Fish Are Learning How to Avoid Getting Caught and We're All to Blame

Commercial fishing is an age-old industry that dexterously transcends any and all barriers it runs up against. It's arguably one of the world's oldest trades to remain wholly intact after industrialization, and it is said to annually contribute around $90 billion to the economy of the US alone.

Despite this, our reign over the ocean is mighty tenuous: there's the omnipresent threat of overfishing, global warming, shifting ocean currents, and a slew of other awesome ills to imperil our status as oceanic overlords.

Well hang on to your harpoons, because this push-and-pull between man and the sea is creating an unusual problem. A breed of über-fish is taking over the oceans.

According to experts, it seems that the fish in the ocean today have learned how to be less catchable than their predecessors. Scientists say it is an evolutionary change driven by our ubiquitous pursuit of the scaled swimmers, and researchers at the University of Glasgow are afraid that future fish populations could become better and better at evading capture.

Dr. Shaun Killen of the University of Glasgow's Institute of Biodiversity, Animal Health and Comparative Medicine led a recent study published in the journal Proceedings of the Royal Society B. He says that an often-overlooked problem in commercial fishing today is that "intense fishing pressure may cause evolutionary changes to the remaining fish that are not captured."

The study, which looked at 43 individual fish, asked whether some were more likely to be captured by trawling than others. It also examined whether this was that due to slower swimming ability and a weaker metabolism.

Indeed, it was the case that stronger fish evaded the trawling net. Dr. Killen told the University of Glasgow News that "fish that escape trawling are those that can propel themselves ahead of the net or move around the outside of the net. The key question is whether those that escape are somehow physiologically or behaviourally different than those that are captured."

The study showed that there was a difference between the winners and losers in this fishing game. The fish that were more likely to be captured had weaker anaerobic capacity and were less able to engage in bouts of intense physical activity. They also had slower metabolic rates. Isn't it always the case that the lady fish go for those with greater gills?

But here's the thing: hunting and fishing by humans is a selective process that drives evolutionary change. As Dr. Killen puts it, "[This] can lead to genetic change within wild populations for specific traits."

In short, the fastest, fittest fish made it out of the trawler's webbed grasp and went on to swim another day. Their spawn will likely inherit their super-fish characteristics and one day, the oceans may well be filled with hordes of perfectly chiseled, Zumba-zealous master fish. And we have commercial fishing to thank for this.

The researchers now want to study fish in the wild to see if they get the same results. Now if only we could give Billy Blanks some gills, we'd really get this ball rolling.