Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 5
Distraction
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Human Factors; Procedure; Environment - Non Weather Related
Aircraft X was on a vector to SPG and issued 3;000 to get below traffic at 4;000. Aircraft X descended to 2;000 into an MVA of 2;700. When I noticed the aircraft's altitude I issued a safety alert and instructed them to climb to 3;000. When I asked the Pilot why they descended to 2;000 they responded that's what they thought they were issued.I should have been scanning quicker and noticed the descent through 2;700. At the time of the occurrence I was trying to figure out a few reroutes for overflight traffic. Since Metroplex was implemented ZMA issues over flights VARSE direct destination. This does not comply most of the time with our LOA's with JAX or F11. They should be getting VARSE direct NITTS or VARSE direct OCF. Not having this distraction could have helped me see the issue sooner.
Controller reported descending an aircraft below the MVA; by mistake. Reporter also shared issues relative to the Metroplex changes.