Cultivating Palmaria palmata - Bord Iascaigh Mhara

Chapter 7: Results of Palmaria longline cultivation trials 2009/2011
and economic analysis
7.1 Case study: cultivation of Palmaria at four Irish sites: Summary of results
7.1.1 Spore release, settlement on culture string and ongrowth of sporelings
In every reproductive season of Palmaria palmata during the course of the project, i.e. winter 2008/09, 2009/10
and 2010/11, fertile tetrasporophytes of Palmaria were found in abundance for sporulation trials at each hatchery
site (DOMMRS, MRI Carna Laboratories, QUB Portaferry). These trials were carried out in order to build up
stocks of seeded string during the period of optimal spore production, and to test the ongrowing potential in the
hatchery and later at sea. Reproductive material was collected fortnightly during low spring tides between
January and May. The core time for reproduction is February to April. Fertile material found before February is
often not fully mature, whereas material collected in May (this is only possible on the colder east coast of Ireland,
i.e. Irish Sea coasts) tends to release only low numbers of spores with low viability (Fig. 7.1).
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Fig. 7.1. Released spores per gram of fertile Palmaria fronds during the
reproductive season. All algal material was collected during low spring tides in
Strangford Lough. Error bars indicate standard deviations.