The 24^th International Seaweed Symposium - ‘Seaweeds in a changing world’

Abstract

The 24th edition of the International Seaweed Symposium (ISS), an academic-industry event that dates back to 1952, was held for the first time in Oceania. The local organizing committee chaired by Professor Catriona Hurd, Institute for Marine and Antarctic Studies, University of Tasmania, and Professor Michael A. Borowitzka, Murdoch University, Western Australia worked tirelessly to curate a program that balanced scientific rigor with engaging discussions, providing ample opportunities for networking and collaboration. “Seaweeds in a changing world” was the theme of this symposium, participants from 48 countries from all over the world attended this symposium from 19-24 February 2023. More than 576 on-site and 207 virtual participants registered for the Symposium who contributed to the success of this event. The International Seaweed Association (ISA) ensures the continued development of seaweed and its benefits and serves as a bridge between research academia and industry. The ISA is ready to celebrate the Silver Jubilee of the ISS and is also proud to announce that the 25th International Seaweed Symposium (ISS) will be held in Victoria, British Columbia, Canada, 4-9 May, 2025 with the Local support of Ocean Networks Canada, Cascadia Seaweed, and the Pacific Seaweed Industry Association (https://iss25.com).

Introduction

It is with great pleasure and a sense of anticipation that we present the proceedings of the 24th International Seaweed Symposium, held in the enchanting city of Hobart, Tasmania, from February 19 to 24, 2023. Hobart, Tasmania, the southernmost state of Australia, surrounded by pristine waters of the Southern Ocean, brought together experts, researchers, and enthusiasts from around the world to explore and celebrate the vast potential of seaweed research and industry. The 24th edition of the International Seaweed Symposium (ISS), an academic-industry event dating back to 1952, was held for the first time in Oceania. At the International Seaweed Association (ISA, https://isaseaweed.org) one of our core activities is to support and hold a tri-annual symposium, within our mission to ensure the continued development of seaweed and its benefits. This symposium serves as a bridge between research academia and industry, a platform for researchers, industry experts, and enthusiasts to converge, exchange ideas, and explore the vast potential of seaweed research and its myriad applications.

The 24th ISS was supported by the International Seaweed Association Council (ISAC) and with major sponsorship support from the Tasmanian Government, the Institute for Marine and Antarctic Studies (IMAS), Fisheries Research and Development Corporation (FRDC), Marine Bioproducts Cooperative Research Centre (MBCRC), several organizations, companies, and Australian associations. The local organizing committee co-chaired by Professor Catriona Hurd, Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, and Professor Michael A. Borowitzka, Murdoch University, Western Australia, curated a program that balanced scientific rigor by engaging in discussions and providing ample opportunities for networking and collaboration. The local organizing committee, headed by Catriona and Michael, was comprised of Alecia Bellgrove, Rocky de Nys, John Huisman, Ian Jameson Catriona MacLeod, Wendy Nelson, Craig Sanderson, Thomas Wernberg, Pia Winberg, Jeffrey Wright, Wei Zhang, Joe Zuccarello and Wouter Visch. The ISA Council is very grateful to all of them for the outstanding and friendly organization.

‘Seaweeds in a changing world’ was the theme of this symposium, and various sessions, and poster presentations served as a melting pot of diverse ideas, cutting-edge research, and collaborative initiatives, maximizing the benefits of this unique gathering. There were workshops, meetings, social events, and excursions that strengthened the bonds within our seaweed community that experienced the growing algae industry, the natural beauty, and the cultural richness of Tasmania. A wonderful place where we found a growing algae industry and strong research groups devoted to the scientific knowledge and development of seaweed. Tasmanian industries use brown seaweeds for fucoidan extraction and beach-cast harvest for alginates, fertilizers, and feeds for agriculture (Hurd et al. 2023).

Participants from 48 countries worldwide attended this symposium. More than 576 on-site and 207 virtual participants were registered for the symposium, who contributed to the success of this event. By continent, the highest on-site representation came from Oceania (53%), but Europe was also well represented (17%), followed by Asia (15%) and America (13%). Online participants from Europe (31%) predominated followed by America (25%), Oceania (22%), and Asia (19%). We extend our heartfelt appreciation to all the presenters, session chairs, sponsors, and volunteers who contributed to the symposium's success. Your dedication and enthusiasm were instrumental in creating an environment conducive to meaningful dialogue and knowledge exchanges.

