Malden-based Pilot Seafood Properties plans a 220,000-square-foot seafood processing plant for up to three companies at Massport’s Marine Terminal property in South Boston, including Boston Sword & Tuna which would relocate from nearby 8 Seafood Way.

The project on a vacant 6.5-acre parcel at the eastern end of the Raymond L. Flynn Marine Park is designed to accommodate medium and large-scale seafood processors. A 300-space parking garage serving the development would include a public seafood market and multi-tenant space on the ground floor, according to a notification filed this week with the Boston Planning and Development Agency.

Pilot previously developed two other parcels in the marine park for Legal Seafoods’ 75,000-square-foot quality control center and the 68,000-square-foot Harbor Seafood Center multi-tenant building at 8 Seafood Way.

A 2016 report prepared for the BPDA was skeptical of the feasibility of more marine-dependent commerce in the 191-acre industrial park.

A proposed updated master plan would encourage more than 4 million square feet of new development, loosening longtime restrictions that parcels be used for marine-dependent industrial use. Those restrictions, according to a BPDA report, have discouraged development in the park because industrial rents typically don’t support the cost of new construction. The proposed changes would encourage developers to build high-bay warehouse space with office or assembly space to attract biotech, advanced manufacturing and e-commerce users.

The changes require approval by the state Executive Office of Energy and Environmental Affairs.