Courses / Building a Gametophyte Seed Bank

Course Content

Introduction to Gametophyte Culturing
Gametophyte Culturing The Kelp Life Cycle
Setting up Your Lab Space
Sourcing Essential Lab Equipment Configuring Your Lab
Water Processing and Culture Media
Sourcing or Making Water Storing and Cooling Water Preparing Solutions
Initiating New Cultures
Sourcing Reproductive Material Sorus Processing  Creating Mixed Cultures Cleaning and Sterilizing Water
Gametophyte Culture Maintenance
Changing Media of Cultures Checking Health of Cultures Other Culture Maintenance (Grinding and Scraping) Identifying and Treating Health Issues Identifying and Treating Contamination
Glossary and Reference Materials
Glossary Templates and Reference Materials
Resources & Tools
Protocol for Preparing Solutions
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Protocol for Packaging and Shipping Sorus Tissue
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Protocol for Processing Sorus Tissue
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Protocol for Creating Mixed Gametophyte Cultures
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Protocol for Changing Media in Gametophyte Cultures
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Protocol for Checking the Health of Cultures
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Protocol for Grinding Gametophyte Biomass
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Protocol for Scraping Gametophyte Biomass
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Lesson 4 Initiating New Cultures

Back to: Building a Gametophyte Seed Bank

Sourcing Reproductive Material

For sugar kelp, sorus material is the dark strip that forms on the kelp blade during fall and spring. For other species, sorus forms on other parts of the plant and may look different. Reference the Species Identification Lesson on the Hub for a more detailed breakdown. Some kelps have phenotypic plasticity, meaning the appearance or shape of the kelp looks different depending on the environment it is growing in. This is seen in sugar kelp in some regions where certain locations have skinny kelp and others have normal kelp. Sorus formation in the wild is triggered by changes in temperature and the intensity and duration of light. When sourcing sorus material for seeding spools or creating cultures, it is important to source material that is relatively clean and free of fouling. Epiphytes from the blades can cause major contamination outbreaks during seed spool rearing and in gametophyte cultures.

Definition

sorus tissue

The reproductive material of kelp. This appears as a dark strip in the center of a sugar kelp blade.

Definition

fouling

Anything on gametophytes, sporophytes, or grow lines that is undesired.

Definition

epiphytes

Algae that grow on other algae and are not parasitic. The brown algae, slip gut, or ectocarpus, is a common example of this.

The exact timing of sorus formation depends on the kelp bed and the water conditions. Normally, sorus will start to develop as temperature, light intensity, and the number of hours of daylight all begin to drop. Each kelp bed is different, and you may have to check the bed multiple times before finding ripe sorus. If you don’t know where kelp beds are near your farm, you can use a marine chart to help you narrow down potential locations where there is a hard surface for kelp attachment. In Alaska, sugar kelp tends to prefer muddy or sandy bottom types, whereas Alaria and Nereocystis (bull kelp) like more exposed locations with stronger wave action. On the East Coast, sugar kelp can be found in rocky-bottomed areas. You may also want to reference available public resources of detailed kelp forest surveys if they are available.

You should follow these guidelines for responsible and effective sorus collection:

  1. Source sorus material from kelp beds within the region where you are growing your kelp.

  2. Only source sorus from kelp beds that are abundant.

  3. Never take all of the fertile blades from one bed. If a bed is sparse, don’t take more than 10% of the available sorus. You can also avoid taking the entire fertile section of a blade.

  4. If a kelp bed looks like it has experienced significant dieback or has little to no sorus, collect from a different bed.

  5. For sugar kelp, leave the holdfast and meristem attached and only take the top portion of the blade. For other species, only take the fertile portion of the blades or sporophylls.

  6. Target blades that have little to no biofouling.

Definition

biofouling

Similar to fouling, but specifically refers to live organisms.

You can collect your sorus by snorkeling, diving, or wading in at low tide. The conditions at the site you choose will determine which method will work best. Review your state’s regulations around sorus collection before you collect, as some jurisdictions require a permit for sorus collection. If farmers are collecting their own sorus and sending it to you for seeding, make sure they are familiar with best practices for collecting, packaging, and shipping sorus ahead of time.

Once you’ve collected ripe sorus material, you will have to transport or ship the sorus to the facility that will be processing it. Keep the blades chilled and damp during transport and shipping. This can be achieved by packing the blades with paper towels dampened with seawater and ice packs. Make sure the blades won’t come in contact with any freshwater, including condensation that may form around the ice packs; it can cause spoiling or blistering. When possible, choose the quickest available shipping option. The blades can be in a properly packed box for up to three days without spoiling. Prepare the sorus no more than 72 hours after the blades are harvested. Complete your sorus release between 18 and 24 hours after processing. 

Click on each part of the process for best practices.

GreenWave Resource
Protocol for Packaging and Shipping Sorus Tissue
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