Holdfast
Have you wondered about what holds down an underwater forest?
It’s the holdfast.
I spent the majority of a recent dive in a sun-soaked Bull Kelp forest. My hope was that the photos I took would communicate the role of the holdfast AND the stunning beauty of being in such forests.
Kelp does not have roots. Rather the algae / kelps get their nutrients through the fronds (leave-like structures) and it is the holdfast that anchors kelp onto rocks.
It’s a tangle of woody structures that you may have seen washed up on the beach.
Holdfast found on the beach.
You can imagine how strong the hold has to be to withstand the buoyancy of the waves, current and the kelp’s floatation (the air-filled pneumatocysts).
If rocks are too light to counter the floatation of the pneumatocyst or the force waves and current, the kelp will change the ocean bottom by carrying away smaller rocks. These holdfasts may end up washed up on the shore where you might see them.
Friend in the forest – Janice Crook. Second buddy on this dive was John Congdon
Green Urchins climbing up the stipe of Bull Kelp where they will feed. Not a problem when there are enough of predators like Sunflower Stars and Sea Otters. It’s a big problem is there are not enough predators as then too much kelp is grazed away leading to “urchin barrens”.
There you go – a daily dose of depth for you.
It may be too that “holdfast” is a concept of great value in these stormy times.
Holdfast dear readers. Holdfast.
The canopy of the Bull Kelp forest.
My additional blog items on kelp include:
The Marine Detective 
2 Responses to “Holdfast”
I love this post! The underwater images of the holdfasts are beautiful. And I appreciate your suggestion to holdfast during these terrifying days.
Really value this comment Wendy. 💙