A biological study of Durvillaea antarctica (Chamisso) Hariot and D ...

22S
Hasegawa (1962) and Kat ... ashima (1972) for L. in .Japa.n.
Kain (1976) recorded a gr~~th
rate of 66 rom per week for L, hype~bo~ea
(Gunn.) J'!'oslie on the Isle of Man. Norton Burrows (1969) recorded
a maximum growth rate of 145 mm per 'l'leek for
Loch Ine in southwest Ireland.
slow
Dupvil
The results of the hole punching
increases distally along the
and t.hat ,there is no localised apical maristent
in the transition region between stipe and lamina
are
showed that
laminae I
most Fucaceae) or
tOaDY
Considering the large amount of lamina
that
is eroded the success of D.
on
shores is undoubtedly due to the absence of any
meristem.
results are in many ways similar to those obtained by De~~.~."Q
who measured the growth of about 20 D.
at
over several months.
He found that growth was more
in the of the lamina than in other of the thallus
and tllat the
of growth varies according to season.
his data did not span a ,,,hole year I DeH;pine ~'las of the that
of D. antaPotioa was in summer
which is in accordance with my own results.
of D.
"las higher at Ohau Point than at
Tautuku, te the of storms at the latter locali
'rhe reasons for this are due to
differences between the
two areas. At Tautuku; Naves roll across First and cascade into
the channel inshore of the Du~vi
During storms the back wash ig
directed down the channel away from the area containing the
marked
>;-!ide D.
marked
Much of the kinetic energy of waves is expended in the
belt before the marked D. antG.r'otica. Although
are subjected to strong drag- f'orces as ',.,aves pass,
most of the
\'laV9 energy is
on the rock slope furthQ'r'
inshore.
calm conditions the marked D, antarctica receive
very little walle action far 4 hours of each tidal cycle.
The coast
is largely beach and stable boulders and loose rocks are
uncommOi1 ..