ROV <em>Deep Discoverer</em>,  meet squid. Squid, meet D2. D2 had a fantastic encounter with a four to six foot squid during the dive’s mid-water transects.

ROV Deep Discoverer, meet squid. Squid, meet D2. D2 had a fantastic encounter with a four to six foot squid during the dive’s mid-water transects. Image courtesy of the NOAA Office of Ocean Exploration and Research, Exploring Puerto Rico’s Seamounts, Trenches, and Troughs. Download larger version (jpg, 1.1 MB).

Dive 5: Mona Canyon – East Wall
April 14, 2015
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Dive 5: Mona Canyon – East Wall

Highlights from Dive 5, which started with mid-water transects to explore the water column followed by exploration of the east wall of Mona Canyon. Video courtesy of the NOAA Office of Ocean Exploration and Research, Océano Profundo 2015: Exploring Puerto Rico’s Seamounts, Trenches, and Troughs. Download (mp4, 35.2 MB)

Dive 05 began with a series of mid-water transects at 100-meter intervals between 800 and 1,200 meters. Fauna documented included squid, arrow worms, jellyfish, siphonophores, and small fish. ROV Deep Discoverer (D2) landed on the seafloor at a depth of 4,000 meters and transited upslope over Late Cretaceous to Middle Eocene basement rock which makes up the core of Puerto Rico and sits below the approimately one-kilometer thick carbonate layer we’d previously dived on. After traversing approximately 100 vertical meters of sedimented seafloor with little fauna, D2 climbed 200 vertical meters of steeply dipping and sometimes near vertical cliffs of outcrop of basement volcanic rocks. Biological observations during the dive included a diversity of sponges, black corals, octocorals, sea stars, fish, shrimp, and squat lobsters. Two exciting highlights from today’s dive were the close encounter with a 1.5-2 meter squid and the documentation of a rare six-arm sea star that had not been recorded, collected, or observed since the specimen was described 130 years ago.