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field that was sampled. For example, the few studies 
that exist to date on the nutritional value of Atlan- 
tic herring have been conducted with limited types of 
analyses or comprise small temporal and spatial ranges 
(e.g., Torcher et al., 1985; Bradford, 1993; Budge et al., 
2002). Jensen et al. (2007) demonstrated that Baltic 
herring do exhibit significant variation in their fatty 
acid composition; however, comparable data are not 
available through most of the range of these fish. In 
fact, the most recent comprehensive examination of the 
lipid profiles of herring from the Bay of Fundy was con- 
ducted by Stoddard 1 over 40 years ago. Considering the 
ecological importance of herring in the Bay of Fundy, 
it is surprising that so little is currently known about 
the nutritional value of this species. 
The high abundance of herring in the Bay of Fundy 
system combined with the role of this species as a main 
prey item creates a perfect model in which to evaluate 
variation in prey quality. We used total lipid content 
and lipid composition (specifically, fatty acid profiles) as 
indices of prey quality for two reasons: 1) the lipids of 
a fish can be used as indicators of its nutritional value 
and overall body condition (Sargent et al., 1988); and 2) 
lipids provide twice the energy per unit of mass when 
metabolized than do proteins and carbohydrates (Had- 
ley, 1985) and therefore are the main determinants of 
the caloric value of lipid-rich fish such as Atlantic her- 
ring. Documenting the individual fatty acid components 
that comprise Atlantic herring lipids also has the poten- 
tial to provide information about the nutritional value of 
a given fish because certain fatty acids have important 
and specific physiological (e.g., the familiar omega-3 
and omega-6 molecules; Pond, 1998, Szlinder-Richert et 
ah, 2010.) and energetic (long-chain saturates; Hadley, 
1985) roles. Fatty acid (chemical profile) data can also 
be used as trophic markers to indicate shifts in diet 
(Bishop et ah, 1983; Budge et ah, 2002; Dalsgaard et 
al., 2003; Budge et al., 2006), however these types of 
trophic studies require an extensive library of data on 
the fatty acid composition of all members of an eco- 
system, which is not currently available for the Bay of 
Fundy. This study is a first step in creating such a prey 
library because the main objective is to determine the 
total lipid content and fatty acid composition of differ- 
ent sizes of Atlantic herring collected between 2005 and 
2008 across ontogenetic, annual, and seasonal scales. 
Materials and methods 
Sample collection 
Atlantic herring samples were provided by local fisher- 
men from stationary weirs or purse-seine nets in the 
Bay of Fundy, New Brunswick, Canada, from 2005 
through 2008. During summer ( June-September), fish 
were collected weekly, whereas during winter (Octo- 
1 Stoddard, J. H. 1967. Studies of the condition (fatness) of 
herring. Fish. Res. Board Can. Manuscript No. 1042, 15 p. 
ber-May) fish were collected more opportunistically. 
Owing to sampling constraints, fish from only a single 
winter season were sampled (2006-07). Spring and fall 
fish were not collected because the largest differences 
in nutritional value were expected to occur between 
the seasons that were the most different in regards to 
climate and ocean productivity (summer and winter). 
All fish from each sampling period (typically 10-30 fish) 
were weighed to the nearest milligram, and their fork 
length was recorded to the nearest millimeter. After 
the initial measurements, 10 fish from each sample 
were selected to encompass the entire size range of the 
individuals collected in each sampling period, and each 
fish was individually homogenized in a food processor 
(KitchenAid®, St. Joseph, MI). Generally, the fish that 
were collected were sexually immature although sexu- 
ally mature individuals were processed when available. 
Subsamples of the homogenate from each fish were 
sealed in cryovials under nitrogen gas and frozen at 
-20°C. Vials were kept extremely full to limit risk of 
oxidation, and all samples were processed within six 
months of collection (Budge et ah, 2002; 2006). 
Analysis of total lipid content and fatty acid composition 
Total lipids were extracted from Atlantic herring sam- 
ples using a modified Folch et al. (1957) chloroform/ 
methanol extraction as described in Budge et al. (2002) 
and Koopman (2007) and are reported as a percentage 
of wet tissue weight. For gas chromatography (GC) 
analysis, fatty acid butyl esters (FABE) were prepared 
from total lipid extracts. Fatty acids were separated 
and analyzed by GC by using a Varian capillary (3800) 
gas choromatograph (Varian Inc, Division of Agilent, 
Santa Clara, CA) with a flame ionization detector (FID) 
in a fused silica column (30 mm lengthx0.25 mm inner 
diameter) (Zebron FFAP; Phenomenex, Inc., Torrance, 
CA). Helium was used as the carrier gas and the gas 
line was equipped with an oxygen and water scrubber. 
The following temperature program was used: start at 
65°C for 2 min, hold at 165°C for 0.40 min after ramping 
at 20°C/min, hold at 215°C for 6.6 min after ramping at 
2°C/min, and hold at 250°C for 5 min after ramping at 
5°C/min. Up to 80 different fatty acids were identified 
by following the methods of Iverson et al. (1997; 2002) 
of which the molecular identities were confirmed by 
gas chromatography and mass spectrometry (S. Budge, 
personal commun. 2 ) by using standard chemicals run on 
both machines. Each fatty acid was described by using 
the nomenclature of A:Bn-X, where A is the number of 
carbon atoms, B is the number of double bonds, and X 
is the position of the double bond closest to the terminal 
methyl group. Peak identification was confirmed in each 
run, and results were integrated with Galaxie GC soft- 
ware (vers. 1.8.501.1, Varian, Inc., Palo Alto, CA). 
2 Budge, Suzanne. 2009. Canadian Institute of Fisheries 
Technology, Dalhousie University, Halifax, Nova Scotia, 
Canada B3J 2X4. 