Plenary sessions, mini-symposium and workshops

Seaweeds, often referred to as the ‘forests of the sea’ are increasingly recognized for their ecological importance, economic value, and untapped potential in various industries. Throughout the weeklong event, we witnessed engaging discussions, thought-provoking presentations, and collaborative initiatives that underscored the dynamism of the seaweed research community. Experts in the field shared their latest findings, addressing critical challenges and charting pathways for future seaweed research and utilization. As we delved into the multifaceted world of seaweed, the symposium covered a wide array of topics ranging from seaweed biology and ecology to advanced cultivation technologies, industrial applications, and sustainable resource management and restoration. Five plenary sessions, fourteen mini symposia, and two workshops were held during the event, with renowned experts offering invaluable insights and sparking discussions that are bound to shape the future of seaweed research and its applications. Before the symposium, some attendees had the opportunity to visit the CSIRO Australian National Algae Culture Collection, a unique resource of Australian biodiversity from tropical Australia to Antarctica, containing living cultures of marine and freshwater species from most microalgal classes (https://www.csiro.au/en/about/facilities-collections/collections/anacc). Others attended the workshops on “Charting a global agenda for kelp restoration” and “Towards a strategy for a global effort to address fundamental gaps in seaweed taxonomic knowledge”.

The symposium program was organized to ease attendance and take advantage of the different subjects around seaweeds (Fig. 1). The following plenary talks were presented:

Fig. 1

Mind map of the topics around seaweed presented at the ISS 24^th scientific program (Elaborated with Algor Lab S.r.l.)

Wendy Nelson (University of Auckland, NZ) presented ‘Rimurimu’ which brought us a view of the traditional use of seaweed by the Māori of Aotearoa New Zealand for food as well as ‘rimurapa’ (bull kelp – Durvillaea).

John M. Huisman (West Australian Herbarium, Perth, Australia) reviewed the collection of Australian seaweeds (with about 20,000 specimens) by the Irish botanist William Henry Harvey to characterize and propose defensible generic reassignments based on morphology and molecular data.

Melinda Coleman (NSW Department of Primary Industries, Australia) showed her efforts to restore lost kelp forests around Australia to boost resilience to future climate change using novel and proactive solutions to assess the vulnerability of kelp forests.

Sébastien Jan (East Coast Ocean Farmers, Madagascar) presented an aquaculture model with euchematoids in Madagascar under the premises of risk management, modern thinking, and social dimension to improve novel cultivation techniques, strengthen collaborations, and support coastal communities.

Helen Fitton (R & D advisor, Australia) showed us the barriers behind the development and commercialization of seaweed extracts as bioactives. She taught us how a comprehensive intellectual property strategy, researchers and companies, can safeguard their innovations for further research and commercialization.

Dorte Krause-Jensen (Aarhus University, Denmark) enlightened us with up-to-date information on the conservation, restoration, and sustainable management of macroalgal beds, providing a nature-based solution that is integral to blue carbon ecosystems for climate change mitigation and supporting various ecosystem services.

Chris Hepburn (University of Otago, NZ) introduced us to the indigenous management of kelp forest ecosystems and associated fisheries in New Zealand, particularly by the Māori, which is rooted in cultural values, traditional knowledge, and a long-term perspective.

Nick Paul (University of the Sunshine Coast, Australia) showed us how Asparagopsis has gained attention in the context of reducing methane emissions from livestock and, of course, the challenges related to scalability, cost-effectiveness, and sustainability of Asparagopsis as a methane-reduction strategy.

Karlotta Rieve (Hatch Blue) showed some of the gaps, innovation opportunities, and new markets identified in a recent report of Hatch (https://seaweedinsights.com) and how this information is crucial for the productive and scalable growth of the Eucheumatoid seaweed industry.

Eun Kyoung Hwang (National University of Fisheries Science, Korea) presented the prospects of seaweed cultivation and breeding in Korea and how these efforts have been shaped by ongoing research, technological advancements, sustainable practices, and market demands by the Korean industry.

Marie Magnusson (University of Waikato, NZ) shared some of the hurdles and bottlenecks in seaweed aquaculture in New Zealand. The transition they faced from small-scale experiments to full-scale implementation to commercially viable seaweed cultivation practices.

Alejandro H. Buschmann (Universidad de Los Lagos, Chile) updated and discussed how seaweed production has been experiencing rapid global expansion and the need for collaboration between scientists, policymakers, industry stakeholders, and local communities to maximize the benefits of expanding industry while minimizing its potential negative impacts.

