The updated guidelines, released as advice for OSPAR today, add new knowledge on the monitoring and measurement techniques that track the ecology of phyto- and other types of plankton in response to changes in the marine environment.
The objective of the guidelines is to ensure the availability and delivery of high-quality phytoplankton data that can be used to evaluate the state of OSPAR's regional set of indicators and eventually its assessments of the status of the seas. These developed indicators can then be used by all OSPAR contracting parties to address requirements of EU directives such as the Marine Strategy Framework Directive (MSFD) and the Water Framework Directive (WFD). In terms of the MSFD, this means work being carried out on the indicators under certain descriptors relevant to plankton – Descriptor 1 on biodiversity, 2 on non-indigenous species, 4 on foodwebs and 5 on eutrophication and harmful algal blooms.
Five ICES expert groups contributed to the work, with the results then reviewed by a group headed by Harri Kuosa, leading researcher at the Finnish Environment Institute (SYKE) in Helsinki. These groups explored additional methods, parameters and considerations as part of the revision, including suggesting modifications to the way in which harmful algal blooms and phytoplankton are both monitored and the data reported to ICES.
On the data side, the guideline revision recommends reporting and novel ways of counting and identifying various classes and rare species of plankton. All of this adds up to the need for long data time-series, for which consistent sampling and analysis is key, in order to detect subtle changes in marine ecosystems. This also enables assessments to distinguish between the various drivers of climate change in the phytoplankton community such as eutrophication. However, much uncertainty still exists in these causal relationships and more research is needed.
Kuosa, with 25 years' experience in monitoring, research and publications on phytoplankton, explained one of the main challenges in the guideline revising process, particularly in light of the end use of OSPAR indicators by its contracting parties.
"I've seen a lot of these guidelines and I know how people interpret the text, so they must be very straightforward and clear," he said.
"We need something more than what is routinely done and must take care that the basic guidelines are written in such a way that everybody can use them. We also need to make sure there is a solid scientific foundation for long-term monitoring, keeping the data as quality assured as possible to ensure they are comparable between regions."
The advice drew on the resources of ICES expert groups: the Working Group on Ballast and Other Ship Vectors (WGBOSV), on Harmful Algal Bloom Dynamics (WGHABD), on Introductions and Transfers of Marine Organisms (WGITMO), on Phytoplankton and Microbial Ecology (WGPME), and the Study Group on Ocean Acidification (SGOA).
Eutrophication, an excess of nutrients in a body of water which triggers an intense growth of plant life, including phytoplankton, is a key field of study for marine science and ICES, especially under the MSFD.
Plankton net. Photo: Sigrun Jonasdottir