A marine sanctuary is a general type of marine protected area (MPA). An MPA is a section of the ocean where a government has placed limits on human activity. Different types of MPAs allow different types of activities, such as scientific research, recreation, or commercial fishing.

It is important to note that MPAs and marine sanctuaries have different names in different countries. The restrictions on extractive activities are dictated by the marine protection legislation in those countries. For example, a marine sanctuary in the United States often allows fishing, but in Ecuador it means an area without fishing.

Sanctuary waters may provide a secure habitat for endangered species. Sanctuaries may also protect shipwrecks and historic artifacts. They serve as outdoor classrooms for schoolchildren and laboratories for researchers who want to better understand and protect the ocean environment. Sanctuaries also protect economically important fisheries.

Marine sanctuaries often have different zones, which allow different activities. A permit system usually regulates these activities, such as fishing or recreational water sports. Only a certain number of permits are issued every year. The permits allow the MPA to prevent overfishing or pollution due to boats or other personal watercraft.

A marine sanctuary's staff also educates the public about responsible behavior. This allows the public to enjoy marine sanctuaries for recreation, tourism, and fishing in a sustainable manner.

Flower Garden Banks National Marine Sanctuary
Flower Garden Banks National Marine Sanctuary is one of 14 underwater areas protected by the National Oceanic and Atmospheric Administration (NOAA). The sanctuary protects three separate sand banks that are located 112 to 184 kilometers (70 to 115 miles) off the coasts of the U.S. states of Texas and Louisiana. These banks are actually underwater mountains called salt domes.

Salt domes formed about 190 million years ago, when the Gulf of Mexico was a shallow sea. The hot, dry climate caused the seawater to evaporate quickly, leaving a thick layer of salt on the seafloor. Eventually, the Gulf of Mexico deepened and rivers, such as the Mississippi, began to flow into it. Mud, sand, and silt were steadily deposited over the salt layers. The pressure from these denser sediments caused the salt layer to push upward. Some salt layers broke through the sediments completely, while others forced the seafloor to bulge upward in mountainous domes. Salt domes occur across the entire northwestern Gulf of Mexico.

Flower Garden Banks received its MPA status for the abundance of marine life. The domes are dotted by coral reefs, which provide a habitat for hundreds of fish, sponges, and invertebrates such as shrimp. The endangered loggerhead sea turtle (Caretta caretta) lives in Flower Garden Banks.

Like most marine sanctuaries, Flower Garden Banks provides different zones for human activities. The MPA has ongoing research projects, so biologists and other scientists can monitor marine life in the area. The brightly colored coral reef ecosystems are a popular site for snorkelers and scuba divers. Commercial fishing is not allowed in the sanctuary, but sport fishing using traditional hook-and-line gear is permitted. By not allowing fishing nets, the sanctuary protects against the accidental bycatch of loggerhead sea turtles.

Pelagos Sanctuary for Mediterranean Marine Animals
The Pelagos Sanctuary for Mediterranean Marine Mammals is a vast marine protected area in the Mediterranean Sea. The Pelagos sanctuary reaches France, Monaco, Italy, the French island of Corsica, and the Italian island of Sardinia.

The sanctuary is a feeding area and breeding ground for a variety of marine mammals called cetaceans. Whales, dolphins, and porpoises are cetaceans. Pelagos sanctuary is home to fin whales, sperm whales (Physeter macrocephalus), Cuvier's beaked whales (Ziphius cavirostris), long-finned pilot whales (Globicephala melas), Risso's dolphins (Grampus griseus), common bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), and short-beaked common dolphins (Delphinus delphis).

The Pelagos sanctuary includes busy ports such as Nice, France; Monte Carlo, Monaco; and Genoa, Italy. The human activity surrounding these ports puts pressure on the marine environment. Pollution linked to cruise ships, fishing vessels, and offshore motorboat racing threatens the habitats and organisms in the sanctuary. This pollution increases during the summer, as tourists migrate to the sanctuary's coast, known as the Riviera.

Restrictions aim to regulate and lessen the impact of these human activities in the sanctuary. The governments of France, Monaco, and Italy have agreed to begin phasing out the release of toxic pollutants in the sanctuary. They also monitor pollution levels and fine individuals or businesses that illegally dump in sanctuary waters.

Fishing is allowed in Pelagos sanctuary. However, permits are required for both commercial and sport fishing. There are also limits on how much fish can be caught and what methods can be used. Limitations are designed to protect the sanctuary's cetacean population. Fishing limits prevent a severe reduction in fish eaten by cetaceans. Fishing methods must reduce the risk that marine mammals (mostly cetaceans and sea turtles) are accidentally caught instead of fish.

By protecting the Pelagos sanctuary from pollution and overfishing, the governments of the Riviera hope to preserve the areas environmental and economic importance.