How long can the world sustain the current level of commercial and recreational fishing?

A vast majority of Australian households have seafood meals throughout the year.

Last year fresh seafood accounted for 49 per cent of all fish consumed, 26 per cent was canned and 25 per cent frozen.

According to the Dept. of Agriculture Australia has the world’s third largest Exclusive Economic Zone. However, the low productivity of our marine waters limits wild capture fisheries production. 

This meant that by 2015 an estimated 70 per cent of the seafood we consumed was imported from other fisheries around the world.

In 2016 the United Nations expected fish stocks in oceans and inland waters to significantly contribute to feeding a global population predicted to reach 9.7 billion by 2050 – even though at least 31.4 percent of fish stocks were estimated as fished at a biologically unsustainable level and therefore overfished and, there has been a general decline in global fish take since 1996. [Food and Agricultural Organisation of the United Nations, 2016 The State of the World’s Fisheries and Aquaculture]

Since then there have been reports that competition with fishing fleets for the remaining Chinook salmon has led to a resident population of Orca experiencing sustained near starvation and studies are now showing that in human-dominated marine ecosystems loss of populations and species is occurring.

Despite the global situation Australians are still being encouraged to eat more seafood, but how long can this continue?

In 2018 another study was published which looked at ocean processes over the next 282 years and this study predicts that the global fish catch will continue its current decline.

Phys Org, 19 April 2018:

Climate change is rapidly warming the Earth and altering ecosystems on land and at sea that produce our food. In the oceans, most added heat from climate warming is still near the surface and will take centuries to work down into deeper waters. But as this happens, it will change ocean circulation patterns and make ocean food chains less productive.

In a recent study, I worked with colleagues from five universities and laboratories to examine how climate warming out to the year 2300 could affect marine ecosystems and global fisheries. We wanted to know how sustained warming would change the supply of key nutrients that support tiny plankton, which in turn are food for fish.

We found that warming on this scale would alter key factors that drive marine ecosystems, including winds, water temperatures, sea ice cover and ocean circulation. The resulting disruptions would transfer nutrients from surface waters down into the deep ocean, leaving less at the surface to support plankton growth.

As marine ecosystems become increasingly nutrient-starved over time, we estimate global fish catch could be reduced 20 percent by 2300, and by nearly 60 percent across the North Atlantic. This would be an enormous reduction in a key food source for millions of people.