Developer that is already planning life-sciences labs in the Flynn Marine Park to file plans for even more waterfront life-sciences labs

Marcus Partners last week told the BPDA it will soon file plans for replacing a seafood-processing plant at 310 Northern Ave. in the Raymond Flynn Marine Park with two buildings aimed at life-sciences research and development.

Marcus, based downtown, says it will pay $20 million to help relocate the four seafood companies that share the current New Boston Seafood Center so it can tear the building down and put up a total of 742,000 square feet of lab and related office space.

Marcus had previously filed plans to replace a former Au Bon Pain factory and warehouse with an eight-story life-sciences R&D building, also in the Flynn park.

The BPDA board, formally meeting as the Economic Development and Industrial Corp., the BPDA arm that runs the Flynn park, approved the basic idea of transferring the lease of the roughly four-acre New Boston Seafood site from the seafood processors to Marcus in November.

With the imminent plan filing by Marcus, the agency will now oversee permitting of the proposal that will benefit it through increased lease payments through at least 2119.

According to BPDA officials, Marcus will initially pay roughly the same rent as the seafood processors for the agency-owned land through January, 2025 - between $306,000 and $413,000 annually. But in 2025, the rent will increase to $3.2 million a year and then, in January, 2027, to $6.8 million. Each year after that will see 3% annual increases, at least through 2119.

In addition to the lease payments, Marcus will also potentially pay $250,000 a year, for at least 30 years, to help harden the industrial park, which sits at sea level, against rising seas. The payments, however, are contingent on the BPDA convincing at least 50% of the tenants in the park, which increasingly has office and research space to go with its more traditional marine industries, to also contribute to keep the area from being inundated.

Also still to be negotiated: Community benefits and payments to BPDA housing and job-training funds, which are done through the agency's overall review of the plans.

November meeting at which the basic idea was discussed and approved:

301 Northern Ave. letter of intent and calendar.