The United States National Marine Sanctuary System protects places in the ocean and Great Lakes for their ecological, cultural, archaeological and historical importance. A sanctuary may contain kelp forests and whales, coral reefs and shipwrecks, or all of these at once. The system began in 1972, and its map has continued to evolve as communities nominate places and scientific understanding grows.
This guide describes the 18 sites shown by NOAA after Papahānaumokuākea became a national marine sanctuary in 2025. Lake Ontario and Chumash Heritage had joined the system in 2024. Status can change as new sanctuaries are designated or management plans are revised, so readers should confirm the current system map before publishing a numerical claim in the future.
The national marine sanctuaries
Channel Islands
Off southern California, this sanctuary surrounds an island chain where cool and warm currents meet. Kelp forests, pinniped rookeries, seabirds and deep habitats make it a natural laboratory. Archaeological and maritime resources add a human history measured in thousands of years.
Chumash Heritage
Designated along California’s central coast after a community nomination led by the Northern Chumash Tribal Council, this sanctuary protects productive upwelling waters, kelp, wildlife and cultural landscapes. Its governance story is as important as its size because it centers Indigenous knowledge and co-stewardship.
Cordell Bank
A rocky bank rises from deep water off northern California but remains below the surface. Seasonal upwelling delivers nutrients that support invertebrates, fish, seabirds and whales. The sanctuary demonstrates how a hidden geological feature can organize an entire food web.
Greater Farallones
Waters north and west of San Francisco include estuaries, reefs, shelf habitat and the Farallon Islands. Strong upwelling drives high productivity, while shipping, fishing and a major metropolitan coastline make management complex.
Monterey Bay
Stretching along central California, Monterey Bay protects kelp forests, rocky shores, deep seafloor and one of North America’s most dramatic submarine canyons. Research institutions, fisheries, tourism and coastal communities make it a highly visible example of science-based sanctuary management.
Olympic Coast
Washington’s outer coast combines sea stacks, reefs, canyons and productive shelf water. The sanctuary overlaps the usual and accustomed fishing areas of coastal treaty tribes, making government-to-government relationships essential to stewardship.
Flower Garden Banks
Far offshore in the Gulf of Mexico, salt domes rise close enough to sunlight to support coral reefs. The sanctuary also includes additional banks with mesophotic reefs, algal-nodule habitat and deep communities. Its clear tropical appearance is remarkable within a sea shaped by river runoff and industry.
Florida Keys
This large sanctuary protects the connected habitats of the Florida Keys: coral reef, seagrass, mangrove and hard bottom. Heavy boating, fishing, tourism, coastal development, disease and heat stress make restoration and visitor behavior especially important.
Gray’s Reef
A compact sanctuary off Georgia protects a ‘live-bottom’ landscape where ledges and rocky outcrops support sponges, corals and fish. It shows that valuable reef habitat is not always a tropical coral structure.
Monitor
The first national marine sanctuary was created around the wreck of USS Monitor off North Carolina. Conservation of the Civil War ironclad established that sanctuary protection can focus on maritime heritage as well as living ecosystems.
Mallows Bay-Potomac River
In Maryland’s tidal Potomac, the remains of more than one hundred vessels create a distinctive cultural landscape and wildlife habitat. Kayakers can explore the area, but the wrecks are protected archaeological resources rather than souvenirs.
Stellwagen Bank
A shallow bank between Cape Ann and Cape Cod concentrates plankton, fish, seabirds and feeding whales. It is also a busy place for shipping, fishing and whale watching, so research on noise, collision risk and habitat use has direct management value.
Thunder Bay
Lake Huron’s cold freshwater preserves an exceptional collection of shipwrecks representing Great Lakes trade and travel. The sanctuary’s clear emphasis on history reminds readers that the national system includes the Great Lakes.
Wisconsin Shipwreck Coast
Along Lake Michigan, wrecks span wooden schooners, steamships and changing maritime technology. Cold freshwater can preserve hulls and cargo remarkably well, while diving and interpretation connect local communities with the lake’s industrial past.
Lake Ontario
This sanctuary protects shipwrecks and aircraft sites in eastern Lake Ontario. The resources document Indigenous travel, military conflict, settlement and commerce across a long-used inland sea.
Hawaiian Islands Humpback Whale
Shallow waters around the main Hawaiian Islands are globally important winter breeding and calving habitat for North Pacific humpback whales. Education, research and safe vessel behavior are central to the sanctuary’s work.
National Marine Sanctuary of American Samoa
Separate protected units encompass coral reefs, deep water, seamount habitat and places of profound Samoan cultural importance. Management connects village relationships, traditional knowledge and modern science across a remote tropical seascape.
Papahānaumokuākea
Designated as a national marine sanctuary in 2025, this vast Northwestern Hawaiian Islands seascape also remains a marine national monument and World Heritage property. Coral reefs, seabirds, monk seals, maritime heritage and Native Hawaiian cultural relationships are protected through layered, cooperative management.
Sanctuaries and marine national monuments
National marine sanctuaries are designated under the National Marine Sanctuaries Act. Marine national monuments are generally established under the Antiquities Act and may be jointly managed by several agencies. Papahānaumokuākea, for example, has monument and sanctuary dimensions and a distinctive co-management structure. The labels matter because authorities, rules and public processes differ.
Sanctuaries are also different from national parks, wildlife refuges, fishery management areas and state marine reserves. These systems can overlap. Overlap is not necessarily duplication; agencies may protect different resources under different laws. Visitors should follow the most protective applicable rule.
