New applications of autonomous biosensors in harmful algal bloom research and monitoring

Blooms of the toxic dinoflagellate Alexandrium fundyense cause recurrent outbreaks of paralytic shellfish poisoning in the Gulf of Maine region of the U.S. The outbreaks can be widespread, covering hundreds of km of coastline,... [ view full abstract ]

Blooms of the toxic dinoflagellate Alexandrium fundyense cause recurrent outbreaks of paralytic shellfish poisoning in the Gulf of Maine region of the U.S. The outbreaks can be widespread, covering hundreds of km of coastline, or localized in small embayments and estuaries. In recent years, our studies of Alexandrium dynamics in both of these systems have incorporated two novel biosensors – the Environmental Sample Processor (ESP) and the Imaging FlowCytobot (IFCB). The ESP uses molecular assays to detect and analyze cells and toxins whereas the IFCB is an automated underwater microscope. This talk will summarize the results and lessons from multiple years of ESP and IFCB deployments in both systems. For the Gulf of Maine work, we highlight a new application – the estimation of shellfish flesh toxicity at nearby shore stations using ESP-derived cell counts in coastal waters. Most recently we have co-deployed the ESP and the IFCB from a specially built observatory raft. These instruments have typically been deployed separately, but in 2016, were used concurrently during a major A. fundyense bloom for the first time. Data collected from each of these instruments are transmitted to our lab in near real-time and we have begun leveraging this data stream for targeted, adaptive sampling of different A. fundyense life cycle stages. One example is our use of a newly developed High-Speed Microscale Imaging System (HSMIS) that is able to record A. fundyense swimming without interference. Clearly, sensors like these can play a significant role in HAB research, monitoring, and management.