CR2025_45 Biodiversity, biogeography and ecology of red calcified coralline algae of Britain

Lead Supervisor: Juliet Brodie, Natural History Museum

Email: j.brodie@nhm.ac.uk

Co-supervisors: John Griffin, Department of Biosciences, Swansea University; Jason Hall-Spencer, University of Plymouth; Rob Mrowicki, Natural History Museum

Background

The red calcified coralline algae are intriguing organisms. Ubiquitous in the world’s seas from the poles to the tropics, they are morphologically highly diverse, slow growing, one of the longest living groups of organisms on the planet (Frantz et al. 2005) and include the deepest known photosynthetic organism to 290 m deep (Littler et al. 1991). As habitat-forming ecosystem engineers, they support a large diversity of organisms making them essential for the conservation of the biodiversity they support. They are an integral component of coral reefs and for coral settlement (Cornwall et al. 2023). Maerl beds, i.e. habitats of free-living coralline algal nodules, are nursery grounds for fish and shellfish (Kamenos et al. 2014). Once not considered significant in carbon sequestration, increasing evidence suggests that calcified coralline algae do play a role in blue carbon (Mao et al., 2024; Burrows et al. 2024). These slow-growing, long-lived habitats are also potentially vulnerable to change. Furthermore, new calcified coralline algae ecosystems are still being discovered. Conversely, they are threatened by ocean acidification, and are impacted by increasing seawater temperatures, pollution and dredging for fish (e.g. Melbourne et al. 2023, McCoy & Kamenos 2015).

These seaweeds are extraordinarily numerous with over 1101 species described so far. The more we look, the more we find. With an estimated 2000 to 10,000 more species still to be discovered, documenting the calcified coralline algae is an immense task. However, the case for doing so is compelling and urgent not least because of the key role these seaweeds play in marine ecosystem function and as such require conservation. The results will also enable us to address why there so many species, how are they distributed and how they are evolutionarily related.

Britain supports a rich seaweed flora (Brodie et al. 2016), including many calcified coralline algae. A comprehensive study was undertaken on British calcified coralline seaweeds thirty years ago (Irvine & Chamberlain 1994) based on traditional techniques. Since then, new species of calcified coralline algae have been described using molecular approaches (Walker et al. 2009, Melbourne et al. 2017) but a comprehensive revision is required using state-of-the-art techniques. With high levels of cryptic diversity in the red algae, it is almost certain that new discoveries will be made.

The project

This project provides a unique opportunity for you to i) document coralline algal diversity of Britain using novel genomic approaches, ii) undertake an in-depth study of species ecology/distribution, iii) explore holobiomes of specific species, iv) determine traits of specific species, and v) study the results in relation to the North Atlantic/rest of the world. You will also be able to explore historical and contemporary collections data at the Natural History Museum (NHM) and work with the members of the Global Seaweed Biodiversity Group. The outcome will provide an important baseline for conservation and management of calcified coralline algae in Britain.

Research methodology

The project will involve field and laboratory work around Britain and at the NHM. To document diversity, specimen collections will be made extensively around Britain. There will also be access to contemporary collections at the NHM. Algal diversity will use a combination of molecular approaches including whole genomes and barcoding. Ecological studies will involve coarse and fine scale mapping of coralline algal habitats with scope for metabarcoding of coralline crusts. Determining biogeographical relationships within and beyond Britain will involve phylogenetic analysis on a global scale in collaboration with international partners.

You will also be part of an interdisciplinary research team at Swansea University, NHM, and Plymouth University. This highly inter-disciplinary project covers taxonomy and phylogenetics of coralline algae, biogeography, ecology, exploration of holobiomes and tools for conservation and management along with outreach/public engagement.

Training opportunities: 

You will have the opportunity to develop a wide range of skills, including fieldwork and ecological techniques. Laboratory skills will be developed in molecular techniques and data analysis, including bioinformatics and phylogenetic reconstruction, with potential for molecular dating in relation to genotypes and biogeographic relationships. There will also be the opportunity to develop networks with the global microbiome/holobiome community. Outreach and engagement will also be included.  You will be part of a multi-disciplinary research team at Swansea University, NHM, and Plymouth University. The project covers taxonomy and phylogenetics of coralline algae, biogeography, ecology, holobiomes and conservation and management tools. 

Student profile:

This project would be suitable for students with a degree in the Biological Sciences, such as Marine Biology or a closely related environmental subject. Familiarity with molecular techniques would be an advantage.

Please note: Due to the nature of this project and to comply with visa regulations, only Home students should apply.

References:

• Brodie, J., Wilbraham, J., Pottas, J. & Guiry, M.D. (2016). A revised check-list of the seaweeds of Britain. Journal of the Marine Biological Association 96: 1005-1029. https://doi.org/1017/S0025315415001484
• Burrows, M., O’Dell, A., Tillin, H., Grundy, S., Sugden, H., Moore, P., Fitzsimmons, C., Austin, W., & Smeaton, C. (2024). The United Kingdom’s Blue Carbon Inventory: assessment of marine carbon storage and sequestration potential in UK seas (including within Marine Protected Areas). Scottish Association for Marine Science. https://www.wildlifetrusts.org/blue-carbon
• Cornwall, C.E., Carlot, J., Branson, O. et al.(2023). Crustose coralline algae can contribute more than corals to coral reef carbonate production. Communications and Earth Environment 4: 105. https://doi.org/10.1038/s43247-023-00766-w
• Frantz, B.R., Foster, M.S. & Riosmena-Rodríguez, R. (2005). Clathromorphum nereostratum (Corallinales, Rhodophyta): the oldest alga? Journal of Phycology 41: 770-773. https://doi.org/10.1111/j.1529-8817.2005.00107.x
• Irvine, L.M. & Chamberlain, Y.M. (1994). Seaweeds of the British Isles Volume 1 Rhodophyta. Part 2B Corallinales, Hildenbrandiales. HMSO, London.
• Kamenos, N.A, Moor, P.G & Hall-Spener, J.M. (2014). Maerl grounds provide both refuge and high growth potential for juvenile queen scallops (Aequipecten opercularis). Journal of Experimental Marine Biology and Ecology 313: 241-254. https://doi.org/10.1016/j.jembe.2004.08.007
• Littler, M.M., Littler, D.S. & Hanisak, M.D. (1991). Deep-water rhodolith distribution, productivity, and growth history at sites of formation and subsequent degradation. Journal of Experimental Marine Biology and Ecology150: 163-182. https://doi.org/10.1016/0022-0981(91)90066-6
• Mao, J., Burdett, H.L. & Kamenos, N.A. (2024). Efficient carbon recycling between calcification and photosynthesis in red coralline algae. Biology Letters20: 20230598. https://doi.org/10.1098/rsbl.2023.0598
• McCoy, S.J. & Kamenos, N.A. (2015). Coralline algae (Rhodophyta) in a changing world: integrating ecological, physiological, and geochemical responses to global change. Journal of Phycology 51: 6-24. https://doi.org/10.1111/jpy.12262
• Melbourne, L., Brodie, J., Rayfield, E., Titelboim, D., Lord, O. & Schmidt, D.N. (2023). Spatial and temporal variation in the structural integrity of British rhodoliths and implications for habitat function. Scientific Reports 13: 13473. https://doi.org/10.1038/s41598-023-40292-5
• Melbourne, L.A, Hernández-Kantún, J.J., Russell^, & Brodie, J. (2017). There is more to maerl than meets the eye: DNA barcoding reveals a new species in Britain, Lithothamnion erinaceum sp. nov. (Hapalidiales, Rhodophyta). European Journal of Phycology 52: 166-178. https://doi.org/10.1080/09670262.2016.1269953
• Walker, R.H., Brodie, J., Russell, S., Irvine, L.M. & Orfanidis, S. (2009). Biodiversity of coralline algae in the northeastern Atlantic including Corallina caespitosa nov. (Corallinoideae, Rhodophyta). Journal of Phycology 45: 287-297. https://doi.org/10.1111/j.1529-8817.2008.00637.x