Research, education and maritime heritage
Sanctuaries function as places for long-term monitoring, technology trials, habitat mapping and restoration. Research permits allow work that would otherwise be restricted, while public programs translate findings through visitor centers, lesson plans and virtual dives. In the Great Lakes and at Monitor, archaeology is a leading theme. At Stellwagen Bank or the Hawaiian Islands, wildlife research may dominate public attention.
Maritime heritage includes more than wrecks. It encompasses routes, working waterfronts, Indigenous cultural landscapes and the knowledge people developed while living with water. Ethical interpretation avoids presenting a shipwreck as treasure and avoids treating Indigenous history as a decorative preface to modern management.
What protection means in practice
A marine protected area is not automatically a no-entry zone. Rules vary by site and may address fishing, anchoring, seabed disturbance, mineral extraction, wildlife approach, discharge, archaeological resources or commercial development. Some areas allow recreation and carefully managed fishing; others contain highly protected zones. The designation name alone does not tell visitors what is permitted. Anyone planning an activity should check the current regulations, maps, seasonal notices and permit requirements published by the responsible authority.
Effective protection requires more than drawing a boundary. Managers need clear objectives, scientific baselines, enforcement, monitoring and a way to adapt when conditions change. They also need durable relationships with Indigenous nations, local communities, fishers, scientists, tourism operators and other users. A well-managed site makes the reasons for its rules understandable and reports whether habitat, wildlife or cultural resources are improving.
Why networks matter
Ocean life moves. Whales migrate, fish shift with temperature, seabirds travel between colonies and feeding grounds, and larvae drift on currents. A single protected site can safeguard an important reef or nursery, but a connected network is more likely to represent different habitats and provide alternative refuges when one place is disturbed. Networks also help protect the sequence of places an animal needs during its life rather than only one visible destination.
Connectivity crosses jurisdictions. Canadian and United States waters share currents, migratory species and shipping routes, while many ecological regions also extend into Mexico and the high seas. Coordination does not require identical laws. It does require compatible monitoring, data sharing and attention to impacts that move across a boundary.
Climate change and adaptive management
Protected boundaries remain fixed while ocean conditions move. Marine heatwaves, sea-level rise, acidification, changing ice and shifting species ranges can transform the ecological character of a site. Managers therefore use protected areas as long-term observatories as well as conservation tools. Repeated surveys can reveal whether a reef is recovering, whether kelp is declining or whether a breeding population is using a new part of the coast.
Adaptive management means updating actions without abandoning the site’s purpose. It may involve seasonal measures, restoration, revised vessel guidance or cooperation with managers outside the boundary. Protection cannot stop global climate change by itself, but intact habitats often have a better chance of absorbing disturbance. Wetlands, reefs, kelp forests and seagrass beds can also support shoreline resilience and store carbon.
Visiting protected waters responsibly
Before a trip, use the official site map rather than a screenshot from an old blog. Check weather, tides, closures, wildlife-distance rules and whether anchoring, drones, fishing or collecting are restricted. Use installed moorings where required, keep a safe speed, pack out waste and clean boating or dive equipment to avoid moving invasive species. On shore, stay on durable surfaces and leave shells, corals and archaeological objects where they are.
Responsible tourism can support guides, museums, visitor centers and coastal businesses while building public support for conservation. The best visit leaves the place unchanged and the visitor better informed. If access is limited or prohibited, virtual dives, public data portals and local cultural centers can provide a meaningful alternative.
Measuring success
Success should be tied to the purpose of the site. Indicators may include coral cover, fish age structure, seabird nesting success, whale use, water quality, damage to shipwrecks or the condition of culturally important places. Managers also track compliance, visitor pressure and whether communities can participate in decisions. A rising headline number for protected area is useful only when the underlying protections are durable and effective.
Long-term results take patience. Some fish populations respond within years, while deep-sea corals or damaged cultural sites may need decades and may never fully recover. Transparent reporting helps the public distinguish between a newly announced boundary and a mature management program with demonstrated outcomes.
Maps, dates and trustworthy information
Protected-area information is time-sensitive. Boundaries can expand, names can change, a final regulation may differ from a proposal, and seasonal notices may temporarily alter access. Use the managing agency’s interactive map and legal documents for operational decisions. A general article is useful for orientation, but it cannot replace current charts, notices to mariners, fishery rules or permit conditions.
When comparing sites, attach a date to area totals and explain what the number includes. Distinguish a designated site from a proposed one and a permanent rule from an interim safeguard. These small editorial habits prevent a conservation guide from becoming misleading as programs evolve. They also make later updates easier because the source and measurement are visible. Readers can then verify changes for themselves.
Frequently asked questions
How many U.S. national marine sanctuaries are there?
NOAA’s system map showed 18 designated sanctuaries after Papahānaumokuākea joined in 2025. Additional sites remain in designation processes, so use NOAA’s current Find Your Sanctuary page for the latest official count.
Can people fish in a national marine sanctuary?
Sometimes. Rules differ among sanctuaries and may include zones, gear limits or species protections. Sanctuary status does not automatically prohibit all fishing, and fishery regulations may be administered under separate authorities.
Are sanctuaries open to visitors?
Most support compatible recreation, but access, anchoring, collecting, drones and wildlife approaches may be restricted. Remote places and sensitive cultural sites may require permits or have no general public access.
Why are shipwrecks protected?
Wrecks are nonrenewable historical records and may also be graves. Removing objects destroys archaeological context. Protection allows research, respectful visitation and public interpretation while leaving the resource intact.
Conclusion
America’s marine sanctuaries are not interchangeable blue parks. Each protects a particular relationship among water, wildlife, history and community. Together they provide research sites, public classrooms and durable safeguards, but their value depends on clear rules, partnership and continued care.