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Marine Survey of Mona - 1972

The main survey of the marine environment was conducted by staff and students from the University of Puerto Rico Department of Marine Sciences.

SCIENTIFIC PERSONNEL

Maximo J. Cerame-Vivas -- Observer (Guest Scientist)
Francisco A. Pagan-Font -- Chief Scientist
Jack Morelock -- Marine Geologist
Walter Hendrick -- Chief Underwater Operations
Gilberto Cintron -- Guest Scientist
Jose A. Gonzalez-Liboy -- Research Associate
Alida Ortiz -- Research Assistant
Edgardo Ortiz -- Research Assistant
Jeffrey Prentice -- Research Assistant
David Fast -- Research Assistant
Dennis Jordan -- Research Assistant
Richard Wallace -- Research Assistant
Ricardo Cortes -- Research Assistant

RECOMMENDATIONS

A detailed study of the marine resources of Mona Island is needed. Duration of the study should be at least two full years. Such a study would De best performed through the establishment of a permanent research station, from which all operations could be carried out. The facility could be constructed and equipped in such a fashion as to allow for terrestrial, aquatic and marine scientists to conduct their work. Results of the comprehensive study would serve to set the guidelines for the future development of Mona.
A permanent facility should be built on Mona Island to be employed in studies of short or long range nature. Scientists could be stationed in Mona on short or long-tour basis. In this way inputs from many parties would be utilized. Priority should De given to Puerto Rican institutions or agencies to conduct such studies.
Approximately, 2,000 acres of land should be set aside for use in scientific endeavors. However, within these 2,000 acres, Iow intensity usage by the public could be permitted.
Areas on the insula: shelf of Mona should also be reserved for scientific purposes. These areas should include, the bottom, the water column and the shoreline.
Studies of marine populations inhabiting the coastal waters of Mona would permit a better understanding of these resources. The results would allow for development of management techniques applicable to populations which are amenable to scientific exploitation or harvesting.

INTRODUCTION

This preliminary assessment was undertaken by a group of scientists and laymen who volunteered their services. Their efforts were oriented toward obtaining much needed knowledge on coastal waters and the littoral resources, which are of great significance to the island as a whole. Mona (with Monito) belongs to the group of enchanting small islands which make up Puerto Rico:s island system. It is one of the two islands (Desecheo being the other) of western Puerto Rico. Mona is the largest of these western islands. It is perhaps the most beautiful and mysterious of all of Puerto Rico's satellite islands. Part of its history is that of Puerto Rico, but Mona can also claim its own historical events. Legends and fantasy are part of that history. Because of these elements, since early times Mona has had an identity of its own.

For decades, the terrestrial environment of the island has been studied, but very little is known about Mona's coastal and underwater worlds.

BACKGROUND

This report was written from information obtained through field observations, collections, and literature review. Perhaps the most significant contributions to the report emanated from personal interviews with fishermen, government officials and other parites who for years had been familiar with the marine resources of Mona. People interviewed belonged to all walks of life. Much of their information was corroborated during the field survey.

The field portion of the study was conducted intensively during the period from September 1 through September 4, 1972. Because of the magnitude of the mission and the time limitation, the work was divided into several operational areas. The task force was divided correspondingly into sub-groups. The areas under consideration were the marine flora, the marine invertebrates, the marine fishes of coastal and coral reef nature, the underwater world in general, the queen conch (Strombus gigas) the West Indian topshell (Cittarium pica) and the spiny lobster (Panulirus argus) resources, the sand beaches, and the marine geological aspects of Mona.

The report does not present a complete picture of marine resources. It gives rather a partial overview of their potential utilization and value, possible courses of action leading toward their rational development and conservation, and their importance or significance relative to similar resources found on mainland Puerto Rico.

