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

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seasonal pattern simila~ to that seen at 'l'autuku; Le. "lith highest
mortality in "'linter and early spring, and lowest mortality over
su.m:mer.
Table 706
Mor'i:alit.y of D. antaretica at Ohau Point.
Time period n- No. % % loss
lost loss per month
23 September 1972 - 30 November 1972 343 6 107 0.8
(2.2 months)
30 November 1972 - 10 April 1973 337 65 19.3 4.4
( 4 . 4 mon th s)
10 April 1973 - 20 September 1973 272 37 13.6 2.5
(5 months)
20 September 1973 - 6 Febru~ry 1974 235 29 12.3 2.6
(4.7 months)
6 February 1974 - 13 November 1974 206 53 25.7 2.7
Table 7.7 (ar Mortality of large plants (>4 m)
at Ohau Point.
Total no. No. % % loss
Time period of plants lost loss per month
September 1972-November 1972 27 1 3.7 1.6
November 1972-April 1973 26 B 30.8 7.0
April 1973-September 1973 18 B 44.0 8.1
September 1973-February 1974 10 1 10.0 2.1
February 1974-November 1974 9 7 77.8 8.3
(b) Mortality of small plants «1 m) at Ohau Point,
Time perioa Total no. No. % ~ lossof
plants lost loss per month
September 1972-November 1972 212 0 0 0
November 1972-April 1973 212 38 17.9 4.1
April 1973-September 1973 174 19 10.9 2.0
September 1973-February 1974 155 20 12.9 2,,8
February 1974-November 1974 134 2.3 17.1 L8