Research project Baltic Fucus in Space – studying how the lunar cycle may affect reproduction of Fucus vesiculosus
How does small gravitational changes, or microgravity, caused by the moon, affect growth and reproduction in bladderwrack? Can macroalgae adapt to the space environment and be used for cultivation in the future? To better understand how a perennial macroalga reacts to changes in hypergravity and microgravity this project, being the first one of it's kind, will study bladderwrack responses during an actual probe flight in space.
Project description
Life on Earth, on land and in the sea, is influenced by e.g. temperature, light and availability of water and nutrients. But also small daily changes in gravity, so-called microgravity, affect biological processes in plants and algae. All biological processes on our planet are influenced by the sun's endogenous circadian rhythm, which is intertwined with tidal rhythm caused by the moon. Many marine organisms exhibit endogenous rhythms that are controlled by tidal fluctuations in water level, ebb and flow and for species with external fertilization, such as corals and macroalgae, it is critical to synchronize their release of gametes, often in the form of eggs and sperm. There is a clear link between tidal variations, the moon's gravitational pull and the release of gametes into the water mass.
The bladderwrack is dioecious, which means that there are separate male and female thalli. For successful fertilization and recruitment of new seedlings, a synchronization of the gamete release from both female and male plants is required. Along the Atlantic coast and in the North Sea where bladderwrack grows in the tidal zone, the algae are exposed to regular air exposure and thus drying in connection with the ebb and flow. Having dried out a bit and then become submerged again when the water returns is the signal for bladderwrack to release its gametes. As the seaweed gets covered with water, the amount of gametes released is high, fertilization is good and it is close to the bottom for the fertilized egg to settle. The conditions for the reproduction of the bladderwrack in the Baltic Sea, on the other hand, differ from tidal coasts.
The Baltic Sea completely lacks tides and also has brackish water. The bladderwrack established itself in the Baltic Sea has adapted to live constantly below the surface, yet managed to synchronize their gamete release around the full and new moons in the evening during the summer months.
During the photosynthesis process, the immediate environment around the seaweed thallus changes. The carbon dioxide content decreases and the oxygen concentration and pH increase. For the bladderwrack, this gives the signal that the water movement is calm and the risk that gametes will be spread and diluted is small. If instead the water movements are large, the bladderwrack will wait with the gamete release for one or more days, until the water is calm again. Without these cyclically synchronized releases of gametes, the bladderwrack cannot reproduce and maintain the Baltic Sea’s large kelp forests with high biodiversity.
Objective
The overall objective of the study is to explore how microgravity can affect growth and reproduction in bladderwrack and to understand how macroalgae can adapt to the space environment and be used for cultivation in the future. To our knowledge, this will be the first study of how a perennial macroalga responds to changes in hypergravity and microgravity during a probe flight.
During the flight, they will be exposed to weightlessness (microgravity) for 6 minutes. In the experiment, small adventitious branches of bladderwrack grown under controlled conditions will be used. One set is launched with the rocket and one remains on the ground as control.
The experiment will provide a first picture of how bladderwrack from the Baltic Sea functions as an organism for further studies outside the Earth's surface. To measure the impact, we plan to identify specific RNA sequences that can be expected to be up- or down-regulated in bladderwrack tissue in response to the changes in gravity. The results are expected to provide insights into adaptation mechanisms or changes at the cellular level of bladderwrack from the Baltic Sea. The response to changes in gravity is primarily expected to affect the processes of photosynthesis and respiration, but we also see possibilities that they can affect cell structure and pigments. We will focus the study on comparing changes in metabolic processes between the parallel flight setup and the ground control.
The experiment we will perform in 2024 should be seen as a preliminary study where we test the bladderwracks physiological response to space travel. We hope that the results will enable a future application to ESA where the aim is to investigate whether the reproduction of the bladderwrack is controlled by microgravity, by investigating whether the synchronization during the release of gametes still occurs in microgravity only.
Project members
Project managers
Lena Kautsky
Professor Emeritus
Ellen Schagerström
Researcher
News
More about this project