Wednesday, March 15, 2017

The challenges of marine technology

If you open up a magazine about marine technology, you will most likely be inundated with advertisements and articles for equipment that can resist corrosion, extreme pressures, and “biofouling”. These are all major threats to the successful deployment of equipment, particularly if it is intended for long-term use. This applies to oceanographic equipment as well: any metal pieces on our equipment must be corrosion resistant, and the sensors will universally work better if organisms don’t take up residence on or near them.
Another view of the recovered rope shown in Olga's post. (Photo credit: Rosalind Echols)

A couple days ago we recovered a length of rope floating in the ocean that we had passed several times while doing a circuit around a region. While rope may seem innocuous, if a ship drives over one and it becomes tangled in the propeller, it can go from a piece of trash to a huge issue, so it made sense to pick it up. When we get it on deck, we discovered that it was covered in gooseneck barnacles. Unfortunately for the barnacles, taking the rope out of the ocean means they won’t be able to survive, but the threat to navigation in this case seemed important.
Close up view of the top of a float. Notice the tiny grain-like creatures clustered around the bottom of the ports. (Photo credit: Rosalind Echols)

When we picked up our floats a few days later, we noticed that there were tiny organisms growing on them, mostly clustered where there are sharp right angles that create some sort of crevice. Upon further inspection at 50x magnification (using a microscope that looks like its heyday was in the 1950s), we pursued some amateur biological classification and decided that they were probably barnacle larvae. In the larval stage, like many other marine organisms (including benthic ones, or those that ultimately live on the bottom of the ocean as adults), they drift freely in the ocean until something comes along that they can attach to. The odds of them finding one of the floats, given the immensity of the ocean, seems staggeringly small, and yet in only 5 days there were hundreds clinging on.
The tiny critter (barnacle larva?) at 50x magnification. Picture taken with a phone through the microscope lens, so please excuse the quality. (Photo credit: Rosalind Echols)

This is just one example of the phenomenon of biofouling, which could also be described in a more positive light as the impressive determination of marine organisms to survive. Any instrument that is going to be in the ocean for a long period of time will likely have to contend with this at some point.

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