Field Notes: a Northwest nature blog
One of the reasons many of us live in the Pacific Northwest is the natural wonders that amaze us all. On this blog Seattle Times writers and photographers will share their explorations of the natural world from snowcaps to whitecaps. Write us at firstname.lastname@example.org with your own sightings, questions and wonders to share.
Local diver captures rare video of octo-mom in Puget Sound
Posted by Sandi Doughton
Baby birds are taking wing across the Puget Sound region this month. But under the surface of the sound, female octopuses still have a lot of work to do before their eggs even hatch.
This poignant cycle of reproduction, which ends with the mother's death, plays out every year -- unseen by all but the luckiest divers. Now, one of those divers has documented the labors of one of those eight-armed mothers.
"It's hard not to get emotional," said underwater videographer Laurynn Evans, who observed the female over a 10-month period. "This mother gives everything of herself."
The story began in November 2009, when Evans and a few companions were diving off Alki Beach. Yes, the water was cold -- but it always is.
"It's equally frigid in November or August," Evans said. "The only difference is that in July you sweat before you get in the water."
The group spotted a female giant Pacific octopus tucked up in a den of broken concrete and rocks. "I put my hand out, and she not only reached out and touched me -- she reached out and grabbed me," said Evans, whose friends call her the "octowhisperer" because of her affinity for the creatures.
Giant Pacifics are the world's largest octopus, averaging about 15 feet from arm tip to arm tip. The biggest can weigh more than 150 pounds, but most range between 30 and 90 pounds.
Evans nicknamed the octopus Opal, and began checking in on her every couple of weeks. By January 2010, Opal had started blocking up the mouth of her den with rocks and old bricks, a sure sign she was about to begin laying eggs.
There also was an octopus corpse near the den -- perhaps the father. Males can mate with more than one female, but they don't survive long after passing on their meter-long packets of sperm.
Within a week, Opal's den was festooned with a lacy curtain of eggs.
The "birthing process" is an arduous one for the sisterhood of giant cephalopods, as Wendy Williams describes in her new book "Kraken."
"When the time comes, in the cave she has chosen, she expels each egg, one by one, then -- using her suckers -- painstakingly braids them together into long chains of eggs she will then attach to the roof of her den. The whole process, which may involve exuding and braiding not quite 100,000 eggs in all, will take her perhaps as much as a month."
Underwater camera work is new for Evans, who has a challenging day job: Principal of Rose Hill Junior High School in the Lake Washington School District. She didn't get her video gear until last June, which is when she began her video log.
Though it's not uncommon for local divers to spot giant Pacific octopuses, it's a rare treat to find a nesting female. In nine years of diving, Evans had only seen one before.
The Seattle Aquarium enlists divers in an annual octopus census every January. This year, they counted 41 giant Pacific octopuses, down from 46 last year, said biologist Kathryn Kegel. After 11 years of counting, there's a hint that populations may cycle up and down.
The aquarium has a permit to capture octopuses for display. "The public just loves them," Kegel said. But the animals are returned to the wild as they approach "senescence," the breeding period that will mark the end of their 3.5- to 4-year life spans.
To minimize human impact on Opal, Evans and her friends made a pact to keep the den's location secret. They visited sparingly.
For nearly seven months, Opal fended off predators and groomed her eggs to keep them free of harmful bacteria or algae. She used her siphon to blow oxygen-rich water across the eggs. Inside each tear drop-shaped egg, the babies gorged on yolk and grew.
"The eggs start out saffron yellow, and as they age they get darker," Evans said. "You can see the tiny octopuses inside the egg casing if you look closely."
While her eggs matured, Opal shrank.
Once they wall themselves into their dens, female giant Pacific octopuses never feed again.
"We watched her get grayer and grayer," Evans said. "The skin just started to hang off her arms."
Near the end of August, the team began diving more frequently in anticipation of the hatch. On Sept. 4, they spotted the first babies.
It was the first week of school for Evans. "I'll never forget it," she said. "As the week unfolded, I'd get up at 5 a.m., get off work at 4, run home, get my stuff, meet to dive, then get home at 11:30."
Her film shows a trickle of offspring at first, then a rush.
"The hatch got bigger and bigger," Evans said. "By the end, it was just babies, babies, babies, everywhere."
One of Opal's last acts was to blow the hatchlings away from the den, sending them toward the surface to begin their journeys. A few days after the last egg hatched, she crawled away from the empty den and died.
"It's just devastating to watch, in a way," said Evans, who did not include the final scene in her film.
The young float and feed for several weeks, before descending to the bottom, where they will spend the rest of their lives. Those that make it, that is.
"It is likely that only one or two or three of all those carefully nurtured tens of thousands of eggs will survive to adulthood and reproductive age," Williams writes.
But the cycle begins anew.
Another female is now in Opal's den, raising her own brood, Evans said.
And Evans' work has found a wide audience.
Since NPR science reporter Robert Krulwich featured it on his "Krulwich wonders" blog earlier this month, the film has received more than 30,000 hits on Youtube.
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