Pulley Ridge

From Wikipedia, the free encyclopedia

Pulley Ridge is a coral reef off the coast of southwestern Florida, United States [1]. The reef lies 40 miles west of the Tortugas Ecological Reserve and stretches north about 60 miles. The ridge has a range of depth from 60-80 meters [2]. Pulley Ridge was originally discovered in 1950. It was found again in 1999 by scientist from the U.S. Geological Survey (USGS) and graduate students from the University of South Florida [3].

Pulley Ridge is the deepest coral reef off the shores of the continental United States. “Although deeper-water corals form reefs in the dark of ocean depths, Pulley Ridge is the deepest photosynthetic coral reef that we know of today,” said Robert Halley, USGS marine geologist.” [4]. Other reefs lie about 46 meters below sea level [5]. During the exploration of Pulley Ridge, scientists found bioluminescent bacteria living in the reef. It is thought that this unique relationship between the bacteria and the coral is what keeps Pulley Ridge alive [6].

Coral Reefs struggle to survive in the world today. “In the past 10 years the world has lost 25% of the known living coral reefs” [7]. Coral reefs are particularly damaged by “…climate change, over fishing and coastal pollution” [8]. Scientists hope that through the exploration of Pulley Ridge they can gain new insight of how reefs function in order to better preserve other reefs [9].

[edit] The First Scientific Dive on Pulley Ridge

The first scientific dive on Pulley Ridge was led by James K Culter of the Mote Marin Laboratory in Sarasota, Florida and included over 40 others. The trip went from 23 June through 1 July 2005. The aim of this mission was to collect primary data and biological samples and to document marine life through still photographs and video [10]. The expedition was done at depths ranging from 200 to 260 feet. “…very few scientific reef investigations are conducted within the depth zone between traditional scuba air limits of 130 feet and deep-sea submersible research at and below 500 feet” [11].

After the expedition Culter made some observations. He noticed some unusual neon colors in the reef. This bioluminescence may have some significance to the ridge. He also mentioned that compared to a shallow reef, there seemed to be fewer fish. Tilefish and groupers were seen at the ridge. He noted that this could have been because they were scared away by the divers or the fish could only come out at night. There appeared to be fewer crustaceans than one would normally see in a shallow reef, but there were several species of algae present [12].

Accomplishments of the expedition[13]:

• 6 deep worker submersible dives, including 21 hours of observations

• ROV deployments from R/V Bellows and R/V Suncoaste

• 55 deep dives by individuals using trimix and rebreathers (11 divers, completing 5 dives each)

• 340 km lines of seismic and side-scan sonar data

• Collection of video, still photos, and biological organisms

• Discovery of luminescent bacteria associated with corals