The typical image of a tropical coral reef is that of shallow reef building (hermatypic) corals and an abundance of reef fish. The origin(s) of such coral reef biodiversity is the subject of much scientific intrigue and investigation, yet the majority (up to 80%) of these reefs extend beyond 30 m (100 ft) and are largely unexplored. With increasing technological advancements in electronically-controlled rebreathers through Poseidon/CisLunar innovations, we have the ability to penetrate these tantalizing depths. In the least destructive and most cost effective way, we can gain access to cryptic species otherwise inaccessible by submersibles. Here at Bishop Museum, we continue to pioneer twilight reef exploration, research and discovery, whilst simultaneously refining safer equipment and protocols for future explorers!
Documenting our respective taxonomic groups at these twilight depths necessitates precision, awareness and speed nested within experience. On descent we scan the reef for potential collecting spots, aware yet unfazed by depth, with precious little time to loose. At a very early age it became clear to me that whilst diving it was unwise to have an imagination beyond the present moment. Besides, why would one need to when you’re living the reality of your imagination!
My fish-collecting dive buddies are kept both in view and at a safe distance so as not to disturb the fish, whilst I select choice sea fan colonies; these look new.
First a photograph, then a sample of the colony, which is placed into a pre-labeled Ziploc bag, itself into a large mesh bag attached to my utility belt.
For precision I photograph my Poseidon rebreather paddle (see figure), which is time synched with my camera for depth and temperature, then off to the next colony…. Seldom is it necessary to travel far. The twilight zone is where I can be situated in a single spot for considerable time without need to move through the sheer abundance and diversity of gorgonian corals alone. In short as with most taxa, gorgonian research is forever wanting and never satisfied!
On ascent into the shallows we again see the silhouette of the boat; we can look but can’t touch, not for an hour or 2 at least. Stuck, on a coral reef with an awesome camera – time for more fun! I chase fish, divers and anything mildly photogenic, I’m having a ball; our decompression obligation is just pure joy, another opportunity to dissolve into my favourite environment. In a cipher I whip off my fins for some moon-walking and somersaults, bouncing from one dead coral head to the next – serious science I’ll have you know!
We surface, and it’s back to base for cylinders and sample processing, which can take upwards to 7 hours. Each bag is drained with the specimen gingerly placed on a black background (aka. a t-shirt) for a scaled image with associate labels each bearing a unique identifier code that pertains specifically to each colony.
Molecular sub-samples are made with the remainder of the colony preserved in 95% ethanol. Specimen preservation is paramount, however ethanol can be a limiting resource. Here Hana Bay Rum (60% proof) saved the day when our specially shipped 95% ethanol leaked from the base of the bottles. Nevertheless, the preservation properties of rum, is in fact historical, with Quoy and Gaimard having committed the cardinal sin of denying the crew of their élixir de vie during the 1826-29 French Expedition L’Astrolabe! ……Sacré bleu!!
Never a dull moment on expedition research!
Gorgonian corals are notoriously difficult to identify, particularly in the field. Their traits can be cryptic leading to much confusion, necessitating other research skills to determine species differences and what is new to science. Therefore, the real species identification begins in ernest on return to the Museum, where multiple character traits are investigated including, morphology, genetics and a thorough historical and comparative investigation. Gorgonians are very little researched with a lot of whatever information available being from expeditions from one or two centuries ago. This is where the work begins and the true evolutionary patterns unfold, and for me is extremely fascinating and nearly as exciting as being down on the reef – but not quite! I’m under no illusion of what a privilege it is to do what I do and to share that commonality with those likeminded and of course you!