In Memoriam Andrzej Witkowski (1955 - 2023)

On September 17, 2023, we were deeply saddened to learn of the passing of our colleague and friend, Professor Andrzej Witkowski, Ph.D., D.Sc. This news was a shock, and it marked the conclusion of a remarkable and fruitful scientific career. Professor Witkowski had been a driving force in various research endeavours and projects, many of which were intricately linked to the mission and goals of Baltic Earth, both indirectly and directly.

Born on 11 October 1955 in a small inland Polish village of Jagodne, he strove vigorously to make his way to the sea through his joint M.Sc. studies in Geology at the University of Warsaw and in Oceanography at the University of Gdańsk, completed in 1979 with a M.Sc. thesis dealing with stratigraphy and geology (“Sedimentological characteristics of the coastal shallows of Puck Lagoon in the Kuźnica-Chałupy area”). Having taken a research and teaching position at the University of Gdańsk and undertaking studies on sedimentological and mineralogical aspects of surface and subsurface sediments of the Gulf of Gdańsk, he established himself as a Polish pioneer of marine palaeoceanography. Those studies led to his 1989 Ph.D. with a thesis on algal mat fossilization processes in clastic sediments of the Puck Bay.

Meanwhile he got interested in diatoms. He realised what a great potential lies in studies of those beautiful creatures on account of their importance in both the present-day ecosystem services, as major primary producers, and in their being excellent proxies for reconstructing past oceanographic and climatic events, conditions and processes in different geographical settings, the Baltic Sea in particular. The first line of research bore fruit in descriptions of numerous new diatom species and in collaborations with a multitude of diatom taxonomists among whom he became a prominent and respected expert. The other line of research resulted in using diatoms for reconstruction of the post-glacial evolution of sedimentary basins with respect to climatic fluctuations and successive stages of the Baltic Sea history, and subsequently in his 1994 D.Sc. degree awarded for the monograph “Recent and fossil diatom flora of the Gulf of Gdańsk, Southern Baltic Sea. Origin, composition and changes of diatom assemblages during the Holocene” published by J.Cramer publishing house in Stuttgart as vol. 28 in the series Bibliotheca Diatomologica.

In 2001, the University of Gdańsk granted him full professorship. During these years at the University of Gdańsk, he described the variability of the structure of diatom taphocoenoses in order to resolve palaeogeographic and palaeoecological problems of the southern Baltic Sea, including human impact. One of Professor Witkowski’s important scientific accomplishments was to describe the so-called anthropogenic diatom assemblage in the superficial sediments of the Gulf of Gdańsk.

During his years at the University of Gdańsk he was a recipient of a number of fellowships which helped him to establish important contacts and to solidify his position in palaeoceanology and diatomology: in 1990/1991 he spent 5 months at the University of Copenhagen as a fellow of the Danish Ministry of Culture; in 1992, a DAAD fellowship brought him for 2 months to the Goethe-University of Frankfurt/Main in Germany, a university he revisited in 1995/1996 for an 18-month-long stay funded by the Alexander von Humboldt fellowship on invitation of Prof. Dr. Horst Lange-Bertalot at the Institute for Ecology, Evolution and Diversity. Another Alexander von Humboldt fellowship allowed him a subsequent 2-month research stay, in 2004, also in Frankfurt.

In addition to his scientific work, he was heavily involved in teaching. He was an excellent lecturer, valued and respected by students.

Having transferred to the University of Szczecin he founded his own Laboratory of Palaeoceanology at the then Faculty of Natural Sciences (now the Institute of Marine and Environmental Sciences). The laboratory, pursuing – from the start – the lines of research championed by Professor Witkowski, became a centre attracting numerous Polish and foreign students and scholars for whom Professor Andrzej Witkowski was an unquestionable authority and mentor. In addition to numerous M.Sc. students he supervised, there was a long series of Ph.D. theses prepared under his guidance and supervision. Besides his Polish Ph.D. students who, upon graduation, continued as post-docs and fully fledged researchers in Poland and abroad, a number of Andrzej Witkowski’s Ph.D. candidates hailed from other parts of the world (China, Indonesia, Turkey, Germany, Portugal, Croatia, Russia). The laboratory was visited by numerous scholars from Poland and abroad (the latter including scientists from Republic of South Africa, India, Vietnam, United Kingdom, France and US, to mention just a few) with whom Andrzej forged lasting collaborations resulting in joint research projects and publications. Professor Andrzej Witkowski maintained particularly close cooperative relationships, including exchange of scientists, with German universities and research institutes, whereby he was particularly supported by the Foundation for Polish Science (Fundacja na rzecz Nauki Polskiej, FNP). Because of his special interest in palaeoecological research on the development of the Baltic Sea during the Late Quaternary, Prof. Witkowski developed a very productive collaboration with the Leibniz Institute for Baltic Sea Research in Warnemünde.

