If Shark Week is leaving you hungry for more and you’re looking to learn about the ocean’s most misunderstood creatures, here are some common misconceptions and frequently asked questions to sink your teeth into!
Are Sharks Attracted to Human Blood?
Human Blood Doesn’t Trigger a Feeding Frenzy
Luckily for those of us who are injury prone, this is not true! Sharks can smell human blood; however, it will not send them into a feeding frenzy or increase the likelihood of an attack. Sharks are more interested in the scents and chemical cues associated with their natural prey than they are in human blood.
Do Sharks Sleep?
Sharks Rest Differently Than We Do
Not in the typical sense. Sharks can rest, but many species need to stay moving in order to keep oxygen-rich water flowing over their gills.
How Sharks Breathe
This form of breathing is called ram ventilation. Other sharks use a different method called buccal pumping, where they actively move water through their mouths and over their gills, allowing them to remain still while continuing to breathe.
Ram ventilation
The shark swims forward with its mouth open so water continuously passes over its gills. Sharks that rely heavily or essentially on ram ventilation tend to be active, open-water swimmers.
Examples include
- great white sharks,
- mako sharks,
- whale sharks, and
- many hammerhead species.
Buccal pumping allows a shark to actively draw water into its mouth and pump it across its gills. This means the shark can breathe while remaining still. It’s particularly common among bottom-dwelling sharks. Examples include nurse sharks, wobbegong sharks, angel sharks, and many catsharks.
Some sharks are capable of switching between the two methods. They can pump water over their gills while resting and use ram ventilation when swimming. Lemon sharks and many reef-associated sharks are examples.
What Do Sharks Feel Like?
Shark Skin Is Like Sandpaper
Sharks are very smooth if touched from nose to tail. However, if touched in the opposite direction, they have a rough, sandpaper-like texture.
Tiny Teeth Cover a Shark’s Skin
This texture is caused by the dermal denticles that make up their skin. These denticles vary in shape from species to species and aid in hydrodynamics as sharks move through the water.
In other words, they reduce drag and help sharks move more efficiently.
How Good Is a Shark’s Eyesight?
Sharks Have Excellent Low-Light Vision
Sharks have excellent eyesight, including impressive vision in low-light conditions.
Many sharks have something called a tapetum lucidum behind the retina, which helps with night vision by reflecting available light.
Detecting Movement and Contrast
Their vision is particularly good at detecting contrast and movement in the water, helping them navigate their environment and locate prey.
How Can I Avoid a Shark Attack?
Be Aware of What’s Happening Around You
There are several things to keep in mind when spending time in the ocean. Avoid areas where people are actively fishing or where baitfish are present, as this activity can attract sharks.
Use caution around river mouths and after heavy rain, when water conditions may be cloudy or murky.
Reduce Unwanted Attention
Reducing excessive splashing and swimming in groups rather than alone can also help reduce unwanted attention.
Most importantly, pay attention to local beach warnings and remember that sharks are wild animals living in their natural environment.
What Can We Do to Help Protect Sharks?
Knowledge Helps Replace Fear With Understanding
Research! Understanding combats fear and brings awareness to the threats sharks face.
Make Shark-Friendly Choices
Sign petitions and encourage lawmakers to advocate for conservation-focused bills. Avoid products that contain shark meat or shark-derived oils, such as squalene, and choose sustainable seafood whenever possible.
Support Shark Conservation
Support nonprofits dedicated to shark and ocean conservation by donating, participating in local events, volunteering, or engaging with and sharing their content on social media.
Spread the Word About Sharks
Teach others about sharks and encourage them to care about one of the ocean’s most important groups of species. The more people understand sharks, the more likely they are to want to protect them.