Warming oceans mean smaller fish

Warming oceans could have a negative impact on fish numbers

Scientists at the University of British Columbia have just published a report in the journal Nature Climate Change indicating that fish will get smaller as climate change warms the oceans and reduces the oxygen available to fish in the water.

The scientists used computer models to come up with global projections. They have come to the conclusion that the maximum body weight of fish could go down by 14 to 20% between 2000 and 2050. The tropics would probably be the regions affected most.

The researchers were surprised at the large decrease the models are predicting. They think we may still be lacking some interesting “piece in the puzzle of understanding climate change effects in the ocean”, says lead author William Cheung from the UBC Fisheries Centre.

It seems likely that it would be harder for bigger fish to get enough oxygen in the water, so they would stop growing earlier. Clearly, this would have big impacts on food security. Fishy food for thought as international action still falls drastically short of what we’d need to limit warming to 2°C.