Diving back into the Gulf of California

MBARI’s two research vessels are scheduled to return to the Gulf of California, Mexico—a region that holds great scientific intrigue and stunning natural beauty. The R/V Western Flyer and R/V Rachel Carson will journey south to Mexico for the third time in a decade. Previous expeditions in 2012 and 2015 yielded tremendous insights for MBARI researchers, but with more answers always come more questions.

Researchers are particularly interested in the Gulf of California because its warm water and expanding oxygen minimum zone are thought to be an analog of what Monterey Bay could become in the future, given a warmer climate. Comparing the distribution patterns of species that live throughout the water column and on the seafloor in the Gulf of California offers a glimpse of how species in Monterey Bay may come to cope with “the ocean of the future”—potentially helping to predict what lies ahead for our local waters.

Seafloor mapping will be a large part of this expedition. Two MBARI mapping autonomous underwater vehicles (AUVs), operated from the R/V Rachel Carson, will provide high-resolution bathymetric maps to help direct subsequent remotely operated vehicle (ROV) operations. A lidar (laser) system mounted on the ROV Doc Ricketts will also be used to provide the scientists with one-centimeter (half-inch) resolution maps. Maps that the AUVs and ROV collect will be used to comprehensively investigate the hydrothermal vent fields that MBARI teams previously discovered in the Pescadero Basin and along the Alarcón Rise.

ROV operations will be conducted off the R/V Western Flyer using both the MiniROV and ROV Doc Ricketts. In addition to MBARI’s suite of robots, the i2MAP (Investigations of Imaging for Midwater Autonomous Platforms) will be used in the Gulf of California for the first time. The i2MAP is equipped with a bioacoustic sensor and a high-resolution camera placed in the nose cone of an AUV. Transects using the i2MAP will allow researchers to estimate the abundance of biological populations within the region. This robotic fleet will give researchers the information needed to further expand our understanding of life in the sea and how it is changing over time.

The expedition’s biological oceanographic studies will focus on the unique diversity and evolutionary history of midwater and seafloor animals. MBARI’s flotilla of autonomous and remotely operated vehicles will also examine animals that are tolerant of low-oxygen conditions in the southern and central Gulf of California basins, continuing to unravel the mysteries of the oxygen minimum zone.