Jul 28, 2020,12:40am EDT
Since the dinosaurs have roamed our planet, there have been sharks. These predators, swimming beneath our ocean’s waves, have survived numerous mass extinctions over the course of our planet’s history, and seem to have evolved to survive anything… except their most formidable opponent yet: us. For most people, an ocean full of sharks is their worst nightmare. But for those who study these animals, the reality of dwindling shark numbers is theirs.
Sharks face a staggering number of threats such as overfishing and bycatch, habitat destruction and degradation, climate change, plastic pollution, and illegal shark finning. In one of the largest collaborative projects yet, the impact these threats have had on our global shark populations has been made glaringly obvious: nearly 20% of the world’s sharks have vanished from reefs thought to be teaming with life.
Coral reefs were once renowned for being abundant with sharks, but these animals have been targeted by both legal and illegal fishers so that today many reefs see few, if any, individuals. By taking sharks out of these highly complex ecosystems, it has triggered a phenomenon called “mesopredator release,” where other large predatory fish will increase in abundance and feed on herbivores. If you’re a fisher, having more of these large fish (that you generally fish for) sounds like an awesome trade! But herbivorous fish are a vital component of this habitat, eating algae that would otherwise overwhelm and potentially kill young corals.ADVERTISINGRecommended For You
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The study, published in the journal Nature, includes over 100 scientists working together to go through 15,000 hours of underwater video from 371 reefs in 58 countries, states and territories to show that sharksare absent on many of our coral reefs. In fact, this new research from Global FinPrint shows they are functionally extinct — which means they are so rare in certain areas they can no longer fulfill their role in the ecosystem. Since 2015, the Global FinPrint team — which is led by researchers at Florida International University (FIU) — has used underwater cameras to pinpoint specific strongholds for sharks and rays.