Sharks, sharks, sharks! It’s Discovery Channel’s Shark Week, which means it’s time to celebrate sharks’ critical role in our marine food webs and ocean health.
The Pacific Seas Aquarium is home to three six-year-old scalloped hammerhead sharks. The sharks have dramatically grown since they first arrived in 2017 as nearly 2-foot-long pups weighing under 10 pounds. Now, they are estimated to be an impressive five to six feet long and range in weight from 70 to 80 pounds.
Speaking of impressive numbers, the sharks can eat up to 4 pounds of fish daily.
“They love to eat,” said staff biologist Tai. “We prepare items such as salmon, herring, capelin, tunny (a species of tuna), sardine, and mahi mahi for the hammerheads daily.”
Tai says they seem to enjoy the tunny, capelin and mahi mahi in particular.
The team of aquarists has a unique way of feeding the sharks to ensure each one receives the food it needs to thrive.
“We use a technique called station training,” explained another staff biologist, Tyler. “The sharks know if they go to a designated station in the water, they will receive a food reward.”
There are many cues that let the sharks know it’s time to eat, including fans turned off, lights turned on, and underwater clicks that signal “food is here.”
By having individual stations, this method allows aquarists to track how many pieces of food each shark receives and guarantees they are getting their proper vitamins and supplements.
Debunking myths
Sharks get a bad rap. Scary movies and heightened media shows sharks in a dark light. But sharks play an essential role in maintaining a healthy ecosystem. They are apex predators and play crucial roles in ocean food webs. If sharks disappeared, ecosystems would become unbalanced which would have negative consequences for ocean health.
Myth: Sharks eat people.
Fact: Shark attacks are rare. Humans are not part of a shark’s diet. Most sharks eat fish or invertebrates, such as squid or shrimp. According to the International Shark Attack File, there were only five shark-related human deaths in 2022 compared to tens of millions of sharks killed annually by people. You are more likely to get killed by a cow than be attacked by a shark.
Myth: If a shark attack has not occurred, they do not live in that area.
Fact: Sharks inhabit all the world’s oceans.
Myth: Shark fins are great to eat.
Fact: Shark fins have no flavor or nutritional value. Shark meat has one of the highest concentrations of mercury of any seafood. Mercury is highly toxic to humans.
Myth: Sharks have no predators.
Fact: A shark’s biggest predators are humans. Many sharks – including hammerhead sharks – are endangered worldwide, with declining populations due to overfishing and shark finning (when the fins of a shark are cut off and the rest of the shark is discarded in the sea to die).
“We should not be afraid of sharks, we should be afraid for sharks,” said Tyler.
How we’re helping
Since 2019, Point Defiance Zoo & Aquarium has worked to help hammerheads by supporting scientists who tag and study them in Hawaii and Baja, Mexico. This helps them understand their habitat to protect them better.
