The ocean is one of the places here on Earth where you can look to find some of the world’s most exotic life forms. Among some of those are cephalopods, which have a strange habit of seeing both positive and negative dramatic population fluctuations over periods of time.
Image Credit: S. Portelli
Cephalopods are a marine animal group that includes invertebrates like cuttlefish, octopus, and squid, and the chemical and biological changes that mankind has inflicted on our plant, not excluding our oceans, may be making things more favorable for them.
Since the 1950’s cephalopods have reportedly seen a ‘boom’ in population, not just in open waters, but even closer to the shorelines between New England and Japan.
More and more cephalopods have been getting entangled in fishing equipment since the 1990’s and although there are more factors to consider before you can assume cephalopod population is increasing, a recent scientific study performed by Zoe Doubleday of the University of Adelaide and others carefully pieced together information gathered from 32 scientific surveys over the course of 60 years.
"The consistency was the biggest surprise," says Zoë Doubleday of Australia's Environment Institute at the University of Adelaide. "Cephalopods are notoriously variable, and population abundance can fluctuate wildly, both within and among species. The fact that we observed consistent, long-term increases in three diverse groups of cephalopods, which inhabit everything from rock pools to open oceans, is remarkable."
It would seem that human intervention over our oceans just might be the leading factor for the population increases in cephalopods. A duo of factors that might be allowing the species to thrive include fishing, which rids the ocean of potential predators, and global warming, which makes the ocean more habitable for the species.
They already have short life spans, fast growth rates, and other differences from many marine species, but human intervention is acting as a catalyst to speed up factors, such as mating and egg-laying, and allowing cephalopods to multiply in great numbers.
The effects of cephalopod numbers increasing may have an effect on the population of other marine life, as they’ll eat just about anything. But that also comes with a double-whammy, because cephalopods will even eat each other if presented with the opportunity. This is nature’s way of dealing with itself.
It would appear that cephalopods are enjoying their glory days in their moment of triumph.
The findings of this study are published in Current Biology.
Source: EurekAlert, Science Magazine