<a href="https://www.greenlifestylemag.com.au/blogs/leon#">The Business of Green</a>

The Business of Green

Money matters in the green world, by Leon Gettler.

Climate change and fish


Credit: iStockphoto

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Climate change will have a massive impact on Australia's fishing industry which exports about $1.5 billion a year. Australia is unique in the global fishing market because we have the world's third largest fishing zone covering 11 million square kilometres and extending up to 200 nautical miles out to sea. There is enormous potential. And global warming could change all that.

Lately, we have had the CSIRO reporting that climate change is pushing fish from Queensland further south. The study found that 43 types of fish are now outside their normal range. Species on the move include rock flathead, tiger sharks and Queensland gropers. The problem is they have nowhere to go once they get to the tip of Tasmania. The study also found that up to 19 species of Tasmanian coastal fish have undergone serious declines.

The impact is also being felt in the oceans and the world's fish population because of ocean acidification (where CO2 increases in the atmosphere, dissolves into the oceans and results in acidification). Researchers have found that baby fish become easy meat for predators, and it's possibly caused by the world's oceans becoming more acidic due to CO2 fallout from human activity. The researchers found that as carbon levels rise and ocean water acidifies, the behavior of baby fish changes dramatically. They lose their sense of caution and swim out to predators. This will have a massive impact on the world's fish supplies.

Ocean acidification will also see the destruction of reefs around the world. When corals become acidified, they can't build their skeletons. They become brittle and break easily, or they grow slower. If we were to continue producing carbon dioxide at the rate we are now, by mid-century every coral reef on the planet will stop growing.

Another recent study says the world's fisheries fisheries could feed 20 million more people if they were better managed. Global fisheries are worth $240 billion and have created thousands of jobs. But the world's fishing supplies have been depleted, and some are beyond repair, because of over-fishing and exploitation.

Stopping over-exploitation and the impact of climate change on fishing stocks is critical given the looming food shortage, which I blogged about last month. Global warming has made that problem even more challenging. It's yet another impact the climate crisis is having on our economies and lifestyles.