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MONA COASTS

The island's coasts, from Punta Este along the North and Northeast capes through Cabo Barrio Nuevo (and one mile beyond), is predominantly cliff type. Beyond El Capitan Cave through Punta Oeste, the coast consists primarily of a wide expanse of excellent white sand beaches with small patches of rocky shores. Beyond Punta Oeste and extending all the way to Punta Este, the coast conditions are again primarily white sand beaches, alternating with patches of rocky shores. The beaches of Mona include Playa de Pajaro, Sardinera, Isabela, Carabinero, Uvero, El Playazo, La Pocita, Los Ingleses, Playa Brava, and Playita del Caigo.

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UNDERWATER WORLD OF MONA

This Section deals with observations made during a series of dives to investigate the relatively deep water along the north coast; the precipitous shelf break on the south, and the surge channels that dominate the outside of the barrier reef on the west.

Objectives

Due to the limited time for underwater explorations, tasks were limited to visual impressions of corals, fishes, rocky environments, caves, tunnels, vegetation, visibility and shipwrecks; documenting with 35 mm photos whenever possible and emphasizing those features that distinguish underwater Mona as unique; or contrast with earlier observations since 1958 on Mona or with those made in Puerto Rican waters.

Dives

Seven dives were made as follows:

Cabo Noreste (Northeast Cape) -divers descended to a maximum depth of 100 ft. and swam with the current, east to west, visually scanning the wall and bottom characteristics for an approximate distance of 125 ft.
Lado oeste (West side) - 18 degrees 0.06 minutes north- 67 degrees 56.3 minutes west-divers swam depths ranging from near surface to thirty five feet and covered approximately 600 ft. to the south.
Suroeste (Southwest) -18 degrees 0.44 north- 67 degrees 56.3 minutes west-divers skin dived and made brief observations at 60 to 80 ft.
A half mile east of Cabo Noreste divers entered the water close to the wall checking small caves, fishes, and rock habitats. They swam with the current, east to west, for about 1000 ft. at depth of approximately 40 ft., making occasional excursions to depths of 80 and 90 ft.
From where number two terminated 1200 ft. to the south
About half way between West Point and Uvero Anchorage on the south coast at 18 degrees, 0.0415 minutes -67 degrees 55.6 minutes- divers descended to 150 ft. along the vertical shelf break.
From the location of dive number two to Cabo Barrio Nuevo. F-3

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Combined observations from seven dives

The north wall descends almost vertically to depths of 90 and 100 ft. Along its face grow huge basket sponges oriented horizontally rather than the usual upright position. Gorgonian corals and plants also aligned at right angles from the cliff face undulating vertically as wave energy dissipates over their flexible forms. Below them, where large slabs and boulders of cliff material have fallen, are ocean surgeonfish, red snapper, yellow tail, school master, queen and french angels, rock hind, red and Nassau grouper, giant parrotfish, rock beauties, margate, and jacks. Fish seem larger and certainly in greater abundance than noted in other waters of similar depth and habitat characteristics around Puerto Rico. These conditions were true because of the prevailing undisturbed conditions. Vertical visibility was 90 ft., whereas horizontal visibility exceeded the vertical on that day. A timed swim with the current by one diver estimated the visibility at 150 ft.

Barracudas swimming in pairs or alone were spotted. One sea turtle slightly more than three feet across swam near the divers, seemingly interested in what they were doing.

A current of approximately 60 feet per minute moved from east to west along the cliff face at the surface and below. Waves breaking along the face sometimes found small caves at the air-water interface. A tremendous force of energy is expended here, driving great volumes of water into the entrances. Divers would be prudent to avoid this type of interface. As one swims away from the cliff face underwater at depth, the rocky environment diminishes and a sandy rather barren bottom emerges. A few small encrusting corals can be seen on limestone slabs and boulders.

