Unknown green algae may cause big harm
There are at least a hundred unknown species of green algae in Swedish waters, and some of them are already causing problems with algal blooms. A new project aims to identify more species of green algae.
“It is important that we are able to distinguish between different species, but doing so with the naked eye can be very challenging,” says Sophie Steinhagen, the researcher leading the project.
Many species of green algae in the class Ulvophyceae are highly adaptive to new environments and living conditions, such as warmer or more nutrient-rich waters. This also means that under the right circumstances they can grow explosively, creating what is known as an algal bloom, covering shorelines with a green sticky mass which causes drastic changes in ecosystem services.
This problem has existed for several years in Denmark, where nutrient pollution from the pig industry has led to several green-algal blooms, but it has also occurred in both the Baltic Sea and along the west coast.
“An algal bloom of this kind can have major negative effects and alter local ecosystems,” says Sophie Steinhagen, researcher at the Department of Marine Sciences.
Many species unknown
According to her, there are at least 100 unknown species of green algae along the Swedish coast. Several of them may be invasive.
“In many cases we do not know which species are exhibiting this explosive growth characteristics or whether they have an invasive character. That makes it very difficult to monitor them and protect our precious oceans,” says Sophie Steinhagen.
Within the growing industry for cultivating green algae there is also a need for more knowledge about their species diversity. Many species of green algae are difficult to tell apart with the naked eye, and some species that look different are in fact the same. It has also turned out that algae believed to belong to one species have actually belonged to different ones.
“Here we need to ensure that the algae being cultivated are truly the native species, those that help strengthen and preserve ecosystems, and nothing else,” says Sophie Steinhagen, who has long researched green algae and their distribution.
Important both for man and ocean
She is now leading a new project funded by the Swedish Taxonomy Initiativ (Artdatabanken), a part of The Swedish University of Agricultural Sciences. Over three years, at least 1,000 samples of green algae will be collected along the Swedish coasts, and in order to accurately identify the various species, the samples will be DNA-barcoded.
The aim of the project includes carrying out the first systematic survey of green-algal diversity in Sweden and creating an open reference library of green-algal DNA for future use and research.
“Green algae are incredibly important for the health of the sea, but they also have potential as a future food source for humans. That is why it is important that we deepen our knowledge of them,” says Sophie Steinhagen.
Text: Mikael Andersson
• Includes, among others, the edible species sea lettuce
• Most species occur in marine environments, but are also found in freshwater and on land
• In Sweden, green algae are found along the entire coastline – 102 species are known in the country
• Species differ greatly in appearance and can be difficult to identify correctly
• Some species (e.g., sea lettuce) have good nutritional values, with relatively high protein content, beneficial polyunsaturated fats, and valuable other biochemical compounds
• Certain species are cultivated commercially and are considered to have high potential as a future food source
