Cultivating Palmaria palmata - Bord Iascaigh Mhara

6.3 Harvesting methods
The optimal size at which Palmaria fronds should be harvested is 30-40 cm in length. It is crucial to monitor the
fronds during the final stages of ongrowth at sea (i.e. after 5 months) to ensure that Palmaria is harvested before
the fronds are overgrown by fouling organisms such as bryozoans. This is especially important when Palmaria is
to be used for human consumption and the top quality is required. It is also important to monitor the sizes of
fronds; with increasing time at sea and increasing size of fronds, individual Palmaria become more easily
detached from the string.
Fig. 6.3. Palmaria cultivated in Strangford Lough. Left: Palmaria on a dropper after 5
months at sea. Right: Palmaria on a net after 5 months at sea; in some parts of the net,
the Palmaria was heavily grazed.
Depending on the development and density of Palmaria fronds on the collectors, either one harvest or multiple
harvests are possible. If the fronds are densely spaced and healthy, it is advisable to harvest the largest fronds
by pulling them off the string to make space which will allow the smaller, suppressed plants to grow out. If this is
done, the size of the Palmaria being harvested may be smaller than the ideal size, i.e. about 15-20 cm, but two
or even three harvests may be possible if the quality of the collectors is good. If the density of the fronds is too
low to support multiple harvests, or growth on the collector is very patchy, all the fronds should be harvested at
one time. Collectors (nets or droppers) are untied from the header rope and brought to the hatchery, where all
the fronds are removed from the string. Further processing depends on the intended use of the Palmaria.
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