Despite just how many people walk the Earth today, some parts of the world are still thought to be ‘untouched’ by human activity. The Chagos archipelago, a group of islands residing in the Indian Ocean, is an adequate example of this.
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Given just how far the Chagos archipelago is from densely-populated continents, researchers expected to witness pristine shark populations there. Sadly, they found just the opposite when they traveled there to investigate. The findings are published in the journal Science Advances.
Fortunately, conservationists have monitored shark populations in the Chagos archipelago for decades. The researchers leveraged a bevy of this existing information throughout their study to discern how shark populations there changed over the years.
They dug into records dating as far back as 1948 and found that shark populations in the Chagos archipelago are diminishing far below recognized baselines despite longstanding beliefs that these so-called “pristine” environments wouldn’t exhibit symptoms of human interaction.
In particular, the researchers found that local grey reef shark populations were up to 20% lower than expected. Furthermore, local silvertip shark populations were up to 93% lower than expected. These figures were generated from computer-based algorithms and compared with known catch data to see how it aligned.
It’s tough to say for sure what caused these shark declines, but the researchers seem confident that overfishing has something to do with it. Many catches are never legitimately reported and slip under the radar, which doesn’t do conservation efforts any justice.
Perhaps the most significant moral to be learned from the study is that even environments seldom visited by humans can exhibit long-lasting effects from our existence. It’s sad but true.