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WP4 - Mussel farm design and harvest


Responsible

Head of Innovation Flemming Møhlenberg, DHI Water-Environment-Health, Hørsholm

Aims

The overall aim is to develop settling lines and production ropes that prevent crowding of mussels and reduce loss of production. A related aim is to test various methods in accordance with the selected designs.

Scientific personnel

  • Flemming Møhlenberg, DHI
  • Mads Joakim Birkeland, DHI


Past activities (Jan 2008 – Mar 2012)

A research- and demonstration line-mussel farm was established in the southern part of Kerteminde Bay, close to the Great Belt in spring 2010. The aim of the establishment of the line-mussel farm in 2010 was to test various methods and achieve valuable experience to be implemented in the farm design prior to the activities in 2011-2012. Further, two ADCPs was deployed at the bottom within the farm for quantifying depth gradients of flows inside and outside of mussel farm.

Ongoing activities (Mar-Dec 2012)

Excessive crowding, low individual growth and mussel loss by sloughing off of the growth lines are characteristic features of mussel farms with low workers attendance, while frequent inspection, seed harvest and ‘re-socking’ can improve farm productivity markedly, but at high operational costs. Alternatively, growth systems that either automatically carries out ‘self-thinning’ when mussels are growing or restricts settling to limited areas of growth lines will constitute near-optimal growth systems that can be implemented at industrial scale. The activities will test 2-3 hypothesis and systems:

  • Settling- and growth lines that expands in length during 2-4 months after settling
  • Abundance and growth of mussels settling on “Swedish” bands deployed folded using wire straps until 2-4 months after settling and unfolded bands.
  • If above successful develop in cooperation with associated company settling- and production bands that elongates ‘automatically’ by e.g. rotting strands
  • Pre-treated settling- and growth lines that prevent settling from certain areas, e.g. after treatment with readily degradable biocide that after 2-4 month allows the growing mussels to inhabit the former treated areas.
  • Settling- and growth lines that structurally include woven material that are avoided by mussel larvae and subsequently degrade allowing growing juveniles to expand to these areas
  • Patent application, if any test is successful.



Fig. 9. Pictures from the MarBioShell research- and demonstration line-mussel farm in the southern part of Kerteminde Bay (Great Belt). From the early stages of farm establishment, settlement of larvae to high density lines and harvested mussels.