‘Reef Biodiversity: an Introduction’ posted on the 4th of February introduced coral reef diversity and the Autonomous Reef Monitoring Structure (ARMS). This post will explore the recovery and processing of these platforms.
|ARMS awaiting removal on left, encapsulated ARMS on right|
We remove the ARMS from the benthos by attaching a milk crate lined with an 80 micron mesh over the center stack of plates comprising the structure. A buoyed rope is then attached to the latching straps on the crate, and the whole unit is pulled to the surface. The milk crate ensures that any recruited organisms within the ARMS will not fall out during transport. Once on the surface and in the small boat, the milk crate encapsulated ARMS is placed within seawater-filled bins and transported back to the Hi‘ialakai.
Back on the ship, the ARMS is disassembled within a tub of seawater. The milk crate is detached, and each layer (plate) is removed individually. The top and bottom of each plate is photographed to document the sessile organisms. Once photographed, a paint brush is used to lightly sweep any motile organisms off the plates and into a bucket of seawater. The plates are then placed in ethanol to preserve the DNA for future molecular processing.
|An example of a plate photograph|
The final task is to scrape the sessile organisms from the all the plates. The scrapings are bulked and preserved. In this manner, we are able to remove, preserve, and store all of the sessile and motile organisms that have recruited to the ARMS.
|ARMS processing in action. Upper left, disassembling; lower right, brushing;|
middle, photography; lower right, sieving; upper right, scraping.
|Examples of invertebrates found within the ARMS|