Lim Phaik Eem (Institute of Ocean and Earth Sciences, University of Malaya, Malaysia) addressed the challenges in Malaysia to safeguard the carrageenophyte cultivation industry promoting sustainable farming practices, assessing environmental impacts, evaluating market dynamics, and regulatory considerations to implement a holistic approach.

Patrick Martone (University of British Columbia, Canada) revisited the consequences of calcification for coralline algal ecology and evolution as an integral process to the functioning and stability of coral reef ecosystems. He showed ongoing research to better understand how these algae respond to environmental changes, adapt over time, and contribute to the overall health and resilience of marine ecosystems.

Ira A. Levine (The Algae Foundation, USA) updated us to the Algae Foundation a non-profit organization dedicated to advancing the algae industry through research, education, and outreach. The Algae Foundation’s mission is to promote the power of algae to transform human society and the environment upon which it depends (https://thealgaefoundation.org) (Levine 2017).

Besides the above, several mini-symposia were also organized on different subjects: Global kelp forest restoration efforts, Australia-China collaborations, Bioplastics, Novel thermal macroalgae processing approaches to enhance valued compound extractions, Genomic selection in economically important kelp of the Eastern Pacific and North Atlantic, Carbon sequestration by macroalgae, Precision Phyconomy, Kelp Blue: Macrocystis cultivation and ocean health, Seaweed-derived sterols in aging-related diseases, Best practice in post-harvest treatment of seaweed, Securing the future of the eucheumatoid seaweed industry in a time of rapid environmental change). Moreover, two formal meetings took place on ‘Australian Seaweed Industry: Growing impact and opportunities’ organized by the Australian Sustainable Seaweed Alliance (ASSA) and another by the Safe Seaweed Coalition, nowadays Global Seaweed Coalition, on the advances of financed projects.

These contributions reflected the rich diversity of research and insights shared by participants around the world at the International Seaweed Symposium. In this proceeding, you may find most of the findings shared with the global seaweed community.

Social program

Beyond the lecture halls, the symposium offered attendees the opportunity to explore Tasmania’s natural wonders and cultural heritage. Tasmanian aboriginal peoples have lived in Tasmania for at least 40,000 years utilizing seaweed as food, shelter, water carriers, and medicine, as well as for ceremonial reasons (Hurd et al. 2023). Around 750 macroalgal species have been currently described from Tasmania, some of which we saw during our stay in Hobart. Social events and excursions provided moments of relaxation and camaraderie, further enhancing the overall experience of the symposium. The organizing committee meticulously crafted a social and cultural program that fostered a sense of community and collaboration.

The symposium was officially opened by Her Excellency the Honorable Barbara Baker AC, Governor of Tasmania, who later invited some guests to a reception at the Government House, an early Victorian country house from 1857, overlooking the Royal Tasmanian Botanical Gardens and the Derwent estuary.

As part of the networking events, early career postdoctoral research meetings and student functions were held at IMAS sponsored by the Australian Sustainable Seaweed Alliance Seaweed as an innovation showcase.

By the end of the symposium, science met art in an exhibition showcasing the incredible impressions of artists who have gone ‘beneath the surface’ to present the ‘Seaweed-Inspired Art Showcase’ to explore the fascinating world of seaweeds at the IMAS exhibitions center. We all have fond memories of all these experiences that enriched our spirits beyond the academic and scientific experiences (Figure 2).

Fig. 2

Joyful moments and memories of the social program and mid-symposium tours: Government House reception, an early Victorian country house from 1857; Science meets art ‘beneath the surface’ with Seaweed-Inspired Art Showcase; Bonorong Wildlife Sanctuary view; Tasman Island Seaweed; and Seaweed Gin

The 24^th ISS student awards

During our closing ceremony, we also awarded brilliant student presentations during this event, bearing in mind that these youngsters will be future seaweed researchers and entrepreneurs who will continue the development of the world seaweed community.

