the changes ahead.

There are already examples of this happening across Australia. Fishers and aquaculture operators are adapting by changing where and when they operate, diversifying the species they target or farm, developing new markets and using better forecasts to plan around changing conditions. Check out Sea Change Australia’s Adaptation Stories for more examples.

The researchers identify three broad ways we can respond:

• Reduce exposure – for example, changing where or when fishing occurs when conditions are unfavourable.
• Reduce sensitivity – for example, diversifying species, markets or income sources.
• Build adaptive capacity – making fisheries management more flexible so it can respond as conditions change.

At Sea Change Australia, we work with seafood communities to understand what climate change means for the people who depend on the ocean and, importantly, what we can do about it.

Research like this helps put individual experiences of changing conditions into a much bigger picture. It can help us understand where the greatest challenges are likely to occur and where we need to focus adaptation efforts.

The full study, Climate Vulnerability of Australian Seafood Systems: A National Assessment of Exposure and Adaptive Capacity, is open access in Fisheries Oceanography.