Answer:
harmful. (more info below)
Step-by-step explanation:
Balanus may compete with Chthamalus through crowding or smothering, but Chthamalus can inhabit higher tide levels than Balanus since it is more immune to desiccation. Lower on the sea, the barnacles of acorn combine with the Endoclades (Turfweed) assemblage, and are also abundant on the shells of acorn. To conclude, it was a bad idea is add the balanus barnacle to the Chthamalus barnacle becuase balanus barnacles can crowd Chthamalus barnacle.
hope this helped!