Stealth, Strength & Deep Phototrophic Gorgonians

We descend - it's a riot of life with gorgonians and fish aplenty, I'm in heaven! Excited, Brian whips over to the biggest gorgonian colony we've seen as yet and assumes position for a photograph. Then we head to collecting; it's on!

Brian_290ft_90m_1_7_2014_BLOG.jpgFigure 1. Brian D. Greene assumes position with a large gorgonian colony (Annella sp.) at 90 m (295 ft) depth, Pohnpei. Image by SJ. Rowley.

The reef is a flat slope absolutely littered with invertebrates, gorgonians being the major players. An abundance of fish carpets the reef darting between the gorgonian fans. The light here penetrates so deeply that it is not necessary to switch my lights on until ~90 m (295 ft) depth, and when I do the pressure is too great that they won't work! So, washed-out shots of gorgonians at depth for this dive.

Briareum_75m[PSs]_BLOG.jpgFigure 2. Unusual observation of the shallow-water zooxanthellate gorgonian coral Briareum at 75 m (246 ft) depth, Pohnpei. What it looked like here (left), what it generally can look like (right)! Images by SJ. Rowley.

Nevertheless, at 75 m (246 ft) I find colonies of the zooxanthellate (possessing single-celled algae just like the hermatypic - reef-building - hard corals) gorgonian Briareum Blainville 1834. To my knowledge, this is the first record of a zooxanthellate gorgonian at such depths.

102m[PS]_BLOG.jpgFigure 3. Instriging species of Nicella at 102 m (335 ft) depth with associate brittlestars, Pohnpei. Image by SJ. Rowley.

Two new gorgonian species to science, new species records, undescribed fish species, and up we go. At 60 m (197 ft), we can clearly see the boat on the surface. Mind blowing!

The_Tow!![PS]_Blog.jpgFigure 4. Brian D. Greene (the guilty party), the tow boat with Rob Whitton, and Kayem (our trusty captain) with Rich L. Pyle engineering our freedom back to base! Images by SJ. Rowley.

Brian is a man of stealth, precision, and strength, such that he renders the boat inoperable as he whips out the engine cord on departure! At full speed we are 45 minutes from base, we get a tow. It must be said, however, that I am frequently impressed by my fishy fix-everything brethren. I observe this scene in recollection of my father who was invariably engaged in a state of 'repair' amidst much fanfare, yet inevitable success. As time persists, I see that even though these boys are indeed highly adept at fixing many an issue, they also have a tendency to be the cause! Much time and effort is consumed. Rich is our chief engineer, spring-boarding ideas at random, typically with great success. Without toolbox, Rich and Kayem (our captain) get us home in the nick of time - the evening downpour ensues.

Lagoon_View_Sunrise[PS]_BLOG.jpgFigure 5. Home sweet home, ready for a full night of specimen processing and cylinder filling at Nihco Marine Park, PohnpeiInvariably, my happy place. Image by SJ. Rowley.

This research was generously supported by: 

The Seaver Foundation


Adapted from Rowley SJ. 2014. Stealth, Strength, and Deep Phototrophic Gorgonians. Bernice P. Bishop Museum. 2nd July 2014.