Culture trials with the brown alga Laminaria longicruris in Chaleur Bay

Description

In the fall of 2005 and winter of 2006, blade kelp (Laminaria longicruris) was cultured in a controlled environment at the Maurice Lamontagne Institute. Nylon threads were seeded with spores from fertile fronds of kelp harvested in Paspébiac Bay. The lines were placed in a tank of enriched sterile sea water in order to promote their germination and development. Two weeks after seeding, the first sporophytes, still at the microscopic stage, were observed on the lines. When the young plants reached an average size of 5-6 mm, six weeks after seeding, 5-cm pieces of nylon line were inserted into the strands of 20-mm polypropylene rope and placed in a flow-through tank with filtered sea water for the winter. In May 2006, the lines bearing the young kelp were transferred to the sea off Paspébiac in order to monitor their growth and development until December 2006. During the first summer of monitoring, the algae were colonized by a bryozoan (Membanipora membranacea, invasive species), which quickly resulted in their loss (August-September). The project, whose aim was to allow the algae to grow until late November, had to be suspended before the end of the trial. A new cohort of young kelp plants was prepared over the winter of 2007 and will be ready for transfer to the sea in late March.

The objectives of this project are:

1. To monitor the seasonal growth (May to December) of kelp produced in the laboratory and transferred to the sea.
2. To evaluate the components of commercial interest of cultivated kelp compared to wild kelp.
3. To identify the physical and chemical characteristics of the culture site in order to determine its potential for future operations.
4. To test two types of culture facilities (horizontal and vertical deployment of lines) and two depths on growth.
5. In 2007, sea culture will begin earlier than in 2006, in order to evaluate the growth of algae between late March and late July, taking advantage of a time window when the bryozoan is absent.
6. Culturing will also be carried out at Grande-Rivière in 2007 in order to compare two sites in terms of production and prevalence of the bryozoan.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2006 - 2008

Ecoregion(s)

Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Louise Gendron
Email: Louise.Gendron@dfo-mpo.gc.ca

Links

Determining optimal culture periods for the Atlantic Kelp (Saccharina longicruris) in Gaspésie, Quebec