Seaweed Farming Mooring Project

The general layout and design of the seaweed farms are based on horizontal cultivation ropes attached to a mooring grid system. The concepts are based on "endless" cultivation ropes that are attached to the load carrying ropes in the mooring grid system and the cultivation ropes are attached/removed during seeding/harvesting. The mooring grid system is left in place after ending the harvesting season and may be re-used for several years. The moorings and the mooring grid systems are based on similar layout and components as used for aquaculture fish farms. 

Our client deployed a demonstration cultivation system for giant kelp. The rig is located approximately 5 miles off the coast of Santa Barbara, CA, USA. It uses a concept with vertical cultivation ropes. This concept is assumed to reduce the hydrodynamic loading in harsh weather conditions, since the cultivation ropes are allowed to move along with the waves. In large waves the small buoys attached to each cultivation rope will submerge and hence the loading on each cultivation rope and the total loading on the rig may be reduced compared to a rig with fixed cultivation ropes.

Anchors, mooring lines and other structural components constitute a significant share of the total construction cost for a seaweed farm.

Anchors: 500kg Plough anchor are used in the mooring grid. Sandy plough anchor is typically shaped like a plow, with a sharp tip and a wider surface area to increase grip on the soft seafloor. It’s widely used in fish farming, oyster mooring line or seaweed cultivation mooring grid.

Mooring Lines: Dia.28mm anchor chain and dia.32mm polypropylene ropes consists mooring lines. 40T Bow shackles are used for connecting bottom chains to anchors and 60T bow shackles are used for connecting chains to thimble spliced PP rope.

Mooring connection plate: Multi-eyes connection plate are used in this grid system to join multi-legs of mooring lines.

Buoys: Cylinder type PE buoys are used as floating components in this system.