BAHÍA DE BANDERAS, Nayarit, Sept. 1, 2026 — Rock oyster harvesting reopened Tuesday along Nayarit’s Pacific coast after a three-month federal closure. The legal season continues through May 31, 2027.
The 2026 federal closure ran from June 1 through Aug. 31. It covered marine and estuarine federal waters from Sinaloa through Chiapas, including Nayarit and Jalisco.
The reopening applies to commercial permit holders. A federal order adopted in 2023 requires each rock oyster to measure at least 90 millimeters along its lower shell before capture.
Direct impact around Banderas Bay
The same federal calendar applies to Jalisco waters, including the coast off Puerto Vallarta. The clearest documented local effect, however, is on the Nayarit side of Banderas Bay.
Oyster divers and harvesters in Bucerías and La Cruz de Huanacaxtle guarded local beds during the closure, according to reporting from the communities in July. They aimed to discourage illegal extraction before the Sept. 1 reopening.
The change restores legal access to wild rock oysters for permit holders in those communities. It does not represent a forecast for restaurant prices or the volume available this season.
During the closure, area restaurants relied on farmed oysters from San Blas and other northern Nayarit municipalities, diver and oyster harvester Alain Paredes told the local reporter.
Paredes said, in comments translated from Spanish, that he hoped the protected period would leave “a good oyster population, a healthy population” by December and January.
The fishery also has a public history in Bucerías. By 2016, local divers had organized the 16th edition of the community’s Oyster Festival at Playa El Punto.
The reopening covers one oyster fishery
The rock oyster is known locally as ostión de roca or ostión de piedra. Federal rules identify it as Crassostrea iridescens. Current scientific literature also classifies it as Striostrea prismatica.
It should not be confused with the pleasure oyster, Crassostrea corteziensis. Federal authorities manage the two species under different calendars.
Under the separate 2026 schedule for pleasure oysters, that fishery remains under a July 15-Nov. 15 closure in the designated Pacific and Gulf of California waters.
The Sept. 1 reopening therefore does not authorize the unrestricted harvest of every oyster species along the Nayarit coast.
How the closure protects reproduction
The governing federal order says the June-through-August closure covers the rock oyster’s principal reproductive period. The dates are based on a technical opinion from the Mexican Institute for Sustainable Fisheries and Aquaculture Research.
A peer-reviewed study led by researchers from the Autonomous University of Nayarit provides more detail.
Researchers examined 322 commercially harvested oysters from Santa Cruz de Miramar, near San Blas. They recorded spawning from May through September, with the highest frequency in July.
The study estimated that rock oysters reached initial sexual maturity at 80.2 millimeters. The current federal minimum for harvesting is 90 millimeters.
Those findings came from oysters collected during 2014 at one Nayarit fishing site. They describe local reproductive patterns but do not measure every oyster bed along the state’s coast.
Nayarit’s larger oyster economy
Nayarit is one of Mexico’s main oyster-producing states, but official totals combine several species and production methods.
The 2023 national fisheries yearbook recorded 2,791 metric tons of total oyster production in Nayarit. That figure includes capture and aquaculture and cannot be assigned solely to the rock oyster season.
The rock oyster fishery itself remains largely artisanal. Federal fisheries documents describe harvesters working by free diving and removing oysters manually from rocky surfaces.
For fishing cooperatives, the reopening determines when that work can resume legally. The next scheduled closure begins June 1, 2027.
The National Aquaculture and Fisheries Commission accepts reports of illegal fishing or improper practices at 669 915 6913. According to the agency, the telephone line operates 24 hours a day.
