Summer plans might be changing this year, but Shark Week is still on the horizon!
There are hundreds of different shark species darting through the oceans worldwide. Some species, like the dwarf lanternshark, are so small they could fit in the palm of your hand while others, like the whale shark are as long as a school bus.
Give your family something fun to look forward to with five bite-size shark facts and tips to help protect our favorite finned friends.
FACT 1: Sharks are not your ordinary fish and are especially sensitive to ocean warming.
TIP: Slow ocean warming by powering down and reducing your energy usage.
Biologically, sharks are a species of fish with fins and gills, but it's their skeletons that set them apart from the rest. Sharks do not have bones. Their skeletons are composed of flexible cartilaginous tissues. Along with rays, sawfish and skates, sharks belong to a special category of non-bony fish called "elasmobranchs."
Sharks are missing another key feature most other fish species share: swim bladders. Gas-filled swim bladders help bony fish stay afloat in the water while sharks rely on their large, oily livers to maintain buoyancy. Unfortunately for sharks, they are still heavier than water and must be constantly swimming or they will sink to the ocean floor.
As sharks literally fight to sink or swim, they face another battle outside of their control: warming oceans. More than 90 percent of the excess heat retained by the planet as a result of increased greenhouse gases is absorbed by the ocean. You can help slow ocean warming by powering down and reducing your energy usage. Turn off your lights and appliances when not in use. Dry clothes on the line instead of in the dryer. Making these little changes in your day to day life goes a long way.
FACT 2: They have strange, scaly skin that can corrode from ocean acidification.
TIP: Prevent an acidic ocean by offsetting your daily carbon impact.
Despite its smooth appearance, the skin of a shark feels as rough as sandpaper. Shark skin is made of tiny dermal denticles, or “skin teeth.” The thin, ridged denticles help with drag reduction, which allows some sharks to cut through water with ease. The scales point towards the shark’s tail, reducing the friction from surrounding water. Thicker denticles with less ridges act as protective gear, keeping parasites from sticking to their skin.
The streamlined design of shark skin has even shaped new technology. Known as biomimicry, scientists and visionaries draw inspiration from patterns and structures in nature. To harness wave energy, engineers created water turbines with a shark tail-like design. At the 2004 Olympics, Michael Phelps wore a swimsuit made from compression fabrics with V-shaped ridges modeled after drag-resistant shark skin.
Sharks may have tough, thick skin, but that’s not enough to protect them from ocean acidification. Rising carbon dioxide levels in the waters can corrode shark’s teeth and scales, compromising their ability to swim, hunt and feed. Learn how you can offset your daily carbon impact and protect the sharks with the EPA’s Carbon Footprint Calculator.
FACT 3: Sharks keep oceans healthy and diverse, and ecosystems degrade without them.
TIP: Keep the balance and support healthy, biodiverse food systems on land.
Scientists often refer to sharks as a “keystone species.” Unlike other animals that only exist in certain parts of the world, sharks live in every ocean on the planet and play a critical role in keeping prey populations in check. As predators, they have the power to weed out weak, sickly animals and remove disease from the ocean.
Sharks can alter the feeding habits of species below them on the food chain. By patrolling over large areas of seagrass and coral reefs, sharks prevent their prey from overgrazing any one area. This behavior helps to increase species diversity and maintain a healthy balance in the ecosystem.
The loss of these top predators in any marine habitat can upset entire ecosystems. As oceans warm, the ambient water temperature pushes shark’s prey to move away from their natural habitats at a greater rate, causing sharks to follow.
One way to help prevent the loss of sharks in diverse habitats is to change up your own eating habits and buy organic and locally grown food as much as you can. Organic farms promote genetic biodiversity in local areas and create less water pollution. If we don’t go so far to find our food, sharks don’t have to go so far to find theirs.
FACT 4: There are no picky eaters here, so ocean plastic is often on the menu.
TIP: Reduce single-use plastic waste in the environment by recycling correctly and with the help of Zero Waste Box™.
While every type of shark has its own specific preferences, these finned creatures are not known for being overly finicky about their food. Sharks are curious predators who hunt with a level of confidence that comes from sitting at the top of the food chain. Their diet can consist of everything from small fish and crustaceans to seals and dolphins. Unfortunately, many sharks also consume floating plastic bags, which look a lot like jellyfish or squid when they are full of water. Unable to digest the plastic, sharks are left feeling full and they stop eating the food they need to survive.
Plastics aren’t just a problem for active predators and scavengers. Filter feeding sharks, who get their food by moving through the water with an open mouth to catch small prey, are very vulnerable to microplastic pollution. In the process of straining their food from the water, filter feeders may also be ingesting toxins associated with plastics, such as heavy metals and phthalates.
You can help take a bite out of ocean plastic pollution! With the Plastic Packaging - Zero Waste Box™, you can properly recycle any plastic packaging including plastic bottles, straws and shopping bags. Now that’s a cause everyone can sink their teeth into!
FACT 5: Sharks are older than dinosaurs, and may be slow to adapt to climate change.
TIP: Help them stick around and see what your city is doing to address planetary risks.
Sharks were swimming through the oceans long before dinosaurs roamed the Earth. That makes them very, very old. The earliest fossil records show that sharks have been around for over 450 million years. And that’s not even the coolest part! Unlike other forms of life on Earth that greatly evolved and adapted over time, most species of shark have stayed more or less the same for millions of years. As perpetual predators at the top of the food chain, there didn’t ever seem to be a reason to change.
Not only have sharks mastered the art of survival without constant adaptation, they have also claimed recognition as some of the longest-living creatures of the sea. Greenland Sharks may live up to 400 years, without even reaching adulthood until they turn 150 years old. Who knew sharks had such strong staying power?
Sadly, sharks’ slow rate of evolution means they will be slower to respond and adapt to climate change than other animals. To make sure sharks are here to stay for the next hundred years and beyond, cities and states need to have plans in place to address climate change and sea level rise. The CDP global database can help you keep track of your city’s progress towards reducing emissions and addressing climate risks.
What’s your favorite shark fact? Tell us in the comments!