CANON Spring 2017 Expedition
Chief Scientist Francisco Chavez
R/V Western Flyer
March 2-8, 2017
Chief Scientist Francisco Chavez is leading a group of researchers during a six-day expedition in Monterey Bay aboard the R/V Western Flyer. The overarching goal of the expedition is to use a fleet of smart, autonomous instruments and shipboard sampling in parallel with two other methods of sampling: net tows and an instrument called an Environmental Sample Processor (ESP) that has been installed inside of a long-range autonomous underwater vehicle (LRAUV).
Aboard the R/V Western Flyer, MBARI researchers will conduct shipboard sampling using a tool called a CTD (an acronym for conductivity, temperature, and depth) that can determine physical properties of seawater. Attached to the CTD are bottles that collect water samples at varying depths. A fleet of smart, autonomous instruments (such as LRAUVs and autonomous surface vehicles) will help researchers identify where to conduct the CTD sampling.
Net tows will be conducted by researchers aboard another ship, the Reuben Lasker, which is operated by the National Oceanic and Atmospheric Administration (NOAA). The Reuben Lasker and the Western Flyer will meet at an offshore upwelling front identified by the autonomous vehicles and conduct their respective methods of sampling in the same location. A long-range AUV, named Aku, will carry an ESP that will also conduct autonomous sampling. All these methods of sampling will be compared to determine if they detect the same organisms.
The importance of eDNA
May 4, 2017
Today we repeated yesterday’s activities of coordinating simultaneous sampling from the R/V Western Flyer (CTD casts), the Reuben Lasker (midwater trawls), and LRAUV Aku (Environmental Sample Processor sampling).
While LRAUV Aku is autonomously collecting samples with a third-generation Environmental Sample Processor (ESP), Research Specialist Kevan Yamahara is also archiving water samples from the CTD rosette using a benchtop ESP on the Western Flyer.
Similar to the way forensic scientists can find genetic clues from suspects at a crime scene, researchers can analyze seawater samples to obtain environmental DNA (eDNA)—DNA that originated from a wide variety of animals—to assess the distribution and relative abundance of animals in a particular location and time. Kevan will compare the eDNA data from the benchtop ESP and LRAUV Aku’s ESP.
Chief Scientist Francisco Chavez was recently awarded a grant through the National Ocean Partnership Program to test the usefulness of eDNA as part of the Marine Biodiversity Observation Network (MBON) program.
MBARI researchers Kris Walz, Julio Harvey, and Katie Pitz are also archiving the same water samples as Kevan using a peristaltic pump system, to determine how different sampling methods affect the types and amounts of genetic material detected in each sample.
A final comparison will come when marine biologists visually examine net samples that were collected aboard the NOAA research vessel Reuben Lasker at the same time as samples were being collected by the Aku ESP and the shipboard ESP. The abundance and taxonomic composition of animals caught in the nets will then be compared with the genetic taxonomies compiled using eDNA.
This evening Francisco led a post-dinner science meeting in which he reviewed the overall research goals of the cruise and the sampling activities for the evening.
With heavy winds predicted throughout the weekend, the Western Flyer will head back to Moss Landing on Friday morning, and our cruise will be suspended until Sunday evening. But while the Western Flyer sits in port, the AUVs, gliders, and wave gliders involved in this project will continue collecting data despite the bad weather. This illustrates the benefits of autonomous platforms and how they allow us to maintain a research presence in the bay when conditions make it uncomfortable or unsafe for humans to be out at sea.
Meeting the Reuben Lasker
May 3, 2017
This is an expedition with many moving parts, and today we added the R/V Reuben Lasker, a NOAA ship, into the mix. We rendezvoused with the ship at an offshore upwelling front (the boundary between cold, nutrient-rich upwelled water and warmer offshore water) that was identified by our fleet of autonomous vehicles. A team funded by the Keck Institute for Space Studies is using observations and models to intelligently direct the AUVs to areas of special interest.
The Reuben Lasker is in Monterey Bay conducting NOAA Southwest Fisheries Science Center’s annual rockfish survey through a series of midwater trawls. Meanwhile, the R/V Western Flyer and long-range AUV Aku (equipped with a third-generation Environmental Sample Processor) is following behind, collecting water samples from the same depths as the trawls.
Researchers aboard the Flyer will analyze their samples in the lab for comparison with Aku’s data and the physical specimens (animals and algae) collected by the Reuben Lasker’s trawl nets. The sampling surveys conducted by both ships will corroborate the data acquired by the autonomous vehicles. These experiments help researchers imagine a future in which a multi-platform, autonomous observing system could provide accurate, real-time data of oceanographic conditions in Monterey Bay.
During coastal upwelling conditions, cold surface water coming in contact with moist air produces fog. This afternoon we saw a shallow layer of fog while sampling along an upwelling front.
Using sound to locate prey
May 2, 2017
Despite the early call time of 4:30 a.m., spirits were pleasant the morning of the first day of the expedition. With a great weather forecast for the next couple of days, there was little to complain about other than wishing for another hour of sleep. The R/V Western Flyer headed toward an area called “C1,” where we conducted the first CTD cast of the expedition.
A CTD cast involves lowering a “rosette” of plastic cylinders over the side of the boat to collect water samples at different depths. The rosette also carries a CTD—a device that measures the water conductivity (salinity), temperature, and depth. Throughout the next six days, we will conduct round-the-clock CTD operations in various locations in Monterey Bay. I’ll write more about these operations in future posts.
This morning, instead of making a straight shot for C1, we zigzagged across Monterey Canyon and used an instrument called a scientific echosounder, which uses sonar to detect physical or biological objects below the ocean’s surface. The presence of humpback whales near Moss Landing the day before we left gave us a good indication that the whales’ favorite prey, anchovies, might be nearby. Indeed, we did see whales and salmon fishermen (salmon also eat anchovies) during our departure.
Research Technician Jeff Sevadjian analyzed the measurements collected from the echosounder and found a strong signal of small organisms close to shore as we steamed out of the harbor; the researchers on board suspect these were anchovies.
Schools of fish, such as sardines or anchovies, can be good indicators of hotspots—places where biological resources are highly concentrated. A major goal of the Spring 2017 CANON experiment is to gain a better understanding of ecosystem processes that influence these hotspots and biological responses by improving scientists’ ability to find and follow these hotspots using smart, autonomous instruments.
Not pictured: Meilina Dalit, Jorie Kennedy