GreenTaxa – biodiversity, taxonomy and systematics of the green algae in Sweden
Short description
The class of green algae (Ulvophyceae) includes familiar species such as sea lettuce. There are an estimated 2,000 species worldwide, but at present we only know of 102 species in Sweden. The group is difficult to classify, and many of the organisms that were previously considered to be individual species have turned out to be complexes of several species. Morphologically, they are difficult to distinguish from one another.
The project will collect samples of green algae from the entire Swedish coast. These will be analysed using molecular and morphological studies and comparisons with historical data.
The aim is, among other things, to describe a number of new species of green algae and to create a national and open DNA library of marine green algae in Sweden. This knowledge is important for identifying and managing invasive and red-listed species.
The results will also support the growing algae cultivation industry, ensuring that only suitable and native species are cultivated.
Facts
Green macroalgae of the class Ulvophyceae include species such as sea lettuce (Ulva lactuca) and are ecologically and economically important. Despite estimates that there may be up to 2,000 species worldwide, only 102 are listed in Sweden. Many of them are taxonomically invalid.
This is because the characteristics of the species can vary a lot depending on the environment in which they are found. There is also widespread hidden diversity, where one species may in fact be a complex of several. This has led to many incorrect identifications, which hinders the management of both red-listed and invasive species.
The main objective is to conduct the first systematic assessment of Ulvophyceae in Sweden to identify the species' diversity, distribution and systematics. This will provide a stable inventory basis for future monitoring and sustainable use of the species.
Method and work structure
The project uses several different methods to determine the different species.
1. An extensive collection of approximately 1,000 samples will be made along the entire Swedish coastline (Skagerrak to the Baltic Sea), from different habitats. Sampling will take place during two seasons (spring and summer) to capture variations in the species.
2. To obtain a reliable ‘genetic fingerprint’, each algae sample will be analysed using DNA barcoding. Specific sequences of the algae's DNA will be used, specifically those that have proven to be very effective in distinguishing between different species of green algae.
3. Classic morphological analysis (studies of the algae's shape, structure and external characteristics) is used in combination with molecular data to assess and clarify the flexibility in how the algae look.
4. Historical specimens from Scandinavian collections will be DNA analysed and compared with contemporary finds to determine whether older species determinations were incorrect. This also establishes DNA sequences that can be used as a reference in research.
Expected results and objectives
The objective is to formally describe at least twelve new species of Ulvophyceae and to compile a new, up-to-date species list and assessment literature describing the ecology, distribution and morphology of the species and identifying possible species that could be confused with them.
National databases such as Artfakta and Artportalen will be updated with genetically verified data.
The goal is also to create a DNA reference library for Swedish green algae. This is crucial for future monitoring, management of endangered or invasive species (such as Ulva australis and Ulva californica), and to support the aquaculture sector in cultivating the right, native species of green algae.
Project participants
Sophie Steinhagen, researcher, University of Gothenburg, Department of Marine Sciences
Ellen Schaegerström, researcher, University of Gothenburg, Department of Biology and Environmental Sciences
Lena Kautsky, professor emeritus, Stockholm University, Department of Ecology, Environment and Plant Sciences
Gunilla Toth, researcher, University of Gothenburg, Department of Marine Sciences
Christina Hallig, environmental analysis specialist, SLU, algae manager, SLU Species Information Centre
Gustav Johansson, plant ecologist, Hydrophyta Ekologikonsult, member of the expert committee for algae, SLU Species Information Centre
