Caulerpa Seaweed Dredging

Johnson Bros Ltd successfully tendered on a proposal put forward by Northland Regional Council to find a solution to remove invasive seaweed in the Bay of Islands. JBL worked with Ngati Kuta and Patukeha to put forward a solution that involved a non-diver assisted methodology.

JBL designed an innovative dredging head tool, which works by sweeping the invasive seaweed off the seafloor up to a large centrifugal pump. The Caulerpa is then pumped into a de-watering geotextile bag. The result is a system that works approximately 50x faster than a diver-assisted suction dredging methodology.

Read more about the ongoing project in the media here: New Zealand-first dredging machine tackles invasive caulerpa in Bay of Islands, Bay of Islands' groundbreaking caulerpa dredging results expected in February

Innovation on the tool continues, with the design and implementation of screening plants on board the barge which allow separation of the Caulerpa from sand and other material.