Algae have been the buzzword of the last few days after the announcement by Prime Minister Stephen Harper and French Prime Minister Jean-Marc Ayrault that the National Research Council of Canada and the Commissariat à l’énergie atomique et aux énergies alternatives of France will collaborate on a project using algae to reduce greenhouse gas emissions in Alberta.
Some confusion has ensued as the project, which will use microalgae to remove some of the greenhouse gases from Alberta oilsand emissions, has been portrayed as a project to make biofuels from seaweeds.
Thierry Chopin, professor of marine biology and algal expert at the University of New Brunswick in Saint John, explains that the mix-up may have come from the confusion that often exists with respect to the use of the terms algae and seaweeds.
Giving a simple definition of what algae are isn’t simple. Algae is a diverse group of organisms sharing only a few characteristics: they do photosynthesis (capturing carbon dioxide and producing oxygen); they do not make flowers and have simple reproductive structures; and they are relatively simple without roots, stems and leaves. Algae can be microscopic, referred to as microalgae (like the unicellular phytoplankton forms); however, they can also be very large organisms, referred to as macroalgae (like the giant kelps that can grow taller than some trees). Algae can be found in marine waters, freshwater, on trees (associated with fungi in lichens), boring in stones, in high altitude snow in glaciers, in geothermal sources and even in deserts.
Seaweeds are only a group within the algae; they are the macroalgae found in the sea. Referring to them as ‘seaweeds’ is unfortunate, as they are far from being the weeds of the sea. In French, they are described as ‘algues marines’ and in Spanish as ‘algas marinas’. There are approximately 10,500 known species of seaweeds. Around 500 species have been used for centuries for human food and medicinal purposes, directly as food or indirectly for the compounds that can be extracted from them. The largest group of organisms cultured at sea is seaweeds, which represents 51% of the total world aquaculture in the marine environment, while fish aquaculture represents only 9%.
All algae, including the ones intended for Alberta and the ones found in the Bay of Fundy, absorb dissolved nutrients, like nitrogen and phosphorus, to grow, while at the same time trapping CO2 and releasing O2. That is why they can be used for bioremediation of either greenhouse gas emissions or of nutrients from fish farms.
Chopin notes that it is interesting to watch people finally realizing that algae can be used for bioremediation and a whole array of valued-added products, not necessarily for biofuels.
“Cultivating algae is relatively expensive”, said Chopin, “so, trying to sell them inexpensively, to be competitive with the present fossil fuels, isn’t an interesting perspective, when more lucrative markets can be found in the more immediate future.”
That is the strategy he has been promoting for coastal regions over the last decade with the development of integrated multi-trophic aquaculture (IMTA).
The seaweeds he is growing in the Bay of Fundy recapture some of the inorganic dissolved nutrients from fish farms. He is also developing new markets in collaboration with industrial partner, Cooke Aquaculture Inc. For instance, seaweeds included in recipes for human consumption, seaweeds as partial substitution in fish feed, seaweeds in cosmetics and, hopefully soon, seaweeds for the production of biogas (methane).
What is key is to diversify the applications and niches based on the same original biomass. Chopin, who is never shy of creating new acronyms, calls it the integrated sequential biorefinery (ISBR) approach.
While the projects are different in terms of the organisms they use and their purposes, they are based on the same principle – use biological remediation, taking advantages of the ecosystem services provided by these extractive organisms; and, while producing a biomass, it’s better to make it a crop with diversified value-added applications.