Piti Bomb Holes Marine Preserve is a

marine protected area A marine protected area (MPA) is a protected area of the world's seas, oceans, estuaries or in the US, the Great Lakes. These marine areas can come in many forms ranging from wildlife refuges to research facilities. MPAs restrict human activity ...

comprising all of Piti Bay on the western coast of

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

, located off of the village of

Piti In relation to a mortgage, PITI (pronounced like the word "pity") is the sum of the monthly principal, interest, taxes, and insurance, the component costs that add up to the monthly mortgage payment in most mortgages. That is, PITI is the sum of th ...

in the

Philippine Sea The Philippine Sea is a List of seas#Marginal seas by ocean, marginal sea of the Pacific Ocean, Western Pacific Ocean east of the list of islands of the Philippines, Philippine Archipelago (hence the name) and the List of seas#Largest seas ...

. The defining "bomb hole" features, named because they look like bomb craters in the reef flat, are actually natural percolation pits where fresh water filters into the shallow lagoon at a depth of . The largest pit houses the commercial Fish Eye Marine Park tourist attraction, which includes a wooden pier to a underwater observatory and a Seawalker tour of the lagoon bottom. It is visited by more than 200,000 people annually. The Piti preserve is the most ecologically diverse of Guam's five marine preserves. The pit around Fish Eye is a popular

snorkeling Snorkeling (American and British English spelling differences#Doubled in British English, British and Commonwealth English spelling: snorkelling) is the practice of human swimming, swimming face down on or through a body of water while breathing ...

and recreational diving site.

Geography

The preserve is , of which is a broad reef flat. It shares a

fringing reef A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows direc ...

line with the regularly fished

Asan Bay Asan Bay is a South Korean bay in the Yellow Sea. Named after the city of Asan immediately to its south, it lies at the mouth of several rivers and separates the provinces of Gyeonggi-do and Chungcheongnam-do South Chungcheong Province (), info ...

reef line. The eastern boundary of the preserve is off the tip of

Asan Point Asan (; ) is a city in South Chungcheong Province, South Korea. It borders the Seoul Capital Area to the north. Asan has a population of approximately 400,000. Asan is known for its many hot springs and is a city of spas. Asan has grown into ...

in the village of Asan-Maina. Asan Point is the western boundary of

Asan Invasion Beach The Asan Invasion Beach is a historic site in the village of Asan, Guam. The beaches of Asan were one of the landing sites of American forces in the 1944 Battle of Guam (1944), Battle of Guam, in which the island was retaken from occupying Japane ...

, the northern invasion beach used by American forces in the 1944 retaking of the island. Therefore, portions of Piti Bomb Holes Marine Preserve around Asan Point also fall under the submarine portions of

War in the Pacific National Historical Park The War in the Pacific National Historical Park is a multi-unit protected area in the United States territory of Guam, which was established in 1978 in honor of those who participated in the Pacific Theater of World War II. Uniquely among the Na ...

's Asan Beach unit. The southern shoreline with Piti includes two beach parks: Tepungan Beach, at the entrance to the Fish Eye Marine Park pier, and Pedro Santos Memorial Park, farther west. Three rivers drain into the preserve: from east to west, these are the Matgue River, the

Taguag River The Taguag River is a river in the United States territory of Guam. See also *List of rivers of Guam This is a list of rivers in Guam, a (U.S. territory) in the western Pacific Ocean. The list is arranged alphabetically by the name of the river. ...

, and the

Masso River The Masso River is a river in the United States territory of Guam and empties into the western Pacific Ocean. See also *List of rivers of Guam References

Rivers of Guam {{Guam-river-stub ...

. The western boundary of the preserve includes portions of

Cabras Island Cabras Island was historically a low-lying finger of land off the coast of Piti, Guam that formed part of the northern protective arm of Apra Harbor. Shortly after the 1944 Battle of Guam it was connected by a causeway to the mainland and exten ...

to Piti Canal, a man-made cut, and includes the Tepungan Channel. Piti Canal and Tepungan Channel are used to intake cooling water intake to the

Guam Power Authority The Guam Power Authority (GPA, ) is an agency of the Government of Guam and Guam's electricity provider. Its headquarters are in Fadian, Mangilao, Guam.Apra Harbor Apra Harbor, also called Port Apra, is a deep-water port on the western side of the United States territory of Guam. It is considered one of the best natural ports in the Pacific Ocean. The harbor is bounded by Cabras Island and the Glass Breakwat ...

