Many areas of the ocean are off-limits to human activity for reasons other than conservation. Zones around coastal military bases may be completely closed for security purposes. Waters around oil platforms often restrict fishing or access in general. Anchoring is forbidden around undersea cables. These restrictions, by the fact that they limit some human impacts on these ocean sites, provide a degree of protection for the ecosystems there. For this reason, they are sometimes referred to as “de facto marine protected areas” – meaning MPAs in practice but not in law.

This month, the US National Marine Protected Areas Center released what may be the world’s first national-scale assessment of de facto MPAs, State of the Nation’s De Facto Marine Protected Areas (see the box at the end of this article). In recognition, MPA News examines how de facto MPAs could be integrated into national MPA systems, and describes a case where one such site has been converted to conservation-minded management.

What is a de facto MPA?

On land, there are many examples where non-conservation areas play important roles in resource management. Some military cases are particularly remarkable. On the Korean peninsula, for example, the 4-km-wide demilitarized zone (DMZ) – a heavily landmined no-man’s land for over 50 years – provides an unlikely wildlife sanctuary to Asiatic black bears, crane species, and perhaps even leopards and tigers, according to scientists. In the US, several endangered species have their most significant populations on military bases, which in some cases are the largest undeveloped spaces remaining in the species’ habitats.

In the marine realm, examples of de facto MPAs are readily found. The new report from the US National MPA Center lists a wide array, including:

  • Anchorage grounds – To protect government vessels or vessels carrying explosives from injury or sabotage;
  • Danger zones – To protect the public from target practice, bombing, rocket firing, or other especially hazardous operations;
  • Lightering zones – To confine and control the transfer of oil and hazardous materials (i.e., lightering);
  • Prohibited areas – To prevent transfer of oil and hazardous materials at sea;
  • Regulated navigation areas and traffic separation schemes – To control vessel traffic around ports and harbors;
  • Restricted areas – To provide security for government operations (and protection of the public from the risks of damage or injury arising from government activity) by prohibiting or limiting public access;
  • Safety zones – To limit access for safety or environmental reasons;
  • Security zones – To safeguard public or private infrastructure from destruction, loss, or injury from sabotage; and
  • Shipping safety fairways – To control the erection of structures in highly trafficked areas.

While the purpose of these areas is not conservation, the areas are, in fact, protective: they protect the public from various military and government activities…they protect military, government, and private facilities from the public…and they protect the public from environmental hazards, such as oil spills and ship collisions.

“Although de facto MPAs are not established or managed for conservation objectives, some may be located in ecologically significant ocean areas,” says Charlie Wahle, a co-author of the report and senior scientist at the National MPA Center. He says that if these sites are to be integrated in conservation efforts in a meaningful manner, steps must be taken.

“The conservation impact of these sites could be augmented in two ways,” says Wahle. “First, through collaborative planning and co-management between operational and conservation agencies, areas currently protected by de facto MPAs could be incorporated into growing networks of conservation MPAs. A new conservation MPA could be overlaid on the same footprint as the existing de facto MPA, but with place-based management measures targeting conservation outcomes.” As an example, Wahle cites Vandenberg State Marine Reserve off the coast of the US state of California. The marine reserve was designated in 2007 over an existing marine security zone for the coastal Vandenberg Air Force Base. Another example is Merritt Island National Wildlife Refuge in the state of Florida, part of which overlaps with the marine security zone for the Kennedy Space Center, where the space shuttle is launched. The overlapping portion of the wildlife refuge is closed to public access due to security concerns of the space center. The remainder of the refuge is open to various recreational activities, including fishing.

“Alternatively,” continues Wahle, “the management agency of a de facto MPA could independently modify its restrictions on access and use to achieve complementary conservation objectives.” Such modifications would use appropriate authorities and guidance from conservation entities, he says. “In both scenarios, existing de facto MPAs could continue to serve their original operational purposes, such as safety zones, while also contributing significantly to environmental security goals.”

Conversion of a de facto MPA: Kaho’olawe Island, Hawai’i

Kaho’olawe Island, 115 km2 in size, is the smallest of the eight main volcanic islands in the Hawaiian archipelago. First settled by people as early as 400 A.D., Kaho’olawe served several uses for Native Hawaiians over the ensuing centuries – as a home to farmers and fishers, a site for religious and cultural ceremonies, and even a navigation training center for trans-Pacific voyaging. In the early 1800s, it was converted to a prison colony, then to ranch land. In the mid-20th century, following the attack on the Pearl Harbor Naval Station, the US military declared martial law over Hawai’i and began using Kaho’olawe as a bombing range. Title to the island was later transferred to the US Navy to continue this use, under the condition that Kaho’olawe be returned in habitable condition when no longer needed by the military.

Native Hawaiian groups filed suit in the 1970s to have the land returned and, after bombing was stopped in 1990, Kaho’olawe was officially transferred back to the state of Hawai’i in 1994. The US government approved a US $400 million cleanup fund. The island and its surrounding waters, which include an extensive and relatively intact reef system, are now the Kaho’olawe Island Reserve. Except for limited trolling (to which the reserve is open two weekends of each month) and subsistence fishing for consumption while on the island (allowed once a month), the marine portion of the reserve is no-take.