Maxwell S. Doty memorial award

The ISAC endowment fund, in memory of Maxwell S. Doty (1916–1996) an accomplished scientist and a visionary seaweed farmer and Honorary Life Member of the ISA, helps us to give each ISS the Maxwell Doty award issued by the ISA for outstanding research in applied phycology. Twenty-one presentations were evaluated at the 24^th International Seaweed Symposium for the award for Valuable Research in Applied Phycology. Three awards of US$ 1500, US$ 1000, and US$ 500 were given to:

1^st Prize to Bienson Ceasar Narvarte (The Marine Science Institute, University of the Philippines, The Philippines) “Impacts of aquaculture nutrient sources: ammonium uptake of commercially important eucheumatoids depends on phosphate levels”

2^nd Prize to Mikaela Young (University of the Sunshine Coast, Australia) “Why do young adults eat seaweed? An Australian case study”

3^rd Prize to Clara Simon (University of Galway, Ireland) “A rapid methodology for the selection of Ulva elite strains tailored to specific growth conditions”

24^th International Seaweed Symposium student awards

Eighty-eight student oral presentations and 48 posters were evaluated by our academic jury during the course of the event. The Best Student Presentation awards were given to outstanding papers presented at the 24^th International Seaweed Symposium, based on the evaluation by the student award committee.

The best student’s oral presentations were awarded to the following:

1^st Prize to Reina Veenhof (Southern Cross University, Australia) “Ecology of kelp gametophytes: grazing in a warming ocean”

2^nd Prize to Alisa Mihaila (University of Waikato, NZ) “The reproductive phenology of Asparagopsis armata in New Zealand – 35 years later”

3^rd Prize to João Trigo (Chalmers University of Technology, Sweden) “Blanching before pH-shift processing of Saccharina latissima retains protein extraction yields while minimizing iodine content”

Best Student poster presentations were awarded to:

1^st Prize to Ellie Paine (University of Tasmania, Australia) “Season regulates the flux of dissolved organic carbon from a temperate seaweed forest”

2^nd Prize to Kristoffer Stedt (University of Gothenburg, Sweden) “Extending sea-based cultivation season of Ulva fenestrata by post-harvest treatment in herring production process Waters”

3^rd Prize to Jaide Phelps (University of Alaska Fairbanks, USA) “The effect of sedimentation on spore settlement and recruitment of the Arctic kelp, Laminaria solidungula”

Moreover, the Kelp Forest Alliance (https://kelpforestalliance.com) presented the Kelp Forest Challenge and awarded for the first time the ‘Kelpie Award’ to:

Tristin McHugh (The Nature Conservancy, USA) “Bull Kelp in Northern California”

Springer Nature Group has been a long-time partner of the ISS, not only furthering our mission to advance phycology research and academic publishing practices with these Proceedings but also funding ‘The Springer Prize’ for students presenting at the 24^th ISS. Book vouchers for Springer Scientific books were awarded to:

Jennifer Hudson (University of NSW, Australia) “RNA-Seq analysis reveals a downregulation of immune associated genes in Delisea pulchra following pathogen exposure”

Juan Montes-Herrera (University of Tasmania, Australia) “Mapping photosynthetic pigments in Antarctic coralline algae (Tethysphytum antarcticum) with hyperspectral imaging”

Jiasui Li (University of NSW, Australia) “Bacterial controlled mitigation of dysbiosis in a seaweed disease”

Allyson Nardelli (University of Tasmania, Australia) “Water motion and seasonality in morphology of Lessonia corrugata”

Luna M. van der Loos (Ghent University, Belgium) “Salinity structures the microbiome of the green seaweed Ulva: functional and taxonomic patterns”

ISA hopes to promote interaction between students and industries so that they not only become part of the ISA community, but also contribute to it, and that the International Seaweed Symposium will be their priority among the conferences.

International Seaweed Association Council

The International Seaweed Symposium (ISS) is not only the oldest seaweed symposium but also our showcase for ISA work and interaction with the seaweed community. On Sunday, February 19, before the 24^th ISS started, the ISAC had its triennial face-to-face meeting. ISAC is the governing body of the ISA with elected members conducting i virtual meetings in between each ISS. During our triannual meeting, ISAC reorganizes and renews the Council members who have the mission to promote applied phycology and seaweed research on a global basis stimulating interactions among researchers, industries, and government representatives in all countries. Four members had their mandate expiring with the 24^th ISS: Erick I. Ask (USA), Alejandro Buschmann (Chile), Stefan Kraan (Ireland), and Shao Jun Pang (China). To all of them, we express our gratitude for their commitment to the ISA. New members joined the ISAC: Loretta Roberson (USA), Ira Levine (USA), Arif Issa Al Mazrui (Tanzania), Yimin Qin (China), Leila Hayashi (Canada) and Catriona Hurd (Australia). For the period 2023–2025, Helena Abreu (Portugal) becomes our first female president, Leila Hayashi (Canada) becomes vice-president, Ira Levine and Loretta Roberson (USA) become treasurer and co-treasurer, Susan Holdt (Denmark) remains secretary general, and I, Daniel Robledo (México), becomes past-president (Fig. 3). Thus, we reinforced gender representation on the Council with 38% of female members; gained the presence of industry with 46% of members from the business or industrial sector and consolidated a balanced geographical representation by Continent: five members from America, three members each from Europe and Asia, and one member each from Africa and Oceania.

