We have a seaweed farm at sea – ropes, anchors, lines, buoys… the only thing that’s missing is seaweed… well, that’s not entirely true; we can pick off quite some flotsam and drifting wrack at our frame; however, we are keen to seed our own crop.
We are extremely lucky that we can use one of the halls at Marine Sales fish plant in Stokksund to seed the ropes. They have little fish processing at this time of year, and we have everything we need here. It’s just a 3 minute boat ride to Skarveskjæret – in fact, we can see the farm from the pier.
This year, our crop will consist of two kelp species, Saccharina latissima (sugar kelp) and Alaria esculenta (winged kelp). For both species, we collected the mother plants from our region earlier in the year. They were propagated by our partner Hortimare, who are now helping us to deploy them at sea. Hortimare has developed special expertise and knowhow on this crucial step in the value chain, and they help new customers in learning the techniques for how to fix the seedlings onto the ropes.
Preparation of cultivation ropes, floats, line connectors and weights is an important preparation job, before the seedlings even arrive.
The method used is ‘direct seeding’, i.e. seedlings (sporophytes) are applied directly to the cultivation ropes by using a specially developed biological glue.
The seedlings are minute (smaller than vanilla seeds) and barely visible with the naked eye. They are quite sensitive (to being exposed to air, wind and fresh water/rain), while also being tough in the sense of surviving many days at sea with little light, low temperatures and rough conditions, and basically waiting for the light to return in late winter.
The seeding solution with billions of minute sporophytes is added to the glue.
In the process of seeding the ropes and transferring them to our farm, many details need to be considered:The amount of glue-sporophyte mixture needs to match the moisture uptake capacity of the ropes, there is a narrow time window for glue application to the ropes and from glue application to deployment at sea.
For all steps in the process, there is a need for mechanising and reducing the manual labour – a new seeding machine under development will be a major improvement compared to the first prototype.
Everyone learns quickly that these seeded ropes are our future in the company and that they must be handled with utmost care.
Again, the weather provides us with challenges, since there are only some days where we can work at the farm. But in the end, we are successful – 4km of seaweed cultivation ropes have been installed safely and are awaiting the onset of spring.
With this first pilot plant, we are testing and trying many different aspects – type of rope, application of seedlings, distance of cultivation ropes from each other, vertical vs. horizontal ropes are just some of them.
Whatever one thinks – we have a plan.