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

72
within 0,3-0.5 m of the band. The narrow zone between is
dominated ~ chi tons and lusona.
Table 4.1 Mean num.bex of and above and \'J i th in the
D. zone at Tautuku. Ten 0,25 m 2 measured in
each area.
ies
Siphona1'ia
zeZandica
Chitons
Above the D.
antarctica 130.4 30.4 3.6
band
Within the
D. antClPctica B.B 10.0 0.0
band
1B.4 0.4
0.0 2.0
These observations suggested that D.
established higher on the shore if grazers such as
become
, or
competitors for space such as barnacles were removed at a time when
the was releasing gametes. Several field were
carried out to investigate this possibility. These are
more in Chapter 2, but for convenience a brief account is
here.
All limpets and chi tons were- kept clear from three areas
identified as AI Band D. Areas A and B \vere at Kean Point,
and Area D was a large isolated rock at Ohau Point (Fig, 2..2),
Earlier r in areas at Kaikoura where the. kelp had been cleared t it
had been observed that the upper limit of the recolonising sward
was above the normal upper limit of the D. anta~Qtica band.
was attributed to the local increase in ~'lave force caused
kelp plants. Therefore at one delimpec.ed site
ke was cut in a,ddi tion to removing the molluscs"
",ay of , at an adjacent site (Area C) the molluscs were
the was removed,
At 'l'autuku of barnacles tvere cleared above the fl,
band on E'irst and Second Slopes (A;-eas e: and F).