Farm Design

The cultivation method and farm design – which are highly influenced by the individual site conditions –  determine what type of equipment is needed on the seaweed farm. Anchors, ropes, culture lines and floats are essential equipment for all cultivation taking place at sea.The material the farmer chooses for each will not only depend on the site conditions, but also on the price and availability of equipment.

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The speed and direction of the ocean current at the farm site tends to determine the type of farm structure (rig) and direction it faces.

Horizontal raft or grid cultivation

Vertical long line method

Horizontal long line method

The farm design differs between countries and regions and can generally be categorised in raft / grid or long line cultivation systems.

Within these, cultivation lines are either set up in a vertical or horizontal rope method.The benefits of using the horizontal rope method are that the seaweed can receive the light evenly and can utilise the space efficiently, resulting in highest yields. This is the most popular method in China. In the vertical rope method, the seeded rope will hang vertically from the floating rope. The advantage of this method is the utilisation of space vertically. The disadvantages is that it is more work intensive and that the seaweed at the bottom receives hardly any light.

Depending on the turbidity of a site the main ropes are installed up to 2 m beneath the water surface and will be adjusted during the grow out cycle, depending on the intensity of sunlight.

Different anchors and floats

Since the substrate beneath the farms varies substantially from farm site to farm site, different types of anchors such as concrete blocks, metal bars, wooden wracks or simply sand sacks or rocks are used. 

In South Korea, the government is trying to promote more environmentally friendly farm equipment. Especially the floaters should all be replaced with proper buoys instead of styrofoam.

Explore another seaweed species:
Eucheumatoids  |  Saccharina |  Undaria  |  PyropiaGracilaria

Or continue to the next Farm Insights