. Tepungan Channel and other parts of the western preserve include a cable trench for

submarine communications cable A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables were laid beginning in the 1850s and car ...

s landing at Piti.

Ecology

Much of the shoreline is fringed by

seagrass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...

es, which provide refuge for juvenile fish, while the three small river mouths provide

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

nursery habitat for many species. The "bomb holes", actually freshwater percolation pits, are the deepest features of the preserve, ranging down to . Two identified species of

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

and one species of

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Piti Bomb Holes Preserve, being found nowhere else in the world. The sinkholes have dense populations of

hard Hard means something that is difficult to do. It may also refer to: * Hardness, resistance of physical materials to deformation or fracture * Hard water, water with high mineral content Arts and entertainment * Hard (TV series), ''Hard'' (TV ser ...

and

soft coral Alcyonacea is the old scientific order name for the informal group known as "soft corals". It is now an unaccepted name for class Octocorallia. It became deprecated . The following text should be considered a historical, outdated way of treatin ...

, supporting fish and invertebrate populations not found elsewhere in the preserve. The Piti preserve is the most ecologically diverse of Guam's five marine protected areas (MPAs), which was the driving factor why it was selected as an MPA site in 1999. Establishment of the preserve resulted in a greater than 100% increase in the number of fish. Unlike Guam's other marine preserves, no fishing of any kind is permitted by default between the Piti shore and outer reef margin. Trolling outward of the reef line is allowed. A 2007 researcher observed many fishermen "fishing the line" in the hopes of catching larger fish coming out of the MPA. The

Guam Department of Agriculture The Guam Department of Agriculture is a government agency in the United States territory of Guam. Its headquarters are in the village Mangilao.Achang Reef Flat Marine Preserves, was the only to create spillover for adjacent fishing areas in all of its studied species, perhaps because it was the only studied area with a continuous reef line. The study found that the Piti Bomb Holes Marine Preserve spillover into the unrestricted fishing area of neighboring Asan Bay for convict surgeonfish, honeycomb grouper, yellowstripe goatfish,

orangespine unicornfish ''Naso lituratus'', the clown unicornfish, orangespined unicornfish, orangespine unicornfish, black-finned unicornfish, Pacific orangespined unicornfish, blackfinned unicornfish or stripefaced unicornfish, is a species of marine ray-finned fish b ...

, and little spinefoot was +14.1%, +7.5%, +30.8%, +25.4%, and +23.7%, respectively. Guam's first coral nursery was established at the Piti preserve in 2013 as a joint project of the

University of Guam University of Guam () (U.O.G.) is a public university, public land-grant university in Mangilao, Guam. It is accredited by the Western Association of Schools and Colleges and offers thirty-four degree programs at the undergraduate level and ele ...

Marine Lab,

UnderWater World Guam UnderWater World Guam is one of the longest tunnel-aquariums in the world and the only oceanarium in the United States territory of Guam. The aquarium opened in 1999 and has more than 2,000 animals representing more than 80 different species. M ...

, and SECORE International. The Piti nursery includes three types of restoration structures: coral tables, A-frames, and coral trees. These structures allow marine biologists to place sexually mature corals next to each other, increases the change of fertilization and new coral growth. A 2019 study noted that there had been significant

coral bleaching Coral bleaching is the process when corals become white due to loss of Symbiosis, symbiotic algae and Photosynthesis, photosynthetic pigments. This loss of pigment can be caused by various stressors, such as changes in water temperature, light, ...

at Piti Bomb Holes in four of the last five years. The study noted that ''

Sinularia maxima ''Sinularia'' is a genus of soft coral in the family Alcyoniidae. They are commonly known as leather corals and currently have 166 described species A species () is often defined as the largest group of organisms in which any two individual ...

'' and the hybrid ''S. maxima x polydactyla'' were more susceptible to bleaching than ''

Sinularia polydactyla ''Sinularia polydactyla'', known as finger leather coral, is a species of soft coral Alcyonacea is the old scientific order name for the informal group known as "soft corals". It is now an unaccepted name for class Octocorallia. It became dep ...

