336 
PACIFIC SCIENCE, Vol. V, October, 1951 
throughout the bay, the number (A plus B 
hauls) taken at each station was expressed as 
a percentage of the total number caught in 
each survey, and the four percentages for 
each station were averaged. This gave the data 
in the last column of Tables 3 and 4. The re- 
sults for the 100 cm. net are portrayed gra- 
phically in Figure 4. 
The following tabulation shows the general 
distribution of eggs according to sector and 
net: 
SECTOR LARGE NET SMALL NETS 
per cent mean per cent per cent mean per cent 
of total per station of total per station 
Southern 75.63 8.40 79.37 8.82 
Middle 19.74 2.47 17.21 2.15 
Northern 4.63 0.77 3.42 0.57 
The results show that eggs were most abun- 
dant in the southern sector, less abundant in 
the middle sector, and least abundant in the 
northern sector. The results for Surveys 1, 2, 
and 3 were fairly consistent with the above 
averages. In Survey 4, however, most eggs 
were found in the middle sector. 
Examination of the temperature and chlor- 
inity data of Table 1 shows no apparent cor- 
respondence between their distribution and 
that of the eggs. For example, the average 
temperature (four surveys) for the three sec- 
tors were respectively 24.7, 24.5, and 24.7°C.; 
the average chlorinities (three surveys) for the 
three sectors were respectively 19-23, 19-11, 
and 19-16 p.p.m. 
In the southern sector of the bay, all four 
surveys showed a peak of abundance of eggs 
in the vicinity of Stations 4 or 5 (Fig- 4, 
Tables 3 and 4). Both the interim surveys and 
casual sampling between surveys indicated the 
persistence of this peculiar distribution. There 
is no apparent relationship between the dis- 
tribution of eggs (Table 3) and the distribu- 
tion of temperatures and chlorinities in the 
southern sector (Table 1). The explanation of 
the focus of abundance of eggs in the north- 
east part of the southern sector is uncertain. 
It seems most likely that the eggs are held 
there in the eddy of a current, but information 
on this possibility must await a study of the 
circulation of water in the bay. If it is found 
that the eggs are held in an eddy system, it 
must still be discovered whether nehu eggs 
are accumulated from widespread spawning 
throughout the sector or whether they result 
from localized spawning near the center of 
the eddy. 
In the middle sector of the bay, all four 
surveys showed larger numbers of eggs in the 
more northerly part. Stations 13 to 17, than ' 
in the more southerly part. Stations 10 to 12 
(Fig. 4, Tables 3 and 4). Although on the | 
average the maximum concentration was at | 
Station 14, the peak of abundance varied from || 
station to station with survey. For example, j; 
the largest number of eggs was encountered i 
at Station 17 in Surveys 1 and 2, at Station 13 I 
in Survey 3, and at Station 14 in Survey 4. |i 
This is in contrast to the relatively stable con- j 
dition found in the southern sector of the bay. || 
Variation in abundance at a station from sur- ' 
vey to survey may be related to variation in 
the number of spawning fish, to variation in | 
the current system in the middle sector, or i 
to both factors. Judging from the topography 
of the middle sector, the current system 
would probably vary to a considerable extent 1 
with strength and direction of the wind and 
with phase of the tide. 
In the northern sector of the bay, eggs were 
encountered in fair numbers only during 
Surveys 1 and 4. In Survey 1 they were rela- 
tively abundant at Stations 20 and 18, and in 
Survey 4, at Stations 20 and 19- On the 
average, the greatest abundance was at Sta- 
tion 20, which is located in the main ship 
channel toward the outside reefs. Either no 
eggs or very few eggs were taken at Stations j 
21, 22, and 23, which are located among the 1 
shoreside reefs in the northernmost part of 
the bay. 
Comparison of Table 1 with Tables 3 and 
4 shows no apparent relationship between 
variation in temperature and chlorinity and 
variation in egg abundance from station to 
station within surveys for either the middle 
or northern sectors of the bay. 