Emmett Aluli, who helped lead the legal effort to transfer Kaho’olawe back to Hawai’i, is chair of the Kaho’olawe Island Reserve Commission (KIRC), which manages the reserve ( Some of the main challenges faced by KIRC, says Aluli, are common to ones encountered by many protected areas – like reducing surface soil erosion and associated runoff to the reef, and controlling alien species. But other challenges are more unique to the reserve, and relate to the island’s modern history.

“Remnant unexploded ordnance (UXO) in the reserve waters is one of our main challenges,” he says. These unexploded bombs, left over from the island’s military days, lie on the seafloor and present a severe hazard. This is one reason why most fishing is banned in the reserve. “The cleanup of Kaho’olawe by the federal government was limited to land-based UXO clearance work with no ocean cleanup,” says Aluli. “This requires our ocean operations always to consider the UXO risk when establishing moorings, anchorages, and other underwater works.”

Illegal fishing activity is another challenge, he says. “Our ocean resources were previously protected within a federal restricted area patrolled by the Navy,” says Aluli. “Upon turnover to the state of Hawai’i, the marine reserve was established to extend two nautical miles offshore, approximately the same distance as the federal restricted area. Our main challenge has been patrolling and enforcing the reserve waters. Poaching increased with the transfer from the Navy: fishermen no longer worried about the bombing or the risk of vessel seizure by the federal government. Under state jurisdiction, our penalties for illegal fishing are mostly low fines.”

Aluli defines the reserve as being more of a marine managed area than a marine protected area, despite the fact that Kaho’olawe is now overseen with the health of its resources in mind. “Our primary purpose for the reserve is the perpetuation of traditional Native Hawaiian practices, which include subsistence fishing and gathering,” he says. “As such, a sustainable ecosystem that is consistent with pre-contact Native Hawaiian conservation restrictions is a necessary component to implement traditional Native Hawaiian practices.”

Aluli says the intention of KIRC was always to allow for subsistence while on the island. “Our establishing legislation included provisions to develop rules to permit fishing consistent with the purpose of the reserve,” he says. “In addition there was pressure from the powerful Maui fishing lobby. The pelagic species that are the primary target species for trolling are not habitat-based, but transient through the reserve. Therefore we felt that allowing limited and controlled trolling, in which vessels must register with the KIRC and submit catch reports, would be a minor compromise to protect the overall health of the intact marine ecosystem.”

For more information:

Charles M. Wahle, National Marine Protected Areas Center, US. E-mail:

Noa Emmett Aluli, KIRC, Hawai’i, US. E-mail:

BOX: Report on de facto MPAs

The report State of the Nation’s De Facto Marine Protected Areas, published by the US National Marine Protected Areas Center, is available at It was co-authored by Rikki Grober-Dunsmore, Charles Wahle, Lisa Wooninck, and Lauren Wenzel.

BOX: The case of Vieques, Puerto Rico

Isla Vieques is 13 km to the east of Puerto Rico, a US island commonwealth in the northeastern Caribbean. Vieques is a municipality of the larger island. Similar to Kaho’olawe Island in Hawai’i, Vieques was used for decades as a US Navy bombing range. A series of protests by Puerto Rican citizens led to the Navy’s departure from the island in 2003, and the military transferred terrestrial portions of the Vieques naval base to the US Fish and Wildlife Service. But the island’s marine area – formerly a danger zone but containing some of the healthiest coral reef habitat in the US territories – remains in limbo. After half a century of strict military protection, Vieques waters have been opened to fishing by Puerto Rico’s Department of Natural Resources while the government decides the area’s future.

Eugenio Piñeiro, a member of the US Caribbean Fishery Management Council and the federal MPA Advisory Committee, says Puerto Rican officials seek to establish an MPA on the site but lack the funds to do it. (At the federal level a bill, HR 5864, has been introduced to the US Congress that would designate one bay on Vieques as a national marine sanctuary.) Piñeiro says commonwealth-level planning efforts have been delayed by conflicting views among various stakeholder groups and scientists on how such an MPA would best be managed.

“The information I get from personal interviews with charter-boat operators and commercial fishermen is that the fishing in Vieques is very good,” says Piñeiro. “Commercial fishing on Vieques takes place in nearshore waters, mostly for reef fish. An increasing amount of recreational fishing activity, coming from the ‘Big Island’ [Puerto Rico], has been observed since the Navy’s departure. The primary target of these fishers is coastal pelagics and also billfish.” He notes there are more than 60,000 registered recreational vessels in Puerto Rico.

Piñeiro, a commercial fishermen himself, says he would like to see the MPA planning proceed. “Once funds are allocated, the creation of an MPA network around Vieques should begin as soon as possible to preserve the natural wonders of this island paradise,” he says. “Vieques may have been used as a Navy range for six decades, but it is still majestic.”

For more information:

Eugenio Piñeiro-Soler, Caribbean Fishery Management Council. E-mail: