Operational Phytoplankton Observations (OPO) Working Group

Operational Phytoplankton Observations (OPO) Working Group

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Working group to develop standards and best practices for the collection and assessment of Operational Phytoplankton Observations (OPO) using particle imaging instruments (PII).

Objective: The OPO Working Group members will create a set of best practices for different PIIs, water types, and sampling approaches. This activity is a follow-up to the Phytoplankton Taxonomy Working Group, which developed standards and practices for image data management and interoperability. The ultimate goal is to have these best practices endorsed by the Global Ocean Observing System (GOOS) and used in large scale ocean observing programs, such as repeat hydrographic programs and ocean observatories, long term ecological time series, as well as funded process study research cruises. The resulting standards and practices will be archived at Ocean Best Practices and in a Limnology and Oceanography Methods-type manuscript.

Justification: The number of particle imaging instruments (PII) for quantifying and identifying phytoplankton in aquatic environments has grown over the last decade, with several instruments now considered to be “mature technologies” with a Technological Readiness Level (TRL) between 7 and 9. Such methods are greatly advancing our capacity to measure Essential Ocean Variables (EOVs) and Essential Biodiversity Variables (EBVs) such as phytoplankton biomass, community composition, functional group, and size distribution, which have traditionally required labor-intensive collection and analysis methods. By enabling automated and high throughput quantification of phytoplankton cell biomass (cell counts, biovolume) and taxonomic diversity over both ocean space and time, PIIs are poised to revolutionize our understanding of planktonic ecosystems and will allow us to effectively monitor global changes over time.

Given that the number of PII currently being used in, or soon to be incorporated into, a variety of ocean observing networks and platforms has grown substantially, now is the time to establish best practices for using these instruments in a quantitative way that can be used to derive robust and sustained measurements of biological and ecological EOVs. Different PIIs have different limitations and commonly-used imaging flow cytometers differ in their data outputs as well as recommended sampling procedures. Each aquatic sampling technique and the volume of water measured will impact the quantitative rigor of the measurements.

Read the full proposal

News & Events

June 27: First working group meeting (virtual)

August 2-4: OPO Working Group meeting (Bigelow Laboratory)

OPO WG Organizing Committee

Sophie Clayton

Aimee Neeley

Nicole Poulton

OPO WG members

Planned Activities and Outcomes

The OPO Working Group will identify challenges associated with quantitative sampling of phytoplankton due to:

1) Different oceanic provinces and biomass levels (e.g., coastal, open ocean)

2) Aquatic sampling techniques (e.g., bottle, underway), profiling or towed technologies, ocean observatories (moorings)

3) Operational differences between current phytoplankton imaging instruments (PIIs) and analysis tools.

The OPO Working Group will develop recommendations for specific instruments and sampling techniques to ensure that phytoplankton measurements are consistent, robust, and quantitative. These guidelines will be published as a peer-reviewed paper for distribution to the broader community, and our goal will be to seek endorsement from the Global Ocean Observing System (GOOS) for the best practices recommendations that emerge from this activity. Additionally, the best practices recommendations will be archived as a document in the Ocean Best Practices System repository.

We will convene two in-person working group meetings August 2-4, 2023, and early 2024, along with asynchronous online activities in preparation for the in-person meetings. OPO Working Group members will also participate in regular synchronous virtual meetings occurring between the in-person meetings.