Harvest of eelgrass seeds for the first time in Denmark

The first eelgrass seeds with the purpose of restoring eelgrass have now been harvested in Denmark. The floating harvesters were in action on the 27 and 28 of June, 2014 in Limfjorden just east of the town of Løgstør.

In a shallow area with a large dense population of eelgrass, eelgrass was harvested with two newly devel-oped harvesters. The purpose of harvesting eelgrass seeds is to sow the seeds in areas where the eelgrass are having difficulties being established. Harvesting of seeds for research in germination, sustainability etc. will be conducted in 2014 and 2015, and harvesting of seeds for sowing in another location in Limfjorden, with the purpose of establishing a demonstration location for sowing and re-establishing of eelgrass populations will also take place.

Første høst af ålegræs i Danmark
Photo: Large populations of eelgrass at Haverslev in Limfjorden. A suitable location for donating. Eelgrass is a species of grass and generates seeds which we harvest when most seeds are mature.

Two types of harvesters
Two reaping machines, which is designed to harvest, have been developed in the project
• Large scale harvester used on shallow areas with large widespread populations of eelgrass
• Small/medium scale harvester used on locations where the eelgrass is more difficult to harvest, for example where the water depth varies or where the eelgrass population is modest

Første høst af ålegræs i Danmark Første høst af ålegræs i Danmark
Photo: Small/medium reaping machine. The reaping machine is pulled through the eelgrass and cuts it 20 cm above the bottom, where after the eelgrass is directed into a large net which hangs on the backside of the machine. The weight of the machine is adjusted in the water, so it can be pulled very neatly across the bottom.

Første høst af ålegræs i Danmark
Photo: Machine used for large scale harvest. Eelgrass is cut and transported by conveyor belt to a platform, where it is collected in bags and brought ashore. The future goal is to separate the seeds from the shoot while being at open water, which will avoid the transport of biomass to land. It will increase the harvest capacity considerably.

Maturation of seeds

The eelgrass is transported to the shore in big bags and the seeds, which drops off the shoot, are matured in containers and sorted.

Første høst af ålegræs i Danmark Første høst af ålegræs i Danmark
Photo: Maturing containers at Kerteminde, where the seeds are separated from the biomass and used for experiments and sown in areas where eelgrass is lacking.