Fig. 3

International Seaweed Association Council members. Top (from left to right): Jeong H. Kim, Norishige Yotsukura, Stefan Kraan, Jaime Zamorano, Leila Hayashi (Vice-president), Loretta Roberson (Treasurer), Arif I.A. Mazrui, Michael A. Borowitzka, Shao Jun Pang; Bottom: Catriona Hurd, Helena Abreu (President), Susan L. Holdt (Secretary General), Daniel Robledo (outgoing President)

At ISAC we also count on the vast experience of Professor Michael A. Borowitzka, the editor-in-chief of the Journal of Applied Phycology, together with the guest editors for each ISS, for the reviewing process of the submitted papers and ensuring their quality.

The operating budget of the ISA has been growing, thanks to the wise financial management of our past treasurer Erick I. Ask allowed us to start planning some strategies benefitting the membership. We are confident that with the refreshing experience of our new treasurer Ira “Ike” Levine and Loretta Roberson (co-treasurer), a more stable budget to invest in the long-term support of ISA activities is secured.

Honorary members

Many prestigious members of the seaweed community have given their time and expertise to the International Seaweed Association Council: Jack L. McLachlan, Canada; Eurico C. Oliveira, Brazil; Mark A. Ragan, Australia; Harry J. Peter Bixler, U.S.A; and Mike D. Guiry, Ireland. We are in debt for all the knowledge, organization, and wisdom put into this Association. During the closing ceremony at Hobart, we were proud to announce the nomination of Hans E. Porse, Denmark, to become a new Honorary member of the ISA. Hans sadly passed away in July last year, but his efforts in the carrageenan industry will be an invaluable legacy to us. The world has lost a man of huge importance for the seaweed and ingredient business. For many years Hans contributed to the industry as head of Copenhagen Pectin (now CP Kelco ApS) as director, president, and chairman of regional and international carrageenan purchase, setting up factories, sales, and marketing.

During the 1970s and the 1980s, Hans initiated the cultivation of Kappaphycus and Eucheuma seaweeds in Indonesia and Zanzibar where commercial cultivation and carrageenan extraction involves approximately 150-200.000 people worldwide. He was also very active in providing updates, requirements, and outlooks for the phycocolloid industry, crucial information to academics and industrialists within the seaweed and business world (Bixler and Porse 2011; Porse and Rudolph 2017). We are grateful for the time we had with Hans - in loving memory (Fig. 4).

Fig. 4

Hans Esben Porse (October 5, 1942-July 14, 2023) became an Honorary member of the International Seaweed Association in February 2023

Igniting innovation: building on the past to advance the seaweed momentum

As reflected on the achievements of the 24^th International Seaweed Symposium, we acknowledge the collective efforts that have elevated our understanding of seaweeds and their vast potential. We hope that these proceedings will serve as a valuable resource for researchers, practitioners, and stakeholders alike, inspiring continued collaboration and innovation in the dynamic field of seaweed research. For the last 10 years, seaweed research and literature has grown significantly around their chemical composition, antioxidant properties, bioactive compounds, bioethanol, and protein content (Fig. 5), in hand with the ten global seaweed markets identified with potential to grow by an additional US$ 11.8 billion by 2030 (World Bank 2023). Accordingly, NGOs, entrepreneurs, country networks, regional programs, alliances, and worldwide organizations are focusing their efforts on supporting seaweed due to its ability to sink carbon, sustain marine biodiversity, employ women, and unlock value chains. We look forward to the continued growth and advancement of seaweed science and industry in the years to come. In this regard, the ISA is ready to celebrate the Silver Jubilee of the ISS and is proud to announce that the 25th International Seaweed Symposium will be held in Victoria, British Columbia, Canada, 4 – 9 May, 2025 with the local support of Ocean Networks Canada, Cascadia Seaweed, and the Pacific Seaweed Industry Association (https://iss25.com). Be ready to Ignite Innovation and join us again in the most important International event around Seaweed, the International Seaweed Symposium.

Fig. 5

Bibliometric Mapping with Web of Science bibliographic databases, citations, and references of scientific publications around ‘seaweed’, for the period 2013-2023. VOSviewer (van Eck & Waltman 2010)