The Aquatron facility at Dalhousie University provides us with the perfect setting to grow eelgrass under controlled conditions in tanks and study the influence of various parameters such as nutrients, temperature, water depth, and light exposure. Research experiments on articial seed germination, sediment quality as well as the role of climate change induced increased temperatures help us better understand how we can increase the efficiency of our replanting efforts.

Current experiments

(1) Impact of temperature and salinity on eelgrass seed storage and germination – Lauren LaPorte (Honours student)

In the summer of 2023 we launched a pilot study to determine how eelgrass seeds can be stored long-term and matured to germination levels under controlled conditions in indoor tanks. For restoration, seeds can be harvested immediately upon maturation in the wild and planted (‘pick and plant’), but this leaves only a very small window to harvest, process, and plant (about two weeks)! Additionally, it is estimated that, in the wild, less than 1% of eelgrass seeds actually germinate and grow into plants.

To lengthen the window of opportunity to plant as well as increase germination rates, mature seed bearing shoots have been harvested and artifically decayed in tanks to naturally release their seeds. 25,000 seeds were then held under various combinations of temperature and salinity levels to study germination rates.

Through this study we hope to discover the best conditions for eelgrass seed storage and what parameters most effectively trigger germination. This knowledge will lay the foundation for further experiments studying the effecs of rising ocean temperatures on seed germination and eelgrass growth. Studies in other countries have shown that seeds matured in tanks have a higher likelihood of survival and a better chance of germination, and we are hopeful our eelgrass seeds will follow this trend!

Shoots are harvested by our students and field technicians for processing.
“Pearls on a string” phase of seeds within the reproductive shoot.
Once seeds drop they can be stored for planting at another time.
Germinated seed – thumb for scale!
Germinated seeds under the microscope.

(2) Resilience of Nova Scotian eelgrass populations to climate change induced stressors – Dr. Kristina Boerder

Climate change-induced warming of coastal waters is pushing eelgrass around Nova Scotia to its tolerance limits. The resilience of eelgrass populations to these increasing temperatures is closely linked to their individual genetic and epigenetic traits. Selecting plants from more resilient populations can greatly enhance the effectiveness of climate-smart eelgrass restoration, yet little is known about climate change impacts on eelgrass genetics around Nova Scotia. We are conducting a study to analyze genetic responses to climate change in local eelgrass populations in the field and the laboratory at the Aquatron to better understand the role genetics play in building resilience of coastal eelgrass restoration projects.

Diving

The Aquatron laboratory is home to multiple different tanks with various purposes. Besides providing tanks for our eelgrass seeds, the Aquatron is also an excellent location for our field technicians to practice diving and get certified for field work! Our team is fully certified with the Canadian Association for Underwater Science and ready to get in the water any time of year.

Large “pool” tank located in the Aquatron laboratory at Dalhousie University