Monitoring the increase in cyanobacteria harmful algal blooms (HABs) in nearshore environments is challenging. Recent development of a long-range autonomous underwater vehicle (AUV) equipped with a 3rd Generation Environmental Sample Processor (3G ESP) for locating and analyzing HABs improves monitoring, sampling and analytical capabilities. This project enhances a 3G ESP / Autonomous Surface Vehicle (ASV) combination for sampling depths under 5 meters for extended periods.
Why We Care
The occurrence and distribution of toxic phytoplankton blooms has been increasing worldwide over the past several decades. In freshwater and coastal ecosystems, the rise of toxic cyanobacteria harmful algal blooms (HABs) have altered biotic components of ecosystems, caused negative economic impacts, adversely affected ecosystem and human health, and impacted drinking water supplies. In certain regions of the Great Lakes ecosystem, for example, cyanobacteria HABs have been a recurrent summer feature since the mid-1990s and their impacts have been well documented. While traditionally viewed as a freshwater issue, cyanobacteria HABs have been expanding rapidly across the freshwater-marine continuum and are now viewed as an emerging threat to coastal estuaries and ecosystems.
Most cyanobacteria HABs occur in coastal and/or shallow water habitats, where waters are warm, nutrient rich, and can experience reduced turbulence. Traditionally these systems have been monitored through ship-based sample collection, which represents a discrete, specific spatial and temporal event (i.e., samples represent conditions at a single time and location). However, phytoplankton blooms are complex, where growth and toxicity are not driven by a single factor but multiple direct and indirect environmental conditions that promote, often quickly, bloom development. The complex interactions between biological, chemical, and physical variables that lead to cyanobacteria HABs within coastal and shallow water systems can shift on short time scales, leading to drastic fluctuations in bloom biomass and toxin concentrations.
As such, monitoring cyanobacteria HABs in nearshore environments in close proximity to human activities is challenging for a number of reasons, including shallow water depths, limited access to sampling locations, difficult environmental conditions, and the expanse of affected coastline.
What We Are Doing
The overarching goal of this project is to provide near-real time, in situ detection of cyanotoxins via the integration of a 3G ESP with an autonomous surface vehicle (ASV) capable of sampling at multiple depths throughout the water column, particularly in depths less than 5 m. The suite of available commercial ASV platforms is large and continues to expand at a rapid pace, including “uncrewed” surface vehicles such as sail drones, wave riders and solar powered propeller-driven platforms.
Monterey Bay Aquarium Research Institute’s (MBARI) recent development and field-testing of a long-range autonomous underwater vehicle (LRAUV) equipped with a 3G ESP for locating and interrogating HABs begins to address cyanobacteria HAB monitoring, sampling and analytical issues in shallow environments. Through a collaboration involving MBARI, NOAA Great Lakes Environmental Research Laboratory (GLERL) , NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML), and NCCOS, the 3G ESP/LRAUV has demonstrated the ability to autonomously perform in situ sample acquisition, processing, and analysis for microcystin in near-real time and sample preservation for post-deployment ‘omics analysis - all accomplished while underway in Lake Erie. However, the scope of these missions was limited by depth (minimum operating depth of 5 m), battery power, and a need to remain submerged for safety reasons.
To accomplish the project goal of incorporating a 3G ESP into a ASV, the project has three objectives: (1) compare maneuverability, agility, and capabilities of the ASV to the LRAUV; (2) improve workflow and refinement of the embedded surface plasmon resonance (SPR) analytical chemistry assays, which will focus on robust and reliable microcystin detection; (3) further integration of the 3G ESP into the ASV; and (4) evaluate performance of the 3G ESP/ASV in the field across multiple spatial and temporal scales (Year 2: western Lake Erie; Year 3: Lake Pontchartrain Basin, LA).
Benefits of this Project
There is increasing recognition within NOAA that deployment of unmanned systems can enable the agency to meet selected mission requirements more efficiently and effectively. The ASVs being tested in this project can further advance NOAA’s ability to acquire, process, and analyze samples in situ and in near-real time.
Combining state-of-the-art ASV technology with the 3G ESP will provide NOAA with scalable, automated biological observing capabilities of unprecedented spatio-temporal resolution, particularly in shallow, coastal systems. The development of a system that can access these shallow nearshore environments and transmit HAB toxin concentration data to shore-based operators in near-real time, as well as facilitate dissemination of this information to resource managers, will support timely decision-making and bloom forecasting for protecting public health and mitigating other HAB socioeconomic impacts.
This project is a multi-investigator and multi-agency collaboration led by Dr. Reagan Errera of NOAA GLERL. Co-investigators include Gregory Doucette (NOAA NCCOS), Steve Ruberg (GLERL), Kelly Goodwin (AOML), Bill Ussler (MBARI), James Birch (MBARI), Christopher Scholin (MBARI) and Sibel Bargu Ates (Louisiana State University).
This project is supported by the NCCOS PCMHAB Program.