Grades K–2 · Organisms
How can kelp stay attached while the sea moves?
Kelp is a large kind of seaweed that can grow in moving seawater. Near its bottom is a tangled, gripping part called a holdfast. It attaches the kelp to a rock.
In the diagramA holdfast anchors kelp to rockmoving waterrockholdfast
The holdfast helps keep the whole kelp from drifting away as water pushes past. Flexible parts above it can bend with the movement. Holding on and bending help in different ways.
A holdfast may look like roots, but kelp does not use it to drink from soil. Kelp takes in needed substances from the surrounding seawater. The holdfast’s main job is anchoring.
About this explanation
Starting knowledge: Recognize seaweed, a rock and water moving around an object.
Sources
- NOAA Office of National Marine Sanctuaries — Kelp Forest