​​​​​​​​The plankton community within ICES is vibrant. The Working Group on Zooplankton Ecology (WGZE) just celebrated 30 years with almost 100 members and the publication of Marine zooplankton time series: essential tools to understand variability in productivity-determining processes in the oceans, a themed set in ICES Journal of Marine Science.

ICES ID Leaflets for Plankton are open access and peer-reviewed taxonomic keys for the identification of zooplankton species and some phytoplankton groups in ICES Area. 

In 2019, co-editors Lidia Yebra, co-chair of WGZE, and Antonina 
dos Santos, SCICOM member for Portugal, revived the series that
had fallen dormant for some years after the former series editor, Alistair Lindley, SAHFOS, retired. ​

The plankton leaflets are an important resource and reference for the marine science community, as they are regularly consulted by scientists and students alike. They represent one of the main sources of online taxonomic guides for plankton identification and can be useful for future building of automatic image analysis of plankton. Leaflets include ecological and molecular information as well as morphological identification keys.

How has plankton monitoring changed since the publication of the first ICES ID Leaftlets for Plankton?

Lidia Yebra: Plankton monitoring, especially at coastal stations, are now spread across all ICES area and adjacent seas (e.g. Mediterranean) and a special Themed Set on this topic was published last year under the auspices of the WGZE. 

Many plankton groups are dealing with serious issues regarding the lack of expertise on how to identify species and funding to support many of the observation sampling points. In this respect, WGZE has been extremely important as it gathers and supports all groups conducting the zooplankton time-series monitoring.​

Have you seen any trends in changing plankton distribution of in ICES ecoregions?​

Antonina dos Santos: We can't answer this question with the information contained in the Leaflets, they are not intended to look at ecology of plankton but rather are taxonomical tools for the identification of species. 

Nevertheless, the first three Leaflets were published in 1939. At that time, monitoring by the Continuous Plankton Recorder was already established, which is one of the longest marine biological monitoring programmes in the world. Studies using the data gathered by this monitoring programme show shifts in plankton species distribution, abundance, and dynamics (see e.g. Beaugrand et al. (2002) Science 296:1692-1694).

Are there new species that have been introduced to ICES area since the series began?
Antonina dos Santos: In almost 100 years of Leaflets history, several plankton species have been introduced in ICES area and the new series of ID Leaflets for Plankton have been taking this into account. For example, ID Leaflet No. 190 shows how to identify larvae of a crab species that have been introduced to ICES area, and a forthcoming leaflet focuses on the alien/introduced copepod family Pseudodiaptomidae.

What role does eDNA metabarcoding play in plankton monitoring?

Lidia Yebra: Despite the development of eDNA metabarcoding methodology in recent years, its application to plankton monitoring is still only beginning within ICES. One of the limiting factors for its implementation in routine monitoring is the lack of comprehensive and expert-curated libraries of DNA barcodes for some of the plankton groups. However, molecular information is presented in the new Leaflets series, namely the available DNA sequences for the species dealt with in each Leaflet.​

How has it been for you to be the series editors?

Lidia Yebra: It has been an adventure. As expected, the taxonomic experts for some plankton groups do not exist and/or are retired/unavailable to dedicate their time to produce the Leaflets. Fortunately, we have also been working with some young taxonomic researchers who have been producing high-quality Leaflets.

Finding an expert willing to produce a Leaflet can sometimes be a time-consuming task and we have had a high percentage of refusals and delays. Nevertheless, we manage to produce both new and updated Leaflets regularly. We have learned a lot and it has been an excellent partnership between us but also with the ICES editor and​ editorial office support.

How do you decide to publish an ID leaflet?

Antonina dos Santos: We decide based on the importance of the plankton groups for zooplankton monitoring within ICES area, on the lack of information available for the group, and on the availability of experts. We also accept suggestions and advice from WGZE members. 

Are all your authors from WGZE?

Lidia Yebra: No, most of them are actually from outside the WGZE community as members of WGZE tend to be ecologist experts and we are searching for taxonomic experts.

​When you took over as series editors, you mentioned that you would update past leaflets: have you been able to do so?

Antonina dos Santos: Yes, four of the twelve new series leaflets are updated old Leaflets.​

Find ICES Identification Leaflets for Plankton No. 200 Xanthidae MacLeay, 1838​ in our online library, along with all our other Identification Leaflets.