113 
Ontogenetic and temporal variability 
in the fat content and fatty acid composition 
of Atlantic herring ( Clupea harengus ) 
from the Bay of Fundy, Canada 
Hillary A. Lane (contact author) 1 - 2 * 
Andrew J. Westgate 2 
Heather N. Koopman 1 2 
Email address for contact author: hillaryannelane@gmail.com 
1 Department of Biology and Marine Biology 
University of North Carolina Wilmington 
601 South College Road 
Wilmington, North Carolina 28403 
* Present address for contact author: University of Maryland 
Department of Biology 
College Park, Maryland 20742 
2 Grand Manan Whale and Seabird Research Station 
24 Route 776 
Grand Manan, New Brunswick, E5G 1A1, Canada. 
Abstract — Atlantic herring (Clupea 
harengus) is an ecologically and 
economically valuable species in 
many food webs, yet surprisingly 
little is known about the variation 
in the nutritional quality of these 
fish. Atlantic herring collected from 
2005 through 2008 from the Bay of 
Fundy, Canada, were examined for 
variability in their nutritional quality 
by using total lipid content (?i = 889) 
and fatty acid composition ( /? = 5 5 1 ) 
as proxies for nutritional value. A 
significant positive relationship was 
found between fish length and total 
lipid content. Atlantic herring also 
had significantly different fatty acid 
signatures by age. Fish from 2005 had 
significantly lower total lipid content 
than fish from 2006 through 2008, 
and all years had significantly dif- 
ferent fatty acid signatures. Summer 
fish were significantly fatter than 
winter fish and had significantly 
different fatty acid signatures. For 
all comparisons (ontogenetic, annual, 
and seasonal) percent concentrations 
of omega-3, -6, and long-chain rnono- 
unsaturated fatty acids were the most 
important for distinguishing between 
the fatty acid signatures of fish. This 
study underscores the importance of 
quantifying variation in prey qual- 
ity synoptically with prey quantity 
in food webs over ontogenetic and 
temporal scales when evaluating the 
effect of prey nutritional quality on 
predators and on modeling trophic 
dynamics. 
Manuscript submitted 11 May 2010. 
Manuscript accepted 9 November 2010. 
Fish. Bull. 109:113-122 (2011). 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National Marine 
Fisheries Service, NOAA. 
Variation in prey abundance has been 
documented in a wide range of food 
webs (e.g., Colwell and Landrum, 
1993; Forsman and Lindell, 1997; 
Greenstreet et al., 1998; Melvin and 
Stephenson, 2007); however, varia- 
tion in the nutritional quality of those 
prey has not been well investigated. In 
most studies to date, the nutritional 
quality of prey is assumed to be con- 
stant over space and time (e.g., Chase, 
2002; Krebs et al., 2003, Womble and 
Sigler, 2006; Woo et al., 2008), despite 
the fact that species can exhibit con- 
siderable variation in their value as 
prey items (e.g., Iverson et al., 2002; 
Diamond and Devlin, 2003; Jensen 
et al., 2007; Huynh and Kitts, 2009). 
Despite the ecological and economic 
importance of Atlantic herring 
(Clupea harengus ), robust temporal 
and ontogenetic data quantifying the 
variation in the nutritional value of 
these fish do not exist. Here we show, 
using Atlantic herring as a model prey 
species, that considerable temporal 
and ontogenetic variation does exist in 
the nutritional value of a given prey 
item, underscoring the importance of 
collecting data on both the quantity 
and quality of prey when evaluating 
its impact on an ecosystem level. 
Atlantic herring are a major por- 
tion of the diet of many upper trophic 
level predators in the western North 
Atlantic (wNA), such as seals, por- 
poises, dolphins, whales, predatory 
fish, sharks, and seabirds (Katona et 
al., 1993, and are also the target of 
several major fisheries (purse seine, 
weir) for human consumption. Her- 
ring feed mainly on zooplankton (De 
Silva, 1973) and thus serve as an im- 
portant connection between lower and 
upper trophic levels in food webs and 
can be considered a keystone prey 
species in this ecosystem (Overholtz 
and Link, 2007). Herring in the wNA 
generally spawn in the fall (Boyar et 
al., 1973; Colton et al., 1979), eggs 
incubate for about 15 days (Messieh 
et al., 1985) and then enter a six- 
month pelagic larval phase (Sinclair 
and Tremblay, 1984). Rapid juvenile 
growth is observed for 1-2 years (An- 
thony, 1972), and maturity occurs at 
around age 3 (O’Brien et al., 1993). 
Historically the biomass of these 
stocks has undergone fluctuations in 
the wNA (Anthony and Waring, 1980; 
Overholtz and Friedland, 2002), but 
little is known about changes in At- 
lantic herring nutritional quality. 
The substantial effort required to 
collect robust spatial and temporal 
data has created prey quality data 
sets that do not adequately capture 
the variability present in the prey 
