We are in port this morning offloading samples, restocking, and changing over some of our team, including our chief scientist. We say farewell to Neil Summer of Ecolyse who has expertly guided this expedition for the past month or so. And, we say hello to our new Chief Scientist Oscar Garcia. (We’ll introduce Oscar in more detail in a future post.)
Mexican Rattail Fish
Today, however, we’d like to introduce you to ROBIO (Robust Biodiversity) lander—our underwater autonomous photographic lander. Thomas Linley is a marine biologist from Oceanlab at the University of Aberdeen in Scotland. He is on board the Gyre for the sole purpose of deploying, monitoring, and analyzing the data returned from ROBIO. Thom has taken ROBIO all over the world on various sea expeditions. We deployed the underwater camera over the weekend and took some interesting pictures that can tell us lots about the deep sea environment. Here, Thom tells us what exactly ROBIO does and why the information it gathers is useful.
How does ROBIO work?
Deep-sea red crabs fighting over bait
The ROBIO lander is a baited, underwater camera. We deploy ROBIO near the well head, and with the help of weights it sinks to the sea floor where it sits for 16 hours. It has a digital camera and flash on board taking a photo every minute. It also has a current meter, a CTD, and a reference cross (metal bars with centimeter markers so that fish can be measured). These tools help us log the environmental parameters of wherever ROBIO comes to rest on the sea floor. The lander also has air-filled glass floats on board that help it return to the surface when we tell it to.
What kind of data are you gathering?
Giant isopod (Pill Bug) and cutthroat eels. The Pill Bug is about the size of a small cat.
From the photos themselves we can get a species list. When we’ve got the reference cross in view, we can also measure the fish and compare differences in species assemblages and in the size of the animals between different sites. But then, we can get a little bit interesting. We can use the current meter data to plot the odor plume—how far the smell of the bait has gone out into the water. By allowing the animals to feed on the bait we can see how long and how much they eat, before they wander off and get bored. This can indicate how much available food is in the area: if they have enough to eat and food isn’t their top priority or if they’re starving and they’ll eat as much as they can.
Using optimum foraging theory, we can determine how the deep sea animals are looking for their next meal. In a nutshell, optimum foraging theory helps explain how animals have evolved to get the maximum amount of food while using the minimum amount of energy. They don’t just search randomly for food. With this information, we can start to make comparisons about how many fish are in the area.
What does that have to do with the possibility of oil on the ocean floor?
ROBIO and what Thom believes to be a Rudis Rattail fish
These are the mobile organisms—the ones that could move to another part of the Gulf if they needed to. If these animals don’t have what they need where they are due to an increase of oil in their environment for example, they go find another place that can sustain their life. Our goal is to generate some nice images and gather data on the megafauna – the larger animals – which we haven’t really looked at yet in this sediment coring activity.
We will most likely be heading back out to sea tonight or tomorrow. Check back soon for our next update from sea!