FISH FARMING TEST SITE EXPOSED TO HIGH WAVES

The aquaculture industry in the Faroe Islands
has been expanding for many years, and new suitable
locations are becoming harder to find, as tidal currents, waves, and
now also wave generated currents, have become an increasing chal-
lenge. Two installations behind sheltering shoals have recently had
heavy losses during severe storms, due to what appears to be strong
wave generated current-jets, and we present data and initial mod-
elling results from one such event.
On the western shelf the 50-year design wave-height Hm0,50 is es-
timated to be 16 m–18 m, but during a similar event, the largest
recorded Hm0 value, behind the shoal in Sandur, was only 4 m,
while the recorded currents were much stronger than tidal models
predicted.
The new challenge is therefore to find areas that are not only shel-
tered from waves and tidal currents, but also from wave gener-
ated currents under severe events. Compared to similar studies of
waves and wave generated currents, the Sandur case is somewhat
unique due to the wave severity, relative deeper settings, and the
link to high resolution fish-net movements. The quite comprehen-
sive recorded data includes wave measurements on the shelf, differ-
ent wave and current measurements in the bay, and measurement
of movement of the cages. The net movements shows time varia-
tions ranging from single wave periods to periods in the order of
surf beat’s.
In the just initiated PhD project the aim is to find suitable numer-
ical models, and use the data from the installation at Sandur, to
determine the best model configuration for this type of consultancy
tasks