'', and it appeared after early events that ''S. polyactyla'' would take over the

niches occupied by ''S. maxima'' and ''S. maxima x polydactyla'' on Guam's back reefs. However, the successive events eventually overcame ''S. polyactylas resistance, with the most likely outcome being continued loss of coral structure as a whole. Before 2013, there were no records of Guam reefs bleaching for at least two decades, as Guam seas had experienced normal temperature ranges during the globally devastating

1997–98 El Niño event The 1997–1998 El Niño was regarded as one of the most powerful El Niño–Southern Oscillation events in recorded history, resulting in widespread droughts, flooding and other natural disasters across the globe. It caused an estimated 16% of ...

. Arrests of fishermen within the Piti Bomb Holes Marine Preserve continue to be made. After a 2020 arrest, Agriculture Director Chelsa Muna-Brecht stated, "The preserves exist to help our reef fish stock replenish, to help our corals recover and thrive, and to ensure our waters are a healthy habitat for our marine life. Each time poachers kill fish and marine life in our (marine preserves), they steal from our community and they risk the health and restoration of our critical ocean habitats."

Fish Eye Marine Park

The underwater observatory at Fish Eye Marine Park was constructed in 1996 in the eastern section of Piti Bay. It is located within the largest "bomb hole" and is the only underwater observatory in

Micronesia Micronesia (, ) is a subregion of Oceania, consisting of approximately 2,000 small islands in the Northwestern Pacific Ocean. It has a close shared cultural history with three other island regions: Maritime Southeast Asia to the west, Poly ...

. It is visited by over 200,000 people annually. The deepest observation window is at about underwater. The observatory is reached by a -long wooden boardwalk. The pier also provides access to the Guam Seawalker business, in which customers put on surface-supplied helmets to look at sea life underwater. The area around the underwater observatory is a snorkeling and

recreational diving Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...

site, referred to as Fish Eye, Fisheye, or Piti Bomb Holes. The easy access, protective fringe reef, and shallow sandy bottom of the pit attract many dive classes. Due to both the many inexperienced diver groups and the feeding conducted at both the observatory and Seawalker locations, local fish are not as skittish as usual. The site is thus well suited to

underwater photography Underwater photography is the practice of capturing images beneath the surface of the water, often done while scuba diving, but can also be done while diving on surface supply, snorkeling, swimming, from a submersible or remotely operated und ...

. Entry is typically done from Tepungan Park, walking or snorkeling out along the right of the pier for , depending on tides. The left of the pier has many seagrasses that are habitat for juvenile fish that may be damaged by walkers. Piti Bomb Holes is a favored spot for introductory night dives; while pier lights are turned off early in the evening, street lighting from

Marine Corps Drive Guam Highway 1 (GH-1), also known as Marine Corps Drive, is one of the primary automobile routes in the United States territory of Guam. It runs in a southwest-to-northeast direction, from the main gate of Naval Base Guam in the southwestern vi ...

along the shore provide some ambient light and easy orientation. The number of divers at Piti Bomb Holes increased dramatically after access to a third location particularly suitable for dive classes, Outhouse Beach on

Apra Harbor Apra Harbor, also called Port Apra, is a deep-water port on the western side of the United States territory of Guam. It is considered one of the best natural ports in the Pacific Ocean. The harbor is bounded by Cabras Island and the Glass Breakwat ...

, was restricted in 2001. In the aftermath of the

September 11, 2001 attacks The September 11 attacks, also known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, crashing the first two into ...

, Outhouse Beach was deemed too close to critical infrastructure around the

Port of Guam The Port of Guam (officially, Jose D. Leon Guerrero Commercial Port) handles over ninety percent of total imports to the United States island territory of Guam. Located in the north of Apra Harbor on Cabras Island, it shares harbor waters with ...

. An estimated 50 to 200 dives occurred daily within a section of Piti Bomb Holes Marine Preserve, putting the number of annual dives at over 18,000. The threshold at which coral damage can rapidly accumulate is 4,000 to 6,000 dives, putting the area hosting the vast majority of divers at severe risk.

References

External links

* {{Guam Piti, Guam Bays of Guam Protected areas of Guam Marine protected areas Underwater diving sites in Guam Marine protected areas of the United States