Johnson et al.: Reproductive success of Clupea pallasl after the Exxon Valdez oil spill 
749 
Russia 
Alaska 
U.S. 
Southeast 
Alaska 
Prince 
William 
Sound 
Canada 
100 km 
Port Chalmers 
100 km 
Ketchikan 
St. Mathews 
Bay 
Rocky Bay 
Sitka 
Figure 1 
Collection sites of mature Pacific herring in Prince William Sound and southeast Alaska in spring 
1995. 
need for more definitive studies to assess the repro- 
ductive success of herring. 
The purpose of this study was to determine if re- 
productive impairment, a possible result of the spill, 
was evident in PWS herring six years after the spill. 
There were two major focuses in the study: 1) a com- 
parison of reproductive success between regions 
(PWS and southeast Alaska [SE]) and 2) a compari- 
son of reproductive success between year classes 
within sites, particularly the 1989 year class (most 
likely impacted by the oil spill) with other year classes 
in PWS. 
Sites sampled within PWS included all areas where 
spawning occurred in 1995; spawning was absent in 
areas that were heavily contaminated with oil in 
1989. For example, Naked Island, which was in the 
middle of the spill trajectory, had 22 km of spawned 
eggs in 1989 (Brown et al., 1996a) but none in 1995. 
Although some have speculated that herring home 
to the same general spawning area each year 
(Zijlstra, 1963; Hourston, 1982), site fidelity is poorly 
understood. Thus, the herring we sampled in PWS 
in 1995 may or may not have been exposed to oil at 
some earlier time in their life history (as adults, eggs, 
or larvae). 
Methods 
Herring were collected at four sites in PWS and at 
three sites in SE (Fig. 1); all sites had been used for 
spawning in previous years. Two of the sites in PWS 
(St. Mathews Bay and Fish Bay) were not directly 
contaminated by the oil spill, whereas the other two 
sites (Port Chalmers and Rocky Bay) were at least 
lightly contaminated. Shortly after the spill, elevated 
hydrocarbon levels were detected in mussels at Rocky 
Bay (Brown et al., 1996b) and in seawater at Port 
Chalmers (Carls 3 ). Additionally at Port Chalmers, 
concentrations of oil metabolites in bile of adult her- 
ring sampled in spring 1990 were similar to metabo- 
lite concentrations observed in 1989. This finding 
suggested continued contamination (Brown et al., 
1996b). Herring were collected in St. Mathews Bay 
on 7 April, in Fish Bay on 14 April, at Port Chalmers 
on 30 April, and in Rocky Bay on 1 May 1995. In SE, 
herring were collected in waters off Sitka on 29-30 
March, in waters near Ketchikan on 11 April, and in 
Seymour Canal on 13 May 1995. 
3 Carls, M. G. 1996. Prince William Sound oil database. Auke 
Bay Laboratory, National Marine Fisheries Service, NOAA, 
11305 Glacier Hwy., Juneau, AK 99801. 