Andrzej Witkowski’s legacy with respect to developing University of Szczecin’s international relations in geosciences over the last 10 years is directly visible in the annual programmes of a series of international seminars at the Institute of Marine and Environmental Sciences, at present titled the Szczecin Marginal Seas Webinars he was a co-convener of.

Other projects he was involved in, and/or was instrumental in developing, included those focusing on, inter alia, changes in circulation during the Late Glacial and Holocene in the Northern Atlantic Ocean, including the Baltic Sea (e.g., projects ERA-NET PLUS BONUS, DZP/POL-NOR) as well as the taxonomy and biogeography of phytoplankton in the context of recent climatic changes (e.g., project TemBioDiaSA). He expanded his research interest during the last decade to answer broader questions in palaeoceanography and -ecology and participated in international projects focussed on the European seas, such as the COST-Action SPLASHCOS dealing with the submerged landscapes of the European palaeoshelf and marginal seas or the tri-lateral Polish-German-Chinese project ERES on the Late Pleistocene development of the South China Sea exemplified by its Beibu Gulf.
Some of the projects required him to take part in scientific expeditions, which he enjoyed tremendously. Indeed, he logged a number of such endeavours, including expeditions to the south African coasts, Madagascar, the Red Sea, the Galapagos as well as cruises on board RV Oceania to Vest Spitsbergen, RV Marion Dufresne to the West Indian Ocean, and RV Maria S. Merian to Greenland.

Andrzej Witkowski’s activities toward strengthening international collaboration and interactions included also his efforts at organising international conferences at the University of Szczecin, starting with a series of smaller international meetings of diatomologists to Geopomerania conferences co-sponsored by the Baltic Earth to a big 18th International Diatom Symposium in September 2004 at Międzyzdroje (about 200 participants) to a huge gathering of the International Phycological Society in 2018 in Szczecin (about 700 participants). Memories from those meetings still linger among the participants.

In his later years, he became more and more interested in the science of climate change, this interest being manifested in organization of two international conferences in Szczecin, in 2009 and 2014 ("Climate Change - the environmental and socio-economic response in the Southern Baltic Region"), in collaboration with Baltic Earth.

For some of the attendees, the conferences provided a stimulus to come to Andrzej Witkowski’s laboratory for a Ph.D. study or a post-doc. A major aid and attraction in this regard has been the Szczecin Diatomological Collection, established by Andrzej Witkowski and his collaborators at the Institute of Marine and Environmental Sciences, University of Szczecin.

The collection gave rise to diatom cultures which have been key to a new research line Andrzej initiated in his laboratory. His research on diatom biodiversity and taxonomy led him to realise that the diatom taxonomy based solely on frustule morphology was not enough, and molecular and genetic studies are necessary as well. Such studies had indeed been initiated by him (phylogeny, taxonomy, biodiversity and biogeography of littoral diatom assemblages in projects supported by the Polish National Science Centre; biodiversity of diatom assemblages of the world ocean’s littoral and sublittoral zones with a particular reference to tropical coral reefs; molecular phylogeny of diatoms and culture-based use of molecular markers in the assessment of biodiversity of diatom assemblages in Project GHaNA) and resulted, as fitting, in a number of research papers and Ph.D. theses for which he and his collaborators were acknowledged, four times (2014, 2015, 2017, 2022), with the highest regional scientific award known as the “West-Pomeranian Nobel”.

In recent years, Andrzej Witkowski became interested in an applied angle of his diatomological research and engaged himself, his laboratory associates and Ph.D. students in studies concerning high-value natural products that can be derived from diatoms (e.g., chitosan, marennine from the blue Haslea cultures, and production of oil from diatom cultures up-scaled from laboratory conditions), again anchoring this research in diatom cultures maintained in his laboratory.

Although heavily involved in research, mentoring and supervision, Andrzej Witkowski did not shy away from administrative duties at the University, first as deputy dean for science at the Faculty of Natural Sciences, University of Szczecin, followed by his taking up the University of Szczecin vice-rectorship for science and international cooperation, culminating in his serving on the University Board. His contribution to science earned him the full membership of the Polish Academy of Sciences.

On top of that, he was a very outgoing, highly social person, always ready to interact informally with his peers, associates and students. He will be remembered as a noble and friendly person, respected and valued – and missed – by the scientific and academic community.

He is survived by his wife Małgorzata, his daughter Agnieszka and his son Jakub to whom we express our most sincere condolences.

Teresa Radziejewska, Małgorzata Witak, Jan Harff, Hans von Storch