160 
Fishery Bulletin 117(3) 
Table 5 
Summary of fyke net sampling of rainbow smelt (Osmerus mordax) in 4 coastal rivers of Massachu¬ 
setts during 2005-2007. Data provided are drainage area of each river; mean monthly discharge 
of each river, given as cubic meters per second averaged for the month of April over the period 
2005-2007; sample size ( n ); mean catch per unit of effort (overnight haul) (CPUE); and frequency 
of occurrence (FOC) in hauls of fyke nets. 
River 
Drainage area (km 2 ) 
Discharge (m 3 /s) 
Year 
n 
CPUE 
FOC 
Parker 
156.4 
2.8 
2005 
924 
35.5 
0.53 
2006 
123 
4.2 
0.66 
2007 
563 
24.5 
0.61 
Saugus 
124.8 
1.9 
2005 
141 
4.4 
0.56 
2006 
1458 
48.6 
0.87 
2007 
2433 
76.0 
0.61 
Fore 
93.5 
2.4 
2005 
2131 
71.0 
0.90 
2006 
1014 
35.0 
0.90 
2007 
3435 
107.3 
0.81 
Jones 
76.7 
2.1 
2005 
489 
15.3 
0.72 
2006 
614 
21.3 
0.93 
2007 
103 
3.2 
0.50 
O) 
c 
0 ) 
TO 
O 
Jones Fore Saugas Parker Trawl 
Jones Fore Saugas Parker Trawl 
Figure 6 
Boxplots of total length of (A) female and (B) male rainbow smelt (Osmerus 
mordax) sampled in Massachusetts in 4 coastal rivers with fyke nets in 2005- 
2007 and in marine waters during a trawl survey in 2004-2007. Lengths of 
female rainbow smelt caught in the Jones River are significantly different 
(Kruskal-Wallis rank sum test: a=0.05) from the lengths of females sam¬ 
pled at all other sampling locations, and the lengths of females from the Fore 
River are significantly different from those of females from the Saugus River. 
Lengths of male rainbow smelt caught in the Jones and Parker Rivers are sig¬ 
nificantly different from lengths of males from all other locations. 
Age analysis For samples caught both with a trawl net in 
marine waters and with a fyke net in coastal rivers, age 2 
was the most abundant age class of rainbow smelt, and 
few rainbow smelt older than age 2 were present (Table 2, 
Fig. 7). Age-1 rainbow smelt composed the next most com¬ 
mon age class with evidence of fluctuations in annual 
recruitment. Despite our collection of a relatively large 
sample of rainbow smelt from the trawl survey (n=634), 
this sample produced only 12 age-3 and 4 age-4 female 
rainbow smelt for fecundity analysis. 
The age data for rainbow smelt from fyke net sampling 
were compared with data from 2 previous studies that 
aged rainbow smelt during spawning runs in the Parker 
and Jones Rivers (Murawski and Cole, 1978; Lawton 
et al. 8 ). A lower proportion of age-1 rainbow smelt were 
caught from the Jones and Parker Rivers in 4 of the 
