National Oceanic and Atmospheric Administration (NOAA) is sponsoring ECOHAB (Ecology and Oceanography of Harmful Algal Blooms) project, which includes researchers from MBARI; the University of California, Santa Cruz; Moss Landing Marine Laboratories; the University of Southern California; NOAA’s National Centers for Coastal Ocean Science; and NASA.
The short-term goal of the ECOHAB project is to determine what environmental conditions are likely to lead to harmful algal blooms. The long-term goal is to build computer models that will allow researchers to predict when and where blooms are most likely to occur.
This year, the researchers will be building on discoveries made during previous ECOHAB experiments conducted in San Pedro Bay in the spring of 2010 and 2013. These experiments indicated that harmful algal blooms often occured in April. This finding prompted researchers to schedule the 2014 experiment during this month.
In addition to the underwater gliders, two robotic DNA labs known as Environmental Sample Processors (ESPs) have already been moored at two locations in the bay. The ESPs are being used to identify types and concentrations of algae and measure the toxins they produce in real time. By the time the experiment reaches its peak in mid April, ECOHAB scientists will be collecting data from the two ESPs, two research vessels, five autonomous underwater vehicles (AUVs), and five drifters.
MBARI’s long-range AUV Daphne will patrol the waters around the ESPs, collecting information on the temperature and chemistry of the water as well as the total amount of algae present. Meanwhile, MBARI’s Dorado AUV will travel back and forth across San Pedro Bay, gathering data and collecting water samples using its on-board artificial intelligence system to identify patches of algae. Along with data collected from ship-board sampling systems and moorings, the AUV data will allow researchers to know when and where harmful blooms are occurring and to examine the processes controlling these blooms.
The large amount of data flowing from all of these observing system components will be challenging to process and analyze. However, software developed by MBARI will enable researchers to manage and visualize the data in real-time. This will help them make day-to-day decisions throughout the experiment.
Algal blooms develop off the California coast in the spring, when blustery northwest winds push surface waters away from the coast. This allows nutrient-rich water to rise up toward the surface. The resulting “upwelled” water acts like fertilizer for diatoms and dinoflagellates—the microscopic algae that dominate California’s coastal waters. Although upwelling is particularly intense in exposed coastal areas such as Monterey Bay (another ECOHAB study site), it also plays a role in producing blooms in the more sheltered waters of San Pedro Bay.
Data from last year’s ECOHAB experiment suggested that two different types of upwelling may affect San Pedro Bay. In addition to upwelling generated by regional northwest winds blowing in the Catalina Channel, upwelling may also be generated in northern San Pedro Bay by brisk afternoon sea breezes. One of the challenges of this year’s experiment will be to determine the relative effects of these two types of upwelling on microscopic algae.
Another exciting result from the 2013 experiment was that researchers discovered a surprising amount of diversity within one group of harmful algae, and learned how the different species within this group were distributed in the water column. After analyzing hundreds of water samples from the 2013 experiment, MBARI Postdoctoral Fellow Holly Bowers found several different species of diatoms in the genus Pseudo-nitzschia that are capable of producing a potent neurotoxin called domoic acid.
ECOHAB researchers are also interested in understanding how the effects of nutrients in upwelled water compare with the effects of nutrients introduced by human-related activities such as urban runoff and sewage disposal in the ocean. This year’s dry winter, followed by late rains, may provide data to help answer this question.
By building on the results of the 2013 ECOHAB experiment, the research team is optimistic that they will get even more useful data this year. As John Ryan, chief scientist on this year’s ECOHAB cruise, aboard the R/V Rachel Carson, explained: “The data show that our 2013 sampling and monitoring strategy was good. The instruments were in the right place. We were just a bit early. Early indications this year are that we arrived at the right time.”