Wrapping up a productive cruise
March 3, 2015
Today we completed our leg of the Gulf of California expedition with a half-day ROV dive close to the port where the Western Flyer docks near La Paz. It was an incredibly productive cruise with ROV Doc Ricketts dives every day, MiniROV dives most days, midwater trawls most nights, and even a few nights of jigging for squid! The entire team is walking away with a lot of data to analyze at home.
I’m a member of MBARI’s video lab, where we archive and annotate all of the ROV video footage. We have over 20,000 hours of video in our archive and over 4.5 million observations in the Video Annotation and Reference System (VARS). My colleagues and I use VARS to make observations about the animals, habitat, and debris that we see, and equipment used, on all MBARI ROV dives. The observations are linked to ancillary data (e.g., CTD and navigation) and are searchable through a query tool. We can look at trends in animal distribution over space and time and make hypotheses about their ecological conditions in which they live.
On this 10-day cruise, we collected about 90 hours of video, which will be annotated in detail back in the lab. Using VARS at sea, we make an outline of the dive, noting samples and taking frame grabs that we can use right away. The bulk of the annotation effort will happen in the MBARI video lab. These 90 hours of video can take anywhere from 180 to 400 hours to annotate. The VARS database is the tool that will allow our scientists to make comparisons between the biodiversity and community of midwater animals present in the Gulf of California versus Monterey Bay.
As I mentioned in the February 24 log, the oxygen minimum zone (OMZ) here in the Gulf is very wide, reaching far shallower and deeper than in many other ocean habitats. As climate changes, it is likely that oxygen minimum zones in other places will expand. Therefore, the Gulf is a good system to study to make predictions about the future of ecosystems in other parts of the world, where OMZs are just starting to expand. Using the VARS database, scientists can ask all sorts of questions about the differences and similarities between the two habitats.
—Susan von Thun