INA Workshop on extant Coccolithophorid research

Institute of Marine Biology of Crete, Heraklion, Greece,
October 1-6, 2003

Extant coccolithophores have attracted a wide range of research over the past decade including much research on topics such as dimethyl sulphide and alkenone production, physiological ecology, carbon uptake mechanisms, remote sensing and modelling of blooms, but also taxonomy-based research on biodiversity, molecular genetics, ecology, biogeography and flux estimation. As a result of the latter strand of research there is now a significant number of specialists world-wide who are identifying and studying extant coccolithophores.

This workshop was proposed to allow these specialists to share research results, gain some training, and discuss methods and research priorities. The workshop was proposed at the INA9 conference in Parma in 2002 and Dr. Maria Triantaphyllou of Athens University who has recently commenced a very productive study of coccolithophores in the Aegean Sea offered to host it. Through collaboration with the Institute of Marine Biology of Crete, Maria was able to organise the meeting at minimal cost in a superb venue. The IMBC is located on the Aegean coast of Crete and we stayed in a very civilised tourist hotel 15 minutes walk down the beach at a specially negotiated discount rate. Late summer is probably an ideal time to visit Greece with the climate still consistently sunny but not oppressively hot, the sea pleasantly warm and the main tourist hordes back home. Needless to say we thoroughly enjoyed the swimming, bars, food, archaeological excursions and remarkably friendly environment.

We also did, however, manage to have a very useful meeting scientifically. In total about 40 people attended the workshop including a large home team from Athens and Crete. There were also substantial contingents from Germany, Italy, the USA and Portugal and a scattering from other countries across Europe and beyond. The British contingent was a bit tricky to enumerate but arguably included in addition to myself, three exiles Ian Probert (Caen), Ric Jordan (Yamagata) and Pat Quinn (Zurich) and two recent imports Jens Herrle (now at Southampton) and Sebastian Meier (now at the NHM working on calcareous dinoflagellate with Susanne Feist-Burkhardt), plus Markus Geisen who is now at Bremerhaven after his extended stay with me at the NHM. Just as importantly as the international diversity there was a wide age range with a healthy predominance of PhD students and young post-docs, and a 50:50 balance of men and women.

We had one training day plus two and a half days of scientific sessions including 17 talks, 15 poster presentations (with 10 minute introductory talks) and 4 workshop sessions. This was a relatively relaxed schedule which allowed everyone to present their work and with a small specialist audience there was an excellent level of discussion, and if the time keeping was rather lax at times it did not seem to matter as we just continued a bit later.

The training day was arranged by Ian Probert and Colomban de Vargas (Rutgers University, New Jersey), with assistance from Markus Geisen and Pat Quinn. Ian and Colomban gave extended overviews on the biology of haptophytes and on application of molecular genetics to planktonic protists. Then Ian, Pat and Markus organised a practical on isolation of cultures of coccolithophores; including demonstration of plankton sampling from the beach and a chance to test our manipulation skills by isolating cells with a micropipette (which makes picking small forams seem very easy). Since most nannoplankton workers still come from a geological background this session was very welcome.

The presentations were organised into sessions on Coccolithophorid Ecology, Biology, Biogeography, Coccolithophores and marine carbonate cycles, and Evolutionary Biodiversity – Taxonomy. In terms of taxonomy we are at a relatively advanced stage, as symbolised by the publication, in time for the meeting, of a new CODENET sponsored Guide to Extant Coccolithophore Taxonomy (Young et al. 2003). However, recent research has highlighted the fact that many conventional species are actually clusters of cryptic or pseudo-cryptic sibling species. New work in this area included documentation of fine scale variation in Florisphaera profunda by Pat Quinn in Coccolithus pelagicus by Aurea Pariente, and in the Papposphaeraceae by Lluisa Cros. In parallel the recent work documenting holococcolith-heterococcolith life-cycle associations continued, with new results from Maria Triantaphylou and extended workshop discussion on the nomenclatural implications. These themes in turn strongly influenced presentations and discussion on ecology of coccolithophores. A key presentation by Patrizia Ziveri on distribution of selected species in the Atlantic based on a large database of Holocene sediment samples both revealed patterns which had previously been barely recognised and showed that this type of biogeographic data urgently needs to be re-collected using modern taxonomy.

There was fine set of sediment trap studies, including a three year series described by Meral Kobrich from off NW Africa with intriguingly strong inter-annual variation. New lines of ecological research were suggested by research of Maria Triantaphylou on the potential of coccolithophores as pollution indicators using both assemblage reduction and malformation as proxies, with disticty encouraging preliminary results, and of Markus Geisen on testing of functional hypotheses through measurement and modelling of the mechanical properties of coccospheres.

Information preservation in the fossil record was a less expected theme but reflects the fact that a key objective of much work on extant coccolithophores has been to provide data for palaeoecological analyses. Harald Andruleit and Jeremy Young highlighted the problem of information loss with only a fraction of the extant biodiversity and assemblage variability being transmitted into the fossil record or even the sediment trap record. Conversely Karl-Heinz Baumann showed that on a large scale there was remarkably high fidelity between the biogeography of coccolithophores in Nordic Seas as observed in the plankton and in the surface sediments. In parallel Marie-Pierre Aubry argued that large scale patterns in the Cenozoic fossil record indicated strong differences from modern ecology and could not be explained away by taphonomic processes. She argued that a major challenge for palaeontologists was to interpret this record, informed by knowledge of modern coccolithophore ecology but aware that the present may be only a partial key to the past.

Perhaps the overall conclusion of the meeting was that we now have firm foundations for future research, especially on coccolithophore ecology, as a result of finally having a reasonable understanding of the biology and taxonomy of coccolithophores. Typical questions identified during the workshop sessions include (1) Will the pattern of global pandemicity indicated by current taxonomy prevail at the finer taxonomic level of pseudo-cryptic species? (2) Is the pattern of holococcolithophore life-cycle stages occupying more oligotrophic niches than the heterococolith life-cycle stages valid as a general model? It is an interesting phase of research and clearly coccolithophores do have the potential to become the best understood group of oceanic phytoplankton.

Jeremy Young