196 
National Marine 
Fisheries Service 
NGAA 
Fishery Bulletin 
^ established in 1881 
Spencer F. Baird 
First U.S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Use of parasites to clarify residency and migration 
patterns of Pacific sardine (Sardinops sagax) in the 
California Current 
Email address for contact author: kym.jacobson@noaa.gov 
Abstract-— Migration patterns of the 
northern subpopulation of the Pacific 
sardine (Sardinops sagax) were exam¬ 
ined by using parasites as biological 
tags. This approach has been employed 
on marine fish species worldwide, but 
it had not yet been used to investigate 
the migratory behavior of this eco¬ 
logically and commercially valuable 
species in the California Current. In 
2005-2008, 14 taxa of parasites were 
recovered from 1388 Pacific sardine 
collected between British Columbia, 
Canada, and Southern California. The 
results of multivariate analyses indi¬ 
cate significant differences in parasite 
communities among all size classes of 
Pacific sardine caught off Vancouver 
Island, British Columbia, compared 
with those caught off Washington and 
Oregon and regions off California. Sig¬ 
nificant differences in parasite commu¬ 
nities also were identified between size 
classes of Pacific sardine: <210, 210- 
219, and >220 mm in standard length. 
Our results support a high degree 
of residency in all size categories of 
Pacific sardine off Vancouver Island 
during the study period, and they indi¬ 
cate that individual sardine behavior 
is not limited to completing an annual 
migration between British Columbia 
or the Pacific Northwest and Southern 
California. These data indicate that 
using parasites as biological tags could 
help clarify annual migration patterns 
of individual Pacific sardine. 
Manuscript submitted 10 September 2018. 
Manuscript accepted 26 July 2019. 
Fish. Bull. 117:196-210 (2019). 
Online publication date: 15 August 2019. 
doi: 10.7755/FB.117.3.7 
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. 
Kym Jacobson (contact author ) 1 
Rebecca Baldwin 2 
Michael Banks 2 
Robert Emmett 1 
1 Newport Research Station 
Northwest Fisheries Science Center 
National Marine Fisheries Service, NOAA 
2032 SE OSU Drive 
Newport, Oregon 97365 
2 Cooperative Institute for Marine Resources Studies 
Hatfield Marine Science Center 
Oregon State University 
2030 SE Marine Science Drive 
Newport, Oregon 97365 
The Pacific sardine (Sardinops sagax) 
is an ecologically important pelagic 
fish in upwelling systems that trans¬ 
fers energy from lower trophic levels 
(phytoplankton and zooplankton) to 
upper trophic predators, including fish, 
marine mammals, and birds (Cury 
et aL, 2000). The Pacific sardine fish¬ 
ery is also economically important, 
providing for bait, aquaculture feed, 
and human consumption (Herrick 
et aL, 2009). In the 1930s and 1940s, 
the Pacific sardine fishery in the Cali¬ 
fornia Current was the largest fishery 
in the Western Hemisphere (reviewed 
in Wolf, 1992). The fishery collapsed 
and was closed off the Pacific North¬ 
west (PNW, Oregon and Washington) 
in 1947 and off Central California in 
1967 (Radovich, 1981). Heavily influ¬ 
enced by ocean conditions, the biomass 
of the Pacific sardine in the Califor¬ 
nia Current System (CCS) fluctuates 
widely. After a substantial biomass 
increase in the late 1980s and 1990s 
(Hargreaves et aL, 1994; Emmett et aL, 
2005), a purse seine fishery reopened in 
California, the PNW, and off Vancouver 
Island in British Columbia, Canada, 
followed by a formal closure in 2015. 
Three subpopulations of the Pacific 
sardine are currently recognized in the 
CCS (reviewed in Smith, 2005). One 
spawns in the Gulf of California, one 
spawns in inshore waters of southern 
Baja California, Mexico, and a north¬ 
ern subpopulation spawns primarily 
off Southern and Central California. 
For the management of Pacific sardine, 
the governments of both the United 
States and Canada assume all Pacific 
sardine of the northern subpopulation 
belong to one northerly migrating stock 
(Hill et al. 1 ). Pacific sardine have also 
spawned successfully further north in 
some years, indicating either a pos¬ 
sible separate spawning population 
1 Hill, K. T., P. R. Crone, E. Dorval, and B. J. 
Macewicz. 2015. Assessment of the Pacific 
sardine resource in 2015 for U.S.A. man¬ 
agement in 2015-16, 116 p. Agenda item 
G.l.a. Pacific Fish. Manage. Counc., Port¬ 
land, OR. [Available from website.] 
