Investigators: Don Anderson, Richard Pierce, Emily Hall, Vincent Lovko, James Culter, Leanne Flewelling, Katherine Hubbard, Matthew Garrett, Kristen Buck, Kristy Lewis, Sergio Alvarez

Institutions: Woods Hole Oceanographic Institution, Florida Fish and Wildlife Commission, More Marine Laboratory, University of South Florida, University of Central Florida,

Abstract/Project description:

Bloom control is arguably the most challenging and controversial aspect of harmful algal bloom (HAB) management, and perhaps the least developed of all areas of HAB science. Here a PCMHAB Phase 2 project is proposed to demonstrate and transition the most globally advanced and widely used marine HAB control strategy to the US. Termed clay flocculation or dispersal, a clay solution is sprayed over the water surface, leading to flocculation of the clay particles with each other and other particles including HAB cells, which then settle to bottom sediments. This method, which uses an inexpensive and environmentally benign mineral has been used for over 20 years in China and Korea on dozens of occasions over large (~100 km²) areas with no significant environmental impacts. Our Chinese collaborators recently modified clay by adding an inorganic polymer used routinely in drinking water purification and lake restoration, thereby reducing the amount of clay needed for a treatment 50 – 100-fold. This breakthrough reduces costs of application and impacts significantly without affecting bloom control efficiency. Despite its routine application in Asia, the technology has not been adopted in the US because of a lack of data on US ecosystems and HAB species, particularly neurotoxic species. For the last several years, members of this project team have been running field and laboratory studies and developing methods to test clay dispersal for control of the Florida HAB species Karenia brevis. Permit exceptions are in hand for three sites and the equipment and methods for dispersing the clay and measuring a wide range of environmental parameters established. Valuable expertise and data obtained through this collaboration are directly applied in this research plan. The overall project goal is to assess the effectiveness, environmental acceptability, costs, and scalability of modified clay dispersal as a Karenia brevis bloom control strategy. Objectives are to: 1) assess the effects of dissolved organic matter on flocculation and modify clay chemistry as necessary to improve flocculation in natural waters; 2) conduct field and laboratory trials using a tiered approach at increasing spatial scales and across different ecosystems to test the efficacy and impacts of clay flocculation; 3) assess the overall effectiveness, feasibility, impacts, scalability, and acceptability of clay as a Karenia bloom control strategy; and 4) assess the socio-economic costs and benefits of clay treatment at several scales. The last objective balances bloom control costs against the values of water quality improvements and reductions in aerosolized toxins and wildlife mortalities. This project is primarily focused on interdisciplinary Demonstration studies in open waters, with targeted laboratory studies to guide these field efforts. The first three years will each include at least one Demonstration field treatment, varying in size and complexity as allowed by the PCMHAB PEA. Year four will be devoted to final analyses and synthesis of project results, and to outreach and technology transition. Through repeated measures of a range of parameters and processes in small- and large-scale field trials, the team will obtain a wealth of data to evaluate the effectiveness and acceptability of clay as a control strategy for Karenia, and ultimately for other HAB species as well. The project is comprehensive and "shovel ready" for Demonstration research, with a high probability of success in the drive to transition this technology to practical implementation in the US.

Investigators: Reagan Errera, Sibel Bargu, James Birch, Gregory Doucette, Casey Godwin, Kelly Goodwin, Steve Ruberg, Christopher Scholin, Bill Ussler, Andrea Vander Woude

Institutions: NOAA’s Great Lakes Environmental Research Laboratory, Louisiana State University, NOAA’s National Centers for Coastal Ocean Science, Cooperative Institute for Great Lakes Research- University of Michigan, NOAA’s Atlantic Oceanographic and Meteorological Laboratory, <Monterey Bay Aquarium Research Institute

Abstract/Project description

Blooms of nuisance and toxic cyanobacteria harmful algal blooms (cHABs) are increasing globally, particularly in coastal and shallow, nearshore environments. Monitoring cHABs 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. MBARI’s recent development and field-testing of a long-range autonomous underwater vehicle (LRAUV) equipped with a 3rd Generation (3G) Environmental Sample Processor (ESP) for locating and interrogating HABs begin to address these issues and have already substantially improved sampling and analytical capabilities. Through a collaboration involving MBARI, GLERL, CIGLR, AOML, and NCCOSCharleston, two-week long field campaigns in 2018 and 2019 using MBARI’s 3G ESP/LRAUV demonstrated in Lake Erie’s western basin the ability of an autonomous mobile platform to 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. 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. Uncrewed surface vehicles (USVs) are a rapidly developing technology that have some distinct advantages compared to autonomous underwater vehicles (AUVs), such as continuous real-time reporting to shore, integration of sensors or sampling devices at multiple water depths, and minimal draft, which permits sampling operations in water depths as shallow as ~1 m. To enhance our temporal and spatial scales of nearreal time data generation and transmission during cHAB events in shallow, coastal systems, we propose to integrate the 3G ESP into an USV platform capable of sampling at multiple depths within the water column, particularly at depths of 5 m or less. In addition to the USV, an uncrewed aircraft system (UAS) will supplement the USV toxin measurements with a single point spectrometer and hyper- spectral cameras to discriminate cHABs nearshore. We will conduct extended field campaigns for the USV and UAS in Lake Erie and Lake Pontchartrain, two shallowwater environments prone to cHABs, during Years 2 and 3 of the project.