Each winter, dozens of divers from the Pacific Northwest enter the frigid waters of the Puget Sound in search of the elusive Giant Pacific octopus. They’re not hunting them for food (fortunately) or to get great photos of these wonderful animals – they count them as a part of an annual, informal census of the octopus who live in the waters between Seattle and Canada.

This unusual count takes place each year, and last month 27 scuba divers, enlisted with the help of the Seattle Aquarium, dove the waters between Seattle and the Canadian border searching for octopus. It’s a huge area to cover, so dive teams focused on diving and surveying 11 sites around Puget Sound. The aquarium asked the divers to count how many octopuses they saw, note the depth, and record the type of hiding spot where they were found. They weren’t disappointed in their findings.

This year, the census counted 28 octopuses, while divers found 17 last year during the survey. It’s great news for divers who enjoy sharing the water with these beautiful creatures, but doesn’t necessarily mean that the populations across the Puget Sound are increasing or decreasing.

“We’ve been watching the numbers go up, then kind of go down, then kind of go back up,” Kegel told the Seattle Times. “That could be having to do with population and mating. As they all peak and mate, they slowly die off, then they start to grow back up again.”

The Giant Pacific octopus can weigh as much as 150 pounds and have tentacles that can span up to 20 feet across. It’s the biggest octopus in the world. The waters off Seattle are one place where they call home, in addition to occupying large range across the Pacific Ocean. They’re known to be one of the smartest creatures in the ocean, and uniquely, they also have a very short lifespan of just three to five years.

To make up for its relatively short life span, the octopus is extremely prolific. It can lay 120,000 up to 400,000 eggs which are intensively cared for by the females. The female stops eating during this care, and her life ends soon after the eggs hatch.

Because the giant Pacific octopus is not on any threatened-species lists, there are no current studies or recent official population counts of octopus in the Puget Sound. It’s unknown how many live in the area, currently or historically.

Octopus commonly prey upon shrimp, crabs, scallops, abalone, clams, lobsters and fish. Food is captured with the help its suckers and then bitten using its tough “beak”. Octopus have also been observed to catch spiny dogfish up to four feet in length while in captivity. Additionally, consumed carcasses of this same shark species have been found in giant Pacific octopus middens in the wild, providing strong evidence of these octopuses preying on small sharks in their natural habitat.

Giant Pacific octopuses are commonly kept on display at aquariums due to their size and interesting physiology, and have demonstrated the ability to recognize humans that they frequently come in contact with. They have the ability to solve simple puzzles, open childproof bottles and use “tools”. The octopus brain has folded lobes (a distinct characteristic of complexity), visual and tactile memory centers. They have about 300 million neurons.They have been known to open tank valves, disassemble expensive equipment and generally wreak havoc in labs and aquariums. Some researchers even claim that they are capable of motor play and having personalities.

For more information on the Seattle Aquarium click here.