It’s not just salmon and lobster that are fleeing warm water

From the University of Glasgow: The majority of fish populations in the sea are responding to global warming by relocating towards colder waters nearer the north and south poles, according to the latest research on the impact of climate change on our oceans.

Analyzing the breadth of current world-wide data on marine fish changes in recent years, researchers from the University of Glasgow have revealed that, in response to ocean warming, many marine fish populations are shifting toward the earth’s poles or are moving to deeper waters – all in a bid to stay cool.

Marine species often have a very narrow liveable temperature range making even small differences in the water impossible to cope with. As a result, marine life changes caused by global warming have been up to seven-fold faster than animal responses on land.

Over the last century, global warming has had substantial impacts on marine ecosystems, with fish species disappearing altogether from some locations. In some cases, marine fish may be able to adapt and change aspects of their biology in order to adapt to warmer conditions. In many cases, however, a change in the geographical range may be the only means of coping with rapid warming.

This latest study examined data on 115 species spanning all major oceanic regions, totalling 595 marine fish population responses to rising sea temperatures – the first time such a comprehensive global analysis has been undertaken.

Carolin Dahms, lead author on the study, said: “It’s possible that rate of warming in some regions may be too fast for fish to adapt, and so relocating may be their best coping strategy. At the same time we see that their ability to do so is also impacted by other factors such as fishing, with commercially exploited species moving more slowly.”

Professor Shaun Killen, senior author of the study, said: “If the prey of these species don’t also move, or if these species become an invasive disturbance in their new location, there could be serious consequences down the road.”

The paper, ‘Temperature change effects on marine fish range shifts: a meta-analysis of ecological and methodological predictors’ is published in Global Change Biology.