The United States is set to formally enforce a wide-ranging seafood import ban under the Marine Mammal Protection Act (MMPA), with the new rules taking effect on January 1, 2026. Tuna is expected to be the first and most heavily affected species, followed closely by mahi-mahi.
The ban targets seafood products sourced from fisheries that fail to meet the MMPA’s “comparability” standards, which require foreign fisheries to demonstrate marine mammal protection measures equivalent to those used by US fisheries. According to the National Marine Fisheries Service (NMFS), part of NOAA Fisheries, any seafood imports from non-compliant fisheries must be accompanied by a government-issued Certificate of Approval (COA) at the time of entry. Shipments lacking a valid COA will be denied customs clearance.
NMFS officials outlined these requirements during an importer network briefing on December 16, confirming that enforcement will be strict once the deadline arrives. The agency estimates that the ban could affect approximately $3.6 billion in seafood trade, a significant share of total US seafood imports, which reached roughly $25.8 billion annually.
Tuna Exports Face the Greatest Exposure
Tuna fisheries across multiple major exporting countries are expected to face severe disruption. Many have been denied MMPA comparability status due to the continued use of fishing methods such as drift nets, gillnets, and entanglement nets, which are considered high-risk for marine mammal bycatch.
In 2024, Vietnam exported nearly $270 million in tuna to the US, much of it produced using methods now restricted under the MMPA framework. Indonesia shipped approximately $244 million worth of tuna, with portions of its bigeye, yellowfin, and skipjack fisheries falling under the ban. Ecuador’s tuna exports exceeded $147 million, and its reliance on gillnet and entanglement net fishing places a substantial portion of that trade at risk.
Additional restrictions will apply to longline-caught tuna from the Philippines and skipjack tuna harvested by Chinese vessels using gillnets, further tightening supply options for US importers.
Mahi-Mahi Supplies Also Under Pressure
The impact on mahi-mahi (dolphinfish) is expected to be similarly disruptive. Fisheries in Peru, Ecuador, Indonesia, Vietnam, Colombia, Malaysia, Sri Lanka, and El Salvador will be barred from exporting mahi-mahi to the US if they fail to meet MMPA standards.
Peru alone exported more than $100 million in mahi-mahi to the US in 2024, while Ecuador shipped approximately $60 million. These volumes now face uncertainty as exporters scramble to secure compliance certification or redirect product to alternative markets.
Compliance Thresholds Rise for the Entire Supply Chain
At present, aside from legal challenges related to swimming crab fisheries, no major new lawsuits have been filed to block the implementation of the MMPA import ban. With the full rollout of the COA system, the compliance burden for seafood exporters and US importers has increased significantly.
Key issues such as fishing methods, processing pathways, transshipment practices, and country-of-origin determination are no longer administrative formalities but central enforcement criteria. As a result, trade risk is shifting from regulatory backrooms to the front line of customs clearance, forcing the global seafood supply chain to adapt well ahead of the 2026 deadline.