I’m a big ocean predator who loves to travel! You can find me in tropical and subtropical oceans around the world, and I make long seasonal migrations all the way from the Equator to the Poles.
I’m a big guy (reaching up to 400 lbs!), but despite our mighty reputation, sharks are under threat from overfishing (including when we’re accidentally caught as bycatch or collected for shark fin soup), pollution and habitat loss. I’m worried about a new threat, too. Ocean acidification occurs when the ocean absorbs carbon and becomes more acidic, which hurts my sense of smell! Scientists showed that we can’t smell food as well after living in ocean acidification conditions expected for the year 2100. Normally we can track food smells with 60% accuracy, but under acidified conditions that number drops to 15%. In the study, we actually avoided food when in those conditions! Apparently this is likely from changes in neurotransmitters that impact my sense of smell.
This is definitely bad news, since my sense of smell is really important to me. It’s how I find food, mates and predators, as well as make my way around the ocean. I’m active at night in the deep, dark ocean, so my sense of smell provides critical information about my surroundings.
Did You Know?
Although we haven’t attacked many humans, we are still considered potentially dangerous. This is mainly because of our big size and our habit of coming close to shore.
Despite our massive migrations, females stay pretty close to home when it comes time to give birth—they’ll often stay near where they were born. We don’t reach sexual maturity until we’re 20 years old, and females only give birth once every three years. That’s because females have a gestation period of 22 months—that’s almost two whole years! Each litter is about six to 12 baby dusky sharks, and they will hang out in inshore nurseries until they’re big enough to venture out in the open ocean. These young sharks have to be careful that they aren’t eaten by larger sharks like bull sharks. But by the time we reach adulthood, no one is really big enough to mess with us!