Kelp

Splashery stretches a drumhead over this Splash's outline, twelve inches across, and finds the ways it can ring. Its lowest is 773.1 Hz, 24 cents flat of G5. The next fifteen are its overtones, and each one draws its own figure: sand gathers on the lines that stay still.

Tap it to bring fish in to nibble the kelp. Hands-on: push the fronds; they sway back.

Kelp is a giant seaweed, a kind of brown algae that grows in cool, shallow seas. It holds on to the rocks with rootlike grips, and little bulbs full of gas keep its long blades floating up toward the light. Kelp can grow so thick that it makes underwater forests, full of fish, snails, sea urchins and sea otters.

The kelp sways gently by itself. Tap it and three little fish swim in, each noses up to a blade for a few nibbles, and the kelp sways away from them, then swings back as they swim off. Giant kelp can grow more than half a meter in a day. With ✋ Hands-on on, push the fronds and they swing after your finger, then sway slowly in the water and drift back.

Made in Splashery. Its code is MIT.

This link opens it in the Playground. To put it on your own page, add the element and one script tag. Every option.