A very exciting area is the drop off on the south. Just a few hundred feet from shore the continental shelf breaks at 50 and 60 ft. The break is shear with a precipitous drop to 150 ft. where a narrow terrace coated with calcareous sediment extends further south and once again drops dramatically to a greater depth. The water is blue and clear. Soft gorgonlan corals flourish in spectacular abundance along the vertical face. A thermocline seen as a change in light refraction and felt by the diver's flesh is easily detected at 130 ft. A stratification of marine growth is noted while descending, and forests of black coral appear around 140 ft.

Above, at depths of 50 and 60 ft., massive corals with vertical reliefs of 15 and 20 ft. are just off from the continental shelf. They appear healthy and extremely well nourished. Fishes of many species swim over, around and into them, while overhead swim barracudas, amberjacks and blue runners. Like the north wall, basket sponges project out horizontally, resembling cannons protruding from a ship's side. On the deepest inside face, lives a hard coral at a depth of 110 ft. Soft corals, delicately laced, shoot out horizontally with their broad faces to the current moving from the east. They sway attractively with the gentle surge but hold slightly to the west, yielding to the current. The corals are unusually large and their numbers are once again much higher than noted in our local waters.

Current velocity in this area is about 80 ft. per minute to the west, at a depth of 80 ft. A diver hanging onto fixed objects resembles a flag in the wind. The current is noticeably reduced below 130 ft. A nurse shark about 5 to 5 1/2 feet in total length swims lazily by at the continental shelf and continental slope interface, totally ignoring the two divers as they photograph the lush garden of soft corals. Visibility is approximately 100 ft. The second drop off at 150 ft. is easily seen, but special dives with special equipment are necessary for its investigation.

Slightly south of Cabo Barrio Nuevo a barrier reef forms in front of a shallow water lagoon spotted with corals. Surge channels extend from the reef to the west, some forming caves large enough for divers to swim in and about. The channels farthest north are heavily laden with cobble stones which diminish as one swims away from the reef seaward. Fish collecting stations have been established both in the lagoon along the rocky shore and seaward to depths of approximately 20 ft. One can readily see the great diversification of species just by sitting on the bottom and watching the fishes and their performance.

The surge channels offer many nooks and crannies for fishes to hide and from which to venture away from the reef proper. An impressive number of "royal grammas" are to be found swimming upside down in these zones. Few sea urchins inhabit these rocky environments. Queen trigger fishes are plentiful. Hard corals encrust much of the limestone base. Gorgonians, while not in abundance, decorate the bottom in colorful fashion. Many flamingo tongue shells were seen attached to sea fans. Red snapper and grouper were seen swimming close to the westward edge of the channels only to then swim quickly away towards deeper water. Barracudas frequent the reef front in pairs. One green moray eel was spotted in a surge channel and two very small spiny lobsters were seen nearby. A current of about 50 ft. per minute moved from south to north and visibility was estimated at a depth of 120 ft. On the morning of the fourth of September as the ship's anchor was being hauled aboard, the visibility was estimated to be 200 ft.

General remarks

The physical characteristics of underwater Mona are vastly different from those in underwater Puerto Rico. One can see and investigate a wide diversification of bottom profiles within the short distance of six miles. Visibility is certainly desirable if not a must for accurate and detailed underwater explorations. Such conditions may be found in most of the coastal waters of Mona. Corals yet unaffected by industrial effluents offer comparative studies for marine ecologists who are now analyzing the deterioration of coral colonies in polluted zones.

After vast underwater experience in Puerto Rico waters the author appreciates the aesthetic value of underwater Mona. While the number of edible type of fishes, such as the grouper and snapper, seem to have diminished since 1958, those remaining certainly have not altered their behavior. The effect of man's predatoriai presence is measurably noticed as one swims about in less harmony with his cold bloeded neighbor. One can recall similar experiences and observations when diving in the waters off Fajardo during the late fifties and into the early sixties. Those times were a critical period when man as an underwater hunter invaded a productive area and reduced its productivity to a paltry level, where divers now rarely see large fish and spiny lobsters.

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