Dive Into an MPA

MPAs harbor some of the most diverse coral reefs in Puerto Rico, including threatened species such as pillar coral.

As you descend through the water column, the underwater world surrounds you. While you might see waving columns of kelp or colorful coral reefs, you won't see lines demarcating boundaries between the open ocean and safeguarded places called marine protected areas (MPAs). This protection makes a difference for the long-term health of the marine resources that divers love and the broader ocean ecosystems of which they are a part.

The MPA landscape is diverse in the United States: The National Oceanic and Atmospheric Administration (NOAA) reports there are more than 1,200 MPAs as defined by the International Union for Conservation of Nature (IUCN), with most areas managed by federal, tribal, territorial, state or local agencies. This unique management framework allows each MPA to be specially tailored to address local challenges.

Ofu lagoon hosts a healthy coral colony of branching Acropora abrotanoides.
Safeguarding a range of marine environments across a broad swath of U.S. waters, MPAs provide a system of protection that allows for ecological connectivity. Many species use multiple habitats and geographic areas throughout their lives; MPAs ensure that areas important to these species are protected regardless of the animals' life stage or seasonal need. Increasingly necessary as species move in response to changing ocean temperatures, the MPA network provides corridors to new habitats and supports the species in new locations.

While the primary function of MPAs is to conserve marine resources, most of them allow some level of public access. Despite common misconceptions, nonconsumptive activities such as diving are typically welcome. The following information describes a few different types of MPAs from around the country that offer a variety of opportunities for divers.
Puerto Rico
Often overlooked by Caribbean divers, Puerto Rico has a lot to offer despite the recent hurricanes. NOAA reported that the 2017 hurricanes damaged an average of 11 percent of Puerto Rico's corals, but there was considerable variability of damage between sites and the amount and species of corals damaged at each site. While the damage remains visible, many great diving opportunities still exist.

Off the main island of Puerto Rico, the smaller islands of Desecheo, Vieques and Culebra offer notable diving spots. These sites are home to protected areas both on land as national wildlife refuges (NWRs) and at sea (part of Puerto Rico's MPA system) in a true "ridge-to-reef" protection approach. These islands are home to the Desecheo National Wildlife Refuge, Desecheo Island Marine Reserve, Vieques National Wildlife Refuge, Vieques Bioluminescent Bay Nature Reserve, Culebra National Wildlife Refuge and Canal Luis Peña Natural Reserve.

Puerto Rico’s Yellow Reef dive site has many sponge-decorated resting stops for this juvenile nurse shark.

Approximately 800 species of fish inhabit the coastal waters around Puerto Rico and the surrounding islands, and Vieques and Culebra are known for their green sea turtle populations. Divers can also see hard and soft corals, sponges, sea fans, nurse sharks, turtles, spotted eagle rays, large slipper lobsters and the occasional manatee or bottlenose dolphin year-round. Winter may bring the sound of humpback whales singing.

Development restrictions in NWRs help to protect fragile marine ecosystems from erosion and sedimentation damage, keeping surrounding waters clear. Restoration projects are also critical. The U.S. Fish and Wildlife Service (USFWS), Island Conservation and other partners, for example, completed a rat eradication project at Desecheo. Research demonstrates that islands without invasive rats have healthier coral reefs with more fish and greater resistance to warming waters. Within the NWR sites, protected beaches offer nesting areas for green and hawksbill sea turtles, while the water holds critical habitat for sea turtles and Acropora (branching) corals. Fishing is prohibited within some areas of the marine reserves, ensuring abundant populations of a variety of fish species.

Popular dive sites are located both inside and outside of protected areas and vary in difficulty due to strong currents, but the waters surrounding each island offer something for all skill levels. Water temperatures range from 74°F to 80°F, with visibility exceeding 100 feet. Check with local authorities about diving regulations. Some terrestrial areas of the NWRs are closed to the public due to unexploded ordnance and to protect fragile ecosystems.
The warm and inviting turquoise waters of Florida are home to hundreds of fish species found swimming around coral reefs, mangroves, seagrass beds and historic shipwrecks. The MPAs of southern Florida, which include Biscayne National Park, will not disappoint visitors who are interested in both the natural wonders of subtropical underwater habitats and an extensive maritime history.


The Mandalay rests in shallow water at Biscayne National Park.
National Park, established in 1968, features a variety of interesting dive sites. An abundance of wildlife exists from the shallow waters among the western mangrove shoreline to biologically diverse coral reef ledges along the park's eastern 60-foot depth boundary. Some ledges along the boundary feature unique drift and wall dives with plenty of vertical relief. The park is also home to 600 species of fish and more than 80 historic shipwrecks. Divers interested in the region's maritime history should explore the park's Maritime Heritage Trail, which features six wreck sites as well as the Fowey Rocks Lighthouse. Multiple mooring buoys are available at each site for convenient access.

The park sits near Miami, and its designation as a national park has allowed the underwater resources to remain as intact and healthy as possible among a growing population. All dives in Biscayne are accessible only by boat.
West Coast
With relatively easy access to some of the most pristine marine areas in the country, West Coast MPAs offer an outstanding diving experience. The California Current produces vibrant ecosystems that provide some of the best cold-water diving in the world. These sites protect vibrant kelp forests, colorful hydrocorals, sea otters, sea lions and hundreds of colorful invertebrates and fishes.

In 1999

A harbor seal swims through a kelp forest in California’s Blue Cavern State
Marine Conservation Area off Catalina Island.
California's legislature established the Marine Life Protection Act (MLPA), which required the state to redesign its system of existing MPAs to more coherently and effectively protect the state's marine life. Implemented incrementally from 2005 to 2012, the MLPA resulted in an ecologically connected network of 124 MPAs. Spanning California's 1,100-mile coast and encompassing approximately 740 square nautical miles, the California MPA network is the largest science-based, ecologically connected network of MPAs in North America and one of the largest in the world. The state manages an enormous diversity of ecosystems and species as well as critical habitats for several species of ecological and economic importance.

Most California MPAs are easily accessible by boat or from shore. While sites vary, the majority of California's MPAs are cold-water dives. The California Department of Fish and Wildlife does not maintain real-time on-site weather or dive conditions, so divers should check local conditions before heading out. Learn more about California's MPAs at californiampas.org.
South Pacific
Although difficult to reach, the far Pacific Ocean offers the reward of relatively pristine diving conditions to those who visit these remote tropical paradises. Warm-water sites protect deep coral reefs and snorkeling-depth corals with vibrantly colored fishes, sea turtles, sharks and many threatened and endangered species. The MPAs in American Samoa protect the only Indo-Pacific corals in the U.S. territories.

With three separate units on the islands of Tutuila, Ofu and Ta'u, the National Park of American Samoa manages and protects 9,500 acres of land and 4,000 acres of water containing wild, scenic paleotropical rainforest, coastal and coral reef environments. Its ecological diversity includes about 950 species of fish, 250 species of coral and 35 species of native birds along with endangered sea turtles and humpback whales. The park provides legal protection to fish and coral reef resources in partnership with local villages and territorial enforcement agencies.

This split-view perspective of Ofu lagoon in the National Park of American Samoa shows the islands of Ofu and Olosega.

The Ofu lagoon is an important living laboratory where researchers are studying the park's temperature-resistant corals. These corals evolved and developed genes to help them survive in unusually warm water. The researchers hope that other corals around the world will be able to similarly evolve to withstand increasing temperatures associated with climate change.

Diving on the islands of Tutuila and Ta'u is limited to a few dive charter boats and private vessels. Spectacular reefs, such as the ones in Ofu lagoon, are accessible from shore in snorkeling depths.
Great Lakes
The cold, clear waters of the Great Lakes feature some of the best freshwater diving opportunities in the world. Great Lakes MPAs protect a significant collection of shipwrecks, dock ruins that double as fish habitats, and other relics of Great Lakes maritime history. Visitors to Great Lakes MPAs will also encounter unique geological formations such as submerged cliffs, sea caves and overhangs.


The steam engine from the Henry Chisholm rests in 140 feet of water in
Lake Superior.
Royale National Park is renowned for its terrestrial features and 10 major shipwrecks. The wrecks scattered around this archipelago in Lake Superior remain in remarkable shape with almost no marine overgrowth, which makes diving them almost akin to visiting a ship shortly after it wrecked.

The park includes all submerged bottom lands within 4 miles of the main island, and these primary wrecks will receive frequent monitoring to assess their integrity over the years. Mooring systems on nine of the wrecks allow for easy access. Divers can view extensive hulls, superstructures, intact machinery and artifacts throughout all these wrecks.

The sites featured in this article are just a small glimpse of the vast diving experiences available throughout the U.S. MPA network. Future issues of Alert Diver will cover other MPAs in more detail. For information about all the sites, visit marineprotectedareas.noaa.gov. Visit an MPA, and appreciate the efforts of these sites to maintain the underwater habitats for the marine life we cherish.

Samantha Brooke is the Coastal Program team lead for the U.S. Fish and Wildlife Service National Wildlife Refuge System. Zachary Cannizzo is a Knauss Fellow with NOAA's Office of National Marine Sanctuaries, National MPA Center. Eva DiDonato is the chief of the Ocean and Coastal Resources Branch of the National Park Service. Special thanks to contributors Jan P. Zegarra (USFWS), Stephen Wertz (CDFW), Brenda Moraska-Lafrancois (NPS), Seth DePasqual (NPS), Michael Ausema (NPS), Irina Irvine (NPS), Eric Brown (NPS) and Shelby Moneysmith (NPS).
What Is an MPA?
Marine protected areas (MPAs) are spaces with valued habitats, species and features in oceans, coasts, estuaries and the Great Lakes that the government has given long-term protection. Federal agencies manage some MPAs, such as those included in national parks, national wildlife refuges and national marine sanctuaries. Most MPAs in the United States, however, are managed at the state, territorial, local or tribal levels. These areas include state parks, beaches and reserves.
Explore More
See more imagery from U.S. MPAs in a bonus online gallery, and then take a virtual tour of Califronia's MPAs at californiampas.org/explore/virtualtours.

© Alert Diver — Q3 Summer 2019