Had effect around hard marine rock again and again? (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

TOLD (had an effect, usually an undesirable one), around H (abbreviation for hard) + REEF (a line of rocks just showing above the surface of the sea = marine rock). The definition seems slightly loose: threefold = triple, but in the sense of quantity or multiple parts rather than repetition.