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31 August 2016

Polar Gigantism Explained

Not a fan of spiders? How about one roughly the size of your face? Well, head to the icy waters of Antarctica and you will find exactly that, as sea spiders, sponges, worms and many other creatures grow to staggering proportions. This is polar gigantism at work.

Img source: cbc.ca / Bret Tobalski
It is a well-documented phenomenon, that marine invertebrates living in colder waters will grow much larger than seen elsewhere, but one that is yet to be fully understood, although there are some promising theories out there.

Img source: sydkab.com
The most prevalent of these theories states that the growth occurs due to the presence of oxygen, more specifically how it is used by the sea life in question. In the extreme cold climate of the poles, life works in a kind of slow-motion, at least in terms of physical processes. The metabolic rate of creatures existing in these regions slows down accordingly, which results in said creatures requiring much less oxygen, but with plenty on offer. It is thought that this overabundance of such a vital component of life could be the driving force behind the growth of these marine giants.

This is far from the only theory out there that aims to answer this question however, and many believe that the exaggerated growth is simply a result of there being fewer predators around the poles. This could have in turn allowed other creatures to either evolve to be larger, or simply have the time to reach their full size before they become lunch to a passing fish.

The final theory relates to the high concentration of silica found in these waters, a compound which many organisms use to craft their shells. It stands to reason for these creatures that, as their shells grew to ever-larger sizes, they themselves would follow suit.

While the exact reasoning behind the occurrence of polar gigantism is still under debate, the phenomenon itself has been recorded in detail. The next question on the minds of researchers relates, once again, to global warming; will these spectacular giants survive the shift in conditions that will undoubtedly follow the melting of ice sheets and the raising of sea levels, or will they become just another footnote of natural history wiped out by the actions of our destructive species?


Sam Bonson

Sam is an aspiring novelist with a passion for fantasy and crime thrillers. He is currently working as a content writer, journalist & editor in an attempt to expand his horizons.