232 
Fishery Bulletin 95(2), 1997 
with low to moderate levels of sediment contamina- 
tion (Malins et ah, 1984), showed little evidence of 
reproductive dysfunction. Although the causative 
agents were not definitively identified, aromatic and 
chlorinated hydrocarbons present in sediments at the 
Duwamish Waterway and Eagle Harbor sites were 
shown to be significant risk factors for the develop- 
ment of these reproductive abnormalities (Johnson 
et ah, 1988; Casillas et al., 1991). The present study 
extends our previous work by examining egg weight 
and fecundity in English sole from the same four sites 
in Puget Sound. 
Fecundity and egg size are important determinants 
of reproductive output in fish (Bagenel, 1973). Fe- 
cundity provides a measure of the potential number 
of offspring a female can produce, whereas egg size 
is an indicator of the nutritional reserves available 
to developing embryos and may strongly influence 
the growth and survival of larval fish (Blaxter and 
Hempel, 1963; Miller et ah, 1988). Both egg size and 
fecundity vary considerably among stocks, species, 
and individuals. However, in most marine teleosts, 
fecundity within a stock or species is highly corre- 
lated with fish size or weight. Egg size is generally 
more constant but may vary with factors such as fish 
age or spawning time or with genetic, nutritional, or 
environmental factors (Hempel and Blaxter, 1967; 
Bagenal, 1971; Gall, 1974; Zastrow et ah, 1989; 
Zamaro, 1992). 
Teleost fish may have either determinate fecun- 
dity, in which egg production is set before the spawn- 
ing season, or indeterminate fecundity, in which egg 
production can be increased, by recruiting additional 
oocytes into vitellogenesis during gonadal develop- 
ment, or reduced through atresia (Hunter and 
Macewicz, 1985a). In Puget Sound English sole popu- 
lations, potential fecundity appears to be determined 
several months before the spawning season because 
these fish recruit a single clutch of oocytes in late 
summer or early fall and no additional oocytes enter 
vitellogenesis prior to spawning in February or 
March (Johnson et ah, 1991). However, the extent to 
which fecundity declines as a result of atresia of de- 
veloping oocytes is unclear. 
In most fish species, both egg size and fecundity 
can be influenced by environmental conditions such 
as water temperature, salinity, and food supply. In 
herring ( Clupea sp. ), for example, water temperature 
60 to 90 days before spawning may be critical in de- 
termining the balance between egg size and num- 
ber. Unusually warm temperature leads to high fe- 
cundity and smaller eggs (Tanasichuk and Ware, 
1987). Other stressors, such as handling or crowd- 
ing, may also be associated with alterations in egg 
size and number; typically, stressed animals produce 
more and smaller eggs than do controls (Contreras- 
Sanchez et ah, 1995; Short et ah, 1995). 
Field and laboratory studies have demonstrated 
that fish exposed to certain chemical contaminants 
exhibit alterations in both egg size and fecundity. 
Contaminant-associated declines in egg size, fecun- 
dity, or in both, have been noted in several marine 
fish species collected from urban embayments, in- 
cluding white croaker and kelp bass from the Los 
Angeles area (Hose et ah, 1989), striped bass from 
San Francisco Bay (Setzler-Hamilton et ah, 1988), 
and winter flounder from Boston Harbor and Long 
Island Sound (Nelson et ah, 1991; Johnson et ah, 
1994). Similarly, white sucker exposed to pulp mill 
effluent in a contaminated lake of Ontario, Canada, 
showed a decrease in egg size and fecundity 
(McMaster et ah, 1991). Reductions in egg size and 
fecundity have also been observed in a number of 
other fish species in conjunction with controlled ex- 
posure to chlorinated and aromatic hydrocarbons and 
to other organic pollutants (reviewed in Kime, 1995). 
These compounds may have direct toxic effects on 
oocytes and supporting cells (Armstrong, 1986), or 
alternatively, may disrupt normal hormonal regula- 
tion of gonadal growth (Donaldson, 1990; Thomas, 
1990). 
Egg production is strongly influenced by the nu- 
tritional status of fish; if this status is extremely poor, 
animals may not reproduce at all (e.g. Burton and 
Idler, 1987), or fecundity may be reduced (Penzak, 
1985; Springate et ah, 1985; Chappaz et ah 1987; 
Rozas and Odum, 1988). Studies also suggest that 
egg size and number may change seasonally or as 
environmental conditions vary, thus maximizing the 
larvae’s probability of survival as food availability 
changes (Buckley et ah, 1991). Interactive effects of 
toxicant exposure and nutrition may also occur. For 
example, toxicants may influence reproductive out- 
put indirectly, by reducing food quality, food abun- 
dance, or the ability of animals to digest food or to 
forage effectively. In some studies where fish were 
exposed to oil or other organic compounds, declines 
in fecundity were associated with reduced food in- 
take and weight loss; thus the contaminants were 
likely affecting reproductive success by reducing the 
animal’s condition (e.g. Ghatak and Konar, 1991). In 
order to account, more precisely, for possible effects 
of nutritional status on egg weight and fecundity in 
English sole from contaminated Puget Sound sites, 
we measured several indicators of nutritional status 
(i.e. condition, plasma glucose and triglyceride lev- 
els, and hepatosomatic index [HSI] ) in sampled fish, 
as well as parameters associated with reproductive 
development and contaminant exposure. Our objec- 
tive in this paper is to describe age and size-specific 
