Cultivating Palmaria palmata - Bord Iascaigh Mhara

Chapter 3: Setting up a seaweed hatchery
3.1 Hatchery facilities for seaweeds
A seaweed hatchery may be planned and built as a new unit or it may be integrated into an existing fish- or
shellfish hatchery. However, certain basic facilities are required for the early stages of seaweed cultivation and
this section outlines these requirements, some of which will be met by similar facilities available in other types of
hatchery for aquaculture. To set up a seaweed hatchery, it is essential to have a temperature-controlled culture
room, equipped with tap water, a supply of seawater and of air, a filter unit for seawater, fluorescent lamps
connected to a timer and variable in height for control of intensity.
Temperature-controlled hatchery unit: This can be an in-built cold-room or a refrigerated container*
which can be installed outside in a yard area. The culture room should have seawater resistant fittings
(including waterproof electric sockets), a non-slip waterproof floor and bottom drainage. The room
should have a supply of tap water and compressed air, and convenient access to seawater.
Since most of our native seaweed species are cultured at relatively low temperatures (5-15°C), and the
hatchery must be kept very clean to avoid contamination of the cultures, it is almost essential to have
additional workspace at normal room temperature that can be used as a wet-laboratory for processing
collected or harvested algal material. Another warmer room for microscope work, preparation of culture
media and collectors, storage etc. would be ideal.
*Industrial refrigerated containers used for global transport are equipped with effective cooling units for
a temperature range between -10 and 20°C. They are of standard width and height but are available in
different lengths and can be purchased second hand. The interior can be customised to the
requirements of a seaweed hatchery, e.g. lining floor and possibly walls with saltwater-resistant
materials such as aluminium or synthetic materials to minimise corrosion. Any holes that are drilled
through the hull of the container for electricity, water and air supplies or for drainage will need to be
carefully insulated to maintain a constant temperature in the container throughout the year. Rupture of
pipes due to frost needs to be avoided, as well as heavy condensation in the aeration pipes in summer
due to temperature differences in and outside the container. Such condensation can collect in U-bends
and block air flow. To deal with this problem, outdoor air pipes should be insulated and a water outlet
should be built into the aeration line before the supply pipes are divided to serve the culture tanks, etc.
Seawater access: A supply of good quality seawater is one of the most essential and most expensive
elements of a hatchery and needs careful consideration. Seawater should be pumped from a fully
marine and unpolluted site. The treatment should comprise coarse filtering, sediment settlement in a
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