How do you count octopuses? Very carefully
Assign to Google Classroom
An unusual census takes place every year. This census checks on the giant Pacific octopus population in Washington's Puget Sound. Volunteer divers are enlisted by the Seattle Aquarium. They take to inland waters to look for their eight-tentacle neighbors.
The giant Pacific octopus lives up to its name. It weighs as much as 150 pounds. Its tentacles can span up to 20 feet. It's the biggest octopus in the world. It calls the waters off Seattle home. But it ranges over the Pacific Ocean.
"The Puget Sound offers good habitat, water temperature and an abundant food source for them," said Kathryn Kegel. She is a Seattle Aquarium biologist.
The giant Pacific octopus is known as one of the smartest creatures in the sea. It lives between three and five years. Once they mate, they die soon after.
"They are big hunters of crab, clams, scallops, things like that," Kegel said.
There are no current studies on the Puget Sound population. It's unknown how many live in the area, Kegel said.
That's where the Seattle Aquarium and its volunteer divers step in.
Twenty-seven divers looked for the giant Pacific octopus. They dove at 11 sites around Puget Sound last month. The aquarium asked the divers to count how many octopuses they saw. The divers noted the depth of their finding and the type of hiding spot.
This year, the census counted 28 octopuses. Divers found 17 last year.
Octopuses hide in their dens during the day. The divers use flashlights and dive in areas known for being octopus homes.
"They were hiding in their holes sleeping," volunteer diver Kathryn Arant said. "They had been eating because there were shells all around them."
Critical thinking challenge: What sort of restrictions would you expect to apply within protected habitats for octopuses?