The constraints to successfully grow seaweeds at the Biodôme de Montréal are well known:
1) The quality of light
2) The bioavailability of micronutrients and nutrients and
3) Their capacity to adhere to a substrate by means of their holdfasts or hapters 1.
In collaboration with Éric Tamigneaux, professor at the École des pêches et de l’aquaculture du Québec (ÉPAQ), a research and development initiative aimed at the culture of Palmaria palmata was initiated by our research team. The main objective was to develop their cultivation and study their bioremediation capacities.
A red seaweed for water purification
The dulse or Palmaria palmata is red seaweed with a nordic distribution along the coasts of the Atlantic. It is collected at low tide, dried and found on the market as a treat or a condiment. Very soon, we might see it live on display in the Rocky Shore exhibit.
Indeed, we have recently succeeded to cultivate this marine plant very efficiently in our laboratories. Bioremediation studies furthermore demonstrated that this red seaweed actively removed nitrates and phosphates from the seawater of the marine exhibits very efficiently, when their optimal growth conditions were met 2.
More seaweeds under culture in a near future
In light of our most recent technological advances, the Biodôme will now evaluate the cultivation of other seaweed of interest such as the bladder wrack (Fucus vesiculosus) and various kelp species (Laminaria saccharina, L. digitata or Saccorhiza dermatodea) that are characterized by long, leathery laminae (blade) and relatively large size supported by their “foot” or stipe. The kelp Agarum clathratum is also a species of interest since it resists very well to the grazing of green urchins.
The introduction of natural seaweeds in our marine ecosystem representations would favour the introduction of animal species, which in the natural environment seek shelter by the rocks intersticial spaces and under the seaweeds. The Biodôme is also involved in a large multi-disciplinary project under the leadership of Merinov, the Québec Centre for Innovation in Aquaculture and Fisheries, in order to identify the best techniques to stimulate the adherence of the seedling to an intermediate substrate for restocking and restoration of the marine and coastal habitats purposes.
1 Holfasts contrary to roots, do not play any absorbtion role (water or nutrient). Those structures enable fixation on the rocks for various species of seaweeds.
2 Tremblay-Gratton et al. En ligne/Online. Bioremediation efficiency of Palmaria palmata and Ulva lactuca for use in a fully recirculated cold-seawater naturalistic exhibit: effect of temperature and high NO3 and PO4 concentrations. Journal of Applied Phycology https://link.springer.com/article/10.1007/s10811-017-1333-x