Kicking Out the Whale Bone Squatters
Some critters help clean whale bones, others just want free lodging.
Published January 8, 2021, By Kelly Fretwell, photos by Grant Callegari
When you have a tough cleaning job, you call in professionals. But what if a hovering horde of tenants in search of free rent move in before the cleaning is done?
The skeleton of a juvenile humpback whale that
washed ashore near our Calvert Island Ecological Observatory in May 2019 needed a deep clean before being reassembled. We hung the bones off our dock, safely encased in thick, tough nets, and let the nearshore scavengers and decomposers remove as much of the remaining flesh as possible.
When skeleton articulator Mike de Roos and his crew members Katie Ford and Claire Schiller hauled the bones to the surface months later, they found an amazing array of marine critters had settled in the free space.
A thick growth of mussels (a banner year for mussels, it seems), countless barnacles, and strings of seaweed cover both the bones and surrounding net. But that’s just the beginning.
Whale bones are prime real estate for encrusting bryozoans. Many of these “moss animals” take up residence on hard surfaces, and their colonies aren’t picky about settling on rock, dock, or bone.
An isopod ( Pentidotea sp.) strikes a deer-in-the-headlights pose on the dock after falling off a piece of bone. Don’t worry. Moving again isn’t an issue for this crustacean—its swimming skills mean it won’t take long to find a new dwelling upon its return to the sea.
The aptly named mossy chiton ( Mopalia muscosa) is pickier about transport, as it’s more of a crawler than a swimmer.
Thanks to some impressive attention to detail by the crew, this tiny sea star is plucked from the smorgasbord of mussels and barnacles.
A shapeless, colorless lump might not immediately catch your eye, but peer closely enough at a brooding transparent tunicate ( Corella inflata) and you’ll get a window into its inner workings. You may even spot some tunicates-to-be tucked away safely inside its brooding chamber!
These dock shrimp ( Pandalus danae) spend a brief period of time on their namesake. They’re regulars under and around docks and pilings, and our Pruth Bay structure is no exception.
A crescent gunnel ( Pholis laeta) also set up shop on the bones. This wriggly resident isn’t bothered by the sudden transition to the terrestrial realm—like others in the gunnel family, it can breathe air when out of water and is often found sheltering under rocks in the intertidal.
A pygmy rock crab ( Glebocarcinus oregonensis) and green urchin ( Strongylocentrotus droebachiensis) join a plethora of worms on an intervertebral disc plate (yes, that’s the cross-section of a humpback whale’s spine!). The crab’s impatient with the photo shoot.
The team catches the pygmy rock crab for a close-up. This crab’s stomach is likely full given the veritable buffet of barnacles, worms, mussels, and more on the bones.
This pair of California sea cucumbers ( ) are less inconspicuous. These finger-sized cukes are still wee baby pickles at this stage. California sea cucumbers can reach a whopping 50 centimeters long. That’s two foot-long sub sandwiches put together! Parastichopus californicus
And the worms! All shapes, sizes, and colors of worm wriggle out from under and between the collection of bones.
Meanwhile, back in the water there’s some organic debris fallout as the goods were lifted from the ocean and cleaned. A school of shiner perch ( Cymatogaster aggregata) appears on the scene to make quick work of the sudden feast.
After a whole lot of additional elbow grease from the crew, the bones were packaged up and barged south to Salt Spring Island for the next stage in their long cleaning saga—a full degreasing. We’re filming that too, so stay tuned.