Very similar to a New Zealand native, Asparagopsis armata which has harpoon-like structures on side branches. It travels on underwater equipment and via natural means, and can smother and displace native species.

Look for the harpoon structures to identify this species:

The New Zealand native, Asparagopsis armata, has harpoon-like structures. The invasive species, Asparagopsis taxiformis, does not have these structures: