Rising Sea Temperatures Are Shrinking Adult Fishes And Food Chain, Study Finds

Global warming is making life hell on Earth for all of us. Whether it's irregular climate change or the impact it's having on the environment.

And now, researchers have discovered that it is also affecting the lives of the fish, which could have devastating consequences for marine life in the oceans.

Reuters

Researchers from Aberdeen looked at 30 years of trawl survey data from the International Council for the Exploration of the Sea for cod, haddock, whiting and saithe fishes. They've discovered that change in water temperature has had a severe impact on the population and growth of fishes.

Their data has revealed that in the North Sea and West of Scotland even though young fish has started to grow faster, and even larger, existing adults have been increasing in size. They claim that as per their data, a reduction in commercial fishery yields is expected in the short term and long term forecasts remain unclear.

This is occurring since warm water is known to possess less amount of oxygen. Moreover, it is also shown to increase metabolic rates in fishes, which boosts demand for oxygen.

Idongesit Ikpewe, of the University of Aberdeen, explains, ¡°Both the changes in juvenile and adult size coincided with increasing sea temperature. Importantly, we observed this pattern in both the North Sea, which has warmed rapidly and the west of Scotland, which has only experienced moderate warming. These findings suggest that even a moderate rise in sea temperature may have an impact on commercial fish species' body sizes.¡±

Reuters

Ikpewe explained that three of the fish species ¡ª cod, whiting and saithe ¡ª are predators that survive on other fishes and are on the higher end of the food chain. This means they have a crucial role in the ecosystems they're a part of. Predator size impacts what prey they can target and a change in body size could completely alter predator-prey relationships, which could have a severe impact on the food chain structure.

He added, ¡°The next stage of our work is to consider the management implications based on modelling these populations. The idea is to work out what the size changes we observed may mean for future fish productivity and yield under different scenarios of warming¡±