Sheep in the Deep

Animals in the ocean live in a world largely without structure, where food and danger can arrive from any direction at any time. Even animals that live on the seafloor are at the mercy of gravity, waiting for food to fall from the surface. Any object that provides safe refuge, or a higher vantage point from which to grab food before the competition, is immediately taken advantage of. Therefore, any hard surface or projection from the seafloor is very quickly colonized by bacteria, algae, and animals, in a process known as “biofouling”.

The monitors in the Jason control van during dive J2-1162, showing the extreme biofouling of junction box MJ01C. Photo Credit: M. Vardaro, UW, V19

An extreme example of this was revealed today during a dive at Oregon Shelf site, which is only 80 meters deep. This means that there is plenty of light reaching the seafloor, and that there are waves and currents that make operating the ROV extremely challenging. Those same currents, along with upwelling (wind-driven water circulation that brings cold, nutrient-rich deep water up into surface waters), supply plenty of food for plants and animals, including the anemones completely covering our junction box at this site.

Sea anemones thrive on one of the Junction Boxes at the Oregon Shelf site. Credit: UW/NSF-OOI/WHOI; V19.

The junction box is a 4-legged platform containing that supplies power and communications to the instruments at this site: it has been installed here since 2014. This fact was very clear when the platform came into view as it is so completely covered in large, white anemones that it looks like a fluffy sheep.

Luckily, the Jason crew were able to unplug the digital still camera and benthic experiment package (BEP; a hard frame protecting the shallow-water instruments at this site) without disturbing the animals too much, although there was one resident shrimp that seemed a little upset. The camera too was covered in barnacles, tunicates (also known as sea squirts), and anemones, and the BEP was host to a number of large lingcod, black cod, and even a sizeable wolf eel!

The digital still camera in 80 meters of water is encrusted with life after only 1 year in the water. Credit: UW/NSF-OOI/WHOI;V19.

The last few dives of the cruise brought back two BEPs and the camera, along with some water samples to verify the instrument data, so we had a lot of cleaning up to do and a very crowded back deck. But it’s always better to get things done while the weather cooperates, so it was good that we could recover these complicated, heavy platforms during this leg of the cruise.

The next step is to steam to Newport to offload equipment and bring on new gear and students for Leg 3! We’ll be doing some more coastal dives to deploy equipment, and making a trip to Southern Hydrate Ridge, an area where natural methane is bubbling up from the seafloor, supporting an entirely different chemosynthetic ecosystem from the one at Axial Seamount. Stay tuned!