6.2
Seasonal Studies of a Pelagic Ecosystem (Meridian 110 0 E)
D. J. TRANTER
The Indian Ocean is a seasonal ocean (RAMAGE, 1969; WYRTKI, 1973). When the
International Indian Ocean Expedition began, Australia was better equipped to make
continuous observations in the eastern segment of the ocean than to study the entire
ocean in anyone aspect. Plans were laid for a series of "seasonal biological cruises".
HOURS
6
12
Ie
24
s
z
20°
Q
I~
I/)
30°
30°
S
@
©
1962
MONTH
1963
A I S
O,N
D
J I F
M , A ,11.1 , J
J , A
i ~ i ~
i ~
i ~ i ~
i ~
I
2
3
4
5
6
CRUISE
Fig. 1. The study area and sampling strategy
It was hoped that these would be useful, not only in their own right, but also as a frame
of reference for biogeography.
In view of the zonal nature of the ocean, a south-north section was chosen for the
study-meridian 110° E. This lay sufficiently close to the coast for logistic purposes,
yet far enough west to penetrate the anti-cyclonic Indian Ocean gyre. The section extended
Seasonal Studies of a Pelagic Ecosystem (Meridian 110 0 E)
D. J. TRANTER
The Indian Ocean is a seasonal ocean (RAMAGE, 1969; WYRTKI, 1973). When the
International Indian Ocean Expedition began, Australia was better equipped to make
continuous observations in the eastern segment of the ocean than to study the entire
ocean in anyone aspect. Plans were laid for a series of "seasonal biological cruises".
HOURS
6
12
Ie
24
s
z
20°
Q
I~
I/)
30°
30°
S
@
©
1962
MONTH
1963
A I S
O,N
D
J I F
M , A ,11.1 , J
J , A
i ~ i ~
i ~
i ~ i ~
i ~
I
2
3
4
5
6
CRUISE
Fig. 1. The study area and sampling strategy
It was hoped that these would be useful, not only in their own right, but also as a frame
of reference for biogeography.
In view of the zonal nature of the ocean, a south-north section was chosen for the
study-meridian 110° E. This lay sufficiently close to the coast for logistic purposes,
yet far enough west to penetrate the anti-cyclonic Indian Ocean gyre. The section extended