NYC Oyster Monitoring Report: 2025

Billion Oyster Project's eighth annual monitoring report — covering twelve active restoration sites across four regional waterbodies: Upper New York Harbor, Lower New York Harbor & Raritan Bay, Jamaica Bay, and Western Long Island Sound. This is the most data-rich report in the series to date, with nearly 14,000 oysters counted and measured and a new mobile-species baseline that expands the program's ecological scope beyond oyster performance alone.

Multi-phase installation and periodic reseeding continue to sustain large oyster populations at long-running sites. Brooklyn Bridge Park holds an estimated ~10.5 million oysters, Head of Bay ~13.8 million, and Soundview Park 5.3–9.1 million. These sites demonstrate that multi-phase restoration — introducing multiple cohorts over successive years — is an effective strategy for maintaining populations despite expected mortality in recruitment-limited systems.

Long-term monitoring confirms that oysters persist for multiple years and reach large sizes across multiple waterbodies. Average shell heights exceed 160 mm at Bush Terminal Park, approach 100 mm at Paerdegat Basin, and surpass 147 mm at Head of Bay — indicating the Harbor's capacity to support mature, reproductively viable oysters. These large individuals represent the breeding stock that any future self-sustaining population will depend on.

Recruitment of wild oyster spat was observed at several sites in 2025, including Soundview Park, Brooklyn Bridge Park, and the Living Breakwaters. However, recruitment remains low and highly variable, and does not currently outweigh mortality. As a result, restored reefs have not yet achieved self-sustaining population dynamics — continued human intervention through reseeding remains necessary.

2025 established the first Harbor-wide quantitative baseline for mobile species use of oyster reefs. Over 580 minnow and sea bass trap deployments across eight sites documented more than 4,000 individual fish, crabs, shrimp, and other invertebrates representing 44 unique taxa. These data represent a significant advancement toward quantifying the habitat value and ecological uplift associated with oyster restoration, and provide a critical baseline for future assessment using approaches such as eDNA and underwater video.

The report marks BOP's strategic transition from pilot-scale experiments to landscape-scale restoration. Several early pilot-scale reefs, while essential to building foundational knowledge, have reached the end of their experimental value. Retiring these projects allows resources to be concentrated on larger, more durable reefs designed to achieve population-level sustainability and ecosystem-scale outcomes — the kind of multi-acre, high-density installations that the data now shows are required for self-sustaining populations.

Collectively, these findings demonstrate that oyster restoration is biologically and technically feasible in New York Harbor, but requires sustained investment, adaptive management, and landscape-scale planning to achieve ecosystem-level outcomes. The report provides site-specific performance grades across growth, mortality, and recruitment for all twelve sites, along with recommended restoration actions for each.