herring
鰽 centers on a specific type of fish: herring. It is a narrow, concrete term without broader abstract extensions.
鰽 combines 魚 (fish) with 曹, which likely contributes the sound. The exact historical development is uncertain, but the structure is a typical phono-semantic compound for a fish name.
The left side is 魚 (fish), and the right side 曹 looks like a container or trough. Imagine a fish packed in a container: that's a herring.
For シュウ, picture a herring being thrown into a shoe: shoe -> シュウ, and the